Sample records for years visual acuity

  1. Reproducibility of visual acuity assessment in normal and low visual acuity.

    PubMed

    Becker, Ralph; Teichler, Gunnar; Gräf, Michael

    2007-01-01

    To assess the reproducibility of measurements of visual acuity in both the upper and lower range of visual acuity. The retroilluminated ETDRS 1 and ETDRS 2 charts (Precision Vision) were used for measurement of visual acuity. Both charts use the same letters. The sequence of the charts followed a pseudorandomized protocol. The examination distance was 4.0 m. When the visual acuity was below 0.16 or 0.03, then the examination distance was reduced to 1 m or 0.4 m, respectively, using an appropriate near correction. Visual acuity measurements obtained during the same session with both charts were compared. A total of 100 patients (age 8-90 years; median 60.5) with various eye disorders, including 39 with amblyopia due to strabismus, were tested in addition to 13 healthy volunteers (age 18-33 years; median 24). At least 3 out of 5 optotypes per line had to be correctly identified to pass this line. Wrong answers were monitored. The interpolated logMAR score was calculated. In the patients, the eye with the lower visual acuity was assessed, and for the healthy subjects the right eye. Differences between ETDRS 1 and ETDRS 2-acuity were compared. The mean logMAR values for ETDRS 1 and ETDRS 2 were -0.17 and -0.14 in the healthy eyes and 0.55 and 0.57 in the entire group. The absolute difference between ETDRS 1 and ETDRS 2 was (mean +/- standard deviation) 0.051 +/- 0.04 for the healthy eyes and 0.063 +/- 0.05 in the entire group. In the acuity range below 0.1 (logMAR > 1.0), the absolute difference (mean +/- standard deviation) between ETDRS 1 and ETDRS 2 of 0.072 +/- 0.04 did not significantly exceed the mean absolute difference in healthy eyes (p = 0.17). Regression analysis (|ETDRS 1 - ETDRS 2| vs. ETDRS 1) showed a slight increase of the difference between the two values with lower visual acuity (p = 0.0505; r = 0.18). Assuming correct measurement, the reproducibilty of visual acuity measurements in the lower acuity range is not significantly worse than in normals.

  2. Distance versus near visual acuity in amblyopia

    PubMed Central

    Christoff, Alex; Repka, Michael X.; Kaminski, Brett M.; Holmes, Jonathan M.; Ch, B

    2011-01-01

    Purpose There are conflicting reports about whether distance and near visual acuity are similar in eyes with amblyopia. The purpose of this study is to compare monocular distance visual acuity with near visual acuity in amblyopic eyes of children. Methods Subjects 2 to 6 years of age were evaluated in a randomized trial of amblyopia therapy for moderate amblyopia (20/40 to 20/80) due to anisometropia, strabismus, or both. Prior to initiating the protocol-prescribed therapy, subjects had best-corrected visual acuity measured with standardized protocols at 3 meters and 0.4 meters using single-surrounded HOTV optotypes. Results A total of 129 subjects were included. The mean amblyopic eye visual acuity was similar at distance and near (mean, 0.45 logMAR at distance versus 0.45 logMAR at near; mean difference, +0.00, 95% CI, −0.03 to 0.03). Of the 129 subjects, 86 (67%) tested within one line at distance and near, 19 (15%) tested more than one logMAR line better at distance, and 24 (19%) tested more than one logMAR line better at near. The mean visual acuity difference between distance and near did not differ by cause of amblyopia, age, or spherical equivalent refractive error. Conclusions We found no systematic difference between distance and near visual acuity in 2- to 6-year-old children with moderate amblyopia associated with strabismus and/or anisometropia. Individual differences between distance and near visual acuity are likely due to test–retest variability. PMID:21907115

  3. [Prevalence of low visual acuity and ophthalmological disorders in six-year-old children from Santa Fe city].

    PubMed

    Verrone, Pablo J; Simi, Marcelo R

    2008-08-01

    Changes in children visual acuity that are not treated carry a high risk of irreversible consequences. To determine the prevalence of low visual acuity and to diagnose the ophthalmologic diseases that cause it in six-year-old children from Santa Fe City, Argentina. Observational, descriptive and transversal design. Visual acuity is defined as the eye's capacity to distinguish separate points and to recognize shapes. It was determined using the Snellen table for farsighted vision on 177 six-year-old children who attended four elementary schools in Santa Fe City. An ophthalmologic examination was performed on those who had low visual acuity and their mothers were interviewed to ascertain the pathological background of their children. The prevalence of low visual acuity was 10.7% (n= 19). The prevalence of amblyopia was 3.9%. Refraction errors were the only cause of low visual acuity. Astigmatism was predominantly frequent. The most frequent pathological backgrounds were: ocular infections, premature birth, history of malnutrition and maternal use of tobacco. The prevalence of low visual acuity found in this study is lower than the one informed in most other studies. This data require confirmation by further studies.

  4. Visual acuity testing in diabetic subjects: the decimal progression chart versus the Freiburg visual acuity test.

    PubMed

    Loumann Knudsen, Lars

    2003-08-01

    To study reproducibility and biological variation of visual acuity in diabetic maculopathy, using two different visual acuity tests, the decimal progression chart and the Freiburg visual acuity test. Twenty-two eyes in 11 diabetic subjects were examined several times within a 12-month period using both visual acuity tests. The most commonly used visual acuity test in Denmark (the decimal progression chart) was compared to the Freiburg visual acuity test (automated testing) in a paired study. Correlation analysis revealed agreement between the two methods (r(2)=0.79; slope=0.82; y-axis intercept=0.01). The mean visual acuity was found to be 15% higher (P<0.0001) with the decimal progression chart than with the Freiburg visual acuity test. The reproducibility was the same in both tests (coefficient of variation: 12% for each test); however, the variation within the 12-month examination period differed significantly. The coefficient of variation was 17% using the decimal progression chart, 35% with the Freiburg visual acuity test. The reproducibility of the two visual acuity tests is comparable under optimal testing conditions in diabetic subjects with macular oedema. However, it appears that the Freiburg visual acuity test is significantly better for detection of biological variation.

  5. Intravitreal aflibercept for neovascular age-related macular degeneration in patients aged 90 years or older: 2-year visual acuity outcomes.

    PubMed

    Chatziralli, Irini; Regan, Shane O; Mohamed, Ryian; Talks, James; Sivaprasad, Sobha

    2018-06-04

    The purpose of this study was to investigate the efficacy of intravitreal aflibercept for neovascular age-related macular degeneration (nAMD) in very elderly patients aged 90 years or older at 2 years after treatment initiation. In this multicentre retrospective data analysis from electronic medical record, consecutive treatment-naive patients with nAMD treated with aflibercept with at least 2 years follow-up were stratified into those aged < 90 years (Group I) and an older cohort aged 90 and over (Group II). We compared the visual acuity (EDTRS letters) outcomes at 4 weekly intervals between the two groups over a 2-year period. The mean visual acuity of Group I at presentation was 56.3 ETDRS letters versus 52.8 letters in Group II. Maximal visual acuity was achieved in both the groups by 6 months after initiating treatment (4.7 vs. 4.0 letters gain). By 2 years, the mean visual acuity of the older cohort fell marginally below their baseline visual acuity (0.8 letter loss), while Group I presented +2.1 letters gain. The number of injections given and the retention rate of the older cohort were no different to the rest of the patients. Very old patients with nAMD benefited from aflibercept, but not to the same degree as the younger patients. The study showed that, on an average, the very elderly patients were able to adhere to the intensive anti-VEGF treatment regimens.

  6. [Schoolchildren's visual acuity in the dynamics of learning].

    PubMed

    Bezrukikh, M M; Voinov, V B; Kul'ba, S N; Shurygina, I P

    2014-12-01

    The results of the screening study of the acuity of schoolchildren between 7 and 17 years old living in Rostov Region of the Russian Federation are discussed in the article. The method of computer optometry was used to measure acuity. 93772 pupils, 48621 girls and 45151 boys, from 150 schools participated in this examination. It was found that there is sustained growth of those with low acuity (0,2 and less) among children of both sexes from junior group (7 years) to the senior (17). The signs of the decline in visual acuity among girls (14%) are manifested earlier than in boys (8%). The decline in visual acuity among 7-8-year-old children is about 3%. While comparing children from rural areas with those from big cities a true dependence of the parameter (acuity) on the factors (city and sex) was found.

  7. [Evaluation of visual acuity in a historical cohort of 137 patients treated for amblyopia by occlusion 30-35 years ago].

    PubMed

    Simonsz-Tóth, B; Loudon, S E; van Kempen-du Saar, H; van de Graaf, E S; Groenewoud, J H; Simonsz, H J

    2007-01-01

    Opinions differ on the course of the visual acuity in the amblyopic eye after cessation of occlusion therapy. This study evaluated visual acuity in a historical cohort treated for amblyopia with occlusion therapy 30-35 years ago. Between 1968 and 1975, 1250 patients had been treated by the orthoptist in the Waterland Hospital in Purmerend, The Netherlands. Of these, 471 received occlusion treatment for amblyopia (prevalence 5.0%, after comparison with the local birth rate). We were able to contact 203 of these patients, 137 were orthoptically re-examined in 2003. We correlated the current visual acuity with the cause of amblyopia, the age at start and end of treatment, the visual acuity at start and end of treatment, fixation, binocular vision and refractive errors. Mean age at the start of treatment was 5.4 +/- 1.9 years, 7.4 +/- 1.7 years at the end and 37 +/- 2.7 years at follow-up. Current visual acuity in the amblyopic eye was correlated with a low visual acuity at the start (p < 0.0001) and end (p < 0.0001) of occlusion therapy, an eccentric fixation (p < 0.0001), and the cause of amblyopia (p = 0.005). At the end of the treatment, patients with a strabismic amblyopia (n = 98) had a visual acuity in the amblyopic eye of 0.29 logMAR +/- 0.3, and in 2003 0.27 +/- 0.3 logMAR. In patients with an anisometropic amblyopia (> 1 D, n = 16) visual acuity had decreased from 0.17 +/- 0.23 logMAR to 0.21 logMAR +/- 0.23. In patients with both strabismic and anisometropic amblyopia (n = 23), visual acuity had decreased from 0.52 logMAR +/- 0.54 to 0.65 logMAR +/- 0.54. Overall, acuity had decreased in 54 patients (39%) after cessation of treatment. Of these, 18 patients had an acuity decrease to less than 50% of their acuity at the end of treatment. In 15 of these 18 patients anisohypermetropia had increased. A decrease in visual acuity after cessation of occlusion therapy occurred in patients with a combined cause of amblyopia or with an increase in anisohypermetropia.

  8. VISUAL ACUITY IN PSEUDOXANTHOMA ELASTICUM.

    PubMed

    Risseeuw, Sara; Ossewaarde-van Norel, Jeannette; Klaver, Caroline C W; Colijn, Johanna M; Imhof, Saskia M; van Leeuwen, Redmer

    2018-04-12

    To assess the age-specific proportion of visual impairment in patients with pseudoxanthoma elasticum (PXE) and to compare this with foveal abnormality and similar data of late age-related macular degeneration patients. Cross-sectional data of 195 patients with PXE were reviewed, including best-corrected visual acuity and imaging. The World Health Organisation criteria were used to categorize bilateral visual impairment. These results were compared with similar data of 131 patients with late age-related macular degeneration from the Rotterdam study. Overall, 50 PXE patients (26.0%) were visually impaired, including 21 (11%) with legal blindness. Visual functioning declined with increasing age. In patients older than 50 years, 37% was visually impaired and 15% legally blind. Foveal choroidal neovascularization was found in 84% of eyes with a best-corrected visual acuity lower than 20/70 (0.30) and macular atrophy in the fovea in 16%. In late age-related macular degeneration patients, 40% were visually impaired and 13% legally blind. Visual impairment started approximately 20 years later as compared with PXE patients. Visual impairment and blindness are frequent in PXE, particularly in patients older than 50 years. Although choroidal neovascularization is associated with the majority of vision loss, macular atrophy is also common. The proportion of visual impairment in PXE is comparable with late age-related macular degeneration but manifests earlier in life.

  9. Visual prognosis better in eyes with less severe reduction of visual acuity one year after onset of Leber hereditary optic neuropathy caused by the 11,778 mutation.

    PubMed

    Mashima, Yukihiko; Kigasawa, Kazuteru; Shinoda, Kei; Wakakura, Masato; Oguchi, Yoshihisa

    2017-10-18

    Patients with Leber hereditary optic neuropathy (LHON) have a progressive decrease of their visual acuity which can deteriorate to <0.1. Some patients can have a partial recovery of their vision in one or both eyes. One prognostic factor associated with a recovery of vision is an early-age onset. The purpose of this study was to determine other clinical factors that are predictive of a good visual recovery. Sixty-one Japanese LHON patients, with the 11,778 mutation and a mean age of 23.1 ± 12.1 years at the onset, were studied. All patients were initially examined at an acute stage of LHON and were followed for 3 to 10 years. At 1 year after the onset, the lowest visual acuity was <0.1 in all eyes. We studied the following parameters of patients with/without a final visual acuity of ≥ 0.2: sex; heavy consumption of cigarettes and alcohol; taking idebenone; mean age at onset; mean lowest visual acuity; and distribution of the lowest and the final visual acuity. Fifteen (24.6%) of the 61 patients or 25 (20.5%) of the 122 eyes had a recovery of their visual acuity to ≥ 0.2. The mean age at onset of these 15 patients with visual recovery to ≥ 0.2 was 17.5 ± 7.7 years, and that of the 46 patients without visual recovery to ≥ 0.2 was 25.0 ± 12.8 years (P = 0.02, Mann-Whitney U test). The mean lowest visual acuity of the 25 eyes with visual recovery ≥ 0.2 was 0.04, and that of the 97 eyes without visual recovery to ≥ 0.2 was 0.015 (P < 0.001, Mann-Whitney U test). Fifty percent (15/30) of the eyes whose lowest visual acuity was ≥ 0.04 during 1 year after the onset had a visual recovery to ≥ 0.2, while 11% (10/92) of the eyes whose the lowest visual acuity was ≤ 0.03 had a visual recovery to ≥ 0.2 (P < 0.001, χ 2 test). There were no significant differences in the other clinical factors. A final visual acuity of ≥ 0.2 was associated with a less severe reduction of the visual acuity at 1 year after the onset

  10. Subnormal visual acuity (SVAS) and albinism in Mexican 12-13-year-old children.

    PubMed

    Sjöström, A; Kraemer, M; Ohlsson, J; Garay-Cerro, G; Abrahamsson, M; Villarreal, G

    2004-01-01

    In a previous study the vision of 1046 12-13-year-olds in Sweden was examined. Of those 67 had some kind of visual disturbances and in 20 no obvious cause was found. In this group, defined as children with subnormal visual acuity syndromes (SVAS), albinism was shown to be a major cause to the visual dysfunction giving a prevalence of about 1%. This is about 100 times higher than previous figures. Albinism can therefore be the cause in many cases of unexplained low visual acuity, at least in Sweden. Subnormal visual acuity is usually found in 2-4% in a pediatric population and is often called 'amblyopia'. The Swedish study showed that in many cases 'amblyopia' should be replaced by 'SVAS' and further investigation. The present Mexican study was designed identically to the Swedish study. The objective was to describe the distribution of visual acuity and the prevalence of ocular disorders, including incidence of subnormal visual acuity (SVAS) and the occurrence of albinism in a Mexican population of 12-13-year-olds. Altogether 1035 children, 12-13 years of age, were examined. A total number of 344 children were referred to the university pediatric eye clinic for further examination. 272 of these had simple refractive errors, 59 were diagnosed with an ophthalmological disorder and 13 children could not be pathologically classified. These were referred to a second ophthalmological examination, including VEP (Visual Evoked Potential) recordings. VEP reveals an asymmetric (right vs. left) cortical response after monocular stimulation in albinism. No child showed iris translucency or any other typical albinoic sign. VEP was recorded from 11 children. Three children showed an asymmetric VEP and were classified as albinos. The VEP response was normal in 8 of the children. The results indicate that albinism is common in Mexico, although not as common as in a similar Swedish population. A prevalence of albinism of approximately 0.3% was found in the Mexican population

  11. RISK FOR LOW VISUAL ACUITY AFTER 1 AND 2 YEARS OF TREATMENT WITH RANIBIZUMAB OR BEVACIZUMAB FOR PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION.

    PubMed

    Westborg, Inger; Albrecht, Susanne; Rosso, Aldana

    2017-11-01

    To investigate how patients with neovascular age-related macular degeneration treated with ranibizumab or bevacizumab respond to treatment in daily clinical practice. Data from the Swedish Macula Register on the treatment received by 3,912 patients during 2011 to 2014 is reported. Patients' characteristics at the first visit, visual acuity, number of injections, and reason for terminating the treatment if applicable are discussed. Furthermore, the risk of having poor vision (visual acuity under 60 Early Treatment Diabetes Retinopathy Study letters or approximately 20/60 Snellen) is calculated for the treated eye after 1 year and 2 years. The treatment outcome depends on the visual acuity at the first visit. For patients with visual acuity more than 60 letters, the risk of having a visual acuity lower than 60 letters after 1 year or 2 years of treatment is approximately 20%. However, for patients with low visual acuity at diagnosis (fewer than 60 letters), the risk is approximately 60%. The risk of having a visual acuity lower than 60 letters does not depend on the choice of treatment drug. Treatment with anti-vascular endothelial growth factor intravitreal injections mainly maintains the visual acuity level, and only approximately 20% and 40% of the patients required vision rehabilitation after 1 year and 2 years, respectively.

  12. Impact of visual acuity on developing literacy at age 4-5 years: a cohort-nested cross-sectional study.

    PubMed

    Bruce, Alison; Fairley, Lesley; Chambers, Bette; Wright, John; Sheldon, Trevor A

    2016-02-16

    To estimate the prevalence of poor vision in children aged 4-5 years and determine the impact of visual acuity on literacy. Cross-sectional study linking clinical, epidemiological and education data. Schools located in the city of Bradford, UK. Prevalence was determined for 11,186 children participating in the Bradford school vision screening programme. Data linkage was undertaken for 5836 Born in Bradford (BiB) birth cohort study children participating both in the Bradford vision screening programme and the BiB Starting Schools Programme. 2025 children had complete data and were included in the multivariable analyses. Visual acuity was measured using a logMAR Crowded Test (higher scores=poorer visual acuity). Literacy measured by Woodcock Reading Mastery Tests-Revised (WRMT-R) subtest: letter identification (standardised). The mean (SD) presenting visual acuity was 0.14 (0.09) logMAR (range 0.0-1.0). 9% of children had a presenting visual acuity worse than 0.2logMAR (failed vision screening), 4% worse than 0.3logMAR (poor visual acuity) and 2% worse than 0.4logMAR (visually impaired). Unadjusted analysis showed that the literacy score was associated with presenting visual acuity, reducing by 2.4 points for every 1 line (0.10logMAR) reduction in vision (95% CI -3.0 to -1.9). The association of presenting visual acuity with the literacy score remained significant after adjustment for demographic and socioeconomic factors reducing by 1.7 points (95% CI -2.2 to -1.1) for every 1 line reduction in vision. Prevalence of decreased visual acuity was high compared with other population-based studies. Decreased visual acuity at school entry is associated with reduced literacy. This may have important implications for the children's future educational, health and social outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  13. Visual acuity and visual field impairment in Usher syndrome.

    PubMed

    Edwards, A; Fishman, G A; Anderson, R J; Grover, S; Derlacki, D J

    1998-02-01

    To determine the extent of visual acuity and visual field impairment in patients with types 1 and 2 Usher syndrome. The records of 53 patients with type 1 and 120 patients with type 2 Usher syndrome were reviewed for visual acuity and visual field area at their most recent visit. Visual field areas were determined by planimetry of the II4e and V4e isopters obtained with a Goldmann perimeter. Both ordinary and logistic regression models were used to evaluate differences in visual acuity and visual field impairment between patients with type 1 and type 2 Usher syndrome. The difference in visual acuity of the better eye between patients with type 1 and type 2 varied by patient age (P=.01, based on a multiple regression model). The maximum difference in visual acuity between the 2 groups occurred during the third and fourth decades of life (with the type 1 patients being more impaired), while more similar acuities were seen in both younger and older patients. Fifty-one percent (n=27) of the type 1 patients had a visual acuity of 20/40 or better in at least 1 eye compared with 72% (n=87) of the type 2 patients (age-adjusted odds ratio, 3.9). Visual field area to both the II4e (P=.001) and V4e (P<.001) targets was more impaired in the better eye of type 1 patients than type 2 patients. A concentric central visual field greater than 20 degrees in at least 1 eye was present in 20 (59%) of the available 34 visual fields of type 1 patients compared with 70 (67%) of the available 104 visual fields of type 2 patients (age-adjusted odds ratio, 2.9) with the V4e target and in 6 (21%) of the available 29 visual fields of type 1 patients compared with 36 (38%) of the available 94 visual fields of type 2 patients (age-adjusted odds ratio, 4.9) with the II4e target. The fraction of patients who had a visual acuity of 20/40 or better and a concentric central visual field greater than 20 degrees to the II4e target in at least 1 eye was 17% (n=5) in the type 1 patients and 35% (n=33

  14. Visual acuity of commercial motor drivers in Ogun State of Nigeria.

    PubMed

    Onabolu, O O; Bodunde, O T; Otulana, T O; Ajibode, H A; Awodein, O G; Onadipe, O J; Jagun, O A

    2012-12-01

    To objectively assess the visual acuity of commercial motor drivers (CMD) in 3 Local Government Areas (LGA) of Ogun State of Nigeria in order to determine their eligibility to drive. The visual acuities of CMDs in 3 LGAS of Ogun state in Nigeria (selected using a multistage sampling technique) were tested with Snellens acuity charts and the eyes examined with bright pen torches and ophthamoscopes. Visual acuity 6/12 or better in the worse eye was taken as adequate to obtain a driving license. The drivers with worse visual acuities were further examined to find the cause of decreased vision. The visual acuities of 524 drivers were determined and analyzed. Their ages ranged from 19-66 years with a mean of 46.8 ±7.2 years. Two hundred and twenty (41.9%) of the drivers were between 40 and 49 years old. Four hundred and four (77.1%) did not have any form of eye test prior to this study. Four hundred and sixty three drivers (88.4%) were eligible to drive while 61 drivers (11.6%) were not eligible. Decreased visual acuity was caused by refractive error in 22(36.1%), cataract in 19(31.2%), glaucoma in 12(19.7%), corneal scar in 5(8.2%) and posterior segment lesions in 3(4.9%). Objective assessment of vision should be an essential component of licensure. Middle aged and elderly drivers are prone to age related ocular diseases and require reassessment of visual status every 3 years when licenses are renewed.

  15. Visual Acuity Reporting in Clinical Research Publications.

    PubMed

    Tsou, Brittany C; Bressler, Neil M

    2017-06-01

    Visual acuity results in publications typically are reported in Snellen or non-Snellen formats or both. A study in 2011 suggested that many ophthalmologists do not understand non-Snellen formats, such as logarithm of the Minimum Angle of Resolution (logMAR) or Early Treatment Diabetic Retinopathy Study (ETDRS) letter scores. As a result, some journals, since at least 2013, have instructed authors to provide approximate Snellen equivalents next to non-Snellen visual acuity values. To evaluate how authors currently report visual acuity and whether they provide Snellen equivalents when their reports include non-Snellen formats. From November 21, 2016, through December 14, 2016, one reviewer evaluated visual acuity reporting among all articles published in 4 ophthalmology clinical journals from November 2015 through October 2016, including 3 of 4 journals that instructed authors to provide Snellen equivalents for visual acuity reported in non-Snellen formats. Frequency of formats of visual acuity reporting and frequency of providing Snellen equivalents when non-Snellen formats are given. The 4 journals reviewed had the second, fourth, fifth, and ninth highest impact factors for ophthalmology journals in 2015. Of 1881 articles reviewed, 807 (42.9%) provided a visual acuity measurement. Of these, 396 (49.1%) used only a Snellen format; 411 (50.9%) used a non-Snellen format. Among those using a non-Snellen format, 145 (35.3%) provided a Snellen equivalent while 266 (64.7%) provided only a non-Snellen format. More than half of all articles in 4 ophthalmology clinical journals fail to provide a Snellen equivalent when visual acuity is not in a Snellen format. Since many US ophthalmologists may not comprehend non-Snellen formats easily, these data suggest that editors and publishing staff should encourage authors to provide Snellen equivalents whenever visual acuity data are reported in a non-Snellen format to improve ease of understanding visual acuity measurements.

  16. Visual acuity deficits in the fellow eyes of children with unilateral amblyopia.

    PubMed

    Varadharajan, Srinivasa; Hussaindeen, Jameel Rizwana

    2012-02-01

    To study the visual acuity deficits and maturation in the fellow eyes of children with unilateral amblyopia who were treated with patching. Medical records of patients aged 4-13 years visiting a tertiary eye care center between January 2003 and December 2007 who were diagnosed for the first time with unilateral amblyopia were reviewed. Subjects included in the study were followed through April 2009. The baseline visual acuity in the fellow eye of amblyopic subjects was compared with that of age-matched healthy subjects. Changes in visual acuity in the amblyopic and fellow eyes during subsequent visits were analyzed. A total of 112 children with amblyopia were included (strabismic, 14; anisometropic, 51; combined mechanism, 47). Baseline visual acuity in the fellow eye of these children differed significantly from that of age-matched controls up to 8 years of age. Average logMAR acuity reached 0.0 at age 5 years in controls versus age 9 years in patients. Although the mean visual acuity of the fellow eyes improved during treatment, 21% developed temporary occlusion amblyopia. Full-time patching had no additional benefit when compared with part-time patching. Visual acuity in the fellow eye of children with unilateral amblyopia is reduced at baseline and matures more slowly than in healthy control patients. The risk for temporary occlusion amblyopia in the fellow eye is similar what has been previously reported. Copyright © 2012 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  17. Transillumination of iris and subnormal visual acuity--ocular albinism?

    PubMed Central

    Sjödell, L.; Sjöström, A.; Abrahamsson, M.

    1996-01-01

    BACKGROUND: A common clinical sign in children with subnormal visual acuity or slow visual development was iris transillumination. This was used as the inclusion criterion in a study of children shown to have a subnormal visual acuity in a general health examination at age 4 years. METHODS: Refraction values, stereopsis, fundus photography, macular and nerve head appearance, and visual evoked response (VER) recordings were studied in 18 children. The clinical results were compared with 64 controls referred to the eye clinic because of subnormal vision from the general health examination or from school health care. RESULTS: Eight children had VERs showing asymmetry typical for albinism. Another four had only small asymmetries on the VER, indicating a lower degree of decussation abnormality. No simple correlation of visual acuity, degree of iris transillumination, stereopsis, or macular pathology and VER asymmetries were found. However, marked iris transillumination in all four quadrants, absence of a foveal reflex, and low visual acuity were weakly correlated. CONCLUSIONS: In a rather homogeneous group of children with iris transillumination and subnormal visual acuity eight of 18 had typical albino VERs. The findings of small atypical VER asymmetries in four children and no asymmetry in six children suggest that albinism may be considered as a description of a heterogeneous group of conditions including maximal decussation rate (100%) in the chiasma to a condition with almost normal (> or = 50%) decussation rate. Images PMID:8795373

  18. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if a central scotoma is present. However, when the lens required to correct distance vision in the poorer eye...

  19. 38 CFR 4.76 - Visual acuity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... distance and near vision using Snellen's test type or its equivalent. (b) Evaluation of visual acuity. (1) Evaluate central visual acuity on the basis of corrected distance vision with central fixation, even if a central scotoma is present. However, when the lens required to correct distance vision in the poorer eye...

  20. Refraction and visual acuity in a national Danish cohort of 4-year-old children of extremely preterm delivery.

    PubMed

    Fledelius, Hans C; Bangsgaard, Regitze; Slidsborg, Carina; laCour, Morten

    2015-06-01

    A recent threefold increase in laser treatment for advanced retinopathy of prematurity (ROP) triggered a nationwide preschool ophthalmic and developmental status among extremely preterm survivors. Here, we discuss refraction and visual acuity. Survivors (n = 178) from a national birth cohort (February 2004 to March 2006) of gestational age <28 weeks (PT) and 56 full-term (FT) controls attended for evaluation at age 4 years. Cycloplegic refraction and keratometry were achieved by Retinomax autokeratorefractor and visual acuities by symbol recognition (HOTV, logMAR). The refractive distribution presented a myopic tail (4.5%) and a hyperopic tail (11.9% ≥+2.5 D) as special preterm features, and corneas were more curved. Astigmatism and anisometropia were only marginally increased, and visual acuities were generally good. Best-corrected binocular median logMAR visual acuity was 0.1 in FT and 0.2 in PT, in Snellen equivalents 0.8 and 0.63. Snellen acuity ≤0.5 occurred across the ROP subgroups, but mainly in those with at least ROP stage 3. Two children had low vision. The overall fair outcome for refraction and function is in accordance with other recent northern Europe experience. The results differ in particular from the poorer ophthalmic outcomes reported in the pioneer US treatment studies (cryotherapy for ROP and ETROP). The diode laser ablations (n = 32) appeared effective in our series; except one child, all treated subjects had good or fair social vision at the age of 4 years. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  1. Visual acuity at 10 years in Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study eyes: effect of retinal residua of retinopathy of prematurity.

    PubMed

    Dobson, Velma; Quinn, Graham E; Summers, C Gail; Hardy, Robert J; Tung, Betty

    2006-02-01

    To describe recognition (letter) acuity at age 10 years in eyes with and without retinal residua of retinopathy of prematurity (ROP). Presence and severity of ROP residua were documented by a study ophthalmologist. Masked testers measured monocular recognition visual acuity (Early Treatment of Diabetic Retinopathy Study) when the children were 10 years old. Two hundred forty-seven of 255 surviving Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) randomized trial patients participated. A reference group of 102 of 104 Philadelphia-based CRYO-ROP study participants who did not develop ROP was also tested. More severe retinal residua were associated with worse visual acuity, regardless of whether retinal ablation was performed to treat the severe acute-phase ROP. However, within each ROP residua category, there was a wide range of visual acuity results. This is the first report of the relation between visual acuity (Early Treatment of Diabetic Retinopathy Study charts) and structural abnormalities related to ROP in a large group of eyes that developed threshold ROP in the perinatal period. Visual deficits are greater in eyes with more severe retinal residua than in eyes with mild or no residua. However, severity of ROP residua does not predict the visual acuity of an individual eye because within a single residua category, acuity may range from near normal to blind.

  2. Functional visual acuity in patients with successfully treated amblyopia: a pilot study.

    PubMed

    Hoshi, Sujin; Hiraoka, Takahiro; Kotsuka, Junko; Sato, Yumiko; Izumida, Shinya; Kato, Atsuko; Ueno, Yuta; Fukuda, Shinichi; Oshika, Tetsuro

    2017-06-01

    The aim of this study was to use conventional visual acuity measurements to quantify the functional visual acuity (FVA) in eyes with successfully treated amblyopia, and to compare the findings with those for contralateral normal eyes. Nineteen patients (7 boys, 12 girls; age 7.5 ± 2.2 years) with successfully treated unilateral amblyopia and the same conventional decimal visual acuity in both eyes (better than 1.0) were enrolled. FVA, the visual maintenance ratio (VMR), maximum and minimum visual acuity, and the average response time were recorded for both eyes of all patients using an FVA measurement system. The differences in FVA values between eyes were analyzed. The mean LogMAR FVA scores, VMR (p < 0.001 for both), and the LogMAR maximum (p < 0.005) and minimum visual acuity (p < 0.001) were significantly poorer for the eyes with treated amblyopia than for the contralateral normal eyes. There was no significant difference in the average response time. Our results indicate that FVA and VMR were poorer for eyes with treated amblyopia than for normal eyes, even though the treatment for amblyopia was considered successful on the basis of conventional visual acuity measurements. These results suggest that visual function is impaired in eyes with amblyopia, regardless of treatment success, and that FVA measurements can provide highly valuable diagnosis and treatment information that is not readily provided by conventional visual acuity measurements.

  3. Perceptual learning in children with visual impairment improves near visual acuity.

    PubMed

    Huurneman, Bianca; Boonstra, F Nienke; Cox, Ralf F A; van Rens, Ger; Cillessen, Antonius H N

    2013-09-17

    This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with normal vision also were divided in three groups, but were measured only at baseline. Dependent variables were single near visual acuity (NVA), crowded NVA, LH line 50% crowding NVA, number of trials, accuracy, performance time, amount of small errors, and amount of large errors. Children with visual impairment trained during six weeks, two times per week, for 30 minutes (12 training sessions). After training, children showed significant improvement of NVA in addition to specific improvements on the training task. The crowded perceptual learning group showed the largest acuity improvements (1.7 logMAR lines on the crowded chart, P < 0.001). Only the children in the crowded perceptual learning group showed improvements on all NVA charts. Children with visual impairment benefit from perceptual training. While task-specific improvements were observed in all training groups, transfer to crowded NVA was largest in the crowded perceptual learning group. To our knowledge, this is the first study to provide evidence for the improvement of NVA by perceptual learning in children with visual impairment. (http://www.trialregister.nl number, NTR2537.).

  4. 21 CFR 886.1150 - Visual acuity chart.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Visual acuity chart. 886.1150 Section 886.1150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1150 Visual acuity chart. (a) Identification...

  5. Maturation of Binocular, Monocular Grating Acuity and of the Visual Interocular Difference in the First 2 Years of Life.

    PubMed

    Costa, Marcelo Fernandes; de Cássia Rodrigues Matos França, Valtenice; Barboni, Mirella Teles Salgueiro; Ventura, Dora Fix

    2018-05-01

    The sweep visual evoked potential method (sVEP) is a powerful tool for measurement of visual acuity in infants. Despite the applicability and reliability of the technique in measuring visual functions the understanding of sVEP acuity maturation and how interocular difference of acuity develops in early infancy, as well as the availability of normality ranges, are rare in the literature. We measured binocular and monocular sVEPS acuities in 481 healthy infants aged from birth to 24 months without ophthalmological diseases. Binocular sVEP acuity was significantly higher than monocular visual acuities for almost all ages. Maturation of monocular sVEP acuity showed 2 longer critical periods while binocular acuity showed three maturation periods in the same age range. We found a systematic variation of the mean interocular acuity difference (IAD) range according to age from 1.45 cpd at birth to 0.31 cpd at 24 months. An additional contribution was the determination of sVEP acuity norms for the entire age range. We conclude that binocular and monocular sVEP acuities have distinct growth curves reflecting different maturation profiles for each function. Differences in IAD range shorten according to age and they should be considered in using the sVEP acuity measurements for clinical diagnosis as amblyopia.

  6. Should we add visual acuity ratios to referral criteria for potential cerebral visual impairment?

    PubMed

    van der Zee, Ymie J; Stiers, Peter; Evenhuis, Heleen M

    To determine whether the assessment of visual acuity ratios might improve the referral of children with (sub)normal visual acuity but at risk of cerebral visual impairment. In an exploratory study, we assessed visual acuity, crowding ratio and the ratios between grating acuity (Teller Acuity Cards-II) and optotype acuity (Cambridge Crowding Cards) in 60 typically developing school children (mean age 5y8m±1y1m), 21 children with ocular abnormalities only (5y7m±1y9m) and 26 children with (suspected) brain damage (5y7m±1y11m). Sensitivities and specificities were calculated for targets and controls from the perspective of different groups of diagnosticians: youth health care professionals (target: children with any visual abnormalities), ophthalmologists and low vision experts (target: children at risk of cerebral visual impairment). For youth health care professionals subnormal visual acuity had the best sensitivity (76%) and specificity (70%). For ophthalmologists and low vision experts the crowding ratio had the best sensitivity (67%) and specificity (79 and 86%). Youth health care professionals best continue applying subnormal visual acuity for screening, whereas ophthalmologists and low vision experts best add the crowding ratio to their routine diagnostics, to distinguish children at risk of visual impairment in the context of brain damage from children with ocular pathology only. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  7. [The relationship between eyeball structure and visual acuity in high myopia].

    PubMed

    Liu, Yi-Chang; Xia, Wen-Tao; Zhu, Guang-You; Zhou, Xing-Tao; Fan, Li-Hua; Liu, Rui-Jue; Chen, Jie-Min

    2010-06-01

    To explore the relationship between eyeball structure and visual acuity in high myopia. Totally, 152 people (283 eyeballs) with different levels of myopia were tested for visual acuity, axial length, and fundus. All cases were classified according to diopter, axial length, and fundus. The relationships between diopter, axial length, fundus and visual acuity were studied. The mathematical models were established for visual acuity and eyeball structure markers. The visual acuity showed a moderate correlation with fundus class, comus, axial length and diopter ([r] > 0.4, P < 0.000 1). The visual acuity in people with the axial length longer than 30.00 mm, diopter above -20.00 D and fundus in 4th class were mostly below 0.5. The mathematical models were established by visual acuity and eyeball structure markers. The visual acuity should decline with axial length extension, diopter deepening and pathological deterioration of fundus. To detect the structure changes by combining different kinds of objective methods can help to assess and to judge the vision in high myopia.

  8. Empiric determination of corrected visual acuity standards for train crews.

    PubMed

    Schwartz, Steven H; Swanson, William H

    2005-08-01

    Probably the most common visual standard for employment in the transportation industry is best-corrected, high-contrast visual acuity. Because such standards were often established absent empiric linkage to job performance, it is possible that a job applicant or employee who has visual acuity less than the standard may be able to satisfactorily perform the required job activities. For the transportation system that we examined, the train crew is required to inspect visually the length of the train before and during the time it leaves the station. The purpose of the inspection is to determine if an individual is in a hazardous position with respect to the train. In this article, we determine the extent to which high-contrast visual acuity can predict performance on a simulated task. Performance at discriminating hazardous from safe conditions, as depicted in projected photographic slides, was determined as a function of visual acuity. For different levels of visual acuity, which was varied through the use of optical defocus, a subject was required to label scenes as hazardous or safe. Task performance was highly correlated with visual acuity as measured under conditions normally used for vision screenings (high-illumination and high-contrast): as the acuity decreases, performance at discriminating hazardous from safe scenes worsens. This empirically based methodology can be used to establish a corrected high-contrast visual acuity standard for safety-sensitive work in transportation that is linked to the performance of a job-critical task.

  9. Visual acuity and visual skills in Malaysian children with learning disabilities

    PubMed Central

    Muzaliha, Mohd-Nor; Nurhamiza, Buang; Hussein, Adil; Norabibas, Abdul-Rani; Mohd-Hisham-Basrun, Jaafar; Sarimah, Abdullah; Leo, Seo-Wei; Shatriah, Ismail

    2012-01-01

    Background: There is limited data in the literature concerning the visual status and skills in children with learning disabilities, particularly within the Asian population. This study is aimed to determine visual acuity and visual skills in children with learning disabilities in primary schools within the suburban Kota Bharu district in Malaysia. Methods: We examined 1010 children with learning disabilities aged between 8–12 years from 40 primary schools in the Kota Bharu district, Malaysia from January 2009 to March 2010. These children were identified based on their performance in a screening test known as the Early Intervention Class for Reading and Writing Screening Test conducted by the Ministry of Education, Malaysia. Complete ocular examinations and visual skills assessment included near point of convergence, amplitude of accommodation, accommodative facility, convergence break and recovery, divergence break and recovery, and developmental eye movement tests for all subjects. Results: A total of 4.8% of students had visual acuity worse than 6/12 (20/40), 14.0% had convergence insufficiency, 28.3% displayed poor accommodative amplitude, and 26.0% showed signs of accommodative infacility. A total of 12.1% of the students had poor convergence break, 45.7% displayed poor convergence recovery, 37.4% showed poor divergence break, and 66.3% were noted to have poor divergence recovery. The mean horizontal developmental eye movement was significantly prolonged. Conclusion: Although their visual acuity was satisfactory, nearly 30% of the children displayed accommodation problems including convergence insufficiency, poor accommodation, and accommodative infacility. Convergence and divergence recovery are the most affected visual skills in children with learning disabilities in Malaysia. PMID:23055674

  10. Phenomenological model of visual acuity

    NASA Astrophysics Data System (ADS)

    Gómez-Pedrero, José A.; Alonso, José

    2016-12-01

    We propose in this work a model for describing visual acuity (V) as a function of defocus and pupil diameter. Although the model is mainly based on geometrical optics, it also incorporates nongeometrical effects phenomenologically. Compared to similar visual acuity models, the proposed one considers the effect of astigmatism and the variability of best corrected V among individuals; it also takes into account the accommodation and the "tolerance to defocus," the latter through a phenomenological parameter. We have fitted the model to the V data provided in the works of Holladay et al. and Peters, showing the ability of this model to accurately describe the variation of V against blur and pupil diameter. We have also performed a comparison between the proposed model and others previously published in the literature. The model is mainly intended for use in the design of ophthalmic compensations, but it can also be useful in other fields such as visual ergonomics, design of visual tests, and optical instrumentation.

  11. Iris pigmentation and photopic visual acuity: a preliminary study.

    PubMed

    Short, G B

    1975-11-01

    Visual acuity under varying conditions of light stress was tested in four human populations. It was found that the density of iris pigmentation had no significant effect on visual acuity under conditions of bright light. While some acclimatization to local light levels was observed, significant population differences in visual acuity were obtained. A hypothesis is advanced at to the adaptive value of varying densities of pigmentation of the iris based on the known heat absorption properties of melanin granules.

  12. Visual Vestibular Interaction in the Dynamic Visual Acuity Test during Voluntary Head Rotation

    NASA Technical Reports Server (NTRS)

    Lee, Moo Hoon; Durnford, Simon; Crowley, John; Rupert, Angus

    1996-01-01

    Although intact vestibular function is essential in maintaining spatial orientation, no good screening tests of vestibular function are available to the aviation community. High frequency voluntary head rotation was selected as a vestibular stimulus to isolate the vestibulo-ocular reflex (VOR) from visual influence. A dynamic visual acuity test that incorporates voluntary head rotation was evaluated as a potential vestibular function screening tool. Twenty-seven normal subjects performed voluntary sinusoidal head rotation at frequencies from 0.7-4.0 Hz under three different visual conditions: visually-enhanced VOR, normal VOR, and visually suppressed VOR. Standardized Baily-Lovie chart letters were presented on a computer monitor in front of the subject, who then was asked to read the letters while rotating his head horizontally. The electro-oculogram and dynamic visual acuity score were recorded and analyzed. There were no significant differences in gain or phase shift among three visual conditions in the frequency range of 2.8 to 4.0 Hz. The dynamic visual acuity score shifted less than 0.3 logMAR at frequencies under 2.0 Hz. The dynamic visual acuity test at frequencies a round 2.0 Hz can be recommended for evaluating vestibular function.

  13. Dynamic Visual Acuity: a Functionally Relevant Research Tool

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Brady, Rachel A.; Miller, Chris A.; Mulavara, Ajitkumar P.; Wood, Scott J.; Cohen, Helen S.; Bloomberg, Jacob J.

    2010-01-01

    Coordinated movements between the eyes and head are required to maintain a stable retinal image during head and body motion. The vestibulo-ocular reflex (VOR) plays a significant role in this gaze control system that functions well for most daily activities. However, certain environmental conditions or interruptions in normal VOR function can lead to inadequate ocular compensation, resulting in oscillopsia, or blurred vision. It is therefore possible to use acuity to determine when the environmental conditions, VOR function, or the combination of the two is not conductive for maintaining clear vision. Over several years we have designed and tested several tests of dynamic visual acuity (DVA). Early tests used the difference between standing and walking acuity to assess decrements in the gaze stabilization system after spaceflight. Supporting ground-based studies measured the responses from patients with bilateral vestibular dysfunction and explored the effects of visual target viewing distance and gait cycle events on walking acuity. Results from these studies show that DVA is affected by spaceflight, is degraded in patients with vestibular dysfunction, changes with target distance, and is not consistent across the gait cycle. We have recently expanded our research to include studies in which seated subjects are translated or rotated passively. Preliminary results from this work indicate that gaze stabilization ability may differ between similar active and passive conditions, may change with age, and can be affected by the location of the visual target with respect to the axis of motion. Use of DVA as a diagnostic tool is becoming more popular but the functional nature of the acuity outcome measure also makes it ideal for identifying conditions that could lead to degraded vision. By doing so, steps can be taken to alter the problematic environments to improve the man-machine interface and optimize performance.

  14. Visual acuity in young elite motorsport athletes: a preliminary report.

    PubMed

    Schneiders, Anthony G; Sullivan, S John; Rathbone, Emma J; Louise Thayer, A; Wallis, Laura M; Wilson, Alexandra E

    2010-05-01

    To determine whether elite motorsport athletes demonstrate superior levels of Visual Acuity than age and sex-matched controls. A cross-sectional observational study. A University vision and balance laboratory. Young male motorsport athletes from the New Zealand Elite Motorsport Academy and healthy age and sex-matched controls. Vision performance tests comprising; Static Visual Acuity (SVA), Dynamic Visual Acuity (DVA), Gaze Stabilization Test (GST), and the Perception Time Test (PTT). Motorsport athletes demonstrated superior visual acuity compared to age and sex-matched controls for all measures, and while this was not statistically significant for SVA, GST and DVA, it reached statistical significance for the PTT (pvisual ability of motorsport athletes demonstrated that they may have superior visual performance when compared to controls. Increased visual acuity and perception time may not only act to increase performance, but may also reduce the risk of potential injury. This study highlights the need for further research into the area of visual performance, particularly in motorsport and other high-speed sports, where such skills might be integral to performance and injury reduction.

  15. [Pilot study to resolve problems of visual acuity assessment in grading vision of the physically handicapped--visual acuity and difficulties in daily life of age-related macular degeneration-].

    PubMed

    Yuzawa, Mitsuko; Ishibashi, Tatsuro; Honda, Yoshihito; Kubota, Nobue

    2010-09-01

    To resolve the problems of visual acuity assessment in grading the vision of the physically handicapped as proposed by the Subcommittee for Promoting the Realization of a Cohesive Society with the Visually Disabled, Science Council of Japan, a method suitable for assessing visual disturbances, and the relationship between the degree of visual disturbances and the degree of difficulty in activities of daily life are clarified. 151 persons with age-related macular degeneration were studied. Examination methods for measuring visual acuity and reading performance were studied, and interviews using the daily living task dependent on vision (DLTV) questionnaire were performed. The correlations between total DLTV score and each examination method were analyzed. The median total DLTV score for each grade of visual acuity of the better eye was calculated. Spearman's correlation coefficient between distance corrected visual acuity of the better eye and total DLTV score was 0.76. Median DLTV scores for visual acuities (better eye) of 0.2, 0.3, 0.4, 0.5 were 65, 73.5, 62, 79 respectively. Visual acuity can be assessed by measuring distant corrected visual acuity of the better eye and setting the upper limit of visual disturbance at either 0.3 or 0.4.

  16. Comparison of visual acuity estimates using three different letter charts under two ambient room illuminations

    PubMed Central

    Chen, Ai-Hong; Norazman, Fatin Nur Najwa; Buari, Noor Halilah

    2012-01-01

    Background: Visual acuity is an essential estimate to assess ability of the visual system and is used as an indicator of ocular health status. Aim: The aim of this study is to investigate the consistency of acuity estimates from three different clinical visual acuity charts under two levels of ambient room illumination. Materials and Methods: This study involved thirty Malay university students aged between 19 and 23 years old (7 males, 23 females), with their spherical refractive error ranging between plano and –7.75D, astigmatism ranging from plano to –1.75D, anisometropia less than 1.00D and with no history of ocular injury or pathology. Right eye visual acuity (recorded in logMAR unit) was measured with Snellen letter chart (Snellen), wall mounted letter chart (WM) and projected letter chart (PC) under two ambient room illuminations, room light on and room light off. Results: Visual acuity estimates showed no statistically significant difference when measured with the room light on and with the room light off (F1,372 = 0.26, P = 0.61). Post-hoc analysis with Tukey showed that visual acuity estimates were significantly different between the Snellen and PC (P = 0.009) and between Snellen and WM (P = 0.002). Conclusions: Different levels of ambient room illumination had no significant effect on visual acuity estimates. However, the discrepancies in estimates of visual acuity noted in this study were purely due to the type of letter chart used. PMID:22446903

  17. Effects of Horizontal Acceleration on Human Visual Acuity and Stereopsis

    PubMed Central

    Horng, Chi-Ting; Hsieh, Yih-Shou; Tsai, Ming-Ling; Chang, Wei-Kang; Yang, Tzu-Hung; Yauan, Chien-Han; Wang, Chih-Hung; Kuo, Wu-Hsien; Wu, Yi-Chang

    2015-01-01

    The effect of horizontal acceleration on human visual acuity and stereopsis is demonstrated in this study. Twenty participants (mean age 22.6 years) were enrolled in the experiment. Acceleration from two different directions was performed at the Taiwan High-Speed Rail Laboratory. Gx and Gy (< and >0.1 g) were produced on an accelerating platform where the subjects stood. The visual acuity and stereopsis of the right eye were measured before and during the acceleration. Acceleration <0.1 g in the X- or Y-axis did not affect dynamic vision and stereopsis. Vision decreased (mean from 0.02 logMAR to 0.25 logMAR) and stereopsis declined significantly (mean from 40 s to 60.2 s of arc) when Gx > 0.1 g. Visual acuity worsened (mean from 0.02 logMAR to 0.19 logMAR) and poor stereopsis was noted (mean from 40 s to 50.2 s of arc) when Gy > 0.1 g. The effect of acceleration from the X-axis on the visual system was higher than that from the Y-axis. During acceleration, most subjects complained of ocular strain when reading. To our knowledge, this study is the first to report the exact levels of visual function loss during Gx and Gy. PMID:25607601

  18. Grating visual acuity results in the early treatment for retinopathy of prematurity study.

    PubMed

    Dobson, Velma; Quinn, Graham E; Summers, C Gail; Hardy, Robert J; Tung, Betty; Good, William V

    2011-07-01

    To compare grating (resolution) visual acuity at 6 years of age in eyes that received early treatment (ET) for high-risk prethreshold retinopathy of prematurity (ROP) with that in eyes that underwent conventional management (CM). In a randomized clinical trial, infants with bilateral, high-risk prethreshold ROP (n = 317) had one eye undergo ET and the other eye undergo CM, with treatment only if ROP progressed to threshold severity. For asymmetric cases (n = 84), the high-risk prethreshold eye was randomized to ET or CM. Grating visual acuity measured at 6 years of age by masked testers using Teller acuity cards. Monocular grating acuity results were obtained from 317 of 370 surviving children (85.6%). Analysis of grating acuity results for all study participants with high-risk prethreshold ROP showed no statistically significant overall benefit of ET (18.1% vs 22.8% unfavorable outcomes; P = .08). When the 6-year grating acuity results were analyzed according to a clinical algorithm (high-risk types 1 and 2 prethreshold ROP), a benefit was seen in type 1 eyes (16.4% vs 25.2%; P = .004) undergoing ET, but not in type 2 eyes (21.3% vs 15.9%; P = .29). Early treatment of eyes with type 1 ROP improves grating acuity outcomes, but ET for eyes with type 2 ROP does not. APPLICATION TO CLINICAL MEDICINE: Type 1 eyes should be treated early; however, based on acuity results at 6 years of age, type 2 eyes should be cautiously monitored for progression to type 1 ROP. Trial Registration clinicaltrials.gov Identifier: NCT00027222.

  19. Military readiness: an exploration of the relationship between marksmanship and visual acuity.

    PubMed

    Wells, Kenney H; Wagner, Heidi; Reich, Lewis N; Hardigan, Patrick C

    2009-04-01

    The United States military relies on visual acuity standards to assess enlistment induction and military occupational specialty eligibility, as well as to monitor soldiers' combat vision readiness. However, these vision standards are not evidence based and may not accurately reflect appropriate standards for military readiness or reflect a correlation between visual acuity and occupational performance. The aim of this study was to investigate the relationship between visual acuity and marksmanship performance using a single blind trial with the Engagement Skills Trainer 2000. Marksmanship performance was evaluated in 28 subjects under simulated day and night conditions with habitual spectacle prescription and contact lenses that created visual blur. Panel Poisson regression using an independent correlation structure revealed significant differences (p < 0.001) as visual acuity decreased from 20/25 to 20/50. We conclude that marksmanship performance decreases as visual acuity decreases. We believe that this relationship supports the use of a visual acuity requirement.

  20. Dynamic visual acuity using "far" and "near" targets

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Bloomberg, Jacob J.

    2005-01-01

    CONCLUSIONS: DVA may be useful for assessing the functional consequences of an impaired gaze stabilization mechanism or for testing the effectiveness of a rehabilitation paradigm. Because target distance influences the relative contributions of canal and otolith inputs, the ability to measure DVA at near and far viewing distances may also lead to tests that will independently assess canal and otolith function. OBJECTIVE: To present and test a methodology that uses dynamic visual acuity (DVA) to assess the efficacy of compensatory gaze mechanisms during a functionally relevant activity that differentially measures canal and otolith function. MATERIAL AND METHODS: The effect of treadmill walking at a velocity of 1.79 m/s on subjects' visual acuity was assessed at each of two viewing distances. A custom-written threshold determination program was used to display Landolt C optotypes on a laptop computer screen during a "far" (4 m) target condition and on a micro-display for a "near" (50 cm) target condition. The walking acuity scores for each target distance were normalized by subtracting a corresponding acuity measure obtained while standing still on the treadmill belt. RESULTS: As predicted by subjective reports of relative target motion, the decrease in visual acuity was significantly greater (p < 0.00001) for the near compared to the far condition.

  1. Relationship between socioeconomic deprivation 
or urban/rural residence and visual acuity before cataract surgery in Northern Scotland.

    PubMed

    Chua, Paul Y; Mustafa, Mohammed S; Scott, Neil W; Kumarasamy, Manjula; Azuara-Blanco, Augusto

    2013-01-01

    To evaluate the influence of socioeconomic factors on visual acuity before cataract surgery. 
 The medical case notes of 240 consecutive patients listed for cataract surgery from January 1, 2010, at Grampian University Hospital, Aberdeen, were reviewed retrospectively. Patients with ocular comorbidity were excluded. Demographics, postal codes, and visual acuity were recorded. Scottish Index of Multiple Deprivation was used to determine the deprivation rank. Home location was classified as urban or rural. The effect of these parameters on preoperative visual acuity was investigated using chi-square tests or Fisher exact test as appropriate. 
 A total of 184 patients (mean 75 years) were included. A total of 127 (69%) patients had visual acuity of 6/12 or better. An association was found between affluence and preoperative visual acuity of 6/12 or better (χ2trend = 4.97, p = 0.03), with a significant rising trend across quintile of deprivation. There was no evidence to suggest association between geographical region and preoperative visual acuity (p = 0.63). 
 Affluence was associated with good visual acuity (6/12 or better) before cataract surgery. There was no difference in preoperative visual acuity between rural and urban populations.

  2. Diagnosing cerebral visual impairment in children with good visual acuity.

    PubMed

    van Genderen, Maria; Dekker, Marjoke; Pilon, Florine; Bals, Irmgard

    2012-06-01

    To identify elements that could facilitate the diagnosis of cerebral visual impairment (CVI) in children with good visual acuity in the general ophthalmic clinic. We retrospectively investigated the clinical characteristics of 30 children with good visual acuity and CVI and compared them with those of 23 children who were referred with a suspicion of CVI, but proved to have a different diagnosis. Clinical characteristics included medical history, MRI findings, visual acuity, crowding ratio (CR), visual field assessment, and the results of ophthalmologic and orthoptic examination. We also evaluated the additional value of a short CVI questionnaire. Eighty-three percent of the children with an abnormal medical history (mainly prematurity and perinatal hypoxia) had CVI, in contrast with none of the children with a normal medical history. Cerebral palsy, visual field defects, and partial optic atrophy only occurred in the CVI group. 41% of the children with CVI had a CR ≥2.0, which may be related to dorsal stream dysfunction. All children with CVI, but also 91% of the children without CVI gave ≥3 affirmative answers on the CVI questionnaire. An abnormal pre- or perinatal medical history is the most important risk factor for CVI in children, and therefore in deciding which children should be referred for further multidisciplinary assessment. Additional symptoms of cerebral damage, i.e., cerebral palsy, visual field defects, partial optic atrophy, and a CR ≥2 may support the diagnosis. CVI questionnaires should not be used for screening purposes as they yield too many false positives.

  3. Visual Acuity Using Head-fixed Displays During Passive Self and Surround Motion

    NASA Technical Reports Server (NTRS)

    Wood, Scott J.; Black, F. Owen; Stallings, Valerie; Peters, Brian

    2007-01-01

    The ability to read head-fixed displays on various motion platforms requires the suppression of vestibulo-ocular reflexes. This study examined dynamic visual acuity while viewing a head-fixed display during different self and surround rotation conditions. Twelve healthy subjects were asked to report the orientation of Landolt C optotypes presented on a micro-display fixed to a rotating chair at 50 cm distance. Acuity thresholds were determined by the lowest size at which the subjects correctly identified 3 of 5 optotype orientations at peak velocity. Visual acuity was compared across four different conditions, each tested at 0.05 and 0.4 Hz (peak amplitude of 57 deg/s). The four conditions included: subject rotated in semi-darkness (i.e., limited to background illumination of the display), subject stationary while visual scene rotated, subject rotated around a stationary visual background, and both subject and visual scene rotated together. Visual acuity performance was greatest when the subject rotated around a stationary visual background; i.e., when both vestibular and visual inputs provided concordant information about the motion. Visual acuity performance was most reduced when the subject and visual scene rotated together; i.e., when the visual scene provided discordant information about the motion. Ranges of 4-5 logMAR step sizes across the conditions indicated the acuity task was sufficient to discriminate visual performance levels. The background visual scene can influence the ability to read head-fixed displays during passive motion disturbances. Dynamic visual acuity using head-fixed displays can provide an operationally relevant screening tool for visual performance during exposure to novel acceleration environments.

  4. The incidence and visual acuity outcomes of children identified with ametropic amblyopia by vision screening.

    PubMed

    Maqsud, Mohammed Aftab; Arblaster, Gemma E

    2015-04-01

    To determine the incidence of ametropic amblyopia within a vision screening program's population and report the visual acuity outcomes of children identified with the condition. The medical records of children who underwent vision screening as their first assessment at 4-5 years of age between September 1, 2005 and August 31, 2006, were retrospectively reviewed. Children referred with ≤0.30 logMAR in each eye with at least 1 year of follow-up had their hospital notes reviewed and data on final visual acuity, refractive error, and follow-up period collected. A total of 33 children identified as having ametropic amblyopia with a follow-up of at least 1 year. The incidence of ametropic amblyopia was 2%-3.2%, depending on the definition used. The mean visual acuity achieved after treatment was 0.12 logMAR, which is significantly less than the age-appropriate mean of 0.00 logMAR (P < 0.01). Ametropic amblyopia responds to treatment, but most children demonstrate persistent reduced visual acuity at age 7 years. The incidence of ametropic amblyopia within a routine vision screening population shows that significant numbers fail to self-present. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  5. Experience-dependent central vision deficits: Neurobiology and visual acuity.

    PubMed

    Williams, Kate; Balsor, Justin L; Beshara, Simon; Beston, Brett R; Jones, David G; Murphy, Kathryn M

    2015-09-01

    Abnormal visual experience during childhood often leads to amblyopia, with strong links to binocular dysfunction that can include poor acuity in both eyes, especially in central vision. In animal models of amblyopia, the non-deprived eye is often considered normal and what limits binocular acuity. This leaves open the question whether monocular deprivation (MD) induces binocular dysfunction similar to what is found in amblyopia. In previous studies of MD cats, we found a loss of excitatory receptors restricted to the central visual field representation in visual cortex (V1), including both eyes' columns. This led us to ask two questions about the effects of MD: how quickly are receptors lost in V1? and is there an impact on binocular acuity? We found that just a few hours of MD caused a rapid loss of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor proteins across all of V1. But after a few days of MD, there was recovery in the visual periphery, leaving a loss of AMPA receptors only in the central region of V1. We reared animals with early MD followed by a long period of binocular vision and found binocular acuity deficits that were greatest in the central visual field. Our results suggest that the greater binocular acuity deficits in the central visual field are driven in part by the long-term loss of AMPA receptors in the central region of V1. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Allen figure and broken wheel visual acuity measurement in preschool children.

    PubMed

    Schmidt, P P

    1992-02-01

    In a masked investigation, 34 preschool children (n = 34, 19 females and 15 males) between the ages of 3 and 5 years (mean age = 4.1 years) enrolled in Project Headstart had their monocular and binocular visual acuity measured using the Broken Wheel and Allen figure methods. The results showed that 1) a greater range in acuity values was found with the Allen figure than Broken Wheel test, despite the identical Snellen equivalent acuity levels and similar probability of guessing criteria used for both Broken Wheel and Allen figure acuity measurement e.g., no strong statistical correlation (rOD = +0.22, rOS = -0.11 and rOU = +0.04; rho OD = +0.22, rho OS = -0.11, rho OU = 0.00) for the two tests was found; and 2) the Broken Wheel test appeared to discriminate between 20/30 and 20/40 acuity performance more consistently than did Allen figure and in a way not attributable to chance (p less than or equal to 0.003). In a separate evaluation, the Broken Wheel test showed consistency in the acuity measured. Broken Wheel acuity measurement, even with an average variation of +/- 5.6 percent from the corresponding Snellen standard, appears to be a valuable clinical tool to measure acuity in young children.

  7. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices.

    PubMed

    Livingstone, I A T; Tarbert, C M; Giardini, M E; Bastawrous, A; Middleton, D; Hamilton, R

    2016-01-01

    Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer's recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  8. Photometric Compliance of Tablet Screens and Retro-Illuminated Acuity Charts As Visual Acuity Measurement Devices

    PubMed Central

    Livingstone, I. A. T.; Tarbert, C. M.; Giardini, M. E.; Bastawrous, A.; Middleton, D.; Hamilton, R.

    2016-01-01

    Mobile technology is increasingly used to measure visual acuity. Standards for chart-based acuity tests specify photometric requirements for luminance, optotype contrast and luminance uniformity. Manufacturers provide some photometric data but little is known about tablet performance for visual acuity testing. This study photometrically characterised seven tablet computers (iPad, Apple inc.) and three ETDRS (Early Treatment Diabetic Retinopathy Study) visual acuity charts with room lights on and off, and compared findings with visual acuity measurement standards. Tablet screen luminance and contrast were measured using nine points across a black and white checkerboard test screen at five arbitrary brightness levels. ETDRS optotypes and adjacent white background luminance and contrast were measured. All seven tablets (room lights off) exceeded the most stringent requirement for mean luminance (≥ 120 cd/m2) providing the nominal brightness setting was above 50%. All exceeded contrast requirement (Weber ≥ 90%) regardless of brightness setting, and five were marginally below the required luminance uniformity threshold (Lmin/Lmax ≥ 80%). Re-assessing three tablets with room lights on made little difference to mean luminance or contrast, and improved luminance uniformity to exceed the threshold. The three EDTRS charts (room lights off) had adequate mean luminance (≥ 120 cd/m2) and Weber contrast (≥ 90%), but all three charts failed to meet the luminance uniformity standard (Lmin/Lmax ≥ 80%). Two charts were operating beyond manufacturer’s recommended lamp replacement schedule. With room lights on, chart mean luminance and Weber contrast increased, but two charts still had inadequate luminance uniformity. Tablet computers showed less inter-device variability, higher contrast, and better luminance uniformity than charts in both lights-on and lights-off environments, providing brightness setting was >50%. Overall, iPad tablets matched or marginally out

  9. A half-mile walk decreases visual acuity in active older people.

    PubMed

    De Oliveira Filho, Ciro Winckler; Dias, Roges Ghidini; Tavares, Graziela Morgana Silva; Santos, Gilmar Moraes; Mazo, Giovana Zarpellon

    2010-06-01

    The influence of a half-mile walk on the visual acuity of older people who engaged in physical activity was examined. 91 elderly people of both sexes (20 men, 71 women; M age = 69 yr., SD = 6) participated. All were assessed before and after the half-mile walking test for visual acuity (Snellen Optotype Scale) and heart rate. The data indicated a significant decrease in visual acuity as a result of the half-mile test.

  10. Acuity-independent effects of visual deprivation on human visual cortex

    PubMed Central

    Hou, Chuan; Pettet, Mark W.; Norcia, Anthony M.

    2014-01-01

    Visual development depends on sensory input during an early developmental critical period. Deviation of the pointing direction of the two eyes (strabismus) or chronic optical blur (anisometropia) separately and together can disrupt the formation of normal binocular interactions and the development of spatial processing, leading to a loss of stereopsis and visual acuity known as amblyopia. To shed new light on how these two different forms of visual deprivation affect the development of visual cortex, we used event-related potentials (ERPs) to study the temporal evolution of visual responses in patients who had experienced either strabismus or anisometropia early in life. To make a specific statement about the locus of deprivation effects, we took advantage of a stimulation paradigm in which we could measure deprivation effects that arise either before or after a configuration-specific response to illusory contours (ICs). Extraction of ICs is known to first occur in extrastriate visual areas. Our ERP measurements indicate that deprivation via strabismus affects both the early part of the evoked response that occurs before ICs are formed as well as the later IC-selective response. Importantly, these effects are found in the normal-acuity nonamblyopic eyes of strabismic amblyopes and in both eyes of strabismic patients without amblyopia. The nonamblyopic eyes of anisometropic amblyopes, by contrast, are normal. Our results indicate that beyond the well-known effects of strabismus on the development of normal binocularity, it also affects the early stages of monocular feature processing in an acuity-independent fashion. PMID:25024230

  11. Screening for Impaired Visual Acuity in Older Adults: US Preventive Services Task Force Recommendation Statement.

    PubMed

    Siu, Albert L; Bibbins-Domingo, Kirsten; Grossman, David C; Baumann, Linda Ciofu; Davidson, Karina W; Ebell, Mark; García, Francisco A R; Gillman, Matthew; Herzstein, Jessica; Kemper, Alex R; Krist, Alex H; Kurth, Ann E; Owens, Douglas K; Phillips, William R; Phipps, Maureen G; Pignone, Michael P

    2016-03-01

    Update of the US Preventive Services Task Force (USPSTF) recommendation on screening for impaired visual acuity in older adults. The USPSTF reviewed the evidence on screening for visual acuity impairment associated with uncorrected refractive error, cataracts, and age-related macular degeneration among adults 65 years or older in the primary care setting; the benefits and harms of screening; the accuracy of screening; and the benefits and harms of treatment of early vision impairment due to uncorrected refractive error, cataracts, and age-related macular degeneration. This recommendation applies to asymptomatic adults 65 years or older who do not present to their primary care clinician with vision problems. The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for impaired visual acuity in older adults. (I statement).

  12. Effect of neodymium:YAG laser capsulotomy on visual function in patients with posterior capsule opacification and good visual acuity.

    PubMed

    Yotsukura, Erisa; Torii, Hidemasa; Saiki, Megumi; Negishi, Kazuno; Tsubota, Kazuo

    2016-03-01

    To evaluate the effect of neodymium:YAG (Nd:YAG) laser capsulotomy on the visual function in patients with posterior capsule opacification (PCO) and good visual acuity. Keio University Hospital, Tokyo, Japan. Observational case series. Eyes were evaluated that had previous cataract surgery with a clinical diagnosis of PCO requiring Nd:YAG laser capsulotomy regardless of a good corrected distance visual acuity (CDVA) (at least 20/20). The CDVA, 10% low contrast visual acuity (LCVA), wavefront aberrations from the 3rd to 6th order, and retinal straylight were measured before and after Nd:YAG laser capsulotomy. The study included 16 eyes of 16 patients (10 men, 6 women; mean age 69.5 years ± 9.3 [SD]). The mean CDVA, LCVA, and straylight after Nd:YAG laser capsulotomy improved significantly (P < .05). The root mean square (RMS) of the 3rd Zernike coefficients (S3) and the RMS of the total higher-order aberrations (HOAs) from the 3rd to 6th order decreased significantly after capsulotomy (P < .05). The straylight correlated significantly with the total HOAs (r = 0.727, P = .002) and S3 (r = 0.748, P = .001) before capsulotomy. Subjective symptoms resolved after capsulotomy in all cases. Neodymium:YAG laser capsulotomy enabled a significant improvement in visual function even in patients with PCO with good visual acuity. Straylight measurements might be useful to determine the indications for Nd:YAG laser capsulotomy when patients report visual disturbances without decreased visual acuity. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. Improvement of visual acuity by refraction in a low-vision population.

    PubMed

    Sunness, Janet S; El Annan, Jaafar

    2010-07-01

    Refraction often may be overlooked in low-vision patients, because the main cause of vision decrease is not refractive, but rather is the result of underlying ocular disease. This retrospective study was carried out to determine how frequently and to what extent visual acuity is improved by refraction in a low-vision population. Cross-sectional study. Seven hundred thirty-nine low-vision patients seen for the first time. A database with all new low-vision patients seen from November 2005 through June 2008 recorded presenting visual acuity using an Early Treatment Diabetic Retinopathy Study chart; it also recorded the best-corrected visual acuity (BCVA) if it was 2 lines or more better than the presenting visual acuity. Retinoscopy was carried out on all patients, followed by manifest refraction. Improvement in visual acuity. Median presenting acuity was 20/80(-2) (interquartile range, 20/50-20/200). There was an improvement of 2 lines or more of visual acuity in 81 patients (11% of all patients), with 22 patients (3% of all patients) improving by 4 lines or more. There was no significant difference in age or in presenting visual acuity between the group that did not improve by refraction and the group that did improve. When stratified by diagnosis, the only 2 diagnoses with a significantly higher rate of improvement than the age-related macular degeneration group were myopic degeneration and progressive myopia (odds ratio, 4.8; 95% confidence interval [CI], 3.0-6.7) and status post-retinal detachment (odds ratio, 7.1; 95% CI, 5.2-9.0). For 5 patients (6% of those with improvement), the eye that was 1 line or more worse than the fellow eye at presentation became the eye that was 1 line or more better than the fellow eye after refraction. A significant improvement in visual acuity was attained by refraction in 11% of the new low-vision patients. Improvement was seen across diagnoses and the range of presenting visual acuity. The worse-seeing eye at presentation may

  14. Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus - a pilot study.

    PubMed

    Teufel, Julian; Bardins, S; Spiegel, Rainer; Kremmyda, O; Schneider, E; Strupp, M; Kalla, R

    2016-01-04

    Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the visual acuity with a fixed Landolt C (static) and during real-time feedback driven condition (dynamic) in gaze straight ahead and (20°) sideward gaze. In the dynamic condition, the Landolt C moved according to the slow phase eye velocity of the downbeat nystagmus. The Shapiro-Wilk test was used to test for normal distribution and one-way ANOVA for comparison. Ten patients with downbeat nystagmus were included in the study. Median age was 76 years and the median duration of symptoms was 6.3 years (SD +/- 3.1y). The mean slow phase velocity was moderate during gaze straight ahead (1.44°/s, SD +/- 1.18°/s) and increased significantly in sideward gaze (mean left 3.36°/s; right 3.58°/s). In gaze straight ahead, we found no difference between the static and feedback driven condition. In sideward gaze, visual acuity improved in five out of ten subjects during the feedback-driven condition (p = 0.043). This study provides proof of concept that non-invasive real-time computer-based visual feedback compensates for the SPV in DBN. Therefore, real-time visual feedback may be a promising aid for patients suffering from oscillopsia and impaired text reading on screen. Recent technological advances in the area of virtual reality displays might soon render this approach feasible in fully mobile settings.

  15. Final visual acuity results in the early treatment for retinopathy of prematurity study.

    PubMed

    Good, William V; Hardy, Robert J; Dobson, Velma; Palmer, Earl A; Phelps, Dale L; Tung, Betty; Redford, Maryann

    2010-06-01

    To compare visual acuity at 6 years of age in eyes that received early treatment for high-risk prethreshold retinopathy of prematurity (ROP) with conventionally managed eyes. Infants with symmetrical, high-risk prethreshold ROP (n = 317) had one eye randomized to earlier treatment at high-risk prethreshold disease and the other eye managed conventionally, treated if ROP progressed to threshold severity. For asymmetric cases (n = 84), the high-risk prethreshold eye was randomized to either early treatment or conventional management. The main outcome measure was ETDRS visual acuity measured at 6 years of age by masked testers. Retinal structure was assessed as a secondary outcome. Analysis of all subjects with high-risk prethreshold ROP showed no statistically significant benefit for early treatment (24.3% vs 28.6% [corrected] unfavorable outcome; P = .15). Analysis of 6-year visual acuity results according to the Type 1 and 2 clinical algorithm showed a benefit for Type 1 eyes (25.1% vs 32.8%; P = .02) treated early but not Type 2 eyes (23.6% vs 19.4%; P = .37). Early-treated eyes showed a significantly better structural outcome compared with conventionally managed eyes (8.9% vs 15.2% unfavorable outcome; P < .001), with no greater risk of ocular complications. Early treatment for Type 1 high-risk prethreshold eyes improved visual acuity outcomes at 6 years of age. Early treatment for Type 2 high-risk prethreshold eyes did not. Application to Clinical Practice Type 1 eyes, not Type 2 eyes, should be treated early. These results are particularly important considering that 52% of Type 2 high-risk prethreshold eyes underwent regression of ROP without requiring treatment. Trial Registration clinicaltrials.gov Identifier: NCT00027222.

  16. SURGICAL OUTCOMES IN PATIENTS WITH MACULAR PUCKER AND GOOD PREOPERATIVE VISUAL ACUITY AFTER VITRECTOMY WITH MEMBRANE PEELING.

    PubMed

    Reilly, Gayatri; Melamud, Alexander; Lipscomb, Peter; Toussaint, Brian

    2015-09-01

    To evaluate whether patients with macular pucker (epiretinal membrane [ERM]) and good preoperative visual acuity (20/50 or better) benefit from small-gauge pars plana vitrectomy with membrane peeling. Retrospective chart review of eyes undergoing small-gauge pars plana vitrectomy for ERM. Inclusion criterion was impaired visual acuity (20/50 or better) due to ERM. Exclusion criteria were preoperative visual acuity of 20/60 or worse, previous surgery (other than uncomplicated cataract surgery), and any documented evidence of macular or corneal disease that would limit visual potential. The main outcome measure was final visual acuity. Secondary outcomes included the role of internal limiting membrane peeling, and the effect of preoperative cystoid macular edema and internal limiting membrane peeling on visual acuity. One hundred and forty eyes met inclusion criteria of which 94% underwent 25-gauge vitrectomy (remainder had 23-gauge). There was a statistically significant improvement in final vision with the mean preoperative visual acuity of 0.305 logMAR (20/40) and 1-year visual acuity of 0.250 logMAR (20/35) (P = 0.0167). Cataract formation in phakic patients had a significant effect on the final visual outcome. Fifty-six of 63 patients (89%) in the phakic cohort developed a visually significant cataract by study end. The mean time to recommendation of cataract surgery was 8.4 months. Thirty-eight eyes (27%) had preoperative cystoid macular edema. Fifty-nine eyes (42%) underwent internal limiting membrane peeling. Neither one of these secondary outcome measures had a significant effect on the final visual outcome. Pars plana vitrectomy is both efficacious and safe an option for patients with ERMs and good preoperative vision. Eyes with an ERM and vision 20/50 or better had a statistically significant improvement in the final visual outcome after small-gauge pars plana vitrectomy surgery. As with large-gauge vitrectomy, cataract formation occurred in most phakic

  17. Preschool visual acuity screening tests.

    PubMed Central

    Friendly, D S

    1978-01-01

    The purpose of the study was to evaluate the relative merits of two screening tests used for visual acuity assessment of preschool children. The tests that were compared were the Good-Lite Company versions of the E-Test and of the STYCAR (Screening Test for Young Children and Retardates). The former is the most popular method for evaluating central acuity in young children in this nation; the STYCAR is a relatively new letter-matching-test developed in England, where it is widely employed. The E-Test poses left-right orientation problems which are eliminated by the symmetrical letters H, T, O and V utilized in the Letter-Matching-Test. Both visual acuity tests were administered on two separate occasions by personnel from the Prevention of Blindness Society of Metropolitan Washington to 633 preschool children in Washington, D.C. By random selection, 150 of the children received the E-Test at both sessions, 162 children received the Letter-Matching-Test at both sessions, 160 chilt athe the second session, and 161 children received the Letter-Matching-Test at the first session and the E-Test at the second session. The author medically examined the eyes of 408 of the 633 children without knowledge of which test had been initially administered. Statistical analysis of the data obtained from the study indicated that the Letter-Matching-Test was significantly better in terms of testability rates, group and individual instruction time, and performance time. The E-Test was more reliable in terms of test-retest acuity scores and was also more valid in terms of agreement between pass-fail results obtained at the first screening session and two levels of pass-fail refraction criteria. Images FIGURE 4 FIGURE 5 FIGURE 7 A FIGURE 7 B FIGURE 9 A FIGURE 9 B PMID:754379

  18. Night vision in barn owls: visual acuity and contrast sensitivity under dark adaptation.

    PubMed

    Orlowski, Julius; Harmening, Wolf; Wagner, Hermann

    2012-12-06

    Barn owls are effective nocturnal predators. We tested their visual performance at low light levels and determined visual acuity and contrast sensitivity of three barn owls by their behavior at stimulus luminances ranging from photopic to fully scotopic levels (23.5 to 1.5 × 10⁻⁶). Contrast sensitivity and visual acuity decreased only slightly from photopic to scotopic conditions. Peak grating acuity was at mesopic (4 × 10⁻² cd/m²) conditions. Barn owls retained a quarter of their maximal acuity when luminance decreased by 5.5 log units. We argue that the visual system of barn owls is designed to yield as much visual acuity under low light conditions as possible, thereby sacrificing resolution at photopic conditions.

  19. Visual Acuity does not Moderate Effect Sizes of Higher-Level Cognitive Tasks

    PubMed Central

    Houston, James R.; Bennett, Ilana J.; Allen, Philip A.; Madden, David J.

    2016-01-01

    Background Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the “common cause” hypothesis of Lindenberger & Baltes, 1994). McGowan, Patterson and Jordan (2013) also found that a surprisingly large number of published cognitive aging studies failed to include adequate measures of visual acuity. However, a recent meta-analysis of three studies (LaFleur & Salthouse, 2014) failed to find evidence that visual acuity moderated or mediated age differences in higher-level cognitive processes. In order to provide a more extensive test of whether visual acuity moderates age differences in higher-level cognitive processes, we conducted a more extensive meta-analysis of topic. Methods Using results from 456 studies, we calculated effect sizes for the main effect of age across four cognitive domains (attention, executive function, memory, and perception/language) separately for five levels of visual acuity criteria (no criteria, undisclosed criteria, self-reported acuity, 20/80-20/31, and 20/30 or better). Results As expected, age had a significant effect on each cognitive domain. However, these age effects did not further differ as a function of visual acuity criteria. Conclusion The current meta-analytic, cross-sectional results suggest that visual acuity is not significantly related to age group differences in higher-level cognitive performance—thereby replicating LaFleur and Salthouse (2014). Further efforts are needed to determine whether other measures of visual functioning (e.g. contrast sensitivity, luminance) affect age differences in cognitive functioning. PMID:27070044

  20. Brief Report: Visual Acuity in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Albrecht, Matthew A.; Stuart, Geoffrey W.; Falkmer, Marita; Ordqvist, Anna; Leung, Denise; Foster, Jonathan K.; Falkmer, Torbjorn

    2014-01-01

    Recently, there has been heightened interest in suggestions of enhanced visual acuity in autism spectrum disorders (ASD) which was sparked by evidence that was later accepted to be methodologically flawed. However, a recent study that claimed children with ASD have enhanced visual acuity (Brosnan et al. in "J Autism Dev Disord"…

  1. The advanced glaucoma intervention study, 6: effect of cataract on visual field and visual acuity. The AGIS Investigators.

    PubMed

    2000-12-01

    To investigate the effect of cataract on visual function and the role of cataract in explaining a race-treatment interaction in outcomes of glaucoma surgery. The Advanced Glaucoma Intervention Study (AGIS) enrolled 332 black patients (451 eyes) and 249 white patients (325 eyes) with advanced glaucoma. Eyes were randomly assigned to an argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy sequence or a trabeculectomy-ALT-trabeculectomy sequence. From the AGIS experience with cataract surgery during follow-up, we estimated the expected change in visual function scores from before cataract surgery to after cataract surgery. Then, for eyes with cataract not removed, we used these estimates of expected change to adjust visual function scores for the presumed effects of cataract. In turn, we used the adjusted scores to obtain cataract-adjusted main outcome measures. Average percent of eyes with decrease of visual field (APDVF) and average percent of eyes with decrease of visual acuity (APDVA). Within the 2 months before cataract surgery, visual acuity was better in eyes of white patients than of black patients by an average of approximately 2 lines on the visual acuity test chart. Cataract surgery improved visual acuity and visual field defect scores, with the amounts of improvement greater when preoperative visual acuity was lower. Adjustments for cataract brought about the following relative reductions: for APDVF, a relative reduction of 5% to 11% in black patients and 9% to 11% in white patients; for APDVA, a relative reduction of 45% to 49% in black patients and 31% to 38% in white patients; and for the APDVF and APDVA race-treatment interactions, relative reductions of 25% and 45%, respectively. On average, visual function scores improved after cataract surgery. The findings of reduced race-treatment interactions after adjustment for cataract do not alter our earlier conclusion that the AGIS 7-year results support use of the ALT

  2. Visual acuity and magnification devices in dentistry.

    PubMed

    Perrin, Philippe; Eichenberger, Martina; Neuhaus, Klaus W; Lussi, Adrian

    2016-01-01

    This review discusses visual acuity in dentistry and the influence of optical aids. Studies based on objective visual tests at a dental working distance were included. These studies show dramatic individual variation independent of the dentists’ age. The limitations due to presbyopia begin at an age of 40 years. Dental professionals should have their near vision tested regularly. Visual deficiencies can be compensated with magnification aids. It is important to differentiate between Galilean and Keplerian loupes. The lightweight Galilean loupes allow an almost straight posture and offer improved ergonomics. Younger dentists profit more from the ergonomic aspects, while dentists over the age of 40 can compensate their age-related visual deficiencies when using this type of loupe. Keplerian loupes, with their superior optical construction, improve the visual performance for dentists of all age groups. The optical advantages come at the cost of ergonomic constraints due to the weight of these loupes. The microscope is highly superior visually and ergonomically, and it is indispensable for the visual control of endodontic treatments.

  3. Visual acuity and legal visual requirement to drive a passenger vehicle.

    PubMed

    Kiel, A W; Butler, T; Alwitry, A

    2003-07-01

    (1). To test the consistency and ease with which number-plates of different component figures can be read under DVLA driving test conditions; (2). to test the relative difficulty of reading corresponding figures on registration plates of white and yellow backgrounds.Design Prospective study of consecutive eligible clinic patients. Ophthalmology outpatients. 210 individuals with a corrected visual acuity with both eyes open of between 6/9 and 6/12. The ability to read three different number-plates under standard DVLA driving-test conditions (ie at 20.5 m in good daylight with glasses if worn) and the ability to read identical number-plates against a white and a yellow background. There is a significant difference between the ease with which three different number-plates can be read depending on their letter and numeral composition, although this did not seem to be significantly affected by whether they were printed on a yellow or white background. Only 92.3% of subjects could read all the number-plates at the legal distance, 96.7% could read at least one number-plate at the legal distance and 3.3% of the test subjects could not read any of the number-plates at 20.5 m. The current test protocol used to obtain a driving licence and, moreover, the test the police will employ to assess visual competence to drive, is highly variable and is unlikely to give consistent repeatable results. The performance of those with equally good visual acuity is unpredictable and is highly dependent on the number-plate they are asked to read. This variability could exclude some who would otherwise pass the test or pass an individual with a visual acuity below accepted standards. The forthcoming changes in the regulations for design of number-plates is an ideal opportunity to standardise the whole testing procedure for driving visual acuity.

  4. Perceptual learning improves contrast sensitivity, visual acuity, and foveal crowding in amblyopia.

    PubMed

    Barollo, Michele; Contemori, Giulio; Battaglini, Luca; Pavan, Andrea; Casco, Clara

    2017-01-01

    Amblyopic observers present abnormal spatial interactions between a low-contrast sinusoidal target and high-contrast collinear flankers. It has been demonstrated that perceptual learning (PL) can modulate these low-level lateral interactions, resulting in improved visual acuity and contrast sensitivity. We measured the extent and duration of generalization effects to various spatial tasks (i.e., visual acuity, Vernier acuity, and foveal crowding) through PL on the target's contrast detection. Amblyopic observers were trained on a contrast-detection task for a central target (i.e., a Gabor patch) flanked above and below by two high-contrast Gabor patches. The pre- and post-learning tasks included lateral interactions at different target-to-flankers separations (i.e., 2, 3, 4, 8λ) and included a range of spatial frequencies and stimulus durations as well as visual acuity, Vernier acuity, contrast-sensitivity function, and foveal crowding. The results showed that perceptual training reduced the target's contrast-detection thresholds more for the longest target-to-flanker separation (i.e., 8λ). We also found generalization of PL to different stimuli and tasks: contrast sensitivity for both trained and untrained spatial frequencies, visual acuity for Sloan letters, and foveal crowding, and partially for Vernier acuity. Follow-ups after 5-7 months showed not only complete maintenance of PL effects on visual acuity and contrast sensitivity function but also further improvement in these tasks. These results suggest that PL improves facilitatory lateral interactions in amblyopic observers, which usually extend over larger separations than in typical foveal vision. The improvement in these basic visual spatial operations leads to a more efficient capability of performing spatial tasks involving high levels of visual processing, possibly due to the refinement of bottom-up and top-down networks of visual areas.

  5. Visual acuity outcomes in eyes with flat corneas after PRK.

    PubMed

    Varssano, David; Waisbourd, Michael; Minkev, Liza; Sela, Tzahi; Neudorfer, Meira; Binder, Perry S

    2013-06-01

    To evaluate the impact of corneal curvatures less than 35 diopters (D) after photorefractive keratectomy (PRK) on visual acuity outcomes. Visual acuity outcomes of 5,410 eyes that underwent PRK from January 2006 to November 2010 were retrospectively analyzed for the impact of postoperative corneal curvatures on visual outcomes. All procedures were performed on a single platform (Allegretto 200Hz excimer laser; Alcon Laboratories, Inc., Irvine, CA). Main outcome measures were postoperative corrected distance visual acuity (CDVA) and loss of CDVA. Corneas with a measured or a calculated postoperative flat meridian less than 35 D and those with a measured postoperative steep meridian less than 35 D had worse postoperative CDVA than corneas with meridians of either 35 D or more (P ≤ .021). However, the preoperative CDVA was worse in the flatter curvatures in all comparisons performed (P ≤ .024). Consequently, the measured or calculated meridian curvature had no effect on CDVA loss (P ≥ .074). Postoperative corneal keratometry values (flat and steep meridians) less than 35 D did not have a predictive effect on the risk of losing visual acuity following myopic PRK performed on the Allegretto 200Hz excimer laser. Copyright 2013, SLACK Incorporated.

  6. Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study.

    PubMed

    Mine, Masashi; Miyata, Kimie; Morikawa, Masayuki; Nishi, Tomo; Okamoto, Nozomi; Kawasaki, Ryo; Yamashita, Hidetoshi; Kurumatani, Norio; Ogata, Nahoko

    2016-01-01

    Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was -0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = -0.10, p < 0.0001). Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5-3.8, p < 0.001) after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment.

  7. Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study

    PubMed Central

    Mine, Masashi; Miyata, Kimie; Morikawa, Masayuki; Nishi, Tomo; Okamoto, Nozomi; Kawasaki, Ryo; Yamashita, Hidetoshi; Kurumatani, Norio; Ogata, Nahoko

    2016-01-01

    Abstract Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was −0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = −0.10, p < 0.0001). Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5–3.8, p < 0.001) after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment. PMID:27610269

  8. The Relationship between OCT-measured Central Retinal Thickness and Visual Acuity in Diabetic Macular Edema

    PubMed Central

    2008-01-01

    Objective To compare optical coherence tomography (OCT)-measured retinal thickness and visual acuity in eyes with diabetic macular edema (DME) both before and after macular laser photocoagulation. Design Cross-sectional and longitudinal study. Participants 210 subjects (251 eyes) with DME enrolled in a randomized clinical trial of laser techniques. Methods Retinal thickness was measured with OCT and visual acuity was measured with the electronic-ETDRS procedure. Main Outcome Measures OCT-measured center point thickness and visual acuity Results The correlation coefficients for visual acuity versus OCT center point thickness were 0.52 at baseline and 0.49, 0.36, and 0.38 at 3.5, 8, and 12 months post-laser photocoagulation. The slope of the best fit line to the baseline data was approximately 4.4 letters (95% C.I.: 3.5, 5.3) better visual acuity for every 100 microns decrease in center point thickness at baseline with no important difference at follow-up visits. Approximately one-third of the variation in visual acuity could be predicted by a linear regression model that incorporated OCT center point thickness, age, hemoglobin A1C, and severity of fluorescein leakage in the center and inner subfields. The correlation between change in visual acuity and change in OCT center point thickening 3.5 months after laser treatment was 0.44 with no important difference at the other follow-up times. A subset of eyes showed paradoxical improvements in visual acuity with increased center point thickening (7–17% at the three time points) or paradoxical worsening of visual acuity with a decrease in center point thickening (18%–26% at the three time points). Conclusions There is modest correlation between OCT-measured center point thickness and visual acuity, and modest correlation of changes in retinal thickening and visual acuity following focal laser treatment for DME. However, a wide range of visual acuity may be observed for a given degree of retinal edema and paradoxical

  9. Visual acuity in adults with Asperger's syndrome: no evidence for "eagle-eyed" vision.

    PubMed

    Falkmer, Marita; Stuart, Geoffrey W; Danielsson, Henrik; Bram, Staffan; Lönebrink, Mikael; Falkmer, Torbjörn

    2011-11-01

    Autism spectrum conditions (ASC) are defined by criteria comprising impairments in social interaction and communication. Altered visual perception is one possible and often discussed cause of difficulties in social interaction and social communication. Recently, Ashwin et al. suggested that enhanced ability in local visual processing in ASC was due to superior visual acuity, but that study has been the subject of methodological criticism, placing the findings in doubt. The present study investigated visual acuity thresholds in 24 adults with Asperger's syndrome and compared their results with 25 control subjects with the 2 Meter 2000 Series Revised ETDRS Chart. The distribution of visual acuities within the two groups was highly similar, and none of the participants had superior visual acuity. Superior visual acuity in individuals with Asperger's syndrome could not be established, suggesting that differences in visual perception in ASC are not explained by this factor. A continued search for explanations of superior ability in local visual processing in persons with ASC is therefore warranted. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  10. Amblyopia: The Thalamus Is a No-Go Area for Visual Acuity.

    PubMed

    Seignette, Koen; Levelt, Christiaan N

    2018-06-18

    When one eye does not function well during development, the visual cortex becomes less responsive to it and visual acuity declines. New research suggests that reduced response strength and deteriorating acuity occur in separate circuits. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Fresnel prisms and their effects on visual acuity and binocularity.

    PubMed Central

    Véronneau-Troutman, S

    1978-01-01

    1. The visual acuity with the Fresnel membrane prism is significantly less than that with the conventional prism of the same power for all prism powers from 12 delta through 30 delata at distance and from 15 delta through 30 delta at near. 2. The difference in the visual acuity between base up and base down, and between base in and base out, is not significantly different for either the Fresnel membrane prism or for the conventional prism. 3. For both Fresnel membrane prism and the conventional prism, the visual acuity when looking straight ahead. 4. Using Fresnel membrane prisms of the same power from different lots, the visual acuity varied significantly. The 30 delta prism caused the widest range in visual acuity. 5. When normal subjects are fitted with the higher powers of the Fresnel membrane prism, fusion and stereopsis are disrupted to such an extent that the use of this device to restore or to improve binocular vision in cases with large-angle deviations is seriously questioned. 6. Moreover, the disruption of fusion and stereopsis is abrupt and severe and does not parallel the decrease in visual acuity. The severely reduced ability to maintain fusion may be related to the optical aberrations, which, in turn, may be due to the molding process and the polyvinyl chloride molding material. 7. Through the flexibility of the membrane prism is a definite advantage, because of its proclivity to reduce visual acuity and increase aberrations its prescription for adults often must be limited to only one eye. 8. For the same reasons in the young child with binocular vision problems, the membrane prism presently available should be prescribed over both eyes only in powers less than 20 delta. When the membrane prism is to be used as a partial occluder (over one eye only), any power can be used. 9. The new Fresnel "hard" prism reduces visual acuity minimally and rarely disrupts binocularity, thus increasing the potential for prismotherapy to establish binocularity. This

  12. Enhanced visual acuity and image perception following correction of highly aberrated eyes using an adaptive optics visual simulator.

    PubMed

    Rocha, Karolinne Maia; Vabre, Laurent; Chateau, Nicolas; Krueger, Ronald R

    2010-01-01

    To evaluate the changes in visual acuity and visual perception generated by correcting higher order aberrations in highly aberrated eyes using a large-stroke adaptive optics visual simulator. A crx1 Adaptive Optics Visual Simulator (Imagine Eyes) was used to correct and modify the wavefront aberrations in 12 keratoconic eyes and 8 symptomatic postoperative refractive surgery (LASIK) eyes. After measuring ocular aberrations, the device was programmed to compensate for the eye's wavefront error from the second order to the fifth order (6-mm pupil). Visual acuity was assessed through the adaptive optics system using computer-generated ETDRS opto-types and the Freiburg Visual Acuity and Contrast Test. Mean higher order aberration root-mean-square (RMS) errors in the keratoconus and symptomatic LASIK eyes were 1.88+/-0.99 microm and 1.62+/-0.79 microm (6-mm pupil), respectively. The visual simulator correction of the higher order aberrations present in the keratoconus eyes improved their visual acuity by a mean of 2 lines when compared to their best spherocylinder correction (mean decimal visual acuity with spherocylindrical correction was 0.31+/-0.18 and improved to 0.44+/-0.23 with higher order aberration correction). In the symptomatic LASIK eyes, the mean decimal visual acuity with spherocylindrical correction improved from 0.54+/-0.16 to 0.71+/-0.13 with higher order aberration correction. The visual perception of ETDRS letters was improved when correcting higher order aberrations. The adaptive optics visual simulator can effectively measure and compensate for higher order aberrations (second to fifth order), which are associated with diminished visual acuity and perception in highly aberrated eyes. The adaptive optics technology may be of clinical benefit when counseling patients with highly aberrated eyes regarding their maximum subjective potential for vision correction. Copyright 2010, SLACK Incorporated.

  13. Visual Acuity and Contrast Sensitivity Development in Children: Sweep Visually Evoked Potential and Psychophysics.

    PubMed

    Almoqbel, Fahad M; Irving, Elizabeth L; Leat, Susan J

    2017-08-01

    The purpose of this study was to investigate the development of visual acuity (VA) and contrast sensitivity in children as measured with objective (sweep visually evoked potential) and subjective, psychophysical techniques, including signal detection theory (SDT), which attempts to control for differences in criterion or behavior between adults and children. Furthermore, this study examines the possibility of applying SDT methods with children. Visual acuity and contrast thresholds were measured in 12 children 6 to 7 years old, 10 children 8 to 9 years old, 10 children 10 to 12 years old, and 16 adults. For sweep visually evoked potential measurements, spatial frequency was swept from 1 to 40 cpd to measure VA, and contrast of sine-wave gratings (1 or 8 cpd) was swept from 0.33 to 30% to measure contrast thresholds. For psychophysical measurements, VA and contrast thresholds (1 or 8 cpd) were measured using a temporal two-alternative forced-choice staircase procedure and also with a yes-no SDT procedure. Optotype (logMAR [log of the minimum angle of resolution]) VA was also measured. The results of the various procedures were in agreement showing that there are age-related changes in threshold values and logMAR VA after the age of 6 years and that these visual functions do not become adult-like until the age of 8 to 9 years at the earliest. It was also found that children can participate in SDT procedures and do show differences in criterion compared with adults in psychophysical testing. These findings confirm a slightly later development of VA and contrast sensitivity (8 years or older) and indicate the importance of using SDT or forced-choice procedures in any developmental study to attempt to overcome the effect of criterion in children.

  14. Visual Acuity Improvement of Amblyopia in an Adult With Levodopa/Carbidopa Treatment.

    PubMed

    Orge, Faruk H; Dar, Suhail A

    2015-09-09

    Amblyopia is the leading cause of visual loss in children, affecting 2% to 3% of the population. Occlusion of the dominant eye is the primary and best treatment, although efficacy decreases after 6 years of age. As a result, levodopa/carbidopa has been explored as an adjunct to conventional therapy and has been shown to have an immediate impact on visual acuity. Several studies to date have shown mixed results on the benefit of supplementing occlusion therapy with levodopa/carbidopa, although they have primarily studied children. The authors describe the oldest patient (46 years old) documented in the literature to have shown improvement in visual acuity using levodopa/carbidopa. He was given a 16-week course at a dose in line with previous studies while being effectively occluded full time due to a glaucomatous right eye with no light perception. On 3-month follow-up, his left eye improved two lines and stabilized at 6 months. Copyright 2015, SLACK Incorporated.

  15. Visual acuity loss and OCT changes as initial signs of leukaemia

    PubMed Central

    Ortiz, Jose M; Ruiz-Moreno, Jose M; Pozo-Martos, Paola; Montero, Javier A

    2010-01-01

    AIM To report two cases where decreased visual acuity was the first symptom of leukaemia and optical coherence tomography (OCT) allowed identification and localization of the retinal lesions. METHODS Retrospective, interventional, case reports. RESULTS One case of lymphoblastic acute leukaemia and chronic lymphoid leukaemia were diagnosed following decreased visual acuity. OCT showed macular serous detachment in the first case. The second case presented hypo fluorescent retinal infiltrates which appeared as hyper reflective lesions by OCT. Retinal changes disappeared and visual acuity was recovered following complete remission of the neoplasm. CONCLUSION OCT is a valuable, non invasive diagnostic tool permitting detection, localization and follow-up of ocular dissemination of neoplasms. PMID:22553573

  16. Eagle-eyed visual acuity: an experimental investigation of enhanced perception in autism.

    PubMed

    Ashwin, Emma; Ashwin, Chris; Rhydderch, Danielle; Howells, Jessica; Baron-Cohen, Simon

    2009-01-01

    Anecdotal accounts of sensory hypersensitivity in individuals with autism spectrum conditions (ASC) have been noted since the first reports of the condition. Over time, empirical evidence has supported the notion that those with ASC have superior visual abilities compared with control subjects. However, it remains unclear whether these abilities are specifically the result of differences in sensory thresholds (low-level processing), rather than higher-level cognitive processes. This study investigates visual threshold in n = 15 individuals with ASC and n = 15 individuals without ASC, using a standardized optometric test, the Freiburg Visual Acuity and Contrast Test, to investigate basic low-level visual acuity. Individuals with ASC have significantly better visual acuity (20:7) compared with control subjects (20:13)-acuity so superior that it lies in the region reported for birds of prey. The results of this study suggest that inclusion of sensory hypersensitivity in the diagnostic criteria for ASC may be warranted and that basic standardized tests of sensory thresholds may inform causal theories of ASC.

  17. The Eye Phone Study: reliability and accuracy of assessing Snellen visual acuity using smartphone technology

    PubMed Central

    Perera, C; Chakrabarti, R; Islam, F M A; Crowston, J

    2015-01-01

    Purpose Smartphone-based Snellen visual acuity charts has become popularized; however, their accuracy has not been established. This study aimed to evaluate the equivalence of a smartphone-based visual acuity chart with a standard 6-m Snellen visual acuity (6SVA) chart. Methods First, a review of available Snellen chart applications on iPhone was performed to determine the most accurate application based on optotype size. Subsequently, a prospective comparative study was performed by measuring conventional 6SVA and then iPhone visual acuity using the ‘Snellen' application on an Apple iPhone 4. Results Eleven applications were identified, with accuracy of optotype size ranging from 4.4–39.9%. Eighty-eight patients from general medical and surgical wards in a tertiary hospital took part in the second part of the study. The mean difference in logMAR visual acuity between the two charts was 0.02 logMAR (95% limit of agreement −0.332, 0.372 logMAR). The largest mean difference in logMAR acuity was noted in the subgroup of patients with 6SVA worse than 6/18 (n=5), who had a mean difference of two Snellen visual acuity lines between the charts (0.276 logMAR). Conclusion We did not identify a Snellen visual acuity app at the time of study, which could predict a patients standard Snellen visual acuity within one line. There was considerable variability in the optotype accuracy of apps. Further validation is required for assessment of acuity in patients with severe vision impairment. PMID:25931170

  18. Measuring the Influence of Galilean Loupe System on Near Visual Acuity of Dentists under Simulated Clinical Conditions

    PubMed Central

    Urlic, Iris; Verzak, Željko; Vranic, Dubravka Negovetic

    2016-01-01

    Aim The purpose of this study was to compare near visual acuity of dentists without optical aids (VSC) with near visual acuity of those using the Galilean telescope system (VGA2) with magnification of x 2.5, and the distance of 350 mm in simulated clinical conditions. Methods The study included 46 dentists (visual acuity 1.0 without correction). A visual acuity testing was carried out using a miniaturized Snellen visual acuity chart which was placed in the cavity of molar teeth mounted in a phantom head in simulated clinical conditions. Near visual acuity for the vicinity was examined: 1) without correction at a distance of 300-400 mm (VSC); 2) with Galilean loupes with magnification of x2.5, focal length of 350mm. Results The distributions of near visual acuity recorded using VSC and VGA2, 5 systems were compared by the Wilcoxon Signed Rank test. The results obtained by Wilcoxon Signed Rank test pointed to a statistically significant difference in the distribution of recorded visual acuity between the VSC and VGA2 optical systems (W = - 403.5; p <0.001). Conclusion If using the VGA2, 5 systems, higher values of the near visual acuity were recorded and subsequently compared to near visual acuity without magnifying aids (VSC). PMID:27847397

  19. Measuring the Influence of Galilean Loupe System on Near Visual Acuity of Dentists under Simulated Clinical Conditions.

    PubMed

    Urlic, Iris; Verzak, Željko; Vranic, Dubravka Negovetic

    2016-09-01

    The purpose of this study was to compare near visual acuity of dentists without optical aids (VSC) with near visual acuity of those using the Galilean telescope system (VGA2) with magnification of x 2.5, and the distance of 350 mm in simulated clinical conditions. The study included 46 dentists (visual acuity 1.0 without correction). A visual acuity testing was carried out using a miniaturized Snellen visual acuity chart which was placed in the cavity of molar teeth mounted in a phantom head in simulated clinical conditions. Near visual acuity for the vicinity was examined: 1) without correction at a distance of 300-400 mm (VSC); 2) with Galilean loupes with magnification of x2.5, focal length of 350mm. The distributions of near visual acuity recorded using VSC and VGA2, 5 systems were compared by the Wilcoxon Signed Rank test. The results obtained by Wilcoxon Signed Rank test pointed to a statistically significant difference in the distribution of recorded visual acuity between the VSC and VGA2 optical systems (W = - 403.5; p <0.001). If using the VGA2, 5 systems, higher values of the near visual acuity were recorded and subsequently compared to near visual acuity without magnifying aids (VSC).

  20. Objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity

    PubMed Central

    Zhu, X; Ye, H; He, W; Yang, J; Dai, J; Lu, Y

    2017-01-01

    Purpose To explore the objective functional visual outcomes of cataract surgery in patients with good preoperative visual acuity. Methods We enrolled 130 cataract patients whose best-corrected visual acuity (BCVA) was 20/40 or better preoperatively. Objective visual functions were evaluated with a KR-1W analyzer before and at 1 month after cataract surgery. Results The nuclear (N), cortical (C), and N+C groups had very high preoperative ocular and internal total high-order aberrations (HOAs), coma, and abnormal spherical aberrations. At 1 month after cataract surgery, in addition to the remarkable increase of both uncorrected visual acuity and BCVA, both ocular and internal HOAs in the three groups decreased significantly after cataract surgery (all P<0.05). Point spread function and modulation transfer functions were also improved significantly in these patients (all P<0.05). Conclusions The objective functional vision of patients with 20/40 or better preoperative BCVA improved significantly after cataract surgery. This finding shows that the arbitrary threshold of BCVA worse than 20/40 in China cannot always be used to determine who will benefit from cataract surgery. PMID:27858933

  1. Vernier But Not Grating Acuity Contributes to an Early Stage of Visual Word Processing.

    PubMed

    Tan, Yufei; Tong, Xiuhong; Chen, Wei; Weng, Xuchu; He, Sheng; Zhao, Jing

    2018-03-28

    The process of reading words depends heavily on efficient visual skills, including analyzing and decomposing basic visual features. Surprisingly, previous reading-related studies have almost exclusively focused on gross aspects of visual skills, while only very few have investigated the role of finer skills. The present study filled this gap and examined the relations of two finer visual skills measured by grating acuity (the ability to resolve periodic luminance variations across space) and Vernier acuity (the ability to detect/discriminate relative locations of features) to Chinese character-processing as measured by character form-matching and lexical decision tasks in skilled adult readers. The results showed that Vernier acuity was significantly correlated with performance in character form-matching but not visual symbol form-matching, while no correlation was found between grating acuity and character processing. Interestingly, we found no correlation of the two visual skills with lexical decision performance. These findings provide for the first time empirical evidence that the finer visual skills, particularly as reflected in Vernier acuity, may directly contribute to an early stage of hierarchical word processing.

  2. Evaluation of a Public Child Eye Health Tertiary Facility for Pediatric Cataract in Southern Nigeria I: Visual Acuity Outcome

    PubMed Central

    Duke, Roseline E.; Adio, Adedayo; Oparah, Sidney K.; Odey, Friday; Eyo, Okon A.

    2016-01-01

    Purpose: A retrospective study of the outcome of congenital and developmental cataract surgery was conducted in a public child eye health tertiary facility in children <16 years of age in Southern Nigeria, as part of an evaluation. Materials and Method: Manual Small Incision Cataract Surgery with or without anterior vitrectomy was performed. The outcome measures were visual acuity (VA) and change (gain) in visual acuity. The age of the child at onset, duration of delay in presentation, ocular co-morbidity, non ocular co-morbidity, gender, and pre operative visual acuity were matched with postoperative visual acuity. A total of 66 children were studied for a period of six weeks following surgery. Results: Forty eight (72.7%) children had bilateral congenital cataracts and 18 (27.3%) children had bilateral developmental cataracts. There were 38(57.6%) males and 28 (42.4%) females in the study. Thirty Five (53%) children had good visual outcome (normal vision range 6/6/ -6/18) post-operatively. The number of children with blindness (vision <3/60) decreased from 61 (92.4%) pre-operatively to 4 (6.1%) post-operatively. Post operative complication occurred in 6.8% of cases six week after surgery. Delayed presentation had an inverse relationship with change (gain) in visual acuity (r = - 0.342; p-value = 0.005). Pre-operative visual acuity had a positive relationship with post operative change (gain) in visual acuity (r = 0.618; p-value = 0.000). Conclusion: Predictors of change in visual acuity in our study were; delayed presentation and pre-operative VA. Cataract surgery in children showed clinical benefit. PMID:27347247

  3. Eye size and visual acuity influence vestibular anatomy in mammals.

    PubMed

    Kemp, Addison D; Christopher Kirk, E

    2014-04-01

    The semicircular canals of the inner ear detect head rotations and trigger compensatory movements that stabilize gaze and help maintain visual fixation. Mammals with large eyes and high visual acuity require precise gaze stabilization mechanisms because they experience diminished visual functionality at low thresholds of uncompensated motion. Because semicircular canal radius of curvature is a primary determinant of canal sensitivity, species with large canal radii are expected to be capable of more precise gaze stabilization than species with small canal radii. Here, we examine the relationship between mean semicircular canal radius of curvature, eye size, and visual acuity in a large sample of mammals. Our results demonstrate that eye size and visual acuity both explain a significant proportion of the variance in mean canal radius of curvature after statistically controlling for the effects of body mass and phylogeny. These findings suggest that variation in mean semicircular canal radius of curvature among mammals is partly the result of selection for improved gaze stabilization in species with large eyes and acute vision. Our results also provide a possible functional explanation for the small semicircular canal radii of fossorial mammals and plesiadapiforms. Copyright © 2014 Wiley Periodicals, Inc.

  4. Effect of water turbidity on the visual acuity of harbor seals (Phoca vitulina).

    PubMed

    Weiffen, Michael; Möller, Bettina; Mauck, Björn; Dehnhardt, Guido

    2006-05-01

    The underwater visual acuity (the angle subtended by the minimal resolvable line width of high contrast square wave gratings at a viewing distance of 2m) of two male harbor seals was determined at different levels of water turbidity. Starting with visual acuity angles of 5.5' and 12.7' in clear water we found visual acuity to decrease rapidly with increasing turbidity at rates of 7.4' and 6.0' per formazin nephelometric unit (FNU). Besides the individual differences in visual performance of the harbor seals tested, our results reveal a dramatic loss of visual acuity even at moderate levels of turbidity. At sites in the German Wadden Sea, where harbor seals are known to roam and forage, we measured turbidity levels exceeding 40FNU. These data suggest that turbidity has to be considered as an important factor in the sensory ecology of pinnipeds.

  5. Relationship between photoreceptor outer segment length and visual acuity in diabetic macular edema.

    PubMed

    Forooghian, Farzin; Stetson, Paul F; Meyer, Scott A; Chew, Emily Y; Wong, Wai T; Cukras, Catherine; Meyerle, Catherine B; Ferris, Frederick L

    2010-01-01

    The purpose of this study was to quantify photoreceptor outer segment (PROS) length in 27 consecutive patients (30 eyes) with diabetic macular edema using spectral domain optical coherence tomography and to describe the correlation between PROS length and visual acuity. Three spectral domain-optical coherence tomography scans were performed on all eyes during each session using Cirrus HD-OCT. A prototype algorithm was developed for quantitative assessment of PROS length. Retinal thicknesses and PROS lengths were calculated for 3 parameters: macular grid (6 x 6 mm), central subfield (1 mm), and center foveal point (0.33 mm). Intrasession repeatability was assessed using coefficient of variation and intraclass correlation coefficient. The association between retinal thickness and PROS length with visual acuity was assessed using linear regression and Pearson correlation analyses. The main outcome measures include intrasession repeatability of macular parameters and correlation of these parameters with visual acuity. Mean retinal thickness and PROS length were 298 mum to 381 microm and 30 microm to 32 mum, respectively, for macular parameters assessed in this study. Coefficient of variation values were 0.75% to 4.13% for retinal thickness and 1.97% to 14.01% for PROS length. Intraclass correlation coefficient values were 0.96 to 0.99 and 0.73 to 0.98 for retinal thickness and PROS length, respectively. Slopes from linear regression analyses assessing the association of retinal thickness and visual acuity were not significantly different from 0 (P > 0.20), whereas the slopes of PROS length and visual acuity were significantly different from 0 (P < 0.0005). Correlation coefficients for macular thickness and visual acuity ranged from 0.13 to 0.22, whereas coefficients for PROS length and visual acuity ranged from -0.61 to -0.81. Photoreceptor outer segment length can be quantitatively assessed using Cirrus HD-OCT. Although the intrasession repeatability of PROS

  6. High visual acuity revealed in dogs

    PubMed Central

    Lind, Olle; Milton, Ida; Andersson, Elin; Jensen, Per

    2017-01-01

    Humans have selectively bred and used dogs over a period of thousands of years, and more recently the dog has become an important model animal for studies in ethology, cognition and genetics. These broad interests warrant careful descriptions of the senses of dogs. Still there is little known about dog vision, especially what dogs can discriminate in different light conditions. We trained and tested whippets, pugs, and a Shetland sheepdog in a two-choice discrimination set-up and show that dogs can discriminate patterns with spatial frequencies between 5.5 and 19.5 cycle per degree (cpd) in the bright light condition (43 cd m-2). This is a higher spatial resolution than has been previously reported although the individual variation in our tests was large. Humans tested in the same set-up reached acuities corresponding to earlier studies, ranging between 32.1 and 44.2 cpd. In the dim light condition (0.0087 cd m-2) the acuity of dogs ranged between 1.8 and 3.5 cpd while in humans, between 5.9 and 9.9 cpd. Thus, humans make visual discrimination of objects from roughly a threefold distance compared to dogs in both bright and dim light. PMID:29206864

  7. High visual acuity revealed in dogs.

    PubMed

    Lind, Olle; Milton, Ida; Andersson, Elin; Jensen, Per; Roth, Lina S V

    2017-01-01

    Humans have selectively bred and used dogs over a period of thousands of years, and more recently the dog has become an important model animal for studies in ethology, cognition and genetics. These broad interests warrant careful descriptions of the senses of dogs. Still there is little known about dog vision, especially what dogs can discriminate in different light conditions. We trained and tested whippets, pugs, and a Shetland sheepdog in a two-choice discrimination set-up and show that dogs can discriminate patterns with spatial frequencies between 5.5 and 19.5 cycle per degree (cpd) in the bright light condition (43 cd m-2). This is a higher spatial resolution than has been previously reported although the individual variation in our tests was large. Humans tested in the same set-up reached acuities corresponding to earlier studies, ranging between 32.1 and 44.2 cpd. In the dim light condition (0.0087 cd m-2) the acuity of dogs ranged between 1.8 and 3.5 cpd while in humans, between 5.9 and 9.9 cpd. Thus, humans make visual discrimination of objects from roughly a threefold distance compared to dogs in both bright and dim light.

  8. Visual Acuity Outcomes of the Boston Keratoprosthesis Type 1: Multicenter Study Results.

    PubMed

    Rudnisky, Christopher J; Belin, Michael W; Guo, Rong; Ciolino, Joseph B

    2016-02-01

    To report logarithm of the minimal angle of resolution (logMAR) visual outcomes of the Boston keratoprosthesis type 1. Prospective cohort study. Preoperative, intraoperative, and postoperative parameters of 300 eyes of 300 patients who underwent implantation of a Boston keratoprosthesis type 1 device between January 2003 and July 2008 by 1 of 19 surgeons at 18 medical centers were collected. After an average of 17.1 ± 14.8 months, visual acuity improved significantly (P < .0001) to a mean final value of 0.89 ± 0.64 (20/150). There were also significantly fewer eyes with light perception (6.7%; n = 19; P < .0001), although 3.1% (n = 9) progressed to no light perception. There was no association between age (P = .08), sex (P = .959), operative side (P = .167), or failure (P = .494) and final visual acuity. The median time to achieve 20/200 visual acuity was 1 month (95% confidence interval 1.0-6.0) and it was retained for an average of 47.8 months. Multivariate analysis, controlling for preoperative visual acuity, demonstrated 2 factors associated with final visual outcome: chemical injury was associated with better final vision (P = .007), whereas age-related macular degeneration was associated with poorer vision (P < .0001). The Boston keratoprosthesis type 1 is an effective device for rehabilitation in advanced ocular surface disease, resulting in a significant improvement in visual acuity. Eyes achieved a mean value of 20/150 (0.89 ± 0.64 logMAR units) after 6 months and this was relatively stable thereafter. The best visual prognosis is observed in chemical injury eyes, whereas the worst prognosis is in aniridia, although the latter has limited visual potential. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. The pigeon's distant visual acuity as a function of viewing angle.

    PubMed

    Uhlrich, D J; Blough, P M; Blough, D S

    1982-01-01

    Distant visual acuity was determined for several viewing angles in two restrained White Carneaux pigeons. The behavioral technique was a classical conditioning procedure that paired presentation of sinusoidal gratings with shock. A conditioned heart rate acceleration during the grating presentation indicated resolution of the grating. The bird's acuity was fairly uniform across a large range of their lateral visual field; performance decreased slightly for posterior stimulus placement and sharply for frontal placements. The data suggest that foveal viewing is relatively less advantageous for acuity in pigeons than in humans. The data are also consistent with the current view that pigeons are myopic in frontal vision.

  10. Retinal Thickness and Visual Acuity in Diabetic Macular Edema: An Optical Coherence Tomography-Based Study.

    PubMed

    Islam, Farrah

    2016-07-01

    To determine the relationship between foveal (retinal) thickness and visual acuity in diabetic macular edema through optical coherence tomography (OCT) mapping software. Cross-sectional descriptive study. The Retina Clinic of Al-Shifa Trust Eye Hospital, Rawalpindi, from August 2011 to August 2012. Eighty eyes of 68 patients with clinical diagnosis of diabetic macular edema, based on complete ophthalmic examination, were enrolled. The best-corrected visual acuity was recorded on logMar scale. OCTimaging was performed through dilated pupil by experienced operator. Foveal thickness was determined. OCTparameters of macular thickness were analysed with baseline variables including age, duration since diagnosed with diabetes, and visual acuity. The mean visual acuity was 0.81 (0.2 - 1.8) logMar units. The average foveal thickness was 395.09 ±142.26 (183 - 825 µm). There was moderate correlation between foveal thickness and visual acuity (rs= 0.574, p < 0.001), absent in those who had visual acuity worse than 1 logMar. There was a weak positive association between foveal thickness and the duration of diabetes (rs=0.249, p < 0.05). There was, however, no correlation between foveal thickness and age (rs= 0.012, p=0.919). There is a moderate correlation between visual acuity and degree of foveal thickening in diabetic macular edema, hence two cannot be used interchangeably in clinical practice.

  11. The Tromsø Eye Study: study design, methodology and results on visual acuity and refractive errors.

    PubMed

    Bertelsen, Geir; Erke, Maja G; von Hanno, Therese; Mathiesen, Ellisiv B; Peto, Tunde; Sjølie, Anne K; Njølstad, Inger

    2013-11-01

    To describe the study design and methodology of the Tromsø Eye Study (TES), and to describe visual acuity and refractive error in the study population. The Tromsø Eye Study is a sub-study of the Tromsø Study, a population-based multipurpose longitudinal study in the municipality of Tromsø, Norway. The Tromsø Eye Study was a part of the sixth survey of the Tromsø Study, conducted from October 2007 through December 2008. The eye examination included information on self-reported eye diseases, assessment of visual acuity and refractive errors, retinal photography and optical coherence tomography. Retinal images were graded for diabetic retinopathy and age-related macular degeneration, and with computer-assisted measurements of arteriolar and venular diameters. In addition, TES researchers have access to the large comprehensive Tromsø Study database including physical examination results, carotid artery ultrasound, electrocardiogram, bone densitometry, cognitive tests, questionnaires, DNA, blood and urine samples and more from the present and the five previous surveys. Visual acuity was assessed in 6459 subjects and refraction in 6566 subjects aged 38-87 years. Snellen visual acuity <20/60 was found in 1.2% (95% CI 0.95-1.5) of the participants and there was no gender difference. Visual impairment increased with age, and in the age group 80-87 years, the overall visual acuity <20/60 was 7.3% (95% CI 3.3-11.2). Spherical equivalent showed an increasing trend with age and there was no clinically relevant difference between men and women. Retinal photography was performed in 6540 subjects. Prevalence of visual impairment was low but increased with age. There was a trend towards hyperopia with age and no clinically relevant difference in refraction between the sexes. TES aims to provide epidemiological research on several eye and eye-related diseases. Owing to a comprehensive data collection, it has the opportunity to explore issues related to environmental factors

  12. Visual acuity and quality of life in dry eye disease: Proceedings of the OCEAN group meeting.

    PubMed

    Benítez-Del-Castillo, José; Labetoulle, Marc; Baudouin, Christophe; Rolando, Maurizio; Akova, Yonca A; Aragona, Pasquale; Geerling, Gerd; Merayo-Lloves, Jesús; Messmer, Elisabeth M; Boboridis, Kostas

    2017-04-01

    Dry eye disease (DED) results in tear film instability and hyperosmolarity, inflammation of the ocular surface and, ultimately, visual disturbance that can significantly impact a patient's quality of life. The effects on visual acuity result in difficulties with driving, reading and computer use and negatively impact psychological health. These effects also extend to the workplace, with a loss of productivity and quality of work causing substantial economic losses. The effects of DED and the impact on vision experienced by patients may not be given sufficient importance by ophthalmologists. Functional visual acuity (FVA) is a measure of visual acuity after sustained eye opening without blinking for at least 10 s and mimics the sustained visual acuity of daily life. Measuring dynamic FVA allows the detection of impaired visual function in patients with DED who may display normal conventional visual acuity. There are currently several tests and methods that can be used to measure dynamic visual function: the SSC-350 FVA measurement system, assessment of best-corrected visual acuity decay using the interblink visual acuity decay test, serial measurements of ocular and corneal higher order aberrations, and measurement of dynamic vision quality using the Optical Quality Analysis System. Although the equipment for these methods may be too large or unaffordable for use in clinical practice, FVA testing is an important assessment for DED. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Factors associated with visual acuity in patients with cystoid macular oedema and Retinitis Pigmentosa.

    PubMed

    Liew, Gerald; Moore, Anthony T; Bradley, Patrick D; Webster, Andrew R; Michaelides, Michel

    2018-06-01

    Retinitis pigmentosa is the most common inherited retinal dystrophy. The factors associated with visual acuity in patients with other retinal diseases are well known, but are poorly understood in patients with retinitis pigmentosa. This knowledge is useful for prognosis and to support secondary endpoints in clinical trials. We conducted a cross-sectional study of consecutive patients recruited from the inherited retinal disease service from January 2012 to December 2012. Central macular thickness (CMT) was measured using spectral domain optical coherence tomography. Data were available for 81 patients and 162 eyes. After multivariable analyses, older age, earlier age of onset of symptoms, and thicker CMT were associated with lower visual acuity. Gender and inheritance pattern were not associated with visual acuity. Each decade older age, younger age of onset, and thicker CMT was associated with 0.12, 0.10, and 0.11 worse logarithm of the minimal angle of resolution units of visual acuity, respectively (p < 0.05 for all). Age, age of onset, and CMT are associated with visual acuity and important factors to measure in studies of retinitis pigmentosa.

  14. Visual acuity estimation from simulated images

    NASA Astrophysics Data System (ADS)

    Duncan, William J.

    Simulated images can provide insight into the performance of optical systems, especially those with complicated features. Many modern solutions for presbyopia and cataracts feature sophisticated power geometries or diffractive elements. Some intraocular lenses (IOLs) arrive at multifocality through the use of a diffractive surface and multifocal contact lenses have a radially varying power profile. These type of elements induce simultaneous vision as well as affecting vision much differently than a monofocal ophthalmic appliance. With myriad multifocal ophthalmics available on the market it is difficult to compare or assess performance in ways that effect wearers of such appliances. Here we present software and algorithmic metrics that can be used to qualitatively and quantitatively compare ophthalmic element performance, with specific examples of bifocal intraocular lenses (IOLs) and multifocal contact lenses. We anticipate this study, methods, and results to serve as a starting point for more complex models of vision and visual acuity in a setting where modeling is advantageous. Generating simulated images of real- scene scenarios is useful for patients in assessing vision quality with a certain appliance. Visual acuity estimation can serve as an important tool for manufacturing and design of ophthalmic appliances.

  15. A phytochemical-rich diet may explain the absence of age-related decline in visual acuity of Amazonian hunter-gatherers in Ecuador.

    PubMed

    London, Douglas S; Beezhold, Bonnie

    2015-02-01

    Myopia is absent in undisturbed hunter-gatherers but ubiquitous in modern populations. The link between dietary phytochemicals and eye health is well established, although transition away from a wild diet has reduced phytochemical variety. We hypothesized that when larger quantities and greater variety of wild, seasonal phytochemicals are consumed in a food system, there will be a reduced prevalence of degenerative-based eye disease as measured by visual acuity. We compared food systems and visual acuity across isolated Amazonian Kawymeno Waorani hunter-gatherers and neighboring Kichwa subsistence agrarians, using dietary surveys, dietary pattern observation, and Snellen Illiterate E visual acuity examinations. Hunter-gatherers consumed more food species (130 vs. 63) and more wild plants (80 vs. 4) including 76 wild fruits, thereby obtaining larger variety and quantity of phytochemicals than agrarians. Visual acuity was inversely related to age only in agrarians (r = -.846, P < .001). As hypothesized, when stratified by age (<40 and ≥ 40 years), Mann-Whitney U tests revealed that hunter-gatherers maintained high visual acuity throughout life, whereas agrarian visual acuity declined (P values < .001); visual acuity of younger participants was high across the board, however, did not differ between groups (P > .05). This unusual absence of juvenile-onset vision problems may be related to local, organic, whole food diets of subsistence food systems isolated from modern food production. Our results suggest that intake of a wider variety of plant foods supplying necessary phytochemicals for eye health may help maintain visual acuity and prevent degenerative eye conditions as humans age. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Impact of Target Distance, Target Size, and Visual Acuity on the Video Head Impulse Test.

    PubMed

    Judge, Paul D; Rodriguez, Amanda I; Barin, Kamran; Janky, Kristen L

    2018-05-01

    The video head impulse test (vHIT) assesses the vestibulo-ocular reflex. Few have evaluated whether environmental factors or visual acuity influence the vHIT. The purpose of this study was to evaluate the influence of target distance, target size, and visual acuity on vHIT outcomes. Thirty-eight normal controls and 8 subjects with vestibular loss (VL) participated. vHIT was completed at 3 distances and with 3 target sizes. Normal controls were subdivided on the basis of visual acuity. Corrective saccade frequency, corrective saccade amplitude, and gain were tabulated. In the normal control group, there were no significant effects of target size or visual acuity for any vHIT outcome parameters; however, gain increased as target distance decreased. The VL group demonstrated higher corrective saccade frequency and amplitude and lower gain as compared with controls. In conclusion, decreasing target distance increases gain for normal controls but not subjects with VL. Preliminarily, visual acuity does not affect vHIT outcomes.

  17. The validity of visual acuity assessment using mobile technology devices in the primary care setting.

    PubMed

    O'Neill, Samuel; McAndrew, Darryl J

    2016-04-01

    The assessment of visual acuity is indicated in a number of clinical circumstances. It is commonly conducted through the use of a Snellen wall chart. Mobile technology developments and adoption rates by clinicians may potentially provide more convenient methods of assessing visual acuity. Limited data exist on the validity of these devices and applications. The objective of this study was to evaluate the assessment of distance visual acuity using mobile technology devices against the commonly used 3-metre Snellen chart in a primary care setting. A prospective quantitative comparative study was conducted at a regional medical practice. The visual acuity of 60 participants was assessed on a Snellen wall chart and two mobile technology devices (iPhone, iPad). Visual acuity intervals were converted to logarithm of minimum angle of resolution (logMAR) scores and subjected to intraclass correlation coefficient (ICC) assessment. The results show a high level of general agreement between testing modality (ICC 0.917 with a 95% confidence interval of 0.887-0.940). The high level of agreement of visual acuity results between the Snellen wall chart and both mobile technology devices suggests that clinicians can use this technology with confidence in the primary care setting.

  18. Short-Term Visual Deprivation, Tactile Acuity, and Haptic Solid Shape Discrimination

    PubMed Central

    Crabtree, Charles E.; Norman, J. Farley

    2014-01-01

    Previous psychophysical studies have reported conflicting results concerning the effects of short-term visual deprivation upon tactile acuity. Some studies have found that 45 to 90 minutes of total light deprivation produce significant improvements in participants' tactile acuity as measured with a grating orientation discrimination task. In contrast, a single 2011 study found no such improvement while attempting to replicate these earlier findings. A primary goal of the current experiment was to resolve this discrepancy in the literature by evaluating the effects of a 90-minute period of total light deprivation upon tactile grating orientation discrimination. We also evaluated the potential effect of short-term deprivation upon haptic 3-D shape discrimination using a set of naturally-shaped solid objects. According to previous research, short-term deprivation enhances performance in a tactile 2-D shape discrimination task – perhaps a similar improvement also occurs for haptic 3-D shape discrimination. The results of the current investigation demonstrate that not only does short-term visual deprivation not enhance tactile acuity, it additionally has no effect upon haptic 3-D shape discrimination. While visual deprivation had no effect in our study, there was a significant effect of experience and learning for the grating orientation task – the participants' tactile acuity improved over time, independent of whether they had, or had not, experienced visual deprivation. PMID:25397327

  19. Short-term visual deprivation, tactile acuity, and haptic solid shape discrimination.

    PubMed

    Crabtree, Charles E; Norman, J Farley

    2014-01-01

    Previous psychophysical studies have reported conflicting results concerning the effects of short-term visual deprivation upon tactile acuity. Some studies have found that 45 to 90 minutes of total light deprivation produce significant improvements in participants' tactile acuity as measured with a grating orientation discrimination task. In contrast, a single 2011 study found no such improvement while attempting to replicate these earlier findings. A primary goal of the current experiment was to resolve this discrepancy in the literature by evaluating the effects of a 90-minute period of total light deprivation upon tactile grating orientation discrimination. We also evaluated the potential effect of short-term deprivation upon haptic 3-D shape discrimination using a set of naturally-shaped solid objects. According to previous research, short-term deprivation enhances performance in a tactile 2-D shape discrimination task - perhaps a similar improvement also occurs for haptic 3-D shape discrimination. The results of the current investigation demonstrate that not only does short-term visual deprivation not enhance tactile acuity, it additionally has no effect upon haptic 3-D shape discrimination. While visual deprivation had no effect in our study, there was a significant effect of experience and learning for the grating orientation task - the participants' tactile acuity improved over time, independent of whether they had, or had not, experienced visual deprivation.

  20. Construction and validation of logMAR visual acuity charts in seven Indian languages.

    PubMed

    Negiloni, Kalpa; Mazumdar, Deepmala; Neog, Aditya; Das, Biman; Medhi, Jnanankar; Choudhury, Mitalee; George, Ronnie Jacob; Ramani, Krishna Kumar

    2018-05-01

    The evaluation of visual impairment requires the measurement of visual acuity with a validated and standard logMAR visual acuity chart. We aimed to construct and validate new logMAR visual acuity chart in Indian languages (Hindi, Bengali, Telugu, Urdu, Kannada, Malayalam, and Assamese). The commonly used font in each language was chosen as the reference and designed to fit the 5 × 5 grid (Adobe Photoshop). Ten letters (easiest to difficult) around median legibility score calculated for each language based on the results of legibility experiment and differing by 10% were selected. The chart was constructed based on the standard recommendations. The repeatability of charts was tested and also compared with a standard English Early Treatment Diabetic Retinopathy Study (ETDRS) logMAR chart for validation. A total of 14 rows (1.0 to -0.3 logMAR) with five letters in each line were designed with the range of row legibility between 4.7 and 5.3 for all the language charts. Each chart showed good repeatability, and a maximum difference of four letters was noted. The median difference in visual acuity was 0.16 logMAR for Urdu and Assamese chart compared to ETDRS English chart. Hindi and Malayalam chart had a median difference of 0.12 logMAR. When compared to the English chart a median difference of 0.14 logMAR was noted in Telugu, Kannada, and Bengali chart. The newly developed Indian language visual acuity charts are designed based on the standard recommendations and will help to assess visual impairment in people of these languages across the country.

  1. Wavefront coherence area for predicting visual acuity of post-PRK and post-PARK refractive surgery patients

    NASA Astrophysics Data System (ADS)

    Garcia, Daniel D.; van de Pol, Corina; Barsky, Brian A.; Klein, Stanley A.

    1999-06-01

    Many current corneal topography instruments (called videokeratographs) provide an `acuity index' based on corneal smoothness to analyze expected visual acuity. However, post-refractive surgery patients often exhibit better acuity than is predicted by such indices. One reason for this is that visual acuity may not necessarily be determined by overall corneal smoothness but rather by having some part of the cornea able to focus light coherently onto the fovea. We present a new method of representing visual acuity by measuring the wavefront aberration, using principles from both ray and wave optics. For each point P on the cornea, we measure the size of the associated coherence area whose optical path length (OPL), from a reference plane to P's focus, is within a certain tolerance of the OPL for P. We measured the topographies and vision of 62 eyes of patients who had undergone the corneal refractive surgery procedures of photorefractive keratectomy (PRK) and photorefractive astigmatic keratectomy (PARK). In addition to high contrast visual acuity, our vision tests included low contrast and low luminance to test the contribution of the PRK transition zone. We found our metric for visual acuity to be better than all other metrics at predicting the acuity of low contrast and low luminance. However, high contrast visual acuity was poorly predicted by all of the indices we studied, including our own. The indices provided by current videokeratographs sometimes fail for corneas whose shape differs from simple ellipsoidal models. This is the case with post-PRK and post-PARK refractive surgery patients. Our alternative representation that displays the coherence area of the wavefront has considerable advantages, and promises to be a better predictor of low contrast and low luminance visual acuity than current shape measures.

  2. Contributing factors to VEP grating acuity deficit and inter-ocular acuity difference in children with cerebral visual impairment.

    PubMed

    Cavascan, Nívea Nunes; Salomão, Solange Rios; Sacai, Paula Yuri; Pereira, Josenilson Martins; Rocha, Daniel Martins; Berezovsky, Adriana

    2014-04-01

    To investigate contributing factors to visual evoked potential (VEP) grating acuity deficit (GAD) and inter-ocular acuity difference (IAD) measured by sweep-VEPs in children with cerebral visual impairment (CVI). VEP GAD was calculated for the better acuity eye by subtracting acuity thresholds from mean normal VEP grating acuity according to norms from our own laboratory. Deficits were categorized as mild (0.17 ≤ deficit < 0.40 log units), moderate (0.40 ≤ deficit < 0.70 log units) or severe (deficit ≥0.70 log units). Maximum acceptable IAD was 0.10 log units. A group of 115 children (66 males-57 %) with ages ranging from 1.2 to 166.5 months (median = 17.7) was examined. VEP GAD ranged from 0.17 to 1.28 log units (mean = 0.68 ± 0.27; median = 0.71), and it was mild in 23 (20 %) children, moderate in 32 (28 %) and severe in 60 (52 %). Severe deficit was significantly associated with older age and anti-seizure drug therapy. IAD ranged from 0 to 0.49 log units (mean = 0.06 ± 0.08; median = 0.04) and was acceptable in 96 (83 %) children. Children with strabismus and nystagmus had IAD significantly larger compared to children with orthoposition. In a large cohort of children with CVI, variable severity of VEP GAD was found, with more than half of the children with severe deficits. Older children and those under anti-seizure therapy were at higher risk for larger deficits. Strabismus and nystagmus provided larger IADs. These results should be taken into account on the clinical management of children with this leading cause of bilateral visual impairment.

  3. Effect of astigmatism on visual acuity in eyes with a diffractive multifocal intraocular lens.

    PubMed

    Hayashi, Ken; Manabe, Shin-Ichi; Yoshida, Motoaki; Hayashi, Hideyuki

    2010-08-01

    To examine the effect of astigmatism on visual acuity at various distances in eyes with a diffractive multifocal intraocular lens (IOL). Hayashi Eye Hospital, Fukuoka, Japan. In this study, eyes had implantation of a diffractive multifocal IOL with a +3.00 diopter (D) addition (add) (AcrySof ReSTOR SN6AD1), a diffractive multifocal IOL with a +4.00 D add (AcrySof ReSTOR SN6AD3), or a monofocal IOL (AcrySof SN60WF). Astigmatism was simulated by adding cylindrical lenses of various diopters (0.00, 0.50, 1.00, 1.50, 2.00), after which distance-corrected acuity was measured at various distances. At most distances, the mean visual acuity in the multifocal IOL groups decreased in proportion to the added astigmatism. With astigmatism of 0.00 D and 0.50 D, distance-corrected near visual acuity (DCNVA) in the +4.00 D group and distance-corrected intermediate visual acuity (DCIVA) and DCNVA in the +3.00 D group were significantly better than in the monofocal group; the corrected distance visual acuity (CDVA) was similar. The DCNVA with astigmatism of 1.00 D was better in 2 multifocal groups; however, with astigmatism of 1.50 D and 2.00 D, the CDVA and DCIVA at 0.5m in the multifocal groups were significantly worse than in the monofocal group, although the DCNVA was similar. With astigmatism of 1.00 D or greater, the mean CDVA and DCNVA in the multifocal groups reached useful levels (20/40). The presence of astigmatism in eyes with a diffractive multifocal IOL compromised all distance visual acuities, suggesting the need to correct astigmatism of greater than 1.00 D. No author has a financial or proprietary interest in any material or method mentioned. Copyright 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  4. Improving Visual Acuity of Myopes through Operant Training: The Evaluation of Psychological and Physiological Mechanisms Facilitating Acuity Enhancement

    DTIC Science & Technology

    1988-12-01

    Suiek. M. ( 1987 ). Voice and Manual Control in Dual Task Situations. Proceedings o* the Human Pactors Society. (31st Annual Meeting): 419-423. FIELDS OF...aberration. Trachtman ( 1987 ) found that a reduction in pupil size alone may improve acuity although accommodation remains unchanged. 18 One means of...that facilitate behaviorally trained visual acuity improvement (Gallaway, Pearl, Winkelstein, & Scheiman, 1987 ). Relatively few eye care practitioners

  5. The (lack of) relation between straylight and visual acuity. Two domains of the point-spread-function.

    PubMed

    van den Berg, Thomas J T P

    2017-05-01

    The effect of cataract and other media opacities on functional vision is typically assessed clinically using visual acuity. In both clinical and basic research, straylight (the functional result of light scattering in the eye) is commonly measured. The purpose of the present study was to determine the link between these two measures: is visual acuity in cataract and other media opacities related to straylight? Interdependence between acuity and straylight is addressed from three different points of view: (1) Methodological: can acuity differences affect the measurement value of straylight, and vice versa? (2) Basic optics: does the optical process of light scattering in the human eye affect both straylight and visual acuity? (3) Statistical: how strongly are acuity and straylight correlated in the practice of important clinical conditions? Experimental and theoretical aspects will be considered, with a focus on normal ageing and cataract formation. (1) Methodological: testing potential effects of acuity, artificially manipulated with positive trial lenses, showed no effect on measured straylight values. Since light scattering in the eye involves a low percentage of the light and has large angular spreading, contrast reduction due to straylight is limited, resulting in virtually absent acuity effects. (2) Basic optics: light scattering from the human donor eye lens is found to have virtually no effect in the centre of the point-spread-function, also for cataractous lenses, resulting in virtually absent acuity effects. (3) Statistical: literature data on straylight and visual acuity show a weak correlation for the important groups of normal ageing and cataract populations. The point-spread-function of the normal ageing and cataractous human eye is built upon two rather independent basic parts. Aberrations control the central peak. Light scattering controls the periphery from about 1° onwards. The way acuity and straylight are measured ensures no confounding between

  6. Low-level laser therapy improves visual acuity in adolescent and adult patients with amblyopia.

    PubMed

    Ivandic, Boris T; Ivandic, Tomislav

    2012-03-01

    The purpose of this study was to examine the effects of low-level laser therapy (LLLT) on visual acuity in adolescent and adult patients with amblyopia. Currently, amblyopia can be treated successfully only in children. In this single-blinded, placebo-controlled study, 178 patients (mean age 46.8 years) with amblyopia caused by ametropia (110 eyes) or strabismus (121 eyes) were included. For LLLT, the area of the macula was irradiated through the conjunctiva from 1 cm distance for 30 sec with laser light (780 nm, 292 Hz, 1:1 duty cycle; average power 7.5 mW; spot area 3 mm(2)). The treatment was repeated on average 3.5 times, resulting in a mean total dose of 0.77 J/cm(2). No occlusion was applied, and no additional medication was administered. Best corrected distant visual acuity was determined using Snellen projection optotypes. In 12 patients (12 eyes), the multifocal visual evoked potential (M-VEP) was recorded. A control group of 20 patients (20 eyes) received mock treatment. Visual acuity improved in ∼90% of the eyes treated with LLLT (p<0.001), increasing by three or more lines in 56.2% and 53.6% of the eyes with amblyopia caused by ametropia and strabismus, respectively. The treatment effect was maintained for at least 6 months. The mean M-VEP amplitude increased by 1207 nV (p<0.001) and mean latency was reduced by 7 msec (p=0.14). No changes were noted in the control group. LLLT led to a significant improvement in visual acuity in adolescent and adult patients with amblyopia caused by ametropia or strabismus.

  7. Creation of an Accurate Algorithm to Detect Snellen Best Documented Visual Acuity from Ophthalmology Electronic Health Record Notes.

    PubMed

    Mbagwu, Michael; French, Dustin D; Gill, Manjot; Mitchell, Christopher; Jackson, Kathryn; Kho, Abel; Bryar, Paul J

    2016-05-04

    Visual acuity is the primary measure used in ophthalmology to determine how well a patient can see. Visual acuity for a single eye may be recorded in multiple ways for a single patient visit (eg, Snellen vs. Jäger units vs. font print size), and be recorded for either distance or near vision. Capturing the best documented visual acuity (BDVA) of each eye in an individual patient visit is an important step for making electronic ophthalmology clinical notes useful in research. Currently, there is limited methodology for capturing BDVA in an efficient and accurate manner from electronic health record (EHR) notes. We developed an algorithm to detect BDVA for right and left eyes from defined fields within electronic ophthalmology clinical notes. We designed an algorithm to detect the BDVA from defined fields within 295,218 ophthalmology clinical notes with visual acuity data present. About 5668 unique responses were identified and an algorithm was developed to map all of the unique responses to a structured list of Snellen visual acuities. Visual acuity was captured from a total of 295,218 ophthalmology clinical notes during the study dates. The algorithm identified all visual acuities in the defined visual acuity section for each eye and returned a single BDVA for each eye. A clinician chart review of 100 random patient notes showed a 99% accuracy detecting BDVA from these records and 1% observed error. Our algorithm successfully captures best documented Snellen distance visual acuity from ophthalmology clinical notes and transforms a variety of inputs into a structured Snellen equivalent list. Our work, to the best of our knowledge, represents the first attempt at capturing visual acuity accurately from large numbers of electronic ophthalmology notes. Use of this algorithm can benefit research groups interested in assessing visual acuity for patient centered outcome. All codes used for this study are currently available, and will be made available online at https://phekb.org.

  8. Creation of an Accurate Algorithm to Detect Snellen Best Documented Visual Acuity from Ophthalmology Electronic Health Record Notes

    PubMed Central

    French, Dustin D; Gill, Manjot; Mitchell, Christopher; Jackson, Kathryn; Kho, Abel; Bryar, Paul J

    2016-01-01

    Background Visual acuity is the primary measure used in ophthalmology to determine how well a patient can see. Visual acuity for a single eye may be recorded in multiple ways for a single patient visit (eg, Snellen vs. Jäger units vs. font print size), and be recorded for either distance or near vision. Capturing the best documented visual acuity (BDVA) of each eye in an individual patient visit is an important step for making electronic ophthalmology clinical notes useful in research. Objective Currently, there is limited methodology for capturing BDVA in an efficient and accurate manner from electronic health record (EHR) notes. We developed an algorithm to detect BDVA for right and left eyes from defined fields within electronic ophthalmology clinical notes. Methods We designed an algorithm to detect the BDVA from defined fields within 295,218 ophthalmology clinical notes with visual acuity data present. About 5668 unique responses were identified and an algorithm was developed to map all of the unique responses to a structured list of Snellen visual acuities. Results Visual acuity was captured from a total of 295,218 ophthalmology clinical notes during the study dates. The algorithm identified all visual acuities in the defined visual acuity section for each eye and returned a single BDVA for each eye. A clinician chart review of 100 random patient notes showed a 99% accuracy detecting BDVA from these records and 1% observed error. Conclusions Our algorithm successfully captures best documented Snellen distance visual acuity from ophthalmology clinical notes and transforms a variety of inputs into a structured Snellen equivalent list. Our work, to the best of our knowledge, represents the first attempt at capturing visual acuity accurately from large numbers of electronic ophthalmology notes. Use of this algorithm can benefit research groups interested in assessing visual acuity for patient centered outcome. All codes used for this study are currently

  9. Visual Acuity and Over-refraction in Myopic Children Fitted with Soft Multifocal Contact Lenses.

    PubMed

    Schulle, Krystal L; Berntsen, David A; Sinnott, Loraine T; Bickle, Katherine M; Gostovic, Anita T; Pierce, Gilbert E; Jones-Jordan, Lisa A; Mutti, Donald O; Walline, Jeffrey J

    2018-04-01

    Practitioners fitting contact lenses for myopia control frequently question whether a myopic child can achieve good vision with a high-add multifocal. We demonstrate that visual acuity is not different than spectacles with a commercially available, center-distance soft multifocal contact lens (MFCL) (Biofinity Multifocal "D"; +2.50 D add). To determine the spherical over-refraction (SOR) necessary to obtain best-corrected visual acuity (BCVA) when fitting myopic children with a center-distance soft MFCL. Children (n = 294) aged 7 to 11 years with myopia (spherical component) of -0.75 to -5.00 diopters (D) (inclusive) and 1.00 D cylinder or less (corneal plane) were fitted bilaterally with +2.50 D add Biofinity "D" MFCLs. The initial MFCL power was the spherical equivalent of a standardized subjective refraction, rounded to the nearest 0.25 D step (corneal plane). An SOR was performed monocularly (each eye) to achieve BCVA. Binocular, high-contrast logMAR acuity was measured with manifest spectacle correction and MFCLs with over-refraction. Photopic pupil size was measured with a pupilometer. The mean (±SD) age was 10.3 ± 1.2 years, and the mean (±SD) SOR needed to achieve BCVA was OD: -0.61 ± 0.24 D/OS: -0.58 ± 0.27 D. There was no difference in binocular high-contrast visual acuity (logMAR) between spectacles (-0.01 ± 0.06) and best-corrected MFCLs (-0.01 ± 0.07) (P = .59). The mean (±SD) photopic pupil size (5.4 ± 0.7 mm) was not correlated with best MFCL correction or the over-refraction magnitude (both P ≥ .09). Children achieved BCVA with +2.50 D add MFCLs that was not different than with spectacles. Children typically required an over-refraction of -0.50 to -0.75 D to achieve BCVA. With a careful over-refraction, these +2.50 D add MFCLs provide good distance acuity, making them viable candidates for myopia control.

  10. Visual acuity, endothelial cell density and polymegathism after iris-fixated lens implantation.

    PubMed

    Nassiri, Nader; Ghorbanhosseini, Saeedeh; Jafarzadehpur, Ebrahim; Kavousnezhad, Sara; Nassiri, Nariman; Sheibani, Kourosh

    2018-01-01

    The purpose of this study was to evaluate the visual acuity as well as endothelial cell density (ECD) and polymegathism after iris-fixated lens (Artiflex ® AC 401) implantation for correction of moderate to high myopia. In this retrospective cross-sectional study, 55 eyes from 29 patients undergoing iris-fixated lens implantation for correction of myopia (-5.00 to -15.00 D) from 2007 to 2014 were evaluated. Uncorrected visual acuity, best spectacle-corrected visual acuity, refraction, ECD and polymegathism (coefficient of variation [CV] in the sizes of endothelial cells) were measured preoperatively and 6 months postoperatively. In the sixth month of follow-up, the uncorrected vision acuity was 20/25 or better in 81.5% of the eyes. The best-corrected visual acuity was 20/30 or better in 96.3% of the eyes, and more than 92% of the eyes had a refraction score of ±1 D from the target refraction. The mean corneal ECD of patients before surgery was 2,803±339 cells/mm 2 , which changed to 2,744±369 cells/mm 2 six months after surgery ( p =0.142). CV in the sizes of endothelial cells before the surgery was 25.7%±7.1% and six months after surgery it was 25.9%±5.4% ( p =0.857). Artiflex iris-fixated lens implantation is a suitable and predictable method for correction of moderate to high myopia. There was no statistically significant change in ECD and polymegathism (CV in the sizes of endothelial cells) after 6 months of follow-up.

  11. Lawn mower injuries as a cause of serious visual acuity impairment - Case reports.

    PubMed

    Jasielska, Monika; Winiarczyk, Mateusz; Bieliński, Paweł; Mackiewicz, Jerzy

    2017-05-11

    [b]Abstract Objective.[/b] The aim of the study is to present four cases of lawn mowers injuries as a cause of serious visual acuity impairment. [b]Materials and Method[/b]. A retrospective study of four patients admitted in 2013-2015 to the Department of Vitreoretinal Surgery in Lublin with severe open or closed globe injury, one with an intraocular foreign body (IOFB). The presence of eye protective equipment was assessed, as well as visual acuity, eye tissue condition before and after treatment, and applied therapy. In all cases an improvement was achieved in local conditions. The intraocular foreign body was removed, wounds sutured and damaged tissues placed in position. All eyeballs were saved. In three cases, visual acuity was improved to a usable level. Three patients underwent pars plana vitrectomy, one with IOFB removal from the vitreous cavity. [b]Conclusions[/b]. Lawn mower induced eye injuries are a significant cause of serious visual acuity impairment or blindness. The presented study shows that lawn mower eye injuries are still a therapeutic, social and economic problem, yet are very preventable with proper eye protection and patients' education. Current prevention strategies are inadequate, and therefore should be updated.

  12. Night-shift work and risk of compromised visual acuity among the workers in an electronics manufacturing company.

    PubMed

    Lin, Yu-Cheng; Ho, Kuo-Jung

    2018-01-01

    To evaluate the association between night-shift work exposure and visual health, this cross-sectional study utilized visual acuity, a surrogate measure for visual function, as a parameter, and performed an analysis comparing visual acuity between daytime and nighttime employees in an electronics manufacturing company. Data of personal histories, occupational records, physical examinations and blood tests was obtained from the electronic health records of workers. The total of 8280 workers including 3098 women and 5182 men, wearing their own daily used eyeglasses, were included in the final analysis. The mean age of the sample population was 34.7 years old (standard deviation = 5.4 years). All workers were divided into 3 work categories - consistent daytime worker (CDW), day-shift worker (DSW) and night-shift worker (NSW). The check-up results of glasses-corrected visual acuity (c-VA) were utilized to classify individuals as good (≥ 1.2, both eyes) and inadequate (< 0.8, the better eye) c-VA. Consistent daytime workers had the highest rate of good c-VA (42.5% vs. 25.1% DSW and 21.1% NSW, p = 0.047). Night-shift workers had the highest rate of inadequate c-VA (CDW, DSW and NSW: 2.6%, 6.2%, and 7.6%, p = 0.03) among all employees. After controlling for covariates, NSW were found at an increased risk for inadequate c-VA (adjusted odds ratio (ORa) = 2.7, 95% confidence interval (CI): 2.0-3.6, vs. CDW), and less likely to have good c-VA (ORa = 0.4, 95% CI: 0.4-0.5, vs. CDW). Night-shift work is moderately associated with compromised visual acuity of employees in this electronics manufacturing company. Int J Occup Med Environ Health 2018;31(1):71-79. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  13. Optimization of neural retinal visual motor strategies in recovery of visual acuity following acute laser-induced macula injury

    NASA Astrophysics Data System (ADS)

    Zwick, Harry; Ness, James W.; Loveday, J.; Molchany, Jerome W.; Stuck, Bruce E.

    1997-05-01

    Laser induced damage to the retina may produce immediate and serious loss in visual acuity as well as subsequent recovery of visual acuity over a 1 to 6 month post exposure period. While acuity may recover, full utilization of the foveal region may not return. In one patient, a superior/temporal preferred retinal location (PRL) was apparent, while a second patient demonstrated significant foveal involvement and contrast sensitivity more reflective of foveal than parafoveal involvement. These conditions of injury wee simulated by using an artificial scotoma technique which optically stabilized a 5 degree opacity in the center of the visual field. The transmission of spatially degraded target information in the scotoma was 0 percent, 5 percent and 95 percent. Contrast sensitivity for the 0 percent and 5 percent transmission scotoma showed broad spatial frequency suppression as opposed to a bipartite contrast sensitivity function with a narrow sensitivity loss at 3 cycles/degree for the 95 percent transmission scotoma. A PRL shift to superior temporal retina with a concomitant change in accommodation was noted as target resolution became more demanding. These findings suggest that restoration of visual acuity in human laser accidents may depend upon the functionality of complex retinal and cortical adaptive mechanisms.

  14. Reduction in Dynamic Visual Acuity Reveals Gaze Control Changes Following Spaceflight

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; Brady, Rachel A.; Miller, Chris; Lawrence, Emily L.; Mulavara Ajitkumar P.; Bloomberg, Jacob J.

    2010-01-01

    INTRODUCTION: Exposure to microgravity causes adaptive changes in eye-head coordination that can lead to altered gaze control. This could affect postflight visual acuity during head and body motion. The goal of this study was to characterize changes in dynamic visual acuity after long-duration spaceflight. METHODS: Dynamic Visual Acuity (DVA) data from 14 astro/cosmonauts were collected after long-duration (6 months) spaceflight. The difference in acuity between seated and walking conditions provided a metric of change in the subjects ability to maintain gaze fixation during self-motion. In each condition, a psychophysical threshold detection algorithm was used to display Landolt ring optotypes at a size that was near each subject s acuity threshold. Verbal responses regarding the orientation of the gap were recorded as the optotypes appeared sequentially on a computer display 4 meters away. During the walking trials, subjects walked at 6.4 km/h on a motorized treadmill. RESULTS: A decrement in mean postflight DVA was found, with mean values returning to baseline within 1 week. The population mean showed a consistent improvement in DVA performance, but it was accompanied by high variability. A closer examination of the individual subject s recovery curves revealed that many did not follow a pattern of continuous improvement with each passing day. When adjusted on the basis of previous long-duration flight experience, the population mean shows a "bounce" in the re-adaptation curve. CONCLUSION: Gaze control during self-motion is altered following long-duration spaceflight and changes in postflight DVA performance indicate that vestibular re-adaptation may be more complex than a gradual return to normal.

  15. Evaluation of visual acuity with Gen 3 night vision goggles

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur; Kaiser, Mary K.

    1994-01-01

    Using laboratory simulations, visual performance was measured at luminance and night vision imaging system (NVIS) radiance levels typically encountered in the natural nocturnal environment. Comparisons were made between visual performance with unaided vision and that observed with subjects using image intensification. An Amplified Night Vision Imaging System (ANVIS6) binocular image intensifier was used. Light levels available in the experiments (using video display technology and filters) were matched to those of reflecting objects illuminated by representative night-sky conditions (e.g., full moon, starlight). Results show that as expected, the precipitous decline in foveal acuity experienced with decreasing mesopic luminance levels is effectively shifted to much lower light levels by use of an image intensification system. The benefits of intensification are most pronounced foveally, but still observable at 20 deg eccentricity. Binocularity provides a small improvement in visual acuity under both intensified and unintensified conditions.

  16. PERSPECTIVE: Is acuity enough? Other considerations in clinical investigations of visual prostheses

    NASA Astrophysics Data System (ADS)

    Lepri, Bernard P.

    2009-06-01

    Visual impairing eye diseases are the major frontier facing ophthalmic research today in light of our rapidly aging population. The visual skills necessary for improving the quality of daily function and life are inextricably linked to these impairing diseases. Both research and reimbursement programs are emphasizing outcome-based results. Is improvement in visual acuity alone enough to improve the function and quality of life of visually impaired persons? This perspective summarizes the types of effectiveness endpoints for clinical investigations of visual prostheses that go beyond visual acuity. The clinical investigation of visual prostheses should include visual function, functional vision and quality of life measures. Specifically, they encompass contrast sensitivity, orientation and mobility, activities of daily living and quality of life assessments. The perspective focuses on the design of clinical trials for visual prostheses and the methods of determining effectiveness above and beyond visual acuity that will yield outcomes that are measured by improved function in the visual world and quality of life. The visually impaired population is the primary consideration in this presentation with particular emphases on retinitis pigmentosa and age-related macular degeneration. Clinical trials for visual prostheses cannot be isolated from the need for medical rehabilitation in order to obtain measurements of effectiveness that produce outcomes/evidence-based success. This approach will facilitate improvement in daily function and quality of life of patients with diseases that cause chronic vision impairment. The views and opinions are those of the author and do not necessarily reflect those of the US Food and Drug Administration, the US Department of Health and Human Services or the Public Health Service.

  17. [Visual acuity in anti-VEGF therapy for AMD : Can specific characteristics in the SD-OCT help?

    PubMed

    Book, B; Ziegler, M; Heimes, B; Gutfleisch, M; Spital, G; Pauleikhoff, D; Lommatzsch, A

    2017-01-01

    The efficacy of anti-VEGF therapy in exudative AMD has been established in several large clinical trials using a fixed injection regimen as well as a SD-OCT-based PRN regimen. In these studies, after the first three injections, an increase of the mean visual acuity was observed, which could be stabilized with constant treatment for up to 24 months. However, the specific course of the visual acuity is very different between individuals. The aim of the present study was to correlate specific initial SD-OCT parameters with the course of visual acuity in order to characterize factors that may be important for the individual visual prognosis. In a prospective case study, the visual course and SD-OCT changes of 156 patients with minimum follow-up of 12 months (mean 80.1 months) were analysed. Visual acuity (LogMar) was investigated at regular intervals and correlated with specific SD-OCT parameters (foveal thickness, height of sub-retinal fluid or presence of associated PED, presence of intra-retinal cysts, length of IS/OS break, choroidal thickness). The initial increase in visual acuity could be stabilized over time. This effect was associated with a decrease in foveal retinal thickness, which also persisted over time. While sub-retinal fluid, presence of PED, and choroidal thickness showed no prognostic relevance for the change in visual acuity, the presence of more advanced central retinal thickness, of intra-retinal cysts or a longer break in the IS/OS junction were associated with a less favourable development of visual acuity. In the present study, the presence of more advanced central retinal thickness, of intra-retinal cysts or a larger IS/OS break correlated significantly with a worse visual prognosis. These might be clinical signs for more extensive pre-existing intra-retinal changes. Further analysis and new diagnostic tools may prove this and may result in specific additive neuroprotective or regenerative therapeutic approaches in exudative AMD.

  18. Clinical vision characteristics of the congenital achromatopsias. I. Visual acuity, refractive error, and binocular status.

    PubMed

    Haegerstrom-Portnoy, G; Schneck, M E; Verdon, W A; Hewlett, S E

    1996-07-01

    Visual acuity, refractive error, and binocular status were determined in 43 autosomal recessive (AR) and 15 X-linked (XL) congenital achromats. The achromats were classified by color matching and spectral sensitivity data. Large interindividual variation in refractive error and visual acuity was present within each achromat group (complete AR, incomplete AR, and XL). However, the number of individuals with significant interocular acuity differences is very small. Most XLs are myopic; ARs show a wide range of refractive error from high myopia to high hyperopia. Acuity of the AR and XL groups was very similar. With-the-rule astigmatism of large amount is very common in achromats, particularly ARs. There is a close association between strabismus and interocular acuity differences in the ARs, with the fixating eye having better than average acuity. The large overlap of acuity and refractive error of XL and AR achromats suggests that these measures are less useful for differential diagnosis than generally indicated by the clinical literature.

  19. Fluctuation in visual acuity during soft toric contact lens wear.

    PubMed

    Chamberlain, Paul; Morgan, Philip B; Moody, Kurt J; Maldonado-Codina, Carole

    2011-04-01

    To quantify changes in visual acuity (VA) with soft toric contact lenses as a result of lens movement and/or rotational instability caused by versional eye movements. A novel chart for vision assessment at near (40 cm) for soft toric contact lenses (VANT chart),consisting of a central, color-coded logMAR panel and eight peripheral letter targets set on a white background measuring 60 × 40 cm was constructed. In the developmental phase of the work, 10 subjects (20 eyes) wore 2 toric lenses in random order, and the impact of rapid and delayed eye versions in 8 directions of gaze on VANT acuity was investigated. In phase 2, 35 subjects (68 eyes) wore 4 toric lenses in random order, and a streamlined clinical protocol using the VANT chart was implemented. Standard assessments of toric lens fit and distance VA were also performed. Testing in the first phase showed no difference for change in VA for rapid vs. delayed version movements, (p = 0.17) but acuity reduction was greater for diagonal compared with horizontal/vertical versions (p = 0.06). As such, testing in phase 2 proceeded using rapid, diagonal versions only. In this second phase, there were differences for low-contrast distance VA measures between lens types (p = 0.02) and for both VANT baseline acuity (p = 0.03) and postversion acuity (p = 0.04), but no differences were found between lenses for magnitude of vision loss (p = 0.91), which was about one line. No relationship was established between the magnitude of vision loss and measured rotational stability (p = 0.75). This work has demonstrated that conventional approaches to measuring VA do not fully replicate the "real world" experience of soft toric lens wearers. The VANT chart has shown that VA is reduced immediately after versional eye movements and suggests that more dynamic methods of assessing visual performance should be considered for soft toric contact lens wearers, especially given the apparent inability of lens stability measurements to predict

  20. Astronaut Charles Conrad during visual acuity experiments over Laredo

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Charles Conrad Jr., pilot for the prime crew on the Gemini 5 space flight, takes pictures of predetermined land areas during visual acuity experiments over Laredo, Texas. The experiments will aid in learning to identify known terrestrial features under controlled conditions.

  1. Visual acuity from far to near and contrast sensitivity in eyes with a diffractive multifocal intraocular lens with a low addition power.

    PubMed

    Hayashi, Ken; Manabe, Shin-Ichi; Hayashi, Hideyuki

    2009-12-01

    To compare visual acuity from far to near, contrast visual acuity, and acuity in the presence of glare (glare visual acuity) between an aspheric diffractive multifocal intraocular lens (IOL) with a low addition (add) power (+3.0 diopters) and a monofocal IOL. Hayashi Eye Hospital, Fukuoka, Japan. This prospective study comprised patients having implantation of an aspheric diffractive multifocal ReSTOR SN6AD1 IOL with a +3.0 D add (multifocal group) or a monofocal AcrySof IQ SN60WF IOL (monofocal group). Visual acuity from far to near distances, contrast acuity, and glare acuity were evaluated 3 months postoperatively. Each IOL group comprised 64 eyes of 32 patients. For monocular and binocular visual acuity, the mean uncorrected and distance-corrected intermediate acuity at 0.5 m and the near acuity at 0.3 m were significantly better in the multifocal group than in the monofocal group (Pacuity at 0.7 m and 1.0 m were similar between the 2 groups. No significant differences were observed between groups in contrast acuity and glare acuity under photopic and mesopic conditions. Furthermore, no significant correlation was found between all-distance acuity and pupil diameter or between visual acuity and IOL decentration and tilt. The diffractive multifocal IOL with a low add power provided significantly better intermediate and near visual acuity than the monofocal IOL. Contrast sensitivity with and without glare was reduced with the multifocal IOL, and all-distance visual acuity was independent of pupil diameter and IOL displacement.

  2. A 5-year audit of cataract surgery outcomes after posterior capsule rupture and risk factors affecting visual acuity.

    PubMed

    Ti, Seng-Ei; Yang, You-Nian; Lang, Stephanie S; Chee, Soon Phaik

    2014-01-01

    To describe the posterior capsule rupture rates and visual outcomes after phacoemulsification, analyze risk factors for poor vision, and compare results of faculty (F) and residents (R). Retrospective audit study. Visual success of all capsule ruptures (2006-2010) was analyzed and compared to uneventful cases. Rupture rates of faculty and residents were compared (χ², P < .05). Success was defined as % best-corrected visual acuity (BCVA) ≥20/40 at 3 months (excluding poor-prognosis eyes) and studied in relation to age, sex, surgeon type, stage of surgery, vitreous loss, dropped nucleus, and other complications (eg, retinal detachment, corneal decompensation, dislocated intraocular lens [IOL]). Final risk factors were identified using multivariate logistic regression analysis. From 2006 to 2010, there were 887 capsule ruptures in 48 377 phacoemulsification cases (rate 1.8%). Uneventful cases had significantly better visual outcomes than capsule ruptures (98.5% vs 93.9%; P < .01). Faculty rupture rates were lower (F = 1.4%) than residents' (R = 3.4%; P < .01), but visual outcomes were similar (F = 93.8%, R = 93.7%; P > .05). Ruptures most frequently occurred during phacoemulsification (59.6%) and irrigation and aspiration (24.8%) stages. Risk factors for poor outcomes included age >65 years, dropped nuclei, and other complications. The overall capsule rupture rate was 1.8%. Although residents had higher rates, visual success matched faculty's, possibly attributable to case mix and close supervision. Associated risk factors for poor vision included age >65 years, dropped nuclei, and postoperative retinal, corneal, and IOL complications. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Effect of occlusion amblyopia after prescribed full-time occlusion on long-term visual acuity outcomes.

    PubMed

    Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard

    2013-01-01

    To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.

  4. Effect of Target Location on Dynamic Visual Acuity During Passive Horizontal Rotation

    NASA Technical Reports Server (NTRS)

    Appelbaum, Meghan; DeDios, Yiri; Kulecz, Walter; Peters, Brian; Wood, Scott

    2010-01-01

    The vestibulo-ocular reflex (VOR) generates eye rotation to compensate for potential retinal slip in the specific plane of head movement. Dynamic visual acuity (DVA) has been utilized as a functional measure of the VOR. The purpose of this study was to examine changes in accuracy and reaction time when performing a DVA task with targets offset from the plane of rotation, e.g. offset vertically during horizontal rotation. Visual acuity was measured in 12 healthy subjects as they moved a hand-held joystick to indicate the orientation of a computer-generated Landolt C "as quickly and accurately as possible." Acuity thresholds were established with optotypes presented centrally on a wall-mounted LCD screen at 1.3 m distance, first without motion (static condition) and then while oscillating at 0.8 Hz (DVA, peak velocity 60 deg/s). The effect of target location was then measured during horizontal rotation with the optotypes randomly presented in one of nine different locations on the screen (offset up to 10 deg). The optotype size (logMar 0, 0.2 or 0.4, corresponding to Snellen range 20/20 to 20/50) and presentation duration (150, 300 and 450 ms) were counter-balanced across five trials, each utilizing horizontal rotation at 0.8 Hz. Dynamic acuity was reduced relative to static acuity in 7 of 12 subjects by one step size. During the random target trials, both accuracy and reaction time improved proportional to optotype size. Accuracy and reaction time also improved between 150 ms and 300 ms presentation durations. The main finding was that both accuracy and reaction time varied as a function of target location, with greater performance decrements when acquiring vertical targets. We conclude that dynamic visual acuity varies with target location, with acuity optimized for targets in the plane of motion. Both reaction time and accuracy are functionally relevant DVA parameters of VOR function.

  5. Comparison of the American Optical Vision Tester and the Armed Forces Far Visual Acuity Test. B-6-133-13

    DTIC Science & Technology

    1954-01-01

    THE AMERICAN OPTICAL VISION TESTER AND THE ARMED FORCES FAR VISUAL ACUITY TEST Comparisons were made of the visual acuity scores of 100 enlisted men on ...the American Optical Vision Tester (with Sloan plates) and on the Armed Forces Far Visual Acuity test. Order of presentation was: AO-left eye, AO...right eye, AFFVAT-left, AFVTAT-right. Correlation coefficients between AO and AFFVAT were around .89. Dispersion of acuity scores was about the same on

  6. Predicting through-focus visual acuity with the eye's natural aberrations.

    PubMed

    Kingston, Amanda C; Cox, Ian G

    2013-10-01

    To develop a predictive optical modeling process that utilizes individual computer eye models along with a novel through-focus image quality metric. Individual eye models were implemented in optical design software (Zemax, Bellevue, WA) based on evaluation of ocular aberrations, pupil diameter, visual acuity, and accommodative response of 90 subjects (180 eyes; 24-63 years of age). Monocular high-contrast minimum angle of resolution (logMAR) acuity was assessed at 6 m, 2 m, 1 m, 67 cm, 50 cm, 40 cm, 33 cm, 28 cm, and 25 cm. While the subject fixated on the lowest readable line of acuity, total ocular aberrations and pupil diameter were measured three times each using the Complete Ophthalmic Analysis System (COAS HD VR) at each distance. A subset of 64 mature presbyopic eyes was used to predict the clinical logMAR acuity performance of five novel multifocal contact lens designs. To validate predictability of the design process, designs were manufactured and tested clinically on a population of 24 mature presbyopes (having at least +1.50 D spectacle add at 40 cm). Seven object distances were used in the validation study (6 m, 2 m, 1 m, 67 cm, 50 cm, 40 cm, and 25 cm) to measure monocular high-contrast logMAR acuity. Baseline clinical through-focus logMAR was shown to correlate highly (R² = 0.85) with predicted logMAR from individual eye models. At all object distances, each of the five multifocal lenses showed less than one line difference, on average, between predicted and clinical normalized logMAR acuity. Correlation showed R² between 0.90 and 0.97 for all multifocal designs. Computer-based models that account for patient's aberrations, pupil diameter changes, and accommodative amplitude can be used to predict the performance of contact lens designs. With this high correlation (R² ≥ 0.90) and high level of predictability, more design options can be explored in the computer to optimize performance before a lens is manufactured and tested clinically.

  7. Visual acuity and refractive errors in a suburban Danish population: Inter99 Eye Study.

    PubMed

    Kessel, Line; Hougaard, Jesper Leth; Mortensen, Claus; Jørgensen, Torben; Lund-Andersen, Henrik; Larsen, Michael

    2004-02-01

    The present study was performed as part of an epidemiological study, the Inter99 Eye Study. The aim of the study was to describe refractive errors and visual acuity (VA) in a suburban Danish population. The Inter99 Eye Study comprised 970 subjects aged 30-60 years and included a random control group as well as groups at high risk for ischaemic heart disease and diabetes mellitus. The present study presents VAs and refractive data from the control group (n = 502). All subjects completed a detailed questionnaire and underwent a standardized general physical and ophthalmic examination including determination of best corrected VA and subjective refractioning. Visual acuity visual function was strabismic amblyopia. Myopia (visual impairment. Myopia was approximately twice as frequent in subjects with a university degree as in the remaining study population.

  8. The Montrachet Study: study design, methodology and analysis of visual acuity and refractive errors in an elderly population.

    PubMed

    Creuzot-Garcher, Catherine; Binquet, Christine; Daniel, Sandrine; Bretillon, Lionel; Acar, Nyiazi; de Lazzer, Aurélie; Arnould, Laurent; Tzourio, Christophe; Bron, Alain M; Delcourt, Cécile

    2016-03-01

    To describe the design of the Montrachet Study (Maculopathy Optic Nerve nuTRition neurovAsCular and HEarT diseases) and to report visual acuity and refractive errors in this elderly population. Participants were recruited in Dijon (France), from the ongoing population-based 3C Study. In 2009-2011, 1153 participants from the 3 Cities Study, aged 75 years or more, had an initial eye examination and were scheduled for eye examinations. The eye examination comprised visual acuity, refraction, visual field, ocular surface assessment, photographs and OCT of the macula and the optic disc, measurement of intra-ocular pressure, central corneal thickness and macular pigment assessment. Information on cardiovascular and neurologic diseases and a large comprehensive database (blood samples, genetic testing, cognitive tests, MRI) were available from the 3C Study. Presenting visual acuity <20/60 in the better eye was found in 2.3% (95% CI 1.5-3.2) of the participants with no gender differences. Visual impairment increased with age from 1.5% (95% CI 0.3-2.7) for those aged 75-79 years to 5.6% (95% CI 2.9-8.4) for patients 85 years and older (p = 0.0003). Spherical equivalent did not differ between men and women (p = 0.8) and decreased with age whatever the lens status. Despite the high prevalence of self-reported eye diseases in this elderly population, visual impairment was low and increased with age. The Montrachet Study may help to better estimate the prevalence of eye diseases in people over 75 years of age and to seek associations with cardiovascular and neurologic diseases and their potential risk factors. © 2015 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

  9. Changes in Intraocular Straylight and Visual Acuity with Age in Cataracts of Different Morphologies

    PubMed Central

    Reus, Nicolaas J.; van den Berg, Thomas J. T. P.

    2017-01-01

    Purpose To investigate the significance of difference in straylight of cataract eyes with different morphologies, as a function of age and visual acuity. Methods A literature review to collect relevant papers on straylight, age, and visual acuity of three common cataract morphologies leads to including five eligible papers for the analysis. The effect of morphology was incorporated to categorize straylight dependency on the two variables. We also determined the amount of progression in a cataract group using a control group. Results The mean straylight was 1.22 log units ± 0.20 (SD) in nuclear (592 eyes), 1.26 log units ± 0.23 in cortical (776 eyes), and 1.48 log units ± 0.34 in posterior subcapsular (75 eyes) groups. The slope of straylight-age relationship was 0.009 (R 2 = 0.20) in nuclear, 0.012 (R 2 = 0.22) in cortical, and 0.014 (R 2 = 0.11) in posterior subcapsular groups. The slope of straylight-visual acuity relationship was 0.62 (R 2 = 0.25) in nuclear, 0.33 (R 2 = 0.13) in cortical, and 1.03 (R 2 = 0.34) in posterior subcapsular groups. Conclusion Considering morphology of cataract provides a better insight in assessing visual functions of cataract eyes, in posterior subcapsular cataract, particularly, in spite of notable elevated straylight, visual acuity might not manifest severe loss. PMID:28831307

  10. Examination of factors affecting gait properties in healthy older adults: focusing on knee extension strength, visual acuity, and knee joint pain.

    PubMed

    Demura, Tomohiro; Demura, Shin-ichi; Uchiyama, Masanobu; Sugiura, Hiroki

    2014-01-01

    Gait properties change with age because of a decrease in lower limb strength and visual acuity or knee joint disorders. Gait changes commonly result from these combined factors. This study aimed to examine the effects of knee extension strength, visual acuity, and knee joint pain on gait properties of for 181 healthy female older adults (age: 76.1 (5.7) years). Walking speed, cadence, stance time, swing time, double support time, step length, step width, walking angle, and toe angle were selected as gait parameters. Knee extension strength was measured by isometric dynamometry; and decreased visual acuity and knee joint pain were evaluated by subjective judgment whether or not such factors created a hindrance during walking. Among older adults without vision problems and knee joint pain that affected walking, those with superior knee extension strength had significantly greater walking speed and step length than those with inferior knee extension strength (P < .05). Persons with visual acuity problems had higher cadence and shorter stance time. In addition, persons with pain in both knees showed slower walking speed and longer stance time and double support time. A decrease of knee extension strength and visual acuity and knee joint pain are factors affecting gait in the female older adults. Decreased knee extension strength and knee joint pain mainly affect respective distance and time parameters of the gait.

  11. Calibration-free gaze tracking for automatic measurement of visual acuity in human infants.

    PubMed

    Xiong, Chunshui; Huang, Lei; Liu, Changping

    2014-01-01

    Most existing vision-based methods for gaze tracking need a tedious calibration process. In this process, subjects are required to fixate on a specific point or several specific points in space. However, it is hard to cooperate, especially for children and human infants. In this paper, a new calibration-free gaze tracking system and method is presented for automatic measurement of visual acuity in human infants. As far as I know, it is the first time to apply the vision-based gaze tracking in the measurement of visual acuity. Firstly, a polynomial of pupil center-cornea reflections (PCCR) vector is presented to be used as the gaze feature. Then, Gaussian mixture models (GMM) is employed for gaze behavior classification, which is trained offline using labeled data from subjects with healthy eyes. Experimental results on several subjects show that the proposed method is accurate, robust and sufficient for the application of measurement of visual acuity in human infants.

  12. A comparison of behavioural (Landolt C) and anatomical estimates of visual acuity in archerfish (Toxotes chatareus).

    PubMed

    Temple, S E; Manietta, D; Collin, S P

    2013-05-03

    Archerfish forage by shooting jets of water at insects above the water's surface. The challenge of detecting small prey items against a complex background suggests that they have good visual acuity, but to date this has never been tested, despite archerfish becoming an increasingly important model species for vertebrate vision. We used a modified Landolt C test to measure visual acuity behaviourally, and compared the results to their predicted minimum separable angle based on both photoreceptor and ganglion cell spacing in the retina. Both measures yielded similar estimates of visual acuity; between 3.23 and 3.57 cycles per degree (0.155-0.140° of visual arc). Such a close match between behavioural and anatomical estimates of visual acuity in fishes is unusual and may be due to our use of an ecologically relevant task that measured the resolving power of the part of the retina that has the highest photoreceptor density and that is used in aligning their spitting angle with potential targets. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Omega 3 fatty acids on child growth, visual acuity and neurodevelopment.

    PubMed

    Campoy, Cristina; Escolano-Margarit, Ma Victoria; Anjos, Tania; Szajewska, Hania; Uauy, Ricardo

    2012-06-01

    The aim of this review is to evaluate the effects of omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation in pregnant and lactating women and infants during postnatal life, on the visual acuity, psychomotor development, mental performance and growth of infants and children. Eighteen publications (11 sets of randomized control clinical trial [RCTs]) assessed the effects of the n-3 LCPUFA supplementation during pregnancy on neurodevelopment and growth, in the same subjects at different time points; 4 publications (2 data sets from RCTs) addressed physiological responses to n-3 LCPUFA supplementation during pregnancy & lactation and 5 publications (3 data sets from RCTs) exclusively during lactation. Some of these studies showed beneficial effects of docosahexaenoic acid (DHA) supplementation during pregnancy and/or lactation especially on visual acuity outcomes and some on long-term neurodevelopment; a few, showed positive effects on growth. There were also 15 RCTs involving term infants who received infant formula supplemented with DHA, which met our selection criteria. Many of these studies claimed a beneficial effect of such supplementation on visual, neural, or developmental outcomes and no effects on growth. Although new well designed and conducted studies are being published, evidence from RCTs does not demonstrate still a clear and consistent benefit of n-3 LCPUFA supplementation during pregnancy and/or lactation on term infants growth, neurodevelopment and visual acuity. These results should be interpreted with caution due to methodological limitations of the included studies.

  14. Distinct eye movement patterns enhance dynamic visual acuity.

    PubMed

    Palidis, Dimitrios J; Wyder-Hodge, Pearson A; Fooken, Jolande; Spering, Miriam

    2017-01-01

    Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics-eye latency, acceleration, velocity gain, position error-and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns-minimizing eye position error, tracking smoothly, and inhibiting reverse saccades-were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA.

  15. Distinct eye movement patterns enhance dynamic visual acuity

    PubMed Central

    Palidis, Dimitrios J.; Wyder-Hodge, Pearson A.; Fooken, Jolande; Spering, Miriam

    2017-01-01

    Dynamic visual acuity (DVA) is the ability to resolve fine spatial detail in dynamic objects during head fixation, or in static objects during head or body rotation. This ability is important for many activities such as ball sports, and a close relation has been shown between DVA and sports expertise. DVA tasks involve eye movements, yet, it is unclear which aspects of eye movements contribute to successful performance. Here we examined the relation between DVA and the kinematics of smooth pursuit and saccadic eye movements in a cohort of 23 varsity baseball players. In a computerized dynamic-object DVA test, observers reported the location of the gap in a small Landolt-C ring moving at various speeds while eye movements were recorded. Smooth pursuit kinematics—eye latency, acceleration, velocity gain, position error—and the direction and amplitude of saccadic eye movements were linked to perceptual performance. Results reveal that distinct eye movement patterns—minimizing eye position error, tracking smoothly, and inhibiting reverse saccades—were related to dynamic visual acuity. The close link between eye movement quality and DVA performance has important implications for the development of perceptual training programs to improve DVA. PMID:28187157

  16. Functional and visual acuity outcomes of cataract surgery in Timor-Leste (East Timor).

    PubMed

    Naidu, Girish; Correia, Marcelino; Nirmalan, Praveen; Verma, Nitin; Thomas, Ravi

    2014-12-01

    To report functional outcomes following cataract surgery in Timor-Leste. Pre- and post-intervention study measuring visual function improvement following cataract surgery. Presenting visual acuity (VA) was measured and visual function documented using the Indian vision function questionnaire (IND-VFQ). All 174 persons undergoing cataract surgery from November 2009 to January 2011 in Timor-Leste were included. Mean age was 65.4 years; 113 (64.9%) were male, 143 (82.1%) were from a rural background and 151 (86.8%) were illiterate. Pre-operatively, 77 of 174 patients (44.3%, 95% confidence interval, CI, 37.0-51.7%) were blind (VA ≤3/60), 77 (44.3%, 95% CI 37.0-51.7%) were visually impaired (VA <6/18->3/60), while 20 (11.5%, 95% CI 7.4-16.9%) had presenting acuity ≥6/18 in the better eye. Following surgery, significant improvement in visual function was demonstrated by an effect size of 2.8, 3.7 and 3.9 in the domains of general functioning, psychosocial impact and visual symptoms, respectively. Four weeks following surgery, 85 patients (48.9%, 95% CI 41.5-66.3%) had a presenting VA ≥6/18, 74 (42.5%, 95% CI 35.3-45.9%) were visually impaired and 15 (8.6%, 95% CI 5.0-13.6%) were blind. IND-VFQ improvement occurred even in patients remaining visually impaired or blind following surgery. In this setting, cataract surgery led to a significant improvement in visual function but the VA results did not meet World Health Organization quality criteria. IND-VFQ results, although complementary to clinical VA outcomes did not, in isolation, reflect the need to improve program quality.

  17. Three-year safety and visual acuity results of epimacular 90 strontium/90 yttrium brachytherapy with bevacizumab for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration.

    PubMed

    Avila, Marcos P; Farah, Michael E; Santos, Arturo; Carla, Livia; Fuji, Gildo; Rossi, Juliana; Nau, Jeffrey

    2012-01-01

    To evaluate the long-term safety and visual acuity outcomes associated with epimacular strontium 90 brachytherapy combined with intravitreal bevacizumab for the treatment of subfoveal choroidal neovascularization because of age-related macular degeneration. Thirty-four treatment-naive patients with predominantly classic, minimally classic, and occult subfoveal choroidal neovascularization lesions participated in this prospective, 2-year, nonrandomized multicenter study. Subjects from 1 center (n = 19) were reconsented and followed-up for 3 years. Each subject received a single 24-Gy beta irradiation treatment via an intraocular delivery device and 2 planned injections of bevacizumab at treatment and 1 month later. Additional bevacizumab therapy was permitted based on prespecified retreatment criteria. Adverse events were observed, and best-corrected visual acuity was measured using Early Treatment Diabetic Retinopathy Study vision charts. Subjects were evaluated every 3 months during the first year of follow-up and every 6 months during Years 2 and 3 of follow-up. All 34 subjects were followed-up for 24 months and 19 were followed-up through 36 months. With up to 24 months of follow-up, 12 of 24 phakic patients (50%) exhibited ≥ 2 grades of progression in Lens Opacification Classification System (LOCS) II lens classification; 5 eyes underwent cataract extraction before the Month 36 visit. There was 1 case of nonproliferative retinopathy identified at 36 months of follow-up that did not have an adverse effect on visual acuity, was stable at 43 months of follow-up, and was isolated to the parafoveal region. Mean best-corrected visual acuity demonstrated an average gain of +15.0 and -4.9 letters at 12 months and 24 months, respectively; the drop in mean gain at Month 24 was largely attributable to cataract formation. At 36 months (n = 19), the mean best-corrected visual acuity was +3.9, 90% (17 of 19) of eyes had lost <15 letters from baseline, 53% (10 of 19) had

  18. MAINTENANCE OF GOOD VISUAL ACUITY IN BEST DISEASE ASSOCIATED WITH CHRONIC BILATERAL SEROUS MACULAR DETACHMENT.

    PubMed

    Gattoussi, Sarra; Boon, Camiel J F; Freund, K Bailey

    2017-08-10

    We describe the long-term follow-up of a patient with multifocal Best disease with chronic bilateral serous macular detachment and unusual peripheral findings associated with a novel mutation in the BEST1 gene. Case report. A 59-year-old white woman was referred for an evaluation of her macular findings in 1992. There was a family history of Best disease in the patient's mother and a male sibling. Her medical history was unremarkable. Best-corrected visual acuity was 20/20 in her right eye and 20/25 in her left eye. The anterior segment examination was normal in both eyes. Funduscopic examination showed multifocal hyperautofluorescent vitelliform deposits with areas of subretinal fibrosis in both eyes. An electrooculogram showed Arden ratios of 1.32 in the right eye and 1.97 in the left eye. Ultra-widefield color and fundus autofluorescence imaging showed degenerative retinal changes in areas throughout the entire fundus in both eyes. Optical coherence tomography, including annual eye-tracked scans from 2005 to 2016, showed persistent bilateral serous macular detachments. Despite chronic foveal detachment, visual acuity was 20/25 in her right eye and 20/40 in her left eye, 24 years after initial presentation. Genetic testing showed a novel c.238T>A (p.Phe80Ile) missense mutation in the BEST1 gene. Some patients with Best disease associated with chronic serous macular detachment can maintain good visual acuity over an extended follow-up. To our knowledge, this is the first report of Best disease associated with this mutation in the BEST1 gene.

  19. Automated Measurement of Visual Acuity in Pediatric Ophthalmic Patients Using Principles of Game Design and Tablet Computers.

    PubMed

    Aslam, Tariq M; Tahir, Humza J; Parry, Neil R A; Murray, Ian J; Kwak, Kun; Heyes, Richard; Salleh, Mahani M; Czanner, Gabriela; Ashworth, Jane

    2016-10-01

    To report on the utility of a computer tablet-based method for automated testing of visual acuity in children based on the principles of game design. We describe the testing procedure and present repeatability as well as agreement of the score with accepted visual acuity measures. Reliability and validity study. Setting: Manchester Royal Eye Hospital Pediatric Ophthalmology Outpatients Department. Total of 112 sequentially recruited patients. For each patient 1 eye was tested with the Mobile Assessment of Vision by intERactIve Computer for Children (MAVERIC-C) system, consisting of a software application running on a computer tablet, housed in a bespoke viewing chamber. The application elicited touch screen responses using a game design to encourage compliance and automatically acquire visual acuity scores of participating patients. Acuity was then assessed by an examiner with a standard chart-based near ETDRS acuity test before the MAVERIC-C assessment was repeated. Reliability of MAVERIC-C near visual acuity score and agreement of MAVERIC-C score with near ETDRS chart for visual acuity. Altogether, 106 children (95%) completed the MAVERIC-C system without assistance. The vision scores demonstrated satisfactory reliability, with test-retest VA scores having a mean difference of 0.001 (SD ±0.136) and limits of agreement of 2 SD (LOA) of ±0.267. Comparison with the near EDTRS chart showed agreement with a mean difference of -0.0879 (±0.106) with LOA of ±0.208. This study demonstrates promising utility for software using a game design to enable automated testing of acuity in children with ophthalmic disease in an objective and accurate manner. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Relationship between Functional Visual Acuity and Useful Field of View in Elderly Drivers

    PubMed Central

    Negishi, Kazuno; Masui, Sachiko; Mimura, Masaru; Fujita, Yoshio; Tsubota, Kazuo

    2016-01-01

    Purpose To investigate the relationship between the functional visual acuity (FVA) and useful field of view (UFOV) in elderly drivers and assess the usefulness of the FVA test to screen driving aptitude in elderly drivers. Methods This study included 45 elderly drivers (31 men, 14 women; mean age, 68.1 years) and 30 younger drivers (26 men, 4 women; mean age, 34.2 years) who drive regularly. All participants underwent measurement of the binocular corrected distant visual acuity (CDVA), binocular corrected distant FVA (CDFVA), and Visual Field with Inhibitory Tasks Elderly Version (VFIT-EV) to measure UFOV. The tear function and cognitive status also were evaluated. Results The CDVA, the CDFVA, cognitive status, and the correct response rate (CAR) of the VFIT-EV were significantly worse in the elderly group than in the control group (P = 0.000 for all parameters). The cognitive status was correlated significantly with the CDVA (r = -0.301, P = 0.009), CDFVA (r = -0.402, P = 0.000), and the CAR of the VFIT-EV (r = 0.348, P = 0.002) in all subjects. The results of the tear function tests were not correlated with the CDVA, CDFVA, or VFIT-EV in any subjects. Stepwise regression analysis for all subjects in the elderly and control groups showed that the CDFVA predicted the CAR most significantly among the clinical factors evaluated. Conclusion The FVA test is a promising method to screen the driving aptitude, including both visual and cognitive functions, in a short time. PMID:26808364

  1. Vision screening in children: Is 7-9 years of age a threshold for visual impairment?

    PubMed

    Ertekin, Yusuf Haydar; Tekin, Murat; Uludag, Aysegul; Arikan, Sedat; Sahin, Erkan Melih

    2016-01-01

    The present study aimed to assess the prevalence of decreased visual acuity, strabismus, and spectacle wear in children aged 5 to 13 years. A cross-sectional study was performed in primary education schools. A total of 1938 participants, including 940 females (48.5%) and 998 males (51.5%) with a mean age 8.96 ± 2.31 (5-13 years old), were screened. The comparisons were performed with gender, age, and age groups. The children attended to vision screening were assigned to three age groups as 5-6 years, 7-9 years, and 10-13 years. The prevalence of the parameters was detected as decreased visual acuity 12.4%, strabismus 2.2%, and spectacle wear 6.9%. The prevalence of decreased visual acuity was significantly higher in girls and in children aged 7-9 years old (p = 0.013, p < 0.001). The prevalence of spectacle wear was significantly higher in girls and in children aged 7-9 years old (p = 0.019, p < 0.001). There was a visual acuity decrease in 33 of 106 (31.1%) children despite wearing own spectacle. There was no significant difference among three age groups for strabismus. Increased prevalence of decreased visual acuity, as well as the higher frequency of spectacle wear in children at ages of 7-9 years old may point out a threshold for visual impairment.

  2. Near visual acuity for everyday activities with accommodative and monofocal intraocular lenses.

    PubMed

    Sanders, Donald R; Sanders, Monica L

    2007-10-01

    To determine the levels of functional near visual acuity required for everyday social reading activities and to compare the levels to those attained with accommodative and monofocal intraocular lenses (LOLs). Font size equivalencies of an Early Treatment Diabetic Retinopathy Study near chart and a variety of commonly read print objects were determined and correlated to the findings of distance-corrected near vision measurements with 2 accommodative (Tetraflex, 1CU) and 1 monofocal (Acrysof MA30) IOLs. The smallest print objects studied were sweetener packets with type between 20/40 (Jaeger [J] 5) and 20/50 (J6). Type in classified ads, stock quotations, and pocket bibles was 20/50 (J6), type in a telephone directory was 20/63 (J8), and type in standard newspapers, journals, and magazines was 20/80 (J9). Tested monocularly, 88% of Tetraflex, 40% of ICU, and 7% of Acrysof MA30 eyes had distance-corrected near vision sufficient to read newspaper and telephone directory print, and 63% of Tetraflex, 30% of 1CU, and 0% of Acrysof MA30 eyes could read classified ads, stock quotations, and pocket bibles, respectively. Tested binocularly after bilateral implantation, 96% of Tetraflex patients could read telephone directory print and 89% could read ads, stock quotations, and pocket bibles. Functional near visual acuity is not equivalent to the bottom-line objective at 20/20 (J1) near visual acuity. No print size was found at or smaller than 20/40 (J5), indicating that a requirement of nearly perfect near visual acuity, while desirable, may not be necessary for patients' social reading needs for accommodative IOLs.

  3. Visual Acuity is Related to Parafoveal Retinal Thickness in Patients with Retinitis Pigmentosa and Macular Cysts

    PubMed Central

    Brockhurst, Robert J.; Gaudio, Alexander R.; Berson, Eliot L.

    2008-01-01

    Purpose To quantify the prevalence and effect on visual acuity of macular cysts in a large cohort of patients with retinitis pigmentosa. Methods In 316 patients with typical forms of retinitis pigmentosa, we measured visual acuities with Early Treatment Diabetic Retinopathy Study (ETDRS) charts, detected macular cysts with optical coherence tomography (OCT), and quantified retinal thicknesses by OCT. We used the FREQ, LOGISTIC, and GENMOD procedures of SAS to evaluate possible risk factors for cyst prevalence and the MIXED procedure to quantify the relationships of visual acuity to retinal thickness measured at different locations within the macula. Results We found macular cysts in 28% of the patients, 40% of whom had cysts in only one eye. Macular cysts were seen most often in patients with dominant disease and not at all in patients with X-linked disease (p = 0.006). In eyes with macular cysts, multiple regression analysis revealed that visual acuity was inversely and independently related to retinal thickness at the foveal center (p = 0.038) and within a ring spanning an eccentricity of 5° to 10° from the foveal center (p = 0.004). Conclusions Macular cysts are a common occurrence in retinitis pigmentosa, especially among patients with dominantly-inherited disease. Visual acuity is influenced by edema in the parafovea, as well as in the fovea. PMID:18552390

  4. A STUDY OF FACTORS ASSOCIATED WITH LOSS OF DISTANT VISUAL ACUITY AMONG CHILDREN FIVE TO ELEVEN YEARS OF AGE IN HIROSHIMA AND NAGASAKI

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miller, R.W.

    1962-08-01

    An evaluation of the effects of inheritance and environment on the loss of distant visual acuity in 7117 Japanese grammar school children is presented. Unique features of the survey included: entry of the child in the study during gestation; measurement of pediatric, neurologic, and dental health, of physical and intellectual growth, and of circumstances of the in utero and home environments, and the opportunity to appraise the effects of inbreeding, since approximately half of those examined were born of parents who were second cousins or more closely related. the results showed that congenital organic lesions of the eye were verymore » signiiicantly higher among children of first cousins than among the outbred children. So great was the increase, it suggested that the eye is more subject to disability mediated by recessive genes than are other organsystems. Loss of distani visual acuity in which no organic lesion was revealed by ophthalmoscopy was attributed to refractive errors; about 80% of the children with 20/70 visual acuity or worse in one or both eyes appeared to have myopia. The role of inheritance was iraplicated by the increasing frequency of the defects as the degree of inbreeding increased, and by the tendency for cases to aggregate in families. Effects of the environment during intra-uterine life, or soon thereafter, were suggested by thc relationship of season of birth to the risk of visual aeuity loss later in childhood and, independently, by the association of birth weight less than 2500 grams with an increased risk of such loss. No association was found between visual acuity loss and socio-economic status physical, neurological, or dental development, or the history or presence of illness. The age-specific prevalence rates were consistently higher in Nagasaki than in Hiroshima. The accumulated evidence suggests that myopia is attributable to a developmental flow in the sclera.« less

  5. Visual acuity of the honey bee retina and the limits for feature detection.

    PubMed

    Rigosi, Elisa; Wiederman, Steven D; O'Carroll, David C

    2017-04-06

    Visual abilities of the honey bee have been studied for more than 100 years, recently revealing unexpectedly sophisticated cognitive skills rivalling those of vertebrates. However, the physiological limits of the honey bee eye have been largely unaddressed and only studied in an unnatural, dark state. Using a bright display and intracellular recordings, we here systematically investigated the angular sensitivity across the light adapted eye of honey bee foragers. Angular sensitivity is a measure of photoreceptor receptive field size and thus small values indicate higher visual acuity. Our recordings reveal a fronto-ventral acute zone in which angular sensitivity falls below 1.9°, some 30% smaller than previously reported. By measuring receptor noise and responses to moving dark objects, we also obtained direct measures of the smallest features detectable by the retina. In the frontal eye, single photoreceptors respond to objects as small as 0.6° × 0.6°, with >99% reliability. This indicates that honey bee foragers possess significantly better resolution than previously reported or estimated behaviourally, and commonly assumed in modelling of bee acuity.

  6. Changes in brain morphology in albinism reflect reduced visual acuity.

    PubMed

    Bridge, Holly; von dem Hagen, Elisabeth A H; Davies, George; Chambers, Claire; Gouws, Andre; Hoffmann, Michael; Morland, Antony B

    2014-07-01

    Albinism, in humans and many animal species, has a major impact on the visual system, leading to reduced acuity, lack of binocular function and nystagmus. In addition to the lack of a foveal pit, there is a disruption to the routing of the nerve fibers crossing at the optic chiasm, resulting in excessive crossing of fibers to the contralateral hemisphere. However, very little is known about the effect of this misrouting on the structure of the post-chiasmatic visual pathway, and the occipital lobes in particular. Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation. Furthermore, mean cortical thickness across entire V1 was significantly greater in these subjects compared to controls and negatively correlated with visual acuity in albinism. Additionally, the group with albinism showed decreased gyrification in the left ventral occipital lobe. While the increase in cortical thickness in V1, also found in congenitally blind subjects, has been interpreted to reflect a lack of pruning, the decreased gyrification in the ventral extrastriate cortex may reflect the reduced input to the foveal regions of the ventral visual stream. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. [One-year longitudinal change in parameters of myopic school children trained by a new accommodative training device--uncorrected visual acuity, refraction, axial length, accommodation, and pupil reaction].

    PubMed

    Watanabe, Kumiko; Hara, Naoto; Kimijima, Masumi; Kotegawa, Yasue; Ohno, Koji; Arimoto, Ako; Mukuno, Kazuo; Hisahara, Satoru; Horie, Hidenori

    2012-10-01

    School children with myopia were trained using a visual stimulation device that generated an isolated blur stimulus on a visual target, with a constant retinal image size and constant brightness. Uncorrected visual acuity, cycloplegic refraction, axial length, dynamic accommodation and papillary reaction were measured to investigate the effectiveness of the training. There were 45 school children with myopia without any other ophthalmic diseases. The mean age of the children was 8.9 +/- 2.0 years (age range; 6-16)and the mean refraction was -1.56 +/- 0.58 D (mean +/- standard deviation). As a visual stimulus, a white ring on a black background with a constant ratio of visual target size to retinal image size, irrespective of the distance, was displayed on a liquid crystal display (LCD), and the LCD was quickly moved from a proximal to a distal position to produce an isolated blur stimulus. Training with this visual stimulus was carried out in the relaxation phase of accommodation. Uncorrected visual acuity, cycloplegic refraction, axial length, dynamic accommodation and pupillary reaction were investigated before training and every 3 months during the training. Of the 45 subjects, 42 (93%) could be trained for 3 consecutive months, 33 (73%) for 6 months, 23 (51%) for 9 months, and 21 (47%) for 12 months. The mean refraction decreased by 0.83 +/- 0.56 D (mean +/- standard deviation) and the mean axial length increased by 0.47 +/- 0.16 mm at 1 year, showing that the training bad some effect in improving the visual acuity. In the tests of the dynamic accommodative responses, the latency of the accommodative-phase decreased from 0.4 +/- 0.2 sec to 0.3 +/- 0.1 sec at 1 year, the gain of the accommodative-phase improved from 69.0 +/- 27.0% to 93.3 +/- 13.4%, the maximum speed of the accommodative-phase increased from 5.1 +/- 2.2 D/sec to 6.8 +/- 2.2 D/sec and the gain of the relaxation-phase significantly improved from 52.1 +/- 26.0% to 72.7 +/- 13.7% (corresponding t

  8. Longitudinal Changes in Visual Acuity and Health Related Quality of Life. The Los Angeles Latino Eye Study

    PubMed Central

    McKean-Cowdin, Roberta; Varma, Rohit; Hays, Ron D.; Wu, Joanne; Choudhury, Farzana; Azen, Stanley P.

    2010-01-01

    Purpose To examine the association between longitudinal changes in visual acuity (VA) and Health Related Quality of Life (HRQOL) in a population-based sample of adult Latinos. Design A population-based cohort study of eye disease in Latinos. Participants 3,169 adult Latino participants who live in the city of La Puente, California. Methods Data for these analyses were collected for the Los Angeles Latino Eye Study (LALES). Distance visual acuity (VA) was measured during a detailed ophthalmologic examination using the standard Early Treatment Diabetic Retinopathy Study protocol at baseline and a 4 year follow-up examination. HRQOL was assessed by the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and the Medical Outcomes Study 12-Item Short-Form Health Survey version 1 (SF-12 v.1). Main Outcome Measures Mean differences in HRQOL composite and subscale scores between baseline and follow-up were calculated for 3,169 participants with complete clinical examination and HRQOL data at both time points. Mean differences and effect sizes (ES) for NEI-VFQ and SF-12 v.1 scores were calculated for 3 categories of VA change over the 4 year follow-up period (VA improved ≥ 2 lines, no change in VA or −2visual acuity (2 line changes or greater) were

  9. Vision screening in children: Is 7-9 years of age a threshold for visual impairment?

    PubMed Central

    Ertekin, Yusuf Haydar; Tekin, Murat; Uludag, Aysegul; Arikan, Sedat; Sahin, Erkan Melih

    2016-01-01

    Objective: The present study aimed to assess the prevalence of decreased visual acuity, strabismus, and spectacle wear in children aged 5 to 13 years. Methods: A cross-sectional study was performed in primary education schools. A total of 1938 participants, including 940 females (48.5%) and 998 males (51.5%) with a mean age 8.96 ± 2.31 (5-13 years old), were screened. The comparisons were performed with gender, age, and age groups. The children attended to vision screening were assigned to three age groups as 5-6 years, 7-9 years, and 10-13 years. Results: The prevalence of the parameters was detected as decreased visual acuity 12.4%, strabismus 2.2%, and spectacle wear 6.9%. The prevalence of decreased visual acuity was significantly higher in girls and in children aged 7-9 years old (p = 0.013, p < 0.001). The prevalence of spectacle wear was significantly higher in girls and in children aged 7-9 years old (p = 0.019, p < 0.001). There was a visual acuity decrease in 33 of 106 (31.1%) children despite wearing own spectacle. There was no significant difference among three age groups for strabismus. Conclusion: Increased prevalence of decreased visual acuity, as well as the higher frequency of spectacle wear in children at ages of 7-9 years old may point out a threshold for visual impairment. PMID:27882020

  10. Photovoltaic restoration of sight with high visual acuity

    PubMed Central

    Lorach, Henri; Goetz, Georges; Smith, Richard; Lei, Xin; Mandel, Yossi; Kamins, Theodore; Mathieson, Keith; Huie, Philip; Harris, James; Sher, Alexander; Palanker, Daniel

    2015-01-01

    Patients with retinal degeneration lose sight due to gradual demise of photoreceptors. Electrical stimulation of the surviving retinal neurons provides an alternative route for delivery of visual information. We demonstrate that subretinal arrays with 70 μm photovoltaic pixels provide highly localized stimulation, with electrical and visual receptive fields of comparable sizes in rat retinal ganglion cells. Similarly to normal vision, retinal response to prosthetic stimulation exhibits flicker fusion at high frequencies, adaptation to static images and non-linear spatial summation. In rats with retinal degeneration, these photovoltaic arrays provide spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in pigmented rats. Ease of implantation of these wireless and modular arrays, combined with their high resolution opens the door to functional restoration of sight. PMID:25915832

  11. Visual acuity, refractive error, and endothelial cell density 6 and 12 months after deep lamellar endothelial keratoplasty.

    PubMed

    Fillmore, Parley D; Sutphin, John E; Goins, Kenneth M

    2010-06-01

    To report the visual acuity, refractive outcome, and endothelial cell density (ECD) up to 1 year after deep lamellar endothelial keratoplasty (DLEK) in a large prospective series. Eighty-six DLEK procedures were performed and evaluated in a prospective interventional case series. Subgroup analysis was performed to compare results from large-incision (9 mm) DLEK (n = 7), small-incision (5-8 mm) DLEK (n = 70), and penetrating keratoplasty (PKP) conversion (n = 9). Outcome measures included best-corrected visual acuity (BCVA), manifest refraction, corneal topographic astigmatism, and ECD. The percentage of eyes that achieved a BCVA of 20/40 or better after DLEK was 55% at 6 months, increasing to 61% at 1 year. Topographic astigmatism and spherical equivalent were not significantly different than preoperative measurements up to 1 year after DLEK (P > 0.05). An endothelial cell loss of 40% at 6 months and 48% by 1 year was observed. The mean ECD after DLEK was 1831 +/- 472 cells per square millimeter at 6 months and 1569 +/- 601 cells per square millimeter at 12 months. When evaluated by incision size, the ECD was better at 2066 +/- 558 cells per square millimeter with a 9-mm incision compared with only 1516 +/- 585 cells per square millimeter with a smaller incision at 1 year, although this did not reach significance (P = 0.075). The endothelial cell loss after penetrating keratoplasty conversion was similar to that in the large-incision group (P > 0.05). DLEK provides good visual acuity (> or =20/40) for the majority of patients at 1 year with stable refractive error compared with baseline. Refractive stability was observed with both large- and small-incision DLEKs; however, worrisome endothelial cell loss was observed, especially with a small-incision technique.

  12. Associations among visual acuity and vision- and health-related quality of life among patients in the multicenter uveitis steroid treatment trial.

    PubMed

    Frick, Kevin D; Drye, Lea T; Kempen, John H; Dunn, James P; Holland, Gary N; Latkany, Paul; Rao, Narsing A; Sen, H Nida; Sugar, Elizabeth A; Thorne, Jennifer E; Wang, Robert C; Holbrook, Janet T

    2012-03-01

    To evaluate the associations between visual acuity and self-reported visual function; visual acuity and health-related quality of life (QoL) metrics; a summary measure of self-reported visual function and health-related QoL; and individual domains of self-reported visual function and health-related QoL in patients with uveitis. Best-corrected visual acuity, vision-related functioning as assessed by the NEI VFQ-25, and health-related QoL as assessed by the SF-36 and EuroQoL EQ-5D questionnaires were obtained at enrollment in a clinical trial of uveitis treatments. Multivariate regression and Spearman correlations were used to evaluate associations between visual acuity, vision-related function, and health-related QoL. Among the 255 patients, median visual acuity in the better-seeing eyes was 20/25, the vision-related function score indicated impairment (median, 60), and health-related QoL scores were within the normal population range. Better visual acuity was predictive of higher visual function scores (P ≤ 0.001), a higher SF-36 physical component score, and a higher EQ-5D health utility score (P < 0.001). The vision-specific function score was predictive of all general health-related QoL (P < 0.001). The correlations between visual function score and general quality of life measures were moderate (ρ = 0.29-0.52). The vision-related function score correlated positively with visual acuity and moderately positively with general QoL measures. Cost-utility analyses relying on changes in generic healthy utility measures will be more likely to detect changes when there are clinically meaningful changes in vision-related function, rather than when there are only changes in visual acuity. (ClinicalTrials.gov number, NCT00132691.).

  13. Visual evoked potential measurement of contrast sensitivity in a case of retinal laser injury reveals visual function loss despite normal acuity

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Harrison, Joseph M.; Zwick, Harry; Longbotham, Harold G.; Ballentine, Charles S.; Pierce, Bennie

    1996-04-01

    Although visual function following retinal laser injuries has traditionally been assessed by measuring visual acuity, this measure only indicates the highest spatial frequency resolvable under high-contrast viewing conditions. Another visual psychophysical parameter is contrast sensitivity (CS), which measures the minimum contrast required for detection of targets over a range of spatial frequencies, and may evaluate visual mechanisms that do not directly subserve acuity. We used the visual evoked potential (VEP) to measure CS in a population of normal subjects and in patients with ophthalmic conditions affecting retinal function, including one patient with a laser injury in the macula. In this patient, the acuity had recovered from Visual stimuli consisted of counterphasing, sinusoidally-modulated luminance gratings presented at various spatial frequencies. VEPs were recorded with a gold cup electrode on the occipital scalp, and were demodulated in real time by a lock-in amplifier referenced to the stimulus counterphase frequency. As each grating was presented, its contrast was swept logarithmically from 0% to 50% over a 12-sec epoch. The CS was scored as the reciprocal of the lowest contrast within the sweep which elicited a response synchronized to the counterphase frequency. We found a CS deficit that appeared for a 3 degree(s) test field but not for larger test fields. These data indicated that contrast sensitivity measurements may reveal alterations in visual neural processing mechanisms not detected with standard clinical tests of acuity.

  14. Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Rosenberg, M.J.F; Peters, B.T.; Reschke, M. F.

    2016-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing the vestibular system and the central nervous system, responsible for coordinating head and eye movements, are adapted to microgravity and must re-adapt to the gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. Dynamic visual acuity (DVA) is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is lightweight and easily portable for quick deployment in the field. The base of the chair is spring-loaded and allows for manual oscillation of the subject. Using a metronome, the chair is vertically oscillated plus or minus 2 cm at 2 Hz by an operator, to simulate walking. While the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous response of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity thresholds were determined both for static (seated) and dynamic (oscillating) conditions. Dynamic visual acuity is defined as the difference between the dynamic and static conditions. Dynamic visual acuity measures will be taken prior to flight (typically L-180, L-90, and L-60) and up to eight times after landing, including up to 3 times on R plus 0. Follow up measurements will be taken at R plus 1 (approximately 36 hours after landing). Long-duration International Space Station crewmembers will be tested once at the refueling stop in Europe and once again upon return to Johnson Space Center. In addition to DVA, subjective ratings of motion sickness will be recorded

  15. Retrospective, controlled observational case study of patients with central retinal vein occlusion and initially low visual acuity treated with an intravitreal dexamethasone implant.

    PubMed

    Winterhalter, Sibylle; Vom Brocke, Gerrit Alexander; Pilger, Daniel; Eckert, Annabelle; Schlomberg, Juliane; Rübsam, Anne; Klamann, Matthias Karl; Gundlach, Enken; Dietrich-Ntoukas, Tina; Joussen, Antonia Maria

    2016-10-27

    Patients with initially low visual acuity were excluded from the therapy approval studies for retinal vein occlusion. But up to 28 % of patients presenting with central retinal vein occlusion have a baseline BCVA of less than 34 ETDRS letters (0.1). The purpose of our study was to assess visual acuity and central retinal thickness in patients suffering from central retinal vein occlusion and low visual acuity (<0.1) in comparison to patients with visual acuity (≥0.1) treated with Dexamethasone implant 0.7 mg for macular edema. Retrospective, controlled observational case study of 30 eyes with macular edema secondary to central retinal vein occlusion, which were treated with a dexamethasone implantation. Visual acuity, central retinal thickness and intraocular pressure were measured monthly. Analyses were performed separately for eyes with visual acuity <0.1 and ≥0.1. Two months post intervention, visual acuity improved only marginally from 0.05 to 0.07 (1 month; p = 0,065) and to 0.08 (2 months; p = 0,2) in patients with low visual acuity as compared to patients with visual acuity ≥0.1 with an improvement from 0.33 to 0.47 (1 month; p = 0,005) and to 0.49 (2 months; p = 0,003). The central retinal thickness, however, was reduced in both groups, falling from 694 to 344 μm (1 month; p = 0.003,) to 361 μm (2 months; p = 0,002) and to 415 μm (3 months; p = 0,004) in the low visual acuity group and from 634 to 315 μm (1 month; p < 0,001) and to 343 μm (2 months; p = 0,001) in the visual acuity group ≥0.1. Absence of visual acuity improvement was related to macular ischemia. In patients with central retinal vein occlusion and initially low visual acuity, a dexamethasone implantation can lead to an important reduction of central retinal thickness but may be of limited use to increase visual acuity.

  16. Impact of colour in the assessment of potential visual acuity in patients with age-related macular degeneration.

    PubMed

    Dorrepaal, Stephen J; Markowitz, Samuel N

    2013-06-01

    To compare chromatic and achromatic potential visual acuity (PVA) in patients with bilateral low vision caused by age-related macular degeneration (AMD). Prospective, nonrandomized, observational case series. Fifty-five patients, representing a consecutive series of patients all presenting with bilateral AMD. Best-corrected visual acuity of each eye was measured using an Early Treatment in Diabetic Retinopathy Study (ETDRS) chart with appropriate near correction. Included were cases with visual acuity of 0.4 logMAR (20/50) or worse in both eyes. Achromatic and chromatic PVA were measured in each eye using white on black and red on yellow flooding E charts at 50 cm in controlled lighting conditions. One hundred and seven eyes from 55 patients were included in the analysis. Mean achromatic and chromatic PVA were 0.69 ± 0.26 and 0.65 ± 0.22 logMAR, respectively. Overall, patients had a significantly higher chromatic than achromatic PVA, with a median difference of 0.1 logMAR (p<0.05). Patients with ETDRS visual acuity worse than 0.9 logMAR also had a significantly higher chromatic than achromatic PVA, with a median difference of 0.1 logMAR (p<0.05). Patients with ETDRS visual acuity between 0.4 and 0.9 logMAR had a trend toward a higher chromatic than achromatic visual acuity that was not significant, with a median difference of 0.1 logMAR (p = 0.8539). Patients with low vision caused by AMD can discern smaller targets when a red on yellow colour scheme is used than when using achromatic white on black charts. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  17. Vision-guided ocular growth in a mutant chicken model with diminished visual acuity

    PubMed Central

    Ritchey, Eric R.; Zelinka, Christopher; Tang, Junhua; Liu, Jun; Code, Kimberly A.; Petersen-Jones, Simon; Fischer, Andy J.

    2012-01-01

    Visual experience is known to guide ocular growth. We tested the hypothesis that vision-guided ocular growth is disrupted in a model system with diminished visual acuity. We examine whether ocular elongation is influenced by form-deprivation (FD) and lens-imposed defocus in the Retinopathy, Globe Enlarged (RGE) chicken. Young RGE chicks have poor visual acuity, without significant retinal pathology, resulting from a mutation in guanine nucleotide-binding protein β3 (GNB3), also known as transducin β3 or Gβ3. The mutation in GNB3 destabilizes the protein and causes a loss of Gβ3 from photoreceptors and ON-bipolar cells. (Ritchey et al. 2010)FD increased ocular elongation in RGE eyes in a manner similar to that seen in wild-type (WT) eyes. By comparison, the excessive ocular elongation that results from hyperopic defocus was increased, whereas myopic defocus failed to significantly decrease ocular elongation in RGE eyes. Brief daily periods of unrestricted vision interrupting FD prevented ocular elongation in RGE chicks in a manner similar to that seen in WT chicks. Glucagonergic amacrine cells differentially expressed the immediate early gene Egr1 in response to growth-guiding stimuli in RGE retinas, but the defocus-dependent up-regulation of Egr1 was lesser in RGE retinas compared to that of WT retinas. We conclude that high visual acuity, and the retinal signaling mediated by Gβ3, is not required for emmetropization and the excessive ocular elongation caused by FD and hyperopic defocus. However, the loss of acuity and Gβ3 from RGE retinas causes enhanced responses to hyperopic defocus and diminished responses to myopic defocus. PMID:22824538

  18. Relationship between binocular vision, visual acuity, and fine motor skills.

    PubMed

    O'Connor, Anna R; Birch, Eileen E; Anderson, Susan; Draper, Hayley

    2010-12-01

    The aims of this study were to analyze the relationship between the performance on fine motor skills tasks and peripheral and bifoveal sensory fusion, phasic and tonic motor fusion, the level of visual acuity (VA) in the poorer seeing eye, and the interocular VA difference. Subjects aged 12 to 28 years with a range of levels of binocular vision and VA performed three tasks: Purdue pegboard (number of pegs placed in 30 s), bead threading task (with two sizes of bead to increase the difficulty, time taken to thread a fixed number of beads), and a water pouring task (accuracy and time to pour a fixed quantity into five glass cylinders). Ophthalmic measures included peripheral (Worth 4 dot) and bifoveal (4 prism diopter) sensory fusion, phasic (prism bar) and tonic (Risley rotary prism) motor fusion ranges, and monocular VA. One hundred twenty-one subjects with a mean age of 18.8 years were tested; 18.2% had a manifest strabismus. Performance on fine motor skills tasks was significantly better in subjects with sensory and motor fusion compared with those without for most tasks, with significant differences between those with and without all measures of fusion on the pegboard and bead task. Both the acuity in the poorer seeing eye (highest r value of all motor tasks = 0.43) and the interocular acuity difference were statistically significantly related to performance on the motor skill tasks. Both sensory and motor fusion and good VA in both eyes are of benefit in the performance of fine motor skills tasks, with the presence of some binocular vision being beneficial compared with no fusion on certain sensorimotor tasks. This evidence supports the need to maximize fusion and VA outcomes.

  19. Visual training paired with electrical stimulation of the basal forebrain improves orientation-selective visual acuity in the rat.

    PubMed

    Kang, Jun Il; Groleau, Marianne; Dotigny, Florence; Giguère, Hugo; Vaucher, Elvire

    2014-07-01

    The cholinergic afferents from the basal forebrain to the primary visual cortex play a key role in visual attention and cortical plasticity. These afferent fibers modulate acute and long-term responses of visual neurons to specific stimuli. The present study evaluates whether this cholinergic modulation of visual neurons results in cortical activity and visual perception changes. Awake adult rats were exposed repeatedly for 2 weeks to an orientation-specific grating with or without coupling this visual stimulation to an electrical stimulation of the basal forebrain. The visual acuity, as measured using a visual water maze before and after the exposure to the orientation-specific grating, was increased in the group of trained rats with simultaneous basal forebrain/visual stimulation. The increase in visual acuity was not observed when visual training or basal forebrain stimulation was performed separately or when cholinergic fibers were selectively lesioned prior to the visual stimulation. The visual evoked potentials show a long-lasting increase in cortical reactivity of the primary visual cortex after coupled visual/cholinergic stimulation, as well as c-Fos immunoreactivity of both pyramidal and GABAergic interneuron. These findings demonstrate that when coupled with visual training, the cholinergic system improves visual performance for the trained orientation probably through enhancement of attentional processes and cortical plasticity in V1 related to the ratio of excitatory/inhibitory inputs. This study opens the possibility of establishing efficient rehabilitation strategies for facilitating visual capacity.

  20. Brief report: the relationship between visual acuity, the embedded figures test and systemizing in autism spectrum disorders.

    PubMed

    Brosnan, Mark J; Gwilliam, Lucy R; Walker, Ian

    2012-11-01

    Enhanced performance upon the Embedded Figures Test (EFT) in individuals with autism spectrum disorder (ASD) has informed psychological theories of the non-social aspects that characterise ASD. The Extreme Male Brain theory of autism proposes that enhanced visual acuity underpins greater attention to detail (assessed by the EFT) which is a prerequisite for Systemizing. To date, however, no study has empirically examined these relationships. 13 males with ASD and 13 male controls were assessed upon tasks argued to reflect these levels of processing. The ASD group were found to have significantly greater visual acuity, EFT performance and Systemizing ability than the control group. However, regression analysis revealed that the strongest relationship was between visual acuity and EFT performance.

  1. The prevalence and causes of visual impairment in seven-year-old children.

    PubMed

    Ghaderi, Soraya; Hashemi, Hassan; Jafarzadehpur, Ebrahim; Yekta, Abbasali; Ostadimoghaddam, Hadi; Mirzajani, Ali; Khabazkhoob, Mehdi

    2018-05-01

    To report the prevalence and causes of visual impairment in seven-year-old children in Iran and its relationship with socio-economic conditions. In a cross-sectional population-based study, first-grade students in the primary schools of eight cities in the country were randomly selected from different geographic locations using multistage cluster sampling. The examinations included visual acuity measurement, ocular motility evaluation, and cycloplegic and non-cycloplegic refraction. Using the definitions of the World Health Organization (presenting visual acuity less than or equal to 6/18 in the better eye) to estimate the prevalence of vision impairment, the present study reported presenting visual impairment in seven-year-old children. Of 4,614 selected students, 4,106 students participated in the study (response rate 89 per cent), of whom 2,127 (51.8 per cent) were male. The prevalence of visual impairment according to a visual acuity of 6/18 was 0.341 per cent (95 per cent confidence interval 0.187-0.571); 1.34 per cent (95 per cent confidence interval 1.011-1.74) of children had visual impairment according to a visual acuity of 6/18 in at least one eye. Sixty-six (1.6 per cent) and 23 (0.24 per cent) children had visual impairment according to a visual acuity of 6/12 in the worse and better eye, respectively. The most common causes of visual impairment were refractive errors (81.8 per cent) and amblyopia (14.5 per cent). Among different types of refractive errors, astigmatism was the main refractive error leading to visual impairment. According to the concentration index, the distribution of visual impairment in children from low-income families was higher. This study revealed a high prevalence of visual impairment in a representative sample of seven-year-old Iranian children. Astigmatism and amblyopia were the most common causes of visual impairment. The distribution of visual impairment was higher in children from low-income families. Cost

  2. The Advanced Glaucoma Intervention Study (AGIS): 12. Baseline risk factors for sustained loss of visual field and visual acuity in patients with advanced glaucoma.

    PubMed

    2002-10-01

    To examine the relationships between baseline risk factors and sustained decrease of visual field (SDVF) and sustained decrease of visual acuity (SDVA). Cohort study of participants in the Advanced Glaucoma Intervention Study (AGIS). This multicenter study enrolled patients between 1988 and 1992 and followed them until 2001; 789 eyes of 591 patients with advanced glaucoma were randomly assigned to one of two surgical sequences, argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy (ATT) or trabeculectomy-ALT-trabeculectomy (TAT). This report is based on data from 747 eyes. Eyes were offered the next intervention in the sequence upon failure of the previous intervention. Failure was based on recurrent intraocular pressure elevation, visual field defect, and disk rim criteria. Study visits occurred every 6 months; potential follow-up ranged from 8 to 13 years. For each intervention sequence, Cox multiple regression analyses were used to examine the baseline characteristics for association with two vision outcomes: SDVF and SDVA. The magnitude of the association is measured by the hazard ratio (HR), where HR for binary variables is the relative change in the hazard (or risk) of the outcome in eyes with the factor divided by the hazard in eyes without the factor, and HR for continuous variables is the relative change in the hazard (or risk) of the outcome in eyes with a unit increase in the factor. Characteristics associated with increased SDVF risk in the ATT sequence are: less baseline visual field defect (hazard ratio [HR] = 0.86, P <.001, 95% CI = 0.82-0.90), male gender (HR = 2.23, P <.001, 1.54-3.23), and worse baseline visual acuity (HR = 0.96, P =.001, 0.94-0.98); in the TAT sequence: less baseline visual field defect (HR = 0.93, P =.001, 0.89-0.97) and diabetes (HR = 1.87, P =.007, 1.18-2.97). Characteristics associated with increased SDVA risk in both treatment sequences are better baseline acuity (ATT: HR = 1.05, P <.001, 1.02-1.09; TAT: HR = 1

  3. Visual outcomes in treated bacterial keratitis: four years of prospective follow-up.

    PubMed

    McClintic, Scott M; Prajna, Namperumalsamy V; Srinivasan, Muthiah; Mascarenhas, Jeena; Lalitha, Prajna; Rajaraman, Revathi; Oldenburg, Catherine E; O'Brien, Kieran S; Ray, Kathryn J; Acharya, Nisha R; Lietman, Thomas M; Keenan, Jeremy D

    2014-05-02

    We described the change in visual acuity experienced by eyes successfully treated for bacterial keratitis. This was a prospective cohort study of a subset of study participants who had previously enrolled in the Steroids for Corneal Ulcers Trial (SCUT). All study participants had been diagnosed with culture-proven bacterial keratitis before enrollment in SCUT and subsequently were randomized to adjunctive topical corticosteroids or placebo. During SCUT, we monitored study participants at enrollment, 3 weeks, 3 months, and 12 months. We invited a subset to complete a comprehensive eye examination approximately 4 years after enrollment in SCUT. Certified refractionists assessed best spectacle-corrected visual acuity (BSCVA) using the same protocol at each study visit. We examined 50 SCUT participants at 4 years after enrollment. Among those in this cohort, mean logMAR BSCVA at enrollment was 0.85 (Snellen equivalent, 20/160; 95% confidence interval [CI], 0.71-0.99). On average, visual acuity improved by 2.9 logMAR lines from enrollment to 3 weeks (P < 0.001), 1.2 lines from 3 weeks to 3 months (P = 0.002), and 0.8 lines from 3 to 12 months (P = 0.01). The BSCVA did not change significantly between 12 months and 4 years (0.04-line improvement, P = 0.88). After controlling for visual acuity at enrollment, BSCVA was not significantly different between the corticosteroid and placebo groups at 4 years (P = 0.53). Cases of bacterial keratitis may continue to demonstrate improvements in visual acuity up to 12 months following diagnosis, but further improvements are unlikely. These findings may guide the appropriate timing of surgical intervention in these patients. (ClinicalTrials.gov number, NCT00324168.).

  4. Environmental Enrichment Promotes Plasticity and Visual Acuity Recovery in Adult Monocular Amblyopic Rats

    PubMed Central

    Bonaccorsi, Joyce; Cenni, Maria Cristina; Sale, Alessandro; Maffei, Lamberto

    2012-01-01

    Loss of visual acuity caused by abnormal visual experience during development (amblyopia) is an untreatable pathology in adults. In some occasions, amblyopic patients loose vision in their better eye owing to accidents or illnesses. While this condition is relevant both for its clinical importance and because it represents a case in which binocular interactions in the visual cortex are suppressed, it has scarcely been studied in animal models. We investigated whether exposure to environmental enrichment (EE) is effective in triggering recovery of vision in adult amblyopic rats rendered monocular by optic nerve dissection in their normal eye. By employing both electrophysiological and behavioral assessments, we found a full recovery of visual acuity in enriched rats compared to controls reared in standard conditions. Moreover, we report that EE modulates the expression of GAD67 and BDNF. The non invasive nature of EE renders this paradigm promising for amblyopia therapy in adult monocular people. PMID:22509358

  5. The cost-effectiveness of Welcome to Medicare visual acuity screening and a possible alternative welcome to medicare eye evaluation among persons without diagnosed diabetes mellitus.

    PubMed

    Rein, David B; Wittenborn, John S; Zhang, Xinzhi; Hoerger, Thomas J; Zhang, Ping; Klein, Barbara Eden Kobrin; Lee, Kris E; Klein, Ronald; Saaddine, Jinan B

    2012-05-01

    To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy. Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population. Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years(QALYs) by 0.008 (95% credible interval [CrI], 0.005-0.011) and increased costs by $94 (95% CrI, −$35 to$222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and$12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective. The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, anew policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective.

  6. Effects of Milk vs Dark Chocolate Consumption on Visual Acuity and Contrast Sensitivity Within 2 Hours: A Randomized Clinical Trial.

    PubMed

    Rabin, Jeff C; Karunathilake, Nirmani; Patrizi, Korey

    2018-04-26

    Consumption of dark chocolate can improve blood flow, mood, and cognition in the short term, but little is known about the possible effects of dark chocolate on visual performance. To compare the short-term effects of consumption of dark chocolate with those of milk chocolate on visual acuity and large- and small-letter contrast sensitivity. A randomized, single-masked crossover design was used to assess short-term visual performance after consumption of a dark or a milk chocolate bar. Thirty participants without pathologic eye disease each consumed dark and milk chocolate in separate sessions, and within-participant paired comparisons were used to assess outcomes. Testing was conducted at the Rosenberg School of Optometry from June 25 to August 15, 2017. Visual acuity (in logMAR units) and large- and small-letter contrast sensitivity (in the log of the inverse of the minimum detectable contrast [logCS units]) were measured 1.75 hours after consumption of dark and milk chocolate bars. Among the 30 participants (9 men and 21 women; mean [SD] age, 26 [5] years), small-letter contrast sensitivity was significantly higher after consumption of dark chocolate (mean [SE], 1.45 [0.04] logCS) vs milk chocolate (mean [SE], 1.30 [0.05] logCS; mean improvement, 0.15 logCS [95% CI, 0.08-0.22 logCS]; P < .001). Large-letter contrast sensitivity was slightly higher after consumption of dark chocolate (mean [SE], 2.05 [0.02] logCS) vs milk chocolate (mean [SE], 2.00 [0.02] logCS; mean improvement, 0.05 logCS [95% CI, 0.00-0.10 logCS]; P = .07). Visual acuity improved slightly after consumption of dark chocolate (mean [SE], -0.22 [0.01] logMAR; visual acuity, approximately 20/12) and milk chocolate (mean [SE], -0.18 [0.01] logMAR; visual acuity, approximately 20/15; mean improvement, 0.04 logMAR [95% CI, 0.02-0.06 logMAR]; P = .05). Composite scores combining results from all tests showed significant improvement after consumption of dark compared with milk chocolate

  7. Assessment of visual disability using visual evoked potentials.

    PubMed

    Jeon, Jihoon; Oh, Seiyul; Kyung, Sungeun

    2012-08-06

    The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for registration from March 2007 to October 2009. The study included 20 normal subjects (20 right eyes: 10 females, 10 males, ages 9-42 years), 18 unilateral amblyopic patients (18 amblyopic eyes, ages 19-36 years), 19 optic neuritis patients (19 eyes: ages 9-71 years), and 10 patients with visual disability having visual pathway lesions. Amplitude and latencies were analyzed and correlations with visual acuity (logMAR) were derived from 20 normal and 18 amblyopic subjects. Correlation of VEP amplitude and visual acuity (logMAR) of 19 optic neuritis patients confirmed relationships between visual acuity and amplitude. We calculated the objective visual acuity (logMAR) of 16 eyes from 10 patients to diagnose the presence or absence of visual disability using relations derived from 20 normal and 18 amblyopic eyes. Linear regression analyses between amplitude of pattern visual evoked potentials and visual acuity (logMAR) of 38 eyes from normal (right eyes) and amblyopic (amblyopic eyes) subjects were significant [y = -0.072x + 1.22, x: VEP amplitude, y: visual acuity (logMAR)]. There were no significant differences between visual acuity prediction values, which substituted amplitude values of 19 eyes with optic neuritis into function. We calculated the objective visual acuity of 16 eyes of 10 patients to diagnose the presence or absence of visual disability using relations of y = -0.072x + 1.22 (-0.072). This resulted in a prediction reference of visual acuity associated with malingering vs. real

  8. Assessment of visual disability using visual evoked potentials

    PubMed Central

    2012-01-01

    Background The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions. Methods A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for registration from March 2007 to October 2009. The study included 20 normal subjects (20 right eyes: 10 females, 10 males, ages 9–42 years), 18 unilateral amblyopic patients (18 amblyopic eyes, ages 19–36 years), 19 optic neuritis patients (19 eyes: ages 9–71 years), and 10 patients with visual disability having visual pathway lesions. Amplitude and latencies were analyzed and correlations with visual acuity (logMAR) were derived from 20 normal and 18 amblyopic subjects. Correlation of VEP amplitude and visual acuity (logMAR) of 19 optic neuritis patients confirmed relationships between visual acuity and amplitude. We calculated the objective visual acuity (logMAR) of 16 eyes from 10 patients to diagnose the presence or absence of visual disability using relations derived from 20 normal and 18 amblyopic eyes. Results Linear regression analyses between amplitude of pattern visual evoked potentials and visual acuity (logMAR) of 38 eyes from normal (right eyes) and amblyopic (amblyopic eyes) subjects were significant [y = −0.072x + 1.22, x: VEP amplitude, y: visual acuity (logMAR)]. There were no significant differences between visual acuity prediction values, which substituted amplitude values of 19 eyes with optic neuritis into function. We calculated the objective visual acuity of 16 eyes of 10 patients to diagnose the presence or absence of visual disability using relations of y = −0.072x + 1.22 (−0.072). This resulted in a prediction reference of visual

  9. Normal Visual Acuity and Electrophysiological Contrast Gain in Adults with High-Functioning Autism Spectrum Disorder.

    PubMed

    Tebartz van Elst, Ludger; Bach, Michael; Blessing, Julia; Riedel, Andreas; Bubl, Emanuel

    2015-01-01

    A common neurodevelopmental disorder, autism spectrum disorder (ASD), is defined by specific patterns in social perception, social competence, communication, highly circumscribed interests, and a strong subjective need for behavioral routines. Furthermore, distinctive features of visual perception, such as markedly reduced eye contact and a tendency to focus more on small, visual items than on holistic perception, have long been recognized as typical ASD characteristics. Recent debate in the scientific community discusses whether the physiology of low-level visual perception might explain such higher visual abnormalities. While reports of this enhanced, "eagle-like" visual acuity contained methodological errors and could not be substantiated, several authors have reported alterations in even earlier stages of visual processing, such as contrast perception and motion perception at the occipital cortex level. Therefore, in this project, we have investigated the electrophysiology of very early visual processing by analyzing the pattern electroretinogram-based contrast gain, the background noise amplitude, and the psychophysical visual acuities of participants with high-functioning ASD and controls with equal education. Based on earlier findings, we hypothesized that alterations in early vision would be present in ASD participants. This study included 33 individuals with ASD (11 female) and 33 control individuals (12 female). The groups were matched in terms of age, gender, and education level. We found no evidence of altered electrophysiological retinal contrast processing or psychophysical measured visual acuities. There appears to be no evidence for abnormalities in retinal visual processing in ASD patients, at least with respect to contrast detection.

  10. Visual Outcomes in Treated Bacterial Keratitis: Four Years of Prospective Follow-up

    PubMed Central

    McClintic, Scott M.; Prajna, Namperumalsamy V.; Srinivasan, Muthiah; Mascarenhas, Jeena; Lalitha, Prajna; Rajaraman, Revathi; Oldenburg, Catherine E.; O'Brien, Kieran S.; Ray, Kathryn J.; Acharya, Nisha R.; Lietman, Thomas M.; Keenan, Jeremy D.

    2014-01-01

    Purpose. We described the change in visual acuity experienced by eyes successfully treated for bacterial keratitis. Methods. This was a prospective cohort study of a subset of study participants who had previously enrolled in the Steroids for Corneal Ulcers Trial (SCUT). All study participants had been diagnosed with culture-proven bacterial keratitis before enrollment in SCUT and subsequently were randomized to adjunctive topical corticosteroids or placebo. During SCUT, we monitored study participants at enrollment, 3 weeks, 3 months, and 12 months. We invited a subset to complete a comprehensive eye examination approximately 4 years after enrollment in SCUT. Certified refractionists assessed best spectacle-corrected visual acuity (BSCVA) using the same protocol at each study visit. Results. We examined 50 SCUT participants at 4 years after enrollment. Among those in this cohort, mean logMAR BSCVA at enrollment was 0.85 (Snellen equivalent, 20/160; 95% confidence interval [CI], 0.71–0.99). On average, visual acuity improved by 2.9 logMAR lines from enrollment to 3 weeks (P < 0.001), 1.2 lines from 3 weeks to 3 months (P = 0.002), and 0.8 lines from 3 to 12 months (P = 0.01). The BSCVA did not change significantly between 12 months and 4 years (0.04-line improvement, P = 0.88). After controlling for visual acuity at enrollment, BSCVA was not significantly different between the corticosteroid and placebo groups at 4 years (P = 0.53). Conclusions. Cases of bacterial keratitis may continue to demonstrate improvements in visual acuity up to 12 months following diagnosis, but further improvements are unlikely. These findings may guide the appropriate timing of surgical intervention in these patients. (ClinicalTrials.gov number, NCT00324168.) PMID:24618327

  11. Astronauts Cooper and Conrad prepare cameras during visual acuity tests

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronauts L. Gordon Cooper Jr. (left), command pilot, and Charles Conrad Jr., pilot, the prime crew of the Gemini 5 space flight, prepare their cameras while aboard a C-130 aircraft flying near Laredo. The two astronauts are taking part in a series of visual acuity experiments to aid them in learning to identify known terrestrial features under controlled conditions.

  12. The Cost-effectiveness of Welcome to Medicare Visual Acuity Screening and a Possible Alternative Welcome to Medicare Eye Evaluation Among Persons Without Diagnosed Diabetes Mellitus

    PubMed Central

    Rein, David B.; Wittenborn, John S.; Zhang, Xinzhi; Hoerger, Thomas J.; Zhang, Ping; Klein, Barbara Eden Kobrin; Lee, Kris E.; Klein, Ronald; Saaddine, Jinan B.

    2013-01-01

    Objective To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy. Design Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population. Results Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years (QALYs) by 0.008 (95% credible interval [CrI], 0.005–0.011) and increased costs by $94 (95% CrI, −$35 to $222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and $12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective. Conclusions The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, a new policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective. PMID:22232367

  13. Decreased visual acuity resulting from glistening and sub-surface nano-glistening formation in intraocular lenses: A retrospective analysis of 5 cases

    PubMed Central

    Matsushima, Hiroyuki; Nagata, Mayumi; Katsuki, Yoko; Ota, Ichiro; Miyake, Kensaku; Beiko, George H.H.; Grzybowski, Andrzej

    2015-01-01

    Background To report on five patients with decreased visual acuity due to glistening and severe sub-surface nano-glistening (SSNG) formation within their intraocular lenses (IOLs). Design Case reports and analysis of extracted IOLs. Participants and samples We report improved visual acuity when IOLs with severe glistening and SSNG were exchanged for clear IOLs in five patients. Methods Case reports. Main outcome measures The main outcome measure was visual acuity. The secondary outcome measure was light transmission. Explanted IOLs were subjected to investigation. Pre- and postoperative slit lamp images of the anterior eye and microscopic images of the extracted IOLs were taken and compared. Light transmission of the IOL was measured using a double beam type spectrophotometer. An integrated value of the percentage light transmittance in the visible light spectrum was calculated. Results We report on five patients whose visual acuity improved when IOLs were exchanged because of severe glistening and SSNG. All of the affected IOLs were MA60BM (Alcon, Forth Wroth Texas, USA) and the original implantation had occurred over a range of 6–15 years prior to the IOL exchange. Light transmission was decreased in all affected lenses compared to a similar control IOL. Conclusions Although only a few reports of cases in which glistening and SSNG have progressed to the level of decreased visual function have been published, the likelihood is that this phenomena will increase as the severity and incidence of these inclusions have been shown to increase with time. Appropriate evaluations of visual function in such patients are needed and consideration should be given to IOL exchange in symptomatic patients. PMID:26586975

  14. Effect of Myopic Defocus on Visual Acuity after Phakic Intraocular Lens Implantation and Wavefront-guided Laser in Situ Keratomileusis

    PubMed Central

    Kamiya, Kazutaka; Shimizu, Kimiya; Igarashi, Akihito; Kawamorita, Takushi

    2015-01-01

    This study aimed to investigate the effect of myopic defocus on visual acuity after phakic intraocular lens (IOL) implantation and wavefront-guided laser in situ keratomileusis (wfg-LASIK). Our prospective study comprised thirty eyes undergoing posterior chamber phakic IOL implantation and 30 eyes undergoing wfg-LASIK. We randomly measured visual acuity under myopic defocus after cycloplegic and non-cycloplegic correction. We also calculated the modulation transfer function by optical simulation and estimated visual acuity from Campbell & Green’s retinal threshold curve. Visual acuity in the phakic IOL group was significantly better than that in the wfg-LASIK group at myopic defocus levels of 0, –1, and –2 D (p < 0.001, p < 0.001, and p = 0.02, Mann-Whitney U-test), but not at a defocus of –3 D (p = 0.30). Similar results were also obtained in a cycloplegic condition. Decimal visual acuity values at a myopic defocus of 0, −1, −2, and -3 D by optical simulation were estimated to be 1.95, 1.21, 0.97, and 0.75 in the phakic IOL group, and 1.39, 1.11, 0.94, and 0.71 in the wfg-LASIK group, respectively. From clinical and optical viewpoints, phakic IOL implantation was superior to wfg-LASIK in terms of the postoperative visual performance, even in the presence of low to moderate myopic regression. PMID:25994984

  15. Gains following perceptual learning are closely linked to the initial visual acuity.

    PubMed

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M; Polat, Uri

    2016-04-28

    The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, -0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA.

  16. Distance and near visual acuity improvement after implantation of multifocal intraocular lenses in cataract patients with presbyopia: a systematic review.

    PubMed

    Agresta, Blaise; Knorz, Michael C; Kohnen, Thomas; Donatti, Christina; Jackson, Daniel

    2012-06-01

    To evaluate uncorrected distance visual acuity (UDVA) as well as uncorrected near visual acuity (UNVA) as outcomes in treating presbyopic cataract patients to assist clinicians and ophthalmologists in their decision-making process regarding available interventions. Medline, Embase, and Evidence Based Medicine Reviews were systematically reviewed to identify studies reporting changes in UDVA and UNVA after cataract surgery in presbyopic patients. Strict inclusion/exclusion criteria were used to exclude any studies not reporting uncorrected visual acuity in a presbyopic population with cataracts implanted with multifocal intraocular lenses (IOLs). Relevant outcomes (UDVA and UNVA) were identified from the studies retrieved through the systematic review process. Twenty-nine studies were identified that reported uncorrected visual acuities, including one study that reported uncorrected intermediate visual acuity. Nine brands of multifocal IOLs were identified in the search. All studies identified in the literature search reported improvements in UDVA and UNVA following multifocal IOL implantation. The largest improvements in visual acuity were reported using the Rayner M-Flex lens (Rayner Intraocular Lenses Ltd) (UDVA, binocular: 1.05 logMAR, monocular: 0.92 logMAR; UNVA, binocular and monocular: 0.83 logMAR) and the smallest improvements were reported using the Acri.LISA lens (Carl Zeiss Meditec) (UDVA, 0.21 decimal; UNVA, 0.51 decimal). The results of this systematic review show the aggregate of studies reporting a beneficial increase in UDVA and UNVA with the use of multifocal IOLs in cataract patients with presbyopia, hence providing evidence to support the hypothesis that multifocal IOLs increase UDVA and UNVA in cataract patients. Copyright 2012, SLACK Incorporated.

  17. Effects of early maternal docosahexaenoic acid intake on neuropsychological status and visual acuity at five years of age of breast-fed term infants.

    PubMed

    Jensen, Craig L; Voigt, Robert G; Llorente, Antolin M; Peters, Sarika U; Prager, Thomas C; Zou, Yali L; Rozelle, Judith C; Turcich, Marie R; Fraley, J Kennard; Anderson, Robert E; Heird, William C

    2010-12-01

    We previously reported better psychomotor development at 30 months of age in infants whose mothers received a docosahexaenoic acid (DHA) (22:6n-3) supplement for the first 4 months of lactation. We now assess neuropsychological and visual function of the same children at 5 years of age. Breastfeeding women were assigned to receive identical capsules containing either a high-DHA algal oil (∼200 mg/d of DHA) or a vegetable oil (containing no DHA) from delivery until 4 months postpartum. Primary outcome variables at 5 years of age were measures of gross and fine motor function, perceptual/visual-motor function, attention, executive function, verbal skills, and visual function of the recipient children at 5 years of age. There were no differences in visual function as assessed by the Bailey-Lovie acuity chart, transient visual evoked potential or sweep visual evoked potential testing between children whose mothers received DHA versus placebo. Children whose mothers received DHA versus placebo performed significantly better on the Sustained Attention Subscale of the Leiter International Performance Scale (46.5 ± 8.9 vs 41.9 ± 9.3, P < .008) but there were no statistically significant differences between groups on other neuropsychological domains. Five-year-old children whose mothers received modest DHA supplementation versus placebo for the first 4 months of breastfeeding performed better on a test of sustained attention. This, along with the previously reported better performance of the children of DHA-supplemented mothers on a test of psychomotor development at 30 months of age, suggests that DHA intake during early infancy confers long-term benefits on specific aspects of neurodevelopment. Copyright © 2010 Mosby, Inc. All rights reserved.

  18. The association of indicators of fetal growth with visual acuity and hearing among conscripts.

    PubMed

    Olsen, J; Sørensen, H T; Steffensen, F H; Sabroe, S; Gillman, M W; Fischer, P; Rothman, K J

    2001-03-01

    Impaired fetal growth is associated with increased susceptibility to several chronic diseases. We studied the association between birth weight, indicators of disproportional fetal growth, and impaired visual acuity and hearing in 4,300 conscripts from a well-defined region in Denmark from August 1, 1993, to July 31, 1994. From the standard health examination for conscripts, we obtained data on sight based on the Snellen's chart and data on hearing acuity based on audiometry. By means of record linkage, we obtained data on outcomes for the conscripts at birth from the Medical Birth Registry. From this registry, we have data on birth weight, gestational age, and birth length that were recorded from existing computerized registers based on the records of midwives. A birth weight of less than 3,000 gm and a body mass index at birth of less than 3.4 were associated with reduced visual acuity and impaired hearing. The results could be due to fetal brain programming or due to confounding, by early birth trauma or other factors.

  19. Desktop publishing and validation of custom near visual acuity charts.

    PubMed

    Marran, Lynn; Liu, Lei; Lau, George

    2008-11-01

    Customized visual acuity (VA) assessment is an important part of basic and clinical vision research. Desktop computer based distance VA measurements have been utilized, and shown to be accurate and reliable, but computer based near VA measurements have not been attempted, mainly due to the limited spatial resolution of computer monitors. In this paper, we demonstrate how to use desktop publishing to create printed custom near VA charts. We created a set of six near VA charts in a logarithmic progression, 20/20 through 20/63, with multiple lines of the same acuity level, different letter arrangements in each line and a random noise background. This design allowed repeated measures of subjective accommodative amplitude without the potential artifact of familiarity of the optotypes. The background maintained a constant and spatial frequency rich peripheral stimulus for accommodation across the six different acuity levels. The paper describes in detail how pixel-wise accurate black and white bitmaps of Sloan optotypes were used to create the printed custom VA charts. At all acuity levels, the physical sizes of the printed custom optotypes deviated no more than 0.034 log units from that of the standard, satisfying the 0.05 log unit ISO criterion we used to demonstrate physical equivalence. Also, at all acuity levels, log unit differences in the mean target distance for which reliable recognition of letters first occurred for the printed custom optotypes compared to the standard were found to be below 0.05, satisfying the 0.05 log unit ISO criterion we used to demonstrate functional equivalence. It is possible to use desktop publishing to create custom near VA charts that are physically and functionally equivalent to standard VA charts produced by a commercial printing process.

  20. CORRELATION OF CLINICAL AND STRUCTURAL PROGRESSION WITH VISUAL ACUITY LOSS IN MACULAR TELANGIECTASIA TYPE 2: MacTel Project Report No. 6-The MacTel Research Group.

    PubMed

    Peto, Tunde; Heeren, Tjebo F C; Clemons, Traci E; Sallo, Ferenc B; Leung, Irene; Chew, Emily Y; Bird, Alan C

    2018-01-01

    To evaluate progression of macular telangiectasia Type 2 lesions and their correlation with visual acuity. An international multicenter prospective study with annual examinations including best-corrected visual acuity (BCVA), fundus photography, fluorescein angiography, and optical coherence tomography images graded centrally. Mixed models were used to estimate progression rates, and a generalized linear model to compute the relative risk of BCVA loss, loss of ellipsoid zone (EZ) reflectivity, development of pigment plaques, or neovascularization. One thousand and fourteen eyes of 507 participants were followed for 4.2 ± 1.6 years. Best-corrected visual acuity decreased 1.07 ± 0.05 letters (mean ± SE) per year. Of all eyes, 15% lost ≥15 letters after 5 years. Of the eyes without EZ loss, 76% developed a noncentral loss. Of the eyes with noncentral loss, 45% progressed to central EZ loss. The rate of BCVA loss in eyes with noncentral EZ loss at baseline was similar to eyes without EZ loss. The rate of BCVA loss was significantly higher in eyes with central EZ loss at baseline (-1.40 ± 0.14 letters, P < 0.001). Ellipsoid zone loss is frequently found in macular telangiectasia Type 2 and is an important structural component reflecting visual function. Its presence in the fovea significantly correlates with worse visual prognosis.

  1. Key drivers of visual acuity gains in neovascular age-related macular degeneration in real life: findings from the AURA study.

    PubMed

    Holz, Frank G; Tadayoni, Ramin; Beatty, Stephen; Berger, Alan; Cereda, Matteo Giuseppe; Hykin, Philip; Staurenghi, Giovanni; Wittrup-Jensen, Kim; Altemark, Andreas; Nilsson, Jonas; Kim, Kun; Sivaprasad, Sobha

    2016-12-01

    To identify predictive markers for the outcomes of anti-vascular endothelial growth factor therapy for neovascular age-related macular degeneration (nAMD). AURA was a retrospective, observational, multicentre study that monitored the 2-year outcomes following intravitreal ranibizumab treatment in patients with nAMD. Using stepwise regression analysis, we evaluated the association between visual acuity outcomes, baseline characteristics and resource utilisation in order to determine which variables are significantly linked to outcomes in AURA. We also examined the relationship between visual acuity outcomes and number of injections received. Analyses were performed using data from year 1 (n=1695) and year 2 completers (n=1184). Logistic analysis showed that baseline visual acuity score, age at start of therapy, number of ophthalmoscopies and optical coherence tomography (OCT) (combined) and number of injections (ranibizumab) were significant (p<0.05) prognostic factors for vision maintenance (loss <15 letters) or vision gain (≥15 letters). Patients who received >7 injections (in 1 year) or >14 injections (over 2 years) gained more letters and demonstrated greater vision maintenance (loss of <15 letters) than patients who received fewer injections. There was a significant (p<0.05) association between number of injections and national reimbursement schemes and OCT. A number of factors that are predictive of treatment outcomes in a real-life setting were identified. Notably, the decline of treatment benefits may be linked to number of injections and a failure to visit clinicians and receive OCT as required. These findings may be helpful in guiding ophthalmologist treatment decisions under limited time and financial constraints. NCT01447043. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Switching from pro re nata to treat-and-extend regimen improves visual acuity in patients with neovascular age-related macular degeneration.

    PubMed

    Kvannli, Line; Krohn, Jørgen

    2017-11-01

    To evaluate the visual outcome after transitioning from a pro re nata (PRN) intravitreal injection regimen to a treat-and-extend (TAE) regimen for patients with neovascular age-related macular degeneration (AMD). A retrospective review of patients who were switched from a PRN regimen with intravitreal injections of bevacizumab, ranibizumab or aflibercept to a TAE regimen. The best corrected visual acuity (BCVA), central retinal thickness (CRT) and type of medication used at baseline, at the time of changing treatment regimen and at the end of the study were analysed. Twenty-one eyes of 21 patients met the inclusion criteria. Prior to the switch, the patients received a mean of 13.8 injections (median, 10; range, 3-39 injections) with the PRN regimen for 44 months (range, 3-100 months), which improved the visual acuity in five patients (24%). After a mean of 6.1 injections (median, 5; range, 3-14 injections) with the TAE regimen over 8 months (range, 2-16 months), the visual acuity improved in 12 patients (57%). The improvement in visual acuity during treatment with the TAE regimen was statistically significant (p = 0.005). The proportion of patients with a visual acuity of 0.2 or better was significantly higher after treatment with the TAE regimen than after treatment with the PRN regimen (p = 0.048). No significant differences in CRT were found between the two treatment regimens. Even after prolonged treatment and a high number of intravitreal injections, switching AMD patients from a PRN regimen to a strict TAE regimen significantly improves visual acuity. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  3. Macular Structures, Optical Components, and Visual Acuity in Preschool Children after Intravitreal Bevacizumab or Laser Treatment.

    PubMed

    Lee, Yung-Sung; See, Lai-Chu; Chang, Shu-Hao; Wang, Nan-Kai; Hwang, Yih-Shiou; Lai, Chi-Chun; Chen, Kuan-Jen; Wu, Wei-Chi

    2018-05-10

    To investigate the macular structures, optical components, and visual acuity in preschool-aged children with a history of type I retinopathy of prematurity who underwent either intravitreal bevacizumab (IVB), laser, or a combination of treatments. Comparative interventional case series. A referred medical center in Taiwan. 80 eyes from 42 patients (33 IVB-treated eyes from 17 children, 24 laser-treated eyes from 13 children, and 23 laser + IVB-treated eyes from 12 children). Spectral-domain optical coherence tomography. The retinal thickness in the foveal area and the associated morphologic changes in foveal depression. Compared with the laser-treated and laser + IVB-treated eyes, the IVB-treated eyes had less myopia and deeper anterior chamber depths but presented similar axial lengths and corneal curvatures (P = .001, .002, .95 and .16, respectively). The IVB-treated eyes had significantly thinner foveal, parafoveal, and perifoveal retinal thicknesses (P < .01 for all) and a higher incidence of foveal depression than the laser- or laser + IVB-treated eyes. The macular and subfoveal choroidal thicknesses did not differ among the groups (P = .21 and .63, respectively). Moreover, compared with the eyes treated with laser or laser + IVB, the IVB-treated eyes had better uncorrected visual acuity, although a significant difference was not observed in best-corrected visual acuity (P = .008 and .29, respectively). Compared with laser therapy, IVB-treated eyes were associated with deeper anterior chamber depths and thinner foveal, parafoveal and perifoveal thicknesses. Moreover, these IVB-treated eyes had less refractive errors and better uncorrected visual acuity. Copyright © 2018. Published by Elsevier Inc.

  4. The Prevalence of Visual Acuity Impairment among School Children at Arada Subcity Primary Schools in Addis Ababa, Ethiopia.

    PubMed

    Darge, Haile Fentahun; Shibru, Getahun; Mulugeta, Abiy; Dagnachew, Yinebeb Mezgebu

    2017-01-01

    Visual impairment and blindness are major public health problems in developing countries where there is no enough health-care service. To determine the prevalence of visual impairment among school children. A school-based cross-sectional study was conducted between 15 June 2015 and 30 November 2015 at Arada subcity primary schools, Addis Ababa, Ethiopia. Two schools were selected randomly, and 378 students were screened from grades 1 to 8 using systematic random sampling method. Snellen chart was used for visual acuity test. Students who had visual acuity of ≤6/12 were further examined by an ophthalmologist to diagnose the reason for low vision. Data was analyzed using SPSS version 20. A total of 378 students were screened, and 192 (50.8%) were females and the remaining 186 (49.2%) were males. The prevalence of visual impairment (VA) of ≤6/12 on either eye was 5.8%, VA < 6/18 on either eye was 1.1%, and VA < 6/18 on the better eye was 0.53%. In this study, color blindness [OR: 19.65, 95% CI (6.01-64.33)] was significantly associated with visual acuity impairment. The prevalence of visual impairment among school children in the study area was 5.8% and school screening is recommended.

  5. Comparison of visual acuity of the patients on the first day after sub-Bowman keratomileusis or laser in situ keratomileusis

    PubMed Central

    Zhao, Wei; Wu, Ting; Dong, Ze-Hong; Feng, Jie; Ren, Yu-Feng; Wang, Yu-Sheng

    2016-01-01

    AIM To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis (SBK) or laser in situ keratomileusis (LASIK). METHODS Data from 5923 eyes in 2968 patients that received LASIK (2755 eyes) or SBK (3168 eyes) were retrospectively analyzed. The eyes were divided into 4 groups according to preoperative spherical equivalent: between -12.00 to -9.00 D, extremely high myopia (n=396, including 192 and 204 in SBK and LASIK groups, respectively); -9.00 to -6.00 D, high myopia (n=1822, including 991 and 831 in SBK and LASIK groups, respectively), -6.00 to -3.00 D, moderate myopia (n=3071, including 1658 and 1413 in SBK and LASIK groups, respectively), and -3.00 to 0.00 D, low myopia (n=634, including 327 and 307 in SBK and LASIK groups, respectively). Uncorrected logMAR visual acuity values of patients were assessed under standard natural light. Analysis of variance was used for comparisons among different groups. RESULTS Uncorrected visual acuity values were 0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK, respectively (P<0.01); visual acuity values of 0.1854±0.1842, 0.0615±0.1326, -0.0033±0.0978, and -0.0164±0.0972 were obtained for patients in the extremely high, high, moderate, and low myopia groups, respectively (P<0.01). In addition, significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup. CONCLUSION Compared with LASIK, SBK is safer and more effective, with faster recovery. Therefore, SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation. PMID:27158619

  6. Comparison of visual acuity of the patients on the first day after sub-Bowman keratomileusis or laser in situ keratomileusis.

    PubMed

    Zhao, Wei; Wu, Ting; Dong, Ze-Hong; Feng, Jie; Ren, Yu-Feng; Wang, Yu-Sheng

    2016-01-01

    To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis (SBK) or laser in situ keratomileusis (LASIK). Data from 5923 eyes in 2968 patients that received LASIK (2755 eyes) or SBK (3168 eyes) were retrospectively analyzed. The eyes were divided into 4 groups according to preoperative spherical equivalent: between -12.00 to -9.00 D, extremely high myopia (n=396, including 192 and 204 in SBK and LASIK groups, respectively); -9.00 to -6.00 D, high myopia (n=1822, including 991 and 831 in SBK and LASIK groups, respectively), -6.00 to -3.00 D, moderate myopia (n=3071, including 1658 and 1413 in SBK and LASIK groups, respectively), and -3.00 to 0.00 D, low myopia (n=634, including 327 and 307 in SBK and LASIK groups, respectively). Uncorrected logMAR visual acuity values of patients were assessed under standard natural light. Analysis of variance was used for comparisons among different groups. Uncorrected visual acuity values were 0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK, respectively (P<0.01); visual acuity values of 0.1854±0.1842, 0.0615±0.1326, -0.0033±0.0978, and -0.0164±0.0972 were obtained for patients in the extremely high, high, moderate, and low myopia groups, respectively (P<0.01). In addition, significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup. Compared with LASIK, SBK is safer and more effective, with faster recovery. Therefore, SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation.

  7. Assessment of Grating Acuity in Infants and Toddlers Using an Electronic Acuity Card: The Dobson Card.

    PubMed

    Mohan, Kathleen M; Miller, Joseph M; Harvey, Erin M; Gerhart, Kimberly D; Apple, Howard P; Apple, Deborah; Smith, Jordana M; Davis, Amy L; Leonard-Green, Tina; Campus, Irene; Dennis, Leslie K

    2016-01-01

    To determine if testing binocular visual acuity in infants and toddlers using the Acuity Card Procedure (ACP) with electronic grating stimuli yields clinically useful data. Participants were infants and toddlers ages 5 to 36.7 months referred by pediatricians due to failed automated vision screening. The ACP was used to test binocular grating acuity. Stimuli were presented on the Dobson Card. The Dobson Card consists of a handheld matte-black plexiglass frame with two flush-mounted tablet computers and is similar in size and form to commercially available printed grating acuity testing stimuli (Teller Acuity Cards II [TACII]; Stereo Optical, Inc., Chicago, IL). On each trial, one tablet displayed a square-wave grating and the other displayed a luminance-matched uniform gray patch. Stimuli were roughly equivalent to the stimuli available in the printed TACII stimuli. After acuity testing, each child received a cycloplegic eye examination. Based on cycloplegic retinoscopy, patients were categorized as having high or low refractive error per American Association for Pediatric Ophthalmology and Strabismus vision screening referral criteria. Mean acuities for high and low refractive error groups were compared using analysis of covariance, controlling for age. Mean visual acuity was significantly poorer in children with high refractive error than in those with low refractive error (P = .015). Electronic stimuli presented using the ACP can yield clinically useful measurements of grating acuity in infants and toddlers. Further research is needed to determine the optimal conditions and procedures for obtaining accurate and clinically useful automated measurements of visual acuity in infants and toddlers. Copyright 2016, SLACK Incorporated.

  8. A logistics evaluation of visual acuity as applied to the Bailey-Lovie chart.

    PubMed

    Pierscionek, B K; Weale, R A

    1999-11-01

    To discover whether as a result of the increasing use of the Bailey-Lovie chart some classes of patients may not be affected by the crowding of the smaller test characters, whose spacing is proportional to their size; and to determine acuities with a logistic function so that all of a patient's responses may be utilized. 112 patients were tested both with the original chart and one in which the horizontal distance is kept constant, i.e., the letters are arranged in vertical columns. All of a patient's responses were recorded so that the constants of the logistic function might be determined. No difference was found for very high and very low acuity scores, but, for intermediate ones, the vertical columns yielded acuity ratings increased by some 13%. The use of the logistics function was successful in that the correlation between stimulus and response was between 0.9 and 1 for some 80% of those examined. A constant horizontal spacing may be of advantage to some patients with a conventionally measured visual acuity of approximately 0.9.

  9. Estimates of underwater and aerial visual acuity in the European beaver Castor fiber L. based on morphological data.

    PubMed

    Mass, A M; Supin, A Ya

    2017-03-01

    The eye optics and topographic distribution of ganglion cells were studied using whole mount preparations from European beaver Castor fiber L. The beaver eye optics provides emmetropia in air and hypermetropia in water. The optometrical measurements predict retinal resolution of the beaver eye around 17' in air and 9' in water. In air, retinal resolution corresponds to the real visual acuity, whereas in water, visual acuity is below the retinal resolution because of the non-precise focusing.

  10. Intermediate visual acuity of presbyopic individuals with and without distance and bifocal lens corrections.

    DOT National Transportation Integrated Search

    1977-03-01

    Visual acuity was determined at the intermediate range for older individuals with various combinations of ocular refractive error (nine subcategories) and accommodative power (three subcategories). Subjects (N=249) read numerals ranging in size to me...

  11. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study.

    PubMed

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = -2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = -1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders.

  12. A New Visual Stimulation Program for Improving Visual Acuity in Children with Visual Impairment: A Pilot Study

    PubMed Central

    Tsai, Li-Ting; Hsu, Jung-Lung; Wu, Chien-Te; Chen, Chia-Ching; Su, Yu-Chin

    2016-01-01

    The purpose of this study was to investigate the effectiveness of visual rehabilitation of a computer-based visual stimulation (VS) program combining checkerboard pattern reversal (passive stimulation) with oddball stimuli (attentional modulation) for improving the visual acuity (VA) of visually impaired (VI) children and children with amblyopia and additional developmental problems. Six children (three females, three males; mean age = 3.9 ± 2.3 years) with impaired VA caused by deficits along the anterior and/or posterior visual pathways were recruited. Participants received eight rounds of VS training (two rounds per week) of at least eight sessions per round. Each session consisted of stimulation with 200 or 300 pattern reversals. Assessments of VA (assessed with the Lea symbol VA test or Teller VA cards), visual evoked potential (VEP), and functional vision (assessed with the Chinese-version Functional Vision Questionnaire, FVQ) were carried out before and after the VS program. Significant gains in VA were found after the VS training [VA = 1.05 logMAR ± 0.80 to 0.61 logMAR ± 0.53, Z = –2.20, asymptotic significance (2-tailed) = 0.028]. No significant changes were observed in the FVQ assessment [92.8 ± 12.6 to 100.8 ±SD = 15.4, Z = –1.46, asymptotic significance (2-tailed) = 0.144]. VEP measurement showed improvement in P100 latency and amplitude or integration of the waveform in two participants. Our results indicate that a computer-based VS program with passive checkerboard stimulation, oddball stimulus design, and interesting auditory feedback could be considered as a potential intervention option to improve the VA of a wide age range of VI children and children with impaired VA combined with other neurological disorders. PMID:27148014

  13. Comparison of contact lens and intraocular lens correction of monocular aphakia during infancy: a randomized clinical trial of HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years.

    PubMed

    Lambert, Scott R; Lynn, Michael J; Hartmann, E Eugenie; DuBois, Lindreth; Drews-Botsch, Carolyn; Freedman, Sharon F; Plager, David A; Buckley, Edward G; Wilson, M Edward

    2014-06-01

    The efficacy and safety of primary intraocular lens (IOL) implantation during early infancy is unknown. To compare the visual outcomes of patients optically corrected with contact lenses vs IOLs following unilateral cataract surgery during early infancy. The Infant Aphakia Treatment Study is a randomized clinical trial with 5 years of follow-up that involved 114 infants with unilateral congenital cataracts at 12 sites. A traveling examiner assessed visual acuity at age 4.5 years. Cataract surgery with or without primary IOL implantation. Contact lenses were used to correct aphakia in patients who did not receive IOLs. Treatment was determined through random assignment. HOTV optotype visual acuity at 4.5 years of age. The median logMAR visual acuity was not significantly different between the treated eyes in the 2 treatment groups (both, 0.90 [20/159]; P = .54). About 50% of treated eyes in both groups had visual acuity less than or equal to 20/200. Significantly more patients in the IOL group had at least 1 adverse event after cataract surgery (contact lens, 56%; IOL, 81%; P = .02). The most common adverse events in the IOL group were lens reproliferation into the visual axis, pupillary membranes, and corectopia. Glaucoma/glaucoma suspect occurred in 35% of treated eyes in the contact lens group vs 28% of eyes in the IOL group (P = .55). Since the initial cataract surgery, significantly more patients in the IOL group have had at least 1 additional intraocular surgery (contact lens, 21%; IOL, 72%; P < .001). There was no significant difference between the median visual acuity of operated eyes in children who underwent primary IOL implantation and those left aphakic. However, there were significantly more adverse events and additional intraoperative procedures in the IOL group. When operating on an infant younger than 7 months of age with a unilateral cataract, we recommend leaving the eye aphakic and focusing the eye with a contact lens. Primary IOL

  14. Visual Acuity Improvement in Continuous vs Divided Occlusion in Anisometropic Amblyopia

    PubMed Central

    Irfani, Irawati; Feriyanto, Feri; Oktarima, Primawita; Kartasasmita, Arief

    2018-01-01

    Purpose: To compare visual acuity improvement between continuous and split part-time occlusion for the treatment of moderate and severe anisometropic amblyopia. Methods: Randomised clinical trials in 6 – 13 y.o children with moderate and severe anisometropic amblyopia. Each patient was consecutively selected with continuous or split part-time occlusion. Best corrected visual acuity’s improvement was followed up to six weeks and statistical data were analyzed using chi square and unpaired t-test. Results: Best corrected visual acuity’s improvement was comparable between continuous and split part-time occlusion (0.20±0.27 vs 0.21±0.25; p = 0.79). Conclusion: Split part-time occlusion may be considered as an alternative treatment for moderate and severe anisometropic amblyopia treatment. PMID:29515681

  15. Visual acuity with simulated and real astigmatic defocus.

    PubMed

    Ohlendorf, Arne; Tabernero, Juan; Schaeffel, Frank

    2011-05-01

    To compare the effects of "simulated" and "real" spherical and astigmatic defocus on visual acuity (VA). VA was determined with letter charts that were blurred by calculated spherical or astigmatic defocus (simulated defocus) or were seen through spherical or astigmatic trial lenses (real defocus). Defocus was simulated using ZEMAX and the Liou-Brennan eye model. Nine subjects participated [mean age, 27.2 ± 1.8 years; logarithm of the minimum angle of resolution (logMAR), -0.1]. Three different experiments were conducted in which VA was reduced by 20% (logMAR 0.0), 50% (logMAR 0.2), or 75% (logMAR 0.5) by either (1) imposing positive spherical defocus, (2) imposing positive and negative astigmatic defocus in three axes (0, 45, and 90°), and (3) imposing cross-cylinder defocus in the same three axes as in (2). Experiment (1): there were only minor differences in VA with simulated and real positive spherical defocus. Experiment (2): simulated astigmatic defocus reduced VA twice as much as real astigmatic defocus in all tested axes (p < 0.01 in all cases). Experiment (3): simulated cross-cylinder defocus reduced VA much more than real cross-cylinder defocus (p < 0.01 in all cases), similarly for all three tested axes. The visual system appears more tolerant against "real" spherical, astigmatic, and cross-cylinder defocus than against "simulated" blur. Possible reasons could be (1) limitations in the modeling procedures to simulate defocus, (2) higher ocular aberrations, and (3) fluctuations of accommodation. However, the two optical explanations (2) and (3) cannot account for the magnitude of the effect, and (1) was carefully analyzed. It is proposed that something may be special about the visual processing of real astigmatic and cross-cylinder defocus-because they have less effect on VA than simulations predict.

  16. Changes in Near Visual Acuity of Over Time in the Astronaut Corps

    NASA Technical Reports Server (NTRS)

    Taiym, Wafa; Wear, Mary L.; Locke, James; Mason, Sara; VanBaalen, Mary

    2014-01-01

    We hypothesized that visual impairment due to intracranial pressure (VIIP) would increase the rate of which presbyopia would occur in the astronaut population, with long durations flyers at an especially high risk. Presbyopia is characterized as the gradual loss of near visual acuity overtime due to a loss in ability to accommodate. It generally develops in the mid-40s and progresses until about age 65. This analysis considered annual vision exams conducted on active NASA astronauts with spaceflight experience currently between the ages of 40 to 60 years of age. Onset of presbyopia was characterized as a shift of at least 20 units on the standard Snellen test from one annual exam to the next. There were 236 short duration and 48 long duration flyers, the majority of whom did experience onset of presbyopia between age 40 and 60. This shift however, did not necessarily come after spaceflight. In comparing the short and long duration flyers the mean age of onset was 47 years old (SD+/-3.7). The mean of onset within the general population is 45 to 47 years old [1, 2]. The mean age of the onset of presbyopia as compared to the general population indicates that space flight does not induce early development of presbyopia.

  17. Possible role for fundus autofluorescence as a predictive factor for visual acuity recovery after epiretinal membrane surgery.

    PubMed

    Brito, Pedro N; Gomes, Nuno L; Vieira, Marco P; Faria, Pedro A; Fernandes, Augusto V; Rocha-Sousa, Amândio; Falcão-Reis, Fernando

    2014-02-01

    To study the potential association between fundus autofluorescence, spectral-domain optical coherence tomography, and visual acuity in patients undergoing surgery because of epiretinal membranes. Prospective, interventional case series including 26 patients submitted to vitrectomy because of symptomatic epiretinal membranes. Preoperative evaluation consisted of a complete ophthalmologic examination, autofluorescence, and spectral-domain optical coherence tomography. Studied variables included foveal autofluorescence (fov.AF), photoreceptor inner segment/outer segment (IS/OS) junction line integrity, external limiting membrane integrity, central foveal thickness, and foveal morphology. All examinations were repeated at the first, third, and sixth postoperative months. The main outcome measures were logarithm of minimal angle resolution visual acuity, fov.AF integrity, and IS/OS integrity. All cases showing a continuous IS/OS line had an intact fov.AF, whereas patients with IS/OS disruption could have either an increased area of foveal hypoautofluorescence or an intact fov.AF, with the latter being associated with IS/OS integrity recovery in follow-up spectral-domain optical coherence tomography imaging. The only preoperative variables presenting a significant correlation with final visual acuity were baseline visual acuity (P = 0.047) and fov.AF grade (P = 0.023). Recovery of IS/OS line integrity after surgery, in patients with preoperative IS/OS disruption and normal fov.AF, can be explained by the presence of a functional retinal pigment epithelium-photoreceptor complex, supporting normal photoreceptor activity. Autofluorescence imaging provides a functional component to the study of epiretinal membranes, complementing the structural information obtained with optical coherence tomography.

  18. Age-Specific Prevalence of Visual Impairment and Refractive Error in Children Aged 3-10 Years in Shanghai, China.

    PubMed

    Ma, Yingyan; Qu, Xiaomei; Zhu, Xiaofeng; Xu, Xun; Zhu, Jianfeng; Sankaridurg, Padmaja; Lin, Senlin; Lu, Lina; Zhao, Rong; Wang, Ling; Shi, Huijing; Tan, Hui; You, Xiaofang; Yuan, Hong; Sun, Sifei; Wang, Mingjin; He, Xiangui; Zou, Haidong; Congdon, Nathan

    2016-11-01

    We assessed changes in age-specific prevalence of refractive error at the time of starting school, by comparing preschool and school age cohorts in Shanghai, China. A cross-sectional study was done in Jiading District, Shanghai during November and December 2013. We randomly selected 7 kindergartens and 7 primary schools, with probability proportionate to size. Chinese children (n = 8398) aged 3 to 10 years were enumerated, and 8267 (98.4%) were included. Children underwent distance visual acuity assessment and refraction measurement by cycloplegic autorefraction and subjective refraction. The prevalence of uncorrected visual acuity (UCVA), presenting visual acuity, and best-corrected visual acuity in the better eye of ≤20/40 was 19.8%, 15.5%, and 1.7%, respectively. Among those with UCVA ≤ 20/40, 93.2% could achieve visual acuity of ≥20/32 with refraction. Only 28.7% (n = 465) of children with UCVA in the better eye of ≤20/40 wore glasses. Prevalence of myopia (spherical equivalent ≤-0.5 diopters [D] in at least one eye) increased from 1.78% in 3-year-olds to 52.2% in 10-year-olds, while prevalence of hyperopia (spherical equivalent ≥+2.0 D) decreased from 17.8% among 3-year-olds to 2.6% by 10 years of age. After adjusting for age, attending elite "high-level" school was statistically associated with greater myopia prevalence. The prevalence of myopia was lower or comparable to that reported in other populations from age 3 to 5 years, but increased dramatically after 6 years, consistent with a strong environmental role of schooling on myopia development.

  19. Increases in the prevalence of reduced visual acuity and myopia in Chinese children in Guangzhou over the past 20 years.

    PubMed

    Xiang, F; He, M; Zeng, Y; Mai, J; Rose, K A; Morgan, I G

    2013-12-01

    To estimate the prevalence of myopia based on reduced unaided visual acuity (VA) in Chinese school children over the past 20 years. Guangzhou school health authorities have measured VA on Grade 1-12 students from 1988 to 2007 annually, using a LogMAR tumbling E chart. VA is reported as Snellen categories: normal (VA ≥ 6/6), mildly reduced (6/9 < VA <6/6), moderately reduced (6/18 < VA ≤ 6/9), and severely reduced VA (VA ≤ 6/18). In 1988, over 80% of children in Grade 1 (age 6 years) and about 30% in Grade 12 (age 17 years) had normal unaided VA. By 2007, this dropped to only 60% in Grade 1 and about 10% in Grade 12. Conversely, the prevalence of moderately and severely reduced unaided VA increased from 6.2% in Grade 1 and 62.5% in Grade 12 in 1988 to 14.5% in Grade 1 and 84.11% in Grade 12 in 2007. This rate was unchanged from 2003 to 2007 at both the Grade 1 and Grade 12 levels. In Guangzhou, the prevalence of reduced unaided VA has increased markedly in the past 20 years, but has stabilized in the past few years. This increase may result from environmental changes, such as increased schooling intensity and urbanization.

  20. Tactile Acuity Charts: A Reliable Measure of Spatial Acuity

    PubMed Central

    Bruns, Patrick; Camargo, Carlos J.; Campanella, Humberto; Esteve, Jaume; Dinse, Hubert R.; Röder, Brigitte

    2014-01-01

    For assessing tactile spatial resolution it has recently been recommended to use tactile acuity charts which follow the design principles of the Snellen letter charts for visual acuity and involve active touch. However, it is currently unknown whether acuity thresholds obtained with this newly developed psychophysical procedure are in accordance with established measures of tactile acuity that involve passive contact with fixed duration and control of contact force. Here we directly compared tactile acuity thresholds obtained with the acuity charts to traditional two-point and grating orientation thresholds in a group of young healthy adults. For this purpose, two types of charts, using either Braille-like dot patterns or embossed Landolt rings with different orientations, were adapted from previous studies. Measurements with the two types of charts were equivalent, but generally more reliable with the dot pattern chart. A comparison with the two-point and grating orientation task data showed that the test-retest reliability of the acuity chart measurements after one week was superior to that of the passive methods. Individual thresholds obtained with the acuity charts agreed reasonably with the grating orientation threshold, but less so with the two-point threshold that yielded relatively distinct acuity estimates compared to the other methods. This potentially considerable amount of mismatch between different measures of tactile acuity suggests that tactile spatial resolution is a complex entity that should ideally be measured with different methods in parallel. The simple test procedure and high reliability of the acuity charts makes them a promising complement and alternative to the traditional two-point and grating orientation thresholds. PMID:24504346

  1. Use of optical coherence tomography to evaluate visual acuity and visual field changes in dengue fever.

    PubMed

    Rhee, Taek Kwan; Han, Jung Il

    2014-02-01

    Dengue fever is a viral disease that is transmitted by mosquitoes and affects humans. In rare cases, dengue fever can cause visual impairment, which usually occurs within 1 month after contracting dengue fever and ranges from mild blurring of vision to severe blindness. Visual impairment due to dengue fever can be detected through angiography, retinography, optical coherence tomography (OCT) imaging, electroretinography, event electroencephalography (visually evoked potentials), and visual field analysis. The purpose of this study is to report changes in the eye captured using fluorescein angiography, indocyanine green, and OCT in 3 cases of dengue fever visual impairment associated with consistent visual symptoms and similar retinochoroidopathic changes. The OCT results of the three patients with dengue fever showed thinning of the outer retinal layer and disruption of the inner segment/outer segment (IS/OS) junction. While thinning of the retina outer layer is an irreversible process, disruption of IS/OS junction is reported to be reversible. Follow-up examination of individuals with dengue fever and associated visual impairment should involve the use of OCT to evaluate visual acuity and visual field changes in patients with acute choroidal ischemia.

  2. The Effect of Gaze Angle on Visual Acuity in Infantile Nystagmus.

    PubMed

    Dunn, Matt J; Wiggins, Debbie; Woodhouse, J Margaret; Margrain, Tom H; Harris, Christopher M; Erichsen, Jonathan T

    2017-01-01

    Most individuals with infantile nystagmus (IN) have an idiosyncratic gaze angle at which their nystagmus intensity is minimized. Some adopt an abnormal head posture to use this "null zone," and it has therefore long been assumed that this provides people with nystagmus with improved visual acuity (VA). However, recent studies suggest that improving the nystagmus waveform could have little, if any, influence on VA; that is, VA is fundamentally limited in IN. Here, we examined the impact of the null zone on VA. Visual acuity was measured in eight adults with IN using a psychophysical staircase procedure with reversals at three horizontal gaze angles, including the null zone. As expected, changes in gaze angle affected nystagmus amplitude, frequency, foveation duration, and variability of intercycle foveation position. Across participants, each parameter (except frequency) was significantly correlated with VA. Within any given individual, there was a small but significant improvement in VA (0.08 logMAR) at the null zone as compared with the other gaze angles tested. Despite this, no change in any of the nystagmus waveform parameters was significantly associated with changes in VA within individuals. A strong relationship between VA and nystagmus characteristics exists between individuals with IN. Although significant, the improvement in VA observed within individuals at the null zone is much smaller than might be expected from the occasionally large variations in intensity and foveation dynamics (and anecdotal patient reports of improved vision), suggesting that improvement of other aspects of visual performance may also encourage use of the null zone.

  3. Efficacy of intravitreal bevacizumab for macular edema following branch retinal vein occlusion stratified by baseline visual acuity.

    PubMed

    Kim, Mirae; Jeong, Seongyong; Sagong, Min

    2017-04-01

    To compare the clinical features and bevacizumab efficacy for macular edema (ME) following branch retinal vein occlusion (BRVO) stratified by baseline visual acuity. This retrospective study included a total 117 eyes from 117 consecutive patients with ME following BRVO, who received PRN intravitreal bevacizumab injection and were followed for more than 6 months. The eyes were categorized into three groups according to baseline best-corrected visual acuity (BCVA) (group A, BCVA <20/200; group B, BCVA ≥20/200 and ≤20/40; group C, BCVA >20/40). Baseline demographics, clinical features, BCVA, and central retinal thickness (CRT) at 1, 3, 6, and 12 months after injection and the number of injections were compared. Groups A-C included 11, 83, and 23 eyes, respectively. The mean baseline CRT was thickest in group A (810.1, 580.8, and 473.5 μm in groups A-C, respectively; p < 0.001) and the percentage of eyes with macular ischemia increased in the worst BCVA group (45.5, 25.0, and 4.3 % in groups A-C, respectively; p = 0.005). The mean BCVA and CRT improved at 1, 3, 6, and 12 months after treatment compared to baseline values in all groups (all, p < 0.001). The number of injections for 6 months was greater in the worst BCVA group (3.2, 2.3, and 1.9 injections in groups A-C, respectively; p = 0.009). In ME following BRVO, baseline visual acuity correlates with macular ischemia and baseline CRT. Intravitreal bevacizumab treatment results in significant anatomical and functional improvement regardless of baseline visual acuity.

  4. Factors Predicting Visual Acuity Outcome in Intermediate, Posterior, and Panuveitis: The Multicenter Uveitis Steroid Treatment (MUST) Trial.

    PubMed

    Kempen, John H; Van Natta, Mark L; Altaweel, Michael M; Dunn, James P; Jabs, Douglas A; Lightman, Susan L; Thorne, Jennifer E; Holbrook, Janet T

    2015-12-01

    To identify factors associated with best-corrected visual acuity (BCVA) presentation and 2-year outcome in 479 intermediate, posterior, and panuveitic eyes. Cohort study using randomized controlled trial data. Multicenter Uveitis Steroid Treatment (MUST) Trial masked BCVA measurements at baseline and at 2 years follow-up used gold-standard methods. Twenty-three clinical centers documented characteristics per protocol, which were evaluated as potential predictive factors for baseline BCVA and 2-year change in BCVA. Baseline factors significantly associated with reduced BCVA included age ≥50 vs <50 years; posterior vs intermediate uveitis; uveitis duration >10 vs <6 years; anterior chamber (AC) flare >grade 0; cataract; macular thickening; and exudative retinal detachment. Over 2 years, eyes better than 20/50 and 20/50 or worse at baseline improved, on average, by 1 letter (P = .52) and 10 letters (P < .001), respectively. Both treatment groups and all sites of uveitis improved similarly. Factors associated with improved BCVA included resolution of active AC cells, resolution of macular thickening, and cataract surgery in an initially cataractous eye. Factors associated with worsening BCVA included longer duration of uveitis (6-10 or >10 vs <6 years), incident AC flare, cataract at both baseline and follow-up, pseudophakia at baseline, persistence or incidence of vitreous haze, and incidence of macular thickening. Intermediate, posterior, and panuveitis have a similarly favorable prognosis with both systemic and fluocinolone acetonide implant treatment. Eyes with more prolonged/severe inflammatory damage and/or inflammatory findings initially or during follow-up have a worse visual acuity prognosis. The results indicate the value of implementing best practices in managing inflammation. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Rosenberg, M. J. F.; Kreutzberg, G. A.; Peters, B. T.; Reschke, M. F.

    2017-01-01

    Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing, the vestibular system and the central nervous system, responsible for coordinating head and eye movements via the vestibulo-occular reflex (VOR), are adapted to microgravity and must re-adapt to the Earth's gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. These effects are caused by retinal slip, or the inability to keep an image focused on their retina, which is thought to drive motion sickness symptoms experienced upon landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Peters et al. (2011) find that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. Previously, the use of stroboscopic goggles has shown to be effective in minimizing motion sickness symptoms due to retinal slip (Reschke et al. 2007). In this study, we simulated the decrement in DVA caused by sensorimotor re-adaptation by using minifying lenses and then testing the efficacy of stroboscopic goggles in preventing retinal slip and improving DVA. Dynamic visual acuity is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is motor-driven and oscillates vertically at 2 Hz with a vertical displacement of +/- 2 cm to simulate the vertical translations that occur while walking. As the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous responses of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity

  6. Resolution acuity versus recognition acuity with Landolt-style optotypes.

    PubMed

    Heinrich, Sven P; Bach, Michael

    2013-09-01

    International standards define acuity as the reciprocal of the threshold gap size of a Landolt C optotype. However, the literature is inconsistent as to what type of acuity is measured with Landolt Cs. The present study addresses this question more directly than previous studies by quantifying the effect of an inherent luminance artifact in Landolt-style optotypes. Two groups of modified optotypes were used. In the first group, each optotype had a single gap structure with the same average luminance. Between optotypes, the gap structures differed in their degree of fineness. In the second group of optotypes, a standard gap was always present, defining the orientation of the optotype. Additional gap structures of the same average luminance, but different fineness, were inserted at the remaining potential gap locations, thereby balancing luminance across potential gap locations. Visual acuity measures were obtained for each optotype variant, using a computer-based test employing a staircase procedure. Similar acuity values were obtained for all optotypes of the first group, and for standard Landolt Cs, irrespective of the fineness of the gap structure. With luminance-balanced optotypes of the second group, measured acuity was halved, compared to standard optotypes. The results support the view that it is recognition acuity, rather than resolution acuity, which is measured with standard Landolt-style optotypes, with the imbalanced luminance distribution serving as a cue. Luminance-balanced optotypes may help to obtain a more veridical estimate of resolution acuity, although recognition acuity may be more relevant in daily living.

  7. Visual acuity measured with luminance-modulated and contrast-modulated noise letter stimuli in young adults and adults above 50 years old

    PubMed Central

    Woi, Pui Juan; Kaur, Sharanjeet; Waugh, Sarah J.; Hairol, Mohd Izzuddin

    2016-01-01

    The human visual system is sensitive in detecting objects that have different luminance level from their background, known as first-order or luminance-modulated (LM) stimuli. We are also able to detect objects that have the same mean luminance as their background, only differing in contrast (or other attributes). Such objects are known as second-order or contrast-modulated (CM), stimuli. CM stimuli are thought to be processed in higher visual areas compared to LM stimuli, and may be more susceptible to ageing. We compared visual acuities (VA) of five healthy older adults (54.0±1.83 years old) and five healthy younger adults (25.4±1.29 years old) with LM and CM letters under monocular and binocular viewing. For monocular viewing, age had no effect on VA [F(1, 8)= 2.50, p> 0.05]. However, there was a significant main effect of age on VA under binocular viewing [F(1, 8)= 5.67, p< 0.05].  Binocular VA with CM letters in younger adults was approximately two lines better than that in older adults. For LM, binocular summation ratios were similar for older (1.16±0.21) and younger (1.15±0.06) adults. For CM, younger adults had higher binocular summation ratio (1.39±0.08) compared to older adults (1.12±0.09). Binocular viewing improved VA with LM letters for both groups similarly. However, in older adults, binocular viewing did not improve VA with CM letters as much as in younger adults. This could reflect a decline of higher visual areas due to ageing process, most likely higher than V1, which may be missed if measured with luminance-based stimuli alone. PMID:28184281

  8. Use of the Dynamic Visual Acuity Test as a screener for community-dwelling older adults who fall.

    PubMed

    Honaker, Julie A; Shepard, Neil T

    2011-01-01

    Adequate function of the peripheral vestibular system, specifically the vestibulo-ocular reflex (VOR; a network of neural connections between the peripheral vestibular system and the extraocular muscles) is essential for maintaining stable vision during head movements. Decreased visual acuity resulting from an impaired peripheral vestibular system may impede balance and postural control and place an individual at risk of falling. Therefore, sensitive measures of the vestibular system are warranted to screen for the tendency to fall, alerting clinicians to recommend further risk of falling assessment and referral to a falling risk reduction program. Dynamic Visual Acuity (DVA) testing is a computerized VOR assessment method to evaluate the peripheral vestibular system during head movements; reduced visual acuity as documented with DVA testing may be sensitive to screen for falling risk. This study examined the sensitivity and specificity of the computerized DVA test with yaw plane head movements for identifying community-dwelling adults (58-78 years) who are prone to falling. A total of 16 older adults with a history of two or more unexplained falls in the previous twelve months and 16 age and gender matched controls without a history of falls in the previous twelve months participated. Computerized DVA with horizontal head movements at a fixed velocity of 120 deg/sec was measured and compared with the Dynamic Gait Index (DGI) a gold standard gait assessment measurement for identifying falling risk. Receiver operating characteristics (ROC) curve analysis and area under the ROC curve (AUC) were used to assess the sensitivity and specificity of the computerized DVA as a screening measure for falling risk as determined by the DGI. Results suggested a link between computerized DVA and the propensity to fall; DVA in the yaw plane was found to be a sensitive (92%) and accurate screening measure when using a cutoff logMAR value of >0.25.

  9. Near-field visual acuity of pigeons: effects of head location and stimulus luminance.

    PubMed

    Hodos, W; Leibowitz, R W; Bonbright, J C

    1976-03-01

    Two pigeons were trained to discriminate a grating stimulus from a blank stimulus of equivalent luminance in a three-key chamber. The stimuli and blanks were presented behind a transparent center key. The procedure was a conditional discrimination in which pecks on the left key were reinforced if the blank had been present behind the center key and pecks on the right key were reinforced if the grating had been present behind the center key. The spatial frequency of the stimuli was varied in each session from four to 29.5 lines per millimeter in accordance with a variation of the method of constant stimuli. The number of lines per millimeter that the subjects could discriminate at threshold was determined from psychometric functions. Data were collected at five values of stimulus luminance ranging from--0.07 to 3.29 log cd/m2. The distance from the stimulus to the anterior nodal point of the eye, which was determined from measurements taken from high-speed motion-picture photographs of three additional pigeons and published intraocular measurements, was 62.0 mm. This distance and the grating detection thresholds were used to calculate the visual acuity of the birds at each level of luminance. Acuity improved with increasing luminance to a peak value of 0.52, which corresponds to a visual angle of 1.92 min, at a luminance of 2.33 log cd/m2. Further increase in luminance produced a small decline in acuity.

  10. How well do you see what you hear? The acuity of visual-to-auditory sensory substitution

    PubMed Central

    Haigh, Alastair; Brown, David J.; Meijer, Peter; Proulx, Michael J.

    2013-01-01

    Sensory substitution devices (SSDs) aim to compensate for the loss of a sensory modality, typically vision, by converting information from the lost modality into stimuli in a remaining modality. “The vOICe” is a visual-to-auditory SSD which encodes images taken by a camera worn by the user into “soundscapes” such that experienced users can extract information about their surroundings. Here we investigated how much detail was resolvable during the early induction stages by testing the acuity of blindfolded sighted, naïve vOICe users. Initial performance was well above chance. Participants who took the test twice as a form of minimal training showed a marked improvement on the second test. Acuity was slightly but not significantly impaired when participants wore a camera and judged letter orientations “live”. A positive correlation was found between participants' musical training and their acuity. The relationship between auditory expertise via musical training and the lack of a relationship with visual imagery, suggests that early use of a SSD draws primarily on the mechanisms of the sensory modality being used rather than the one being substituted. If vision is lost, audition represents the sensory channel of highest bandwidth of those remaining. The level of acuity found here, and the fact it was achieved with very little experience in sensory substitution by naïve users is promising. PMID:23785345

  11. [The key parameters of design research and analysis of the Chinese reading visual acuity chart].

    PubMed

    Wang, Chen-xiao; Liu, Zhi-hui; Gao, Ji-tuo; Guo, Ying-xuan; He, Ji-cang; Qu, Jia; Lü, Fan

    2013-06-01

    Reading is a visual function human being used to understand environmental events based on writing materials. This study investigated the feasibility of reading visual acuity chart in assessment of reading ability by analysis of the key factors involved in the design of the visual acuity chart. The reading level was determined as grade 3 primary school with Song as the font and 30 characters included in the sentences. Each of the sentences consisted of 27 commonly-used Chinese characters (9 characters between any two punctuations) and 3 punctuations. There were no contextual clues between the 80 sentences selected. The characters had 13 different sizes with an increment of 0.1 log unit (e.g.1.2589) and 2.5 pt was determined as the critical threshold. Readable test for visual target was followed as (1) 29 candidates with a raw or corrected visual acuity (VA)of at least 1.0 were selected to read 80 selected sentences with the size of characters of 2.5 pt at a distance of 40 cm, (2) the time used for reading with the number of characters wrongly read was recorded, (3) 39 sentences were selected as visual targets based on reading speed, effective reading position and total number of character strokes, (4) The 39 selected sentences were then randomly divided into 3 groups with no significant difference among the groups in the 3 factors listed at (3) with paired t-test. This reading visual chart was at level of Grade 3 primary school with a total stroke number of 165-210(Mean 185 ± 10), 13 font sizes a 0.1 log unit increment, a song pattern and 2.5 pt as the critical threshold. All candidates achieved 100% correct in reading test under 2.5 pt with an effective reading speed as 120.65-162 wpm (Mean 142.93 ± 11.80) and effective reading position as 36.03-61.48(Mean 48.85 ± 6.81). The reading test for the 3 groups of sentences showed effective reading speed as (142.49 ± 12.14) wpm,(142.86 ± 12.55) wpm and (143.44 ± 11.63) wpm respectively(t1-2 = -0.899, t2-3 = -1

  12. All-distance visual acuity and contrast visual acuity in eyes with a refractive multifocal intraocular lens with minimal added power.

    PubMed

    Hayashi, Ken; Yoshida, Motoaki; Hayashi, Hideyuki

    2009-03-01

    To compare visual acuity (VA) from far to near distances, photopic and mesopic contrast VA, and contrast VA in the presence of a glare source (glare VA), between eyes with a new refractive multifocal intraocular lens (IOL) with added power of only +3.0 diopters and those with a monofocal IOL. Comparative, nonrandomized, interventional study. Forty-four eyes of 22 patients who were scheduled for implantation of a refractive multifocal IOL (Hoya SFX MV1; Tokyo, Japan) and 44 eyes of 22 patients scheduled for implantation of a monofocal IOL. All patients underwent phacoemulsification with bilateral implantation of either multifocal or monofocal IOLs. At approximately 3 months after surgery, monocular and binocular VA from far to near distances was measured using the all-distance vision tester (Kowa AS-15; Tokyo, Japan), whereas photopic and mesopic contrast VA and glare VA were examined using the Contrast Sensitivity Accurate Tester (Menicon CAT-2000, Nagoya, Japan). Pupillary diameter and the degree of IOL decentration and tilt were correlated with VA at all distances. Mean VA in both the multifocal and monofocal IOL groups decreased gradually from far to near distances. When comparing the 2 groups, however, both uncorrected and best distance-corrected intermediate VA at 0.5 m and near VA at 0.3 m in the multifocal IOL group were significantly better than those in the monofocal IOL group (P

  13. Early treatment of tuberculous uveitis improves visual outcome: a 10-year cohort study.

    PubMed

    Anibarro, Luis; Cortés, Eliana; Chouza, Ana; Parafita-Fernández, Alberto; García, Juan Carlos; Pena, Alberto; Fernández-Cid, Carlos; González-Fernández, África

    2018-06-04

    Diagnosis of tuberculous uveitis (TBU) is often challenging and is usually made after excluding other causes of uveitis. We analysed the characteristics of TBU and variables associated with visual outcome. A retrospective, observational analysis was performed in patients with presumptive TBU who were started on specific TB treatment between January 2006 and June 2016. Demographic, clinical, radiological, analytical and ophthalmic examination variables were studied. After completing TB treatment, a follow-up of at least 9 months was performed. A univariate and logistic regression analysis was applied to identify the variables associated with visual acuity and recurrences of uveitis. Forty affected eyes of 24 individuals were identified; 79% of patients were diagnosed during the last 3 years of the study period. Median delay from onset of symptoms to diagnosis was 12 weeks. Loss of visual acuity was the most frequent symptom (87.5%). Posterior uveitis was the most frequent localization (72.9%); 19 patients (79.2%) presented at least one of the Gupta signs predictive of TBU, but there were no confirmed diagnoses. There was improvement in visual acuity in 74.4% of the eyes, but a complete response was achieved only in 56.4%. There was recurrence in two patients. The initiation of treatment ≥ 24 weeks after onset of symptoms was significantly associated with no improvement (p = 0.026). TBU can cause permanent damage to visual acuity, particularly in patients with delayed diagnosis. A prompt initiation of systemic TB treatment is essential to improve visual prognosis.

  14. Second-year visual acuity outcomes of nAMD patients treated with aflibercept: data analysis from the UK Aflibercept Users Group.

    PubMed

    Almuhtaseb, H; Johnston, R L; Talks, J S; Lotery, A J

    2017-11-01

    PurposeTo audit the visual acuity (VA) outcomes achieved at the end of year two in 17 UK centres, which followed the year 1 VIEW protocol in year 1, but a variable approach in year 2 for aflibercept for neovascular macular degeneration (nAMD).Patients and methodsRetrospective data analysis, from an electronic medical record, of a consecutive series of treatment-naive nAMD patients who received aflibercept for 2 consecutive years, having followed the VIEW protocol in year one, defined as eyes having received 7 or 8 injections from baseline.ResultsThe mean number of intravitreal injections (IVI)s during year 2 was 3.7 in 1180 eyes (1083 patients). The mean baseline VA of the whole cohort was 56.3 ETDRS letters, improving to 61.3 at 1 year (+5) and 59.1 (+2.8) at the end of year 2. The mean VA letter score at the end of year 2, stratified by number of IVIs into three groups was as follows: group A, 57.3 (gain of +1.7) (44% of eyes (/=6 IVIs)). Even though there were VA gains in the three groups over the 2-years, there was a drop in VA in year one to two. Eyes that received >/=6 IVIs (group C) had a smaller reduction of VA during year 2 than those which received year 1 results in higher VA gains in year 2 of treatment.

  15. Effects of corneal irregular astigmatism on visual acuity after conventional and femtosecond laser-assisted Descemet's stripping automated endothelial keratoplasty.

    PubMed

    Tomida, Daisuke; Yamaguchi, Takefumi; Ogawa, Akiko; Hirayama, Yumiko; Shimazaki-Den, Seika; Satake, Yoshiyuki; Shimazaki, Jun

    2015-07-01

    To compare short-term outcomes of Descemet's stripping automated endothelial keratoplasty (DSAEK) using a graft prepared with either a femtosecond laser or a microkeratome. Thirty-eight patients underwent DSAEK with grafts prepared with either a femtosecond laser (f-DSAEK; 21 eyes) or a microkeratome (m-DSAEK; 17 eyes). Visual acuity, endothelial cell density, regular astigmatism and irregular astigmatism were compared between the two groups preoperatively and at 1, 3, and 6 months post-operatively. Fourier analysis was conducted to calculate astigmatism of the anterior and posterior surfaces, and total cornea, using anterior segment optical coherence tomography (AS-OCT). Visual acuity (logMAR) improved from 1.20 ± 0.60 to 0.43 ± 0.25 after m-DSAEK (P < 0.001) and from 1.20 ± 0.57 to 0.77 ± 0.33 after f-DSAEK (P = 0.0028) at 6 months following DSAEK. Visual acuity after m-DSAEK was significantly better than after f-DSAEK at 1, 3, and 6 months (P < 0.05). AS-OCT corneal images revealed greater irregularities on the posterior surfaces of f-DSAEK grafts compared to m-DSAEK grafts. Irregular astigmatism of the total cornea and the posterior surface was significantly larger after f-DSAEK than after m-DSAEK, although there was no significant difference in irregular astigmatism of the anterior surface at 6 months. Postoperative visual acuity was significantly correlated with the postoperative irregular astigmatism of the total cornea (r = 0.6657 and P < 0.001) and the anterior (r = 0.416, P = 0.016) and posterior surfaces (r = 0.7046, P < 0.001). Visual outcomes after f-DSAEK were poor compared to conventional m-DSAEK due to an increase in irregular astigmatism caused by posterior surface irregularities.

  16. PROSPECTIVE EVALUATION OF VISUAL ACUITY AGREEMENT BETWEEN STANDARD EARLY TREATMENT DIABETIC RETINOPATHY STUDY CHART AND A HANDHELD EQUIVALENT IN EYES WITH RETINAL PATHOLOGY.

    PubMed

    Rahimy, Ehsan; Reddy, Sahitya; DeCroos, Francis Char; Khan, M Ali; Boyer, David S; Gupta, Omesh P; Regillo, Carl D; Haller, Julia A

    2015-08-01

    To evaluate the visual acuity agreement between a standard back-illuminated Early Treatment Diabetic Retinopathy Study (ETDRS) chart and a handheld internally illuminated ETDRS chart. Two-center prospective study. Seventy patients (134 eyes) with retinal pathology were enrolled between October 2012 and August 2013. Visual acuity was measured using both the ETDRS chart and the handheld device by masked independent examiners after best protocol refraction. Examination was performed in the same room under identical illumination and testing conditions. The mean number of letters seen was 63.0 (standard deviation: 19.8 letters) and 61.2 letters (standard deviation: 19.1 letters) for the ETDRS chart and handheld device, respectively. Mean difference per eye between the ETDRS and handheld device was 1.8 letters. A correlation coefficient (r) of 0.95 demonstrated a positive linear correlation between ETDRS chart and handheld device measured acuities. Intraclass correlation coefficient was performed to assess the reproducibility of the measurements made by different observers measuring the same quantity and was calculated to be 0.95 (95% confidence interval: 0.93-0.96). Agreement was independent of retinal disease. The strong correlation between measured visual acuity using the ETDRS and handheld equivalent suggests that they may be used interchangeably, with accurate measurements. Potential benefits of this device include convenience and portability, as well as the ability to assess ETDRS visual acuity without a dedicated testing lane.

  17. Visual acuity and astigmatism in periocular infantile hemangiomas treated with oral beta-blocker versus intralesional corticosteroid injection.

    PubMed

    Herlihy, Erin P; Kelly, John P; Sidbury, Robert; Perkins, Jonathan A; Weiss, Avery H

    2016-02-01

    Periocular infantile hemangiomas (PIH) can induce anisometropic astigmatism, a risk factor for amblyopia. Oral beta-blocker therapy has largely supplanted systemic or intralesional corticosteroids. The purpose of this study was to evaluate the effect and time course of these treatment modalities on visual acuity and induced astigmatism. The medical records of patients with PIH treated with oral propanolol between November 2008 and July 2013 were retrospectively reviewed for data on visual acuity and astigmatism. Patients with incomplete pre- and post-treatment ophthalmic examinations were excluded. Results were compared to those of a similar cohort treated with intralesional corticosteroid injection. Mean astigmatism in affected eyes was 1.90 D before propranolol and 1.00 D after; patients showed a monophasic reduction in astigmatism over 12 months. By comparison, patients treated with corticosteroid injection showed a biphasic response, with an immediate steep decrease followed by a slow monophasic decline, paralleling propranolol-treated patients. Oral propranolol treatment caused a 47% reduction in mean induced astigmatism, less than the 63% reduction reported for the cohort treated with corticosteroid. No patient had visual acuity in the affected eye more than 1 standard devation below the age-matched norm, and none experienced significant side effects when treated with oral propranolol. In this patient cohort oral beta-blocker was well-tolerated. Treatment was therefore often initiated prior to the induction of significant astigmatism, with treatment effects comparable to steroid treatment. Visual outcomes were good. Early treatment may minimize the potential effect of astigmatism on postnatal visual development. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  18. Higher-order aberrations and best-corrected visual acuity in Native American children with a high prevalence of astigmatism

    PubMed Central

    Miller, Joseph M.; Harvey, Erin M.; Schwiegerling, Jim

    2016-01-01

    Purpose To determine whether higher-order aberrations (HOAs) in children from a highly astigmatic population differ from population norms and whether HOAs are associated with astigmatism and reduced best-corrected visual acuity. Methods Subjects were 218 Tohono O’odham Native American children 5–9 years of age. Noncycloplegic HOA measurements were obtained with a handheld Shack-Hartmann sensor (SHS). Signed (z06s to z14s) and unsigned (z06u to z14u) wavefront aberration Zernike coefficients Z(3,−3) to Z(4,4) were rescaled for a 4 mm diameter pupil and compared to adult population norms. Cycloplegic refraction and best-corrected logMAR letter visual acuity (BCVA) were also measured. Regression analyses assessed the contribution of astigmatism (J0) and HOAs to BCVA. Results The mean root-mean-square (RMS) HOA of 0.191 ± 0.072 μm was significantly greater than population norms (0.100 ± 0.044 μm. All unsigned HOA coefficients (z06u to z14u) and all signed coefficients except z09s, z10s, and z11s were significantly larger than population norms. Decreased BCVA was associated with astigmatism (J0) and spherical aberration (z12u) but not RMS coma, with the effect of J0 about 4 times as great as z12u. Conclusions Tohono O’odham children show elevated HOAs compared to population norms. Astigmatism and unsigned spherical aberration are associated with decreased acuity, but the effects of spherical aberration are minimal and not clinically significant. PMID:26239206

  19. LONG-TERM RETROSPECTIVE ANALYSIS OF VISUAL ACUITY AND OPTICAL COHERENCE TOPOGRAPHIC CHANGES AFTER SINGLE VERSUS DOUBLE PEELING DURING VITRECTOMY FOR MACULAR EPIRETINAL MEMBRANES.

    PubMed

    Jung, Jesse J; Hoang, Quan V; Ridley-Lane, Megan L; Sebrow, Dov B; Dhrami-Gavazi, Elona; Chang, Stanley

    2016-11-01

    To determine the long-term effect of internal limiting membrane with associated epiretinal membrane (ERM) peeling versus single peeling alone in terms of best-corrected visual acuity and anatomical outcomes on spectral-domain optical coherence tomography. This retrospective comparative cohort study of patients who had follow-up of >1 year and underwent surgery for ERM by a single surgeon (S.C.) from January 1, 2008 to December 31, 2012 compared cases in which the internal limiting membrane was stained with brilliant blue G to facilitate double peeling (n = 42) and single peeling (n = 43) of the ERM alone for up to 3 years of follow-up. For continuous variables, an independent two-tailed t-test was performed. For binary variables, the Fisher's exact test was performed. Statistical significance was defined as P < 0.05. Eighty-five of 142 patients fit the inclusion criteria. At the last follow-up, the single-peeling group were more likely to have ERM remaining in the central fovea postoperatively (P = 0.0020, becoming significant by postoperative Year 1, P = 0.022) and less likely to develop inner retinal dimpling (P = 0.000, becoming significant by postoperative Month 3, P = 0.015). At 3 years, central foveal thickness had decreased in the single-peeling group by -136.9 µm and by -84.1 μm in the double-peeling group, which was not significantly different (P = 0.08). Mean best-corrected visual acuity improved in both the groups at all time points. There was no statistically significant difference between the 2 groups at 3 years (P = 0.44; single-peeling group, 0.32 ± 0.42, Snellen 20/42; double-peeling group, 0.23 ± 0.27, Snellen 20/34). Brilliant blue G-assisted internal limiting membrane peeling for ERM results in a more thorough removal of residual ERM around the paracentral fovea. However, there is no difference in long-term best-corrected visual acuity at 3 years and a greater likelihood of inner retinal dimpling.

  20. Local Tumor Control, Visual Acuity, and Survival After Hypofractionated Stereotactic Photon Radiotherapy of Choroidal Melanoma in 212 Patients Treated Between 1997 and 2007

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dunavoelgyi, Roman; Dieckmann, Karin, E-mail: karin.dieckmann@meduniwien.ac.at; Gleiss, Andreas

    2011-09-01

    Purpose: To evaluate long-term local tumor control, visual acuity, and survival after hypofractionated linear accelerator-based stereotactic photon radiotherapy in patients with choroidal melanoma. Methods and Materials: Between 1997 and 2007, 212 patients with choroidal melanoma unsuitable for ruthenium-106 brachytherapy or local resection were treated stereotactically at a linear accelerator with 6-MV photon beams at the Medical University of Vienna in five fractions over 7 days. Twenty-four patients received a total dose of 70 Gy (five fractions of 14 Gy), 158 a total dose of 60 Gy (five fractions of 12 Gy) and 30 patients a total dose of 50 Gymore » (five fractions of 10 Gy) applied on the 80% isodose. Ophthalmologic examinations were performed at baseline and every 3 months in the first 2 years, every 6 months until 5 years, and once a year thereafter until 10 years after radiotherapy. Assessment of visual acuity, routine ophthalmologic examinations, and measurement of tumor base dimension and height using standardized A-scan and B-scan echography were done at each visit. Funduscopy and fluorescein angiography were done when necessary to document tumor response. Results: Median tumor height and volume decreased from 4.8 mm and 270.7 mm{sup 3} at baseline to 2.6 mm and 86.6 mm{sup 3} at the last individual follow-up, respectively (p < 0.001, p < 0.001). Median visual acuity decreased from 0.55 at baseline to hand motion at the last individual follow-up (p < 0.001). Local tumor control was 95.9% after 5 years and 92.6% after 10 years. Thirty-two patients developed metastatic disease, and 22 of these patients died during the follow-up period. Conclusion: Hypofractionated stereotactic photon radiotherapy with 70 to 50 Gy delivered in five fractions in 7 days is sufficient to achieve excellent local tumor control in patients with malignant melanoma of the choroid. Disease outcome and vision are comparable to those achieved with proton beam radiotherapy

  1. The relation of functional visual acuity measurement methodology to tear functions and ocular surface status.

    PubMed

    Kaido, Minako; Ishida, Reiko; Dogru, Murat; Tsubota, Kazuo

    2011-09-01

    To investigate the relation of functional visual acuity (FVA) measurements with dry eye test parameters and to compare the testing methods with and without blink suppression and anesthetic instillation. A prospective comparative case series. Thirty right eyes of 30 dry eye patients and 25 right eyes of 25 normal subjects seen at Keio University School of Medicine, Department of Ophthalmology were studied. FVA testing was performed using a FVA measurement system with two different approaches, one in which measurements were made under natural blinking conditions without topical anesthesia (FVA-N) and the other in which the measurements were made under the blink suppression condition with topical anesthetic eye drops (FVA-BS). Tear function examinations, such as the Schirmer test, tear film break-up time, and fluorescein and Rose Bengal vital staining as ocular surface evaluation, were performed. The mean logMAR FVA-N scores and logMAR Landolt visual acuity scores were significantly lower in the dry eye subjects than in the healthy controls (p < 0.05), while there were no statistical differences between the logMAR FVA-BS scores of the dry eye subjects and those of the healthy controls. There was a significant correlation between the logMAR Landolt visual acuities and the logMAR FVA-N and logMAR FVA-BS scores. The FVA-N scores correlated significantly with tear quantities, tear stability and, especially, the ocular surface vital staining scores. FVA measurements performed under natural blinking significantly reflected the tear functions and ocular surface status of the eye and would appear to be a reliable method of FVA testing. FVA measurement is also an accurate predictor of dry eye status.

  2. Correlation Between Near-Vision Acuity and the Incidence of Peritoneal Dialysis-Related Infections.

    PubMed

    Kojima, Shigeki; Sakurada, Tsutomu; Koitabashi, Kenichiro; Kojima, Kaori; Watanabe, Shiika; Uchida, Daisuke; Kaneshiro, Nagayuki; Konno, Yusuke; Shibagaki, Yugo

    Peritoneal dialysis (PD)-related infections (PDIs) such as peritonitis, exit-site infection, and tunnel infection are serious complications affecting patients on PD. Because patients with diabetes (DM) and of older age have increased in number in Japan, the number of patients with visual impairment is estimated also to have increased. Near vision is necessary for performing proper PD daily care. However, no studies have reported whether visual impairment is likely to increase the risk of PDIs.Our study included 31 PD patients (16 men, 15 women; mean age: 61.5 ± 11.8 years; mean PD duration: 27.3 ± 20.3 months; 38.7% with DM; 54.8% wearing glasses) who performed their own PD care. At our facility and related facilities, we used a standard near-vision test chart, which classifies vision into 12 grades, from 0.1 (poor) to 1.5 (clear), to assess near-vision binocular visual acuity in those patients between March 2015 and September 2015. In addition, we retrospectively examined the medical records of the patients to determine their history of PDIs. We then evaluated the correlation between near-vision acuity and the incidence of PDIs.Mean measured near-vision acuity was 0.61 ± 0.29, and we observed no significant difference in the visual acuity of patients with and without DM (0.55 ± 0.31 vs. 0.63 ± 0.26 respectively, p = 0.477). In addition, we observed no significant difference in the incidence of PDIs between patients with and without DM (1.298 ± 1.609 per year vs. 1.164 ± 0.908 per year respectively, p = 0.804). We did not find a correlation between near-vision acuity and the incidence of PDIs (r = -0.071, p = 0.795).

  3. Dynamic Visual Acuity While Walking in Normals and Labyrinthine-Deficient Patients

    NASA Technical Reports Server (NTRS)

    Hillman, Edward J.; Bloomberg, Jacob J.; McDonald, P. Vernon; Cohen, Helen S.

    1996-01-01

    We describe a new, objective, easily administered test of dynamic visual acuity (DVA) while walking. Ten normal subjects and five patients with histories of severe bilateral vestibular dysfunctions participated in this study. Subjects viewed a visual display of numerals of different font sizes presented on a laptop computer while they stood still and while they walked on a motorized treadmill. Treadmill speed was adapted for 4 of 5 patients. Subjects were asked to identify the numerals as they appeared on the computer screen. Test results were reasonably repeatable in normals. The percent correct responses at each font size dropped slightly while walking in normals and dropped significantly more in patients. Patients performed significantly worse than normals while standing still and while walking. This task may be useful for evaluating post-flight astronauts and vestibularly impaired patients.

  4. Contrast sensitivity measured by two different test methods in healthy, young adults with normal visual acuity.

    PubMed

    Koefoed, Vilhelm F; Baste, Valborg; Roumes, Corinne; Høvding, Gunnar

    2015-03-01

    This study reports contrast sensitivity (CS) reference values obtained by two different test methods in a strictly selected population of healthy, young adults with normal uncorrected visual acuity. Based on these results, the index of contrast sensitivity (ICS) is calculated, aiming to establish ICS reference values for this population and to evaluate the possible usefulness of ICS as a tool to compare the degree of agreement between different CS test methods. Military recruits with best eye uncorrected visual acuity 0.00 LogMAR or better, normal colour vision and age 18-25 years were included in a study to record contrast sensitivity using Optec 6500 (FACT) at spatial frequencies of 1.5, 3, 6, 12 and 18 cpd in photopic and mesopic light and CSV-1000E at spatial frequencies of 3, 6, 12 and 18 cpd in photopic light. Index of contrast sensitivity was calculated based on data from the three tests, and the Bland-Altman technique was used to analyse the agreement between ICS obtained by the different test methods. A total of 180 recruits were included. Contrast sensitivity frequency data for all tests were highly skewed with a marked ceiling effect for the photopic tests. The median ICS for Optec 6500 at 85 cd/m2 was -0.15 (95% percentile 0.45), compared with -0.00 (95% percentile 1.62) for Optec at 3 cd/m2 and 0.30 (95% percentile 1.20) FOR CSV-1000E. The mean difference between ICSFACT 85 and ICSCSV was -0.43 (95% CI -0.56 to -0.30, p<0.00) with limits of agreement (LoA) within -2.10 and 1.22. The regression line on the difference of average was near to zero (R2=0.03). The results provide reference CS and ICS values in a young, adult population with normal visual acuity. The agreement between the photopic tests indicated that they may be used interchangeably. There was little agreement between the mesopic and photopic tests. The mesopic test seemed best suited to differentiate between candidates and may therefore possibly be useful for medical selection purposes.

  5. A nationwide population-based survey on visual acuity, near vision, and self-reported visual function in the adult population in Finland.

    PubMed

    Laitinen, Arja; Koskinen, Seppo; Härkänen, Tommi; Reunanen, Antti; Laatikainen, Leila; Aromaa, Arpo

    2005-12-01

    To estimate the prevalence rates of habitual visual acuity (VA) levels and visual impairment in Finland and to assess their correlation with self-reported visual function. Cross-sectional population-based study. Subjects were selected randomly from the Finnish population aged 30 years or older. Of 7979 eligible people, 7393 (93%) were interviewed, 6771 (85%) were examined, and 6663 (84%) had distance VA assessed. Participants underwent a home interview and a comprehensive examination including measuring binocular VA for distance and for near with the participants' current spectacles, if any. The level of VA for distance and for near with current spectacle correction. The self-reported capability to read newsprint and television text and the ability to move about without being restricted by reduced vision. The prevalence of good to moderate VA for distance (VA> or =0.5 [> or =20/40]) measured with current spectacles was 95.9%, and 87.4% had a VA level of 0.8 (20/25) or better. The prevalence of habitual visual impairment (VA< or =0.25 [< or =20/80]) was 1.6%, and 0.5% were blind (VA<0.1 [<20/200]). The prevalence of visual impairment increased significantly with age (P<0.001), especially in the age group of 65 to 74 years and upward. There was no gender difference in VA for distance, but decreased near vision (VA< or =0.25 [< or =20/80]) was significantly more common in men than in women (P<0.01). By applying the imputated numbers of visually impaired and blind participants to the Finnish population (approximately 3 million aged 30 years or older), there were approximately 65000 (2.1%) visually impaired and 17000 (0.6%) blind adult persons in the country in 2000. The correlation between self-reported visual ability and measured visual function was moderate but statistically significant (r = 0.27-0.40; P<0.0001). The proportion of people with reading difficulties or who were unable to read newsprint has decreased 7% during the last 2 decades. Functional visual

  6. Reliability of Snellen charts for testing visual acuity for driving: prospective study and postal questionnaire

    PubMed Central

    Currie, Zanna; Bhan, Archana; Pepper, Irene

    2000-01-01

    Objectives To assess the ability of patients with binocular 6/9 or 6/12 vision on the Snellen chart (Snellen acuity) to read a number plate at 20.5 m (the required standard for driving) and to determine how health professionals advise such patients about driving. Design Prospective study of patients and postal questionnaire to healthcare professionals. Subjects 50 patients with 6/9 vision and 50 with 6/12 vision and 100 general practitioners, 100 optometrists or opticians, and 100 ophthalmologists. Setting Ophthalmology outpatient clinics in Sheffield. Main outcome measures Ability to read a number plate at 20.5 m and health professionals' advice about driving on the basis of visual acuity. Results 26% of patients with 6/9 vision failed the number plate test, and 34% with 6/12 vision passed it. Of the general practitioners advising patients with 6/9 vision, 76% said the patients could drive, 13% said they should not drive, and 11% were unsure. Of the general practitioners advising patients with 6/12 vision, 21% said the patients could drive, 54% said they should not drive, and 25% were unsure. The level of acuity at which optometrists, opticians, and ophthalmologists would advise drivers against driving ranged from 6/9−2 (ability to read all except two letters on the 6/9 line of the Snellen chart) to less than 6/18. Conclusions Snellen acuity is a poor predictor of an individual's ability to meet the required visual standard for driving. Patients with 6/9 vision or less should be warned that they may fail to meet this standard, but those with 6/12 vision should not be assumed to be below the standard. PMID:11039964

  7. New Method of Screening Young Children for Defects in Visual Acuity*

    PubMed Central

    Withnell, Allan; Wilson, H. E.

    1968-01-01

    The methods used at present for screening young children's vision have disadvantages, such as that the child's intelligence can affect the result. In a new method three white cards are used; these are printed with one, two, or three black blocks arranged so that if a child can correctly state the number of blocks at 6 metres the visual acuity is at least 6/9. When tested on 186 children the new method gave better results than conventional tests; eight children with defective vision were picked up only by the new method and none were missed. PMID:5681052

  8. New method of screening young children for defects in visual acuity.

    PubMed

    Withnell, A; Wilson, H E

    1968-10-19

    The methods used at present for screening young children's vision have disadvantages, such as that the child's intelligence can affect the result. In a new method three white cards are used; these are printed with one, two, or three black blocks arranged so that if a child can correctly state the number of blocks at 6 metres the visual acuity is at least 6/9. When tested on 186 children the new method gave better results than conventional tests; eight children with defective vision were picked up only by the new method and none were missed.

  9. Proximal versus distal cue utilization in spatial navigation: the role of visual acuity?

    PubMed

    Carman, Heidi M; Mactutus, Charles F

    2002-09-01

    Proximal versus distal cue use in the Morris water maze is a widely accepted strategy for the dissociation of various problems affecting spatial navigation in rats such as aging, head trauma, lesions, and pharmacological or hormonal agents. Of the limited number of ontogenetic rat studies conducted, the majority have approached the problem of preweanling spatial navigation through a similar proximal-distal dissociation. An implicit assumption among all of these studies has been that the animal's visual system is sufficient to permit robust spatial navigation. We challenged this assumption and have addressed the role of visual acuity in spatial navigation in the preweanling Fischer 344-N rat by training animals to locate a visible (proximal) or hidden (distal) platform using double or null extramaze cues within the testing environment. All pups demonstrated improved performance across training, but animals presented with a visible platform, regardless of extramaze cues, simultaneously reached asymptotic performance levels; animals presented with a hidden platform, dependent upon location of extramaze cues, differentially reached asymptotic performance levels. Probe trial performance, defined by quadrant time and platform crossings, revealed that distal-double-cue pups demonstrated spatial navigational ability superior to that of the remaining groups. These results suggest that a pup's ability to spatially navigate a hidden platform is dependent on not only its response repertoire and task parameters, but also its visual acuity, as determined by the extramaze cue location within the testing environment. The standard hidden versus visible platform dissociation may not be a satisfactory strategy for the control of potential sensory deficits.

  10. Effects of smoking on visual acuity of central serous chorioretinopathy patients.

    PubMed

    Türkcü, Fatih Mehmet; Yüksel, Harun; Sahin, Alparslan; Cinar, Yasin; Cingü, Kürşat; Arı, Seyhmus; Sahin, Muhammed; Altındağ, Suat; Caça, Ihsan

    2014-06-01

    The aim of this study was to evaluate the differences, in terms of visual outcome and treatment needs, between smokers and non-smokers central serous chorioretinopathy (CSCR) patients. The files of 252 patients diagnosed with CSCR who had presented to the Retina Unit of the Ophthalmology Clinic at Dicle University Medical School in Turkey were retrospectively evaluated. Eighty-four smokers, with a known history of smoking of at least one pack-year, and 133 non-smokers were included, whereas 35 patients with additional pathologies were excluded from the study. Of the patients, 192 (88.5%) were male and 25 (11.5%) were female. The mean patient age was 38.8 ± 8.1 years (range: 20-68 years). Visual acuity (VA) of the smoker and non-smoker groups was measured as 0.45 ± 0.35 and 0.24 ± 0.28 logarithm of the minimum angle of resolution (logMar), respectively, at the first visit; 0.19 ± 0.29 and 0.06 ± 0.14 logMar at the sixth month; and 0.07 ± 0.14 and 0.02 ± 0.05 logMar at the ninth month. VA measurements at presentation and during all examinations (1th, 6th and 9th month) were significantly different for the two groups. VA was lower in the smoker group. In 27 patients (12.4%), an additional treatment modality was needed. Of the 27 patients, only 8 (6%) were non-smokers, whereas 19 (22.6%) were smokers. There was no difference between groups in the recurrence rate during follow-up (p = 0.907); 14 (16.7%) smokers and 8 (19.0%) non-smokers experienced a recurrence. This study has shown that patients selected and who are current smokers have poorer vision and need longer treatment.

  11. Parafoveal magnification: visual acuity does not modulate the perceptual span in reading.

    PubMed

    Miellet, Sébastien; O'Donnell, Patrick J; Sereno, Sara C

    2009-06-01

    Models of eye guidance in reading rely on the concept of the perceptual span-the amount of information perceived during a single eye fixation, which is considered to be a consequence of visual and attentional constraints. To directly investigate attentional mechanisms underlying the perceptual span, we implemented a new reading paradigm-parafoveal magnification (PM)-that compensates for how visual acuity drops off as a function of retinal eccentricity. On each fixation and in real time, parafoveal text is magnified to equalize its perceptual impact with that of concurrent foveal text. Experiment 1 demonstrated that PM does not increase the amount of text that is processed, supporting an attentional-based account of eye movements in reading. Experiment 2 explored a contentious issue that differentiates competing models of eye movement control and showed that, even when parafoveal information is enlarged, visual attention in reading is allocated in a serial fashion from word to word.

  12. Comparison on testability of visual acuity, stereo acuity and colour vision tests between children with learning disabilities and children without learning disabilities in government primary schools

    PubMed Central

    Abu Bakar, Nurul Farhana; Chen, Ai-Hong

    2014-01-01

    Context: Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. Aims: The purpose of this study was to compare the testability of visual acuity using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) and Cambridge Crowding Cards, stereo acuity using Lang Stereo test II and Butterfly stereo tests and colour perception using Colour Vision Test Made Easy (CVTME) and Ishihara's Test for Colour Deficiency (Ishihara Test) between children in mainstream classes and children with learning disabilities in special education classes in government primary schools. Materials and Methods: A total of 100 primary school children (50 children from mainstream classes and 50 children from special education classes) matched in age were recruited in this cross-sectional comparative study. The testability was determined by the percentage of children who were able to give reliable respond as required by the respective tests. ‘Unable to test’ was defined as inappropriate response or uncooperative despite best efforts of the screener. Results: The testability of the modified ETDRS, Butterfly stereo test and Ishihara test for respective visual function tests were found lower among children in special education classes (P < 0.001) but not in Cambridge Crowding Cards, Lang Stereo test II and CVTME. Conclusion: Non verbal or “matching” approaches were found to be more superior in testing visual functions in children with learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities. PMID:24008790

  13. Comparison on testability of visual acuity, stereo acuity and colour vision tests between children with learning disabilities and children without learning disabilities in government primary schools.

    PubMed

    Abu Bakar, Nurul Farhana; Chen, Ai-Hong

    2014-02-01

    Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. The purpose of this study was to compare the testability of visual acuity using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) and Cambridge Crowding Cards, stereo acuity using Lang Stereo test II and Butterfly stereo tests and colour perception using Colour Vision Test Made Easy (CVTME) and Ishihara's Test for Colour Deficiency (Ishihara Test) between children in mainstream classes and children with learning disabilities in special education classes in government primary schools. A total of 100 primary school children (50 children from mainstream classes and 50 children from special education classes) matched in age were recruited in this cross-sectional comparative study. The testability was determined by the percentage of children who were able to give reliable respond as required by the respective tests. 'Unable to test' was defined as inappropriate response or uncooperative despite best efforts of the screener. The testability of the modified ETDRS, Butterfly stereo test and Ishihara test for respective visual function tests were found lower among children in special education classes ( P < 0.001) but not in Cambridge Crowding Cards, Lang Stereo test II and CVTME. Non verbal or "matching" approaches were found to be more superior in testing visual functions in children with learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities.

  14. "Far" and "Near" Visual Acuity While Walking and the Collective Contributions of Non-Ocular Mechanisms to Gaze Stabilization

    NASA Technical Reports Server (NTRS)

    Peters, Brian T.; vanEmmerik, Richard E. A.; Bloomberg, Jacob J.

    2006-01-01

    Gaze stabilization was quantified in subjects (n=11) as they walked on a motorized treadmill (1.8 m/s) and viewed visual targets at two viewing distances. A "far" target was positioned at 4 m (FAR) in front of the subject and the "near" target was placed at a distance of 0.5 m (NEAR). A direct measure of visual acuity was used to assess the overall effectiveness of the gaze stabilization system. The contributions of nonocular mechanisms to the gaze goal were also quantified using a measure of the distance between the subject and point in space where fixation of the visual target would require the least eye movement amplitude (i.e. the head fixation distance (HFD)). Kinematic variables mirrored those of previous investigations with the vertical trunk translation and head pitch signals, and the lateral translation and head yaw signals maintaining what appear as antiphase relationships. However, an investigation of the temporal relationships between the maxima and minima of the vertical translation and head pitch signals show that while the maximum in vertical translation occurs at the point of the minimum head pitch signal, the inverse is not true. The maximum in the head pitch signal lags the vertical translation minimum by an average of greater than 12 percent of the step cycle time. Three HFD measures, one each for data in the sagittal and transverse planes, and one that combined the movements from both planes, all revealed changes between the FAR and NEAR target viewing conditions. This reorganization of the nonocular degrees of freedom while walking was consistent with a strategy to reduce the magnitude of the eye movements required when viewing the NEAR target. Despite this reorganization, acuity measures show that image stabilization is not occurring while walking and viewing the NEAR target. Group means indicate that visual acuity is not affected while walking in the FAR condition, but a decrement of 0.15 logMAR (i.e. 1.5 eye chart lines) exists between the

  15. A double dissociation of the acuity and crowding limits to letter identification, and the promise of improved visual screening

    PubMed Central

    Song, Shuang; Levi, Dennis M.; Pelli, Denis G.

    2014-01-01

    Here, we systematically explore the size and spacing requirements for identifying a letter among other letters. We measure acuity for flanked and unflanked letters, centrally and peripherally, in normals and amblyopes. We find that acuity, overlap masking, and crowding each demand a minimum size or spacing for readable text. Just measuring flanked and unflanked acuity is enough for our proposed model to predict the observer's threshold size and spacing for letters at any eccentricity. We also find that amblyopia in adults retains the character of the childhood condition that caused it. Amblyopia is a developmental neural deficit that can occur as a result of either strabismus or anisometropia in childhood. Peripheral viewing during childhood due to strabismus results in amblyopia that is crowding limited, like peripheral vision. Optical blur of one eye during childhood due to anisometropia without strabismus results in amblyopia that is acuity limited, like blurred vision. Furthermore, we find that the spacing:acuity ratio of flanked and unflanked acuity can distinguish strabismic amblyopia from purely anisometropic amblyopia in nearly perfect agreement with lack of stereopsis. A scatter diagram of threshold spacing versus acuity, one point per patient, for several diagnostic groups, reveals the diagnostic power of flanked acuity testing. These results and two demonstrations indicate that the sensitivity of visual screening tests can be improved by using flankers that are more tightly spaced and letter like. Finally, in concert with Strappini, Pelli, Di Pace, and Martelli (submitted), we jointly report a double dissociation between acuity and crowding. Two clinical conditions—anisometropic amblyopia and apperceptive agnosia—each selectively impair either acuity A or the spacing:acuity ratio S/A, not both. Furthermore, when we specifically estimate crowding, we find a double dissociation between acuity and crowding. Models of human object recognition will need

  16. Correlation between postoperative area of high autofluorescence in macula and visual acuity after macular hole closure.

    PubMed

    Zhang, Peng; Shang, Qingli; Ma, Jingxue; Hao, Yuhua; Ye, Cunxi

    2017-03-20

    To determine the correlation between the preoperative basal diameter of macular hole, the postoperative area of high autofluorescence (AF) in macula, and visual acuity in full-thickness macular hole. Forty-nine patients with full-thickness macular hole who underwent vitrectomy and C3F8 filling were reviewed. The preoperative diameter of macular hole, the 6 months postoperative area of high AF in macula if it existed, the length of inner segment/outer segment (IS/OS) defect, and visual acuity were obtained. The correlation between them was determined. At postoperative 6 months, the rate of high AF in macula was 63.3%. There were statistical differences between with and without high AF groups in postoperative best-corrected visual acuity (BCVA) (t = -2.751, p = 0.008), preoperative basal diameter of macular hole (t = -4.946, p = 0.00001), and postoperative length of IS/OS defect (t = -8.351, p<0.00001). Simple linear regression analysis showed high positive correlations between preoperative basal diameter of macular hole and area of high AF (p<0.00001, r = 0.893), postoperative length of IS/OS defect and area of high fundus AF (FAF) (p<0.00001, r = 0.779), and negative correlations between area of high AF and postoperative BCVA (p = 0.037, r = 0.375). There was low correlation between diameter of macular hole and postoperative BCVA (p = 0.112). The preoperative basal diameter of macular hole and postoperative length of IS/OS defect decides the postoperative area of high AF in macula to some degree, and the postoperative area of high AF in macula can be an evaluating indicator for poor macular function recovery.

  17. Comparison of monochromatic aberrations in young adults with different visual acuity and refractive errors.

    PubMed

    Yazar, Seyhan; Hewitt, Alex W; Forward, Hannah; McKnight, Charlotte M; Tan, Alex; Mountain, Jenny A; Mackey, David A

    2014-03-01

    To compare the monochromatic aberrations in a large cohort of 20-year-old Australians with differing levels of visual acuity and explore the relationship between these aberrations and refractive error. Lions Eye Institute, Perth, Western Australia, Australia. Cross-sectional analysis of a population-based cohort. Monochromatic aberrations were measured using a Zywave II wavefront aberrometer with natural pupils in a dark room. The logMAR corrected distance visual acuity (CDVA) was measured monocularly under normal illumination. Cycloplegic autorefraction was also performed. The study enrolled 2039 eyes of 1040 participants. Data from 1007 right eyes were analyzed. The median CDVA and spherical equivalent were -0.06 logMAR (interquartile range [IQR], -0.10 to 0.00) and +0.25 diopters (D) (IQR, -0.38 to 0.63), respectively. The median 6.0 mm higher-order aberration (HOA) was 0.58 μm (IQR, 0.44 to 0.79). Coma-like aberrations and 3rd-, 4th-, and 5th-order HOAs were significantly different between subjects with a CDVA of -0.10 logMAR or better and those with a CDVA worse than -0.10 logMAR. Fourth-order aberrations Z(4,-4) (P=.024) and Z(4,-2) (P=.029) and 2nd-order aberration Z(2,0) (P<.001) differed significantly between myopic eyes, emmetropic eyes, and hyperopic eyes. Subjects with higher myopia had slightly higher total HOAs. The HOAs in this population were marginally higher than previously reported values. The findings confirm there is a difference in monochromatic aberrations between different vision and refractive groups. Results in this study will benefit decision-making processes in the clinical setting. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. Contrast visual acuity in patients with retinitis pigmentosa assessed by a contrast sensitivity tester.

    PubMed

    Oishi, Maho; Nakamura, Hajime; Hangai, Masanori; Oishi, Akio; Otani, Atsushi; Yoshimura, Nagahisa

    2012-01-01

    To assess contrast visual acuity (CVA) in patients with retinitis pigmentosa (RP) and compare the result with standard visual acuity (VA), retinal thickness, status of inner segment/outer segment junction, and central visual field. Thirty-nine eyes of 39 patients with RP and 39 eyes of 39 healthy individuals were studied. To see the difference in CVA between RP patients and normal controls, only subjects with standard VA of 1.0 (20/20) or better were included. This was a cross-sectional study. CVA in various light conditions was measured with CAT-2000 and was compared between patients and controls. CVA of patients was further analyzed for association with other parameters including foveal retinal thickness, outer nuclear layer thickness, the status of inner segment/outer segment junction measured with optical coherence tomography (OCT), and visual field mean deviation (MD) measured with Humphrey field analyzer 10-2 program. CVA impairment was evident in RP patients compared to controls (P < 0.01, in all measurement conditions). Multivariate analysis showed association of logarithm of the minimum angle of resolution (logMAR) with CVAs in several conditions. None of the OCT measurements was associated with CVA. When patients were divided into three groups based on MD, the most advanced group (MD worse than or equal to -20 dB) showed impairment of mesopic CVA (P < 0.05, under mesopic condition of 100% without glare, with glare, and 25% without glare). CVA impairment was confirmed in RP patients, especially in advanced cases. CVA measured with CAT-2000 may be a useful tool for assessing foveal function in RP patients.

  19. Femtosecond-Assisted LASIK Versus PRK: Comparison of 6-Month Visual Acuity and Quality Outcome for High Myopia.

    PubMed

    Hashemi, Hassan; Miraftab, Mohammad; Ghaffari, Reza; Asgari, Soheila

    2016-11-01

    To compare the results of femtosecond-assisted laser in situ keratomileusis (femto-LASIK) and photorefractive keratectomy with mitomycin C (PRK-MMC) for the correction of myopia more than 7.0 diopters (D). In this comparative nonrandomized trial, 60 eyes (30 eyes in each group) were enrolled. Patients were tested for uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, ocular and corneal aberrations, and contrast sensitivity (CS) before surgery and at 3 and 6 months postoperatively. Mean preoperative myopia was -8.65±1.51 and -8.04±1.70 D in the femto-LASIK and PRK-MMC groups, respectively (P=0.149). Intergroup differences in baseline indices were not statistically significant. At 6 months after surgery, UDVA showed an improving trend, but it was better in the femto-LASIK group (P=0.026). CDVA in the two groups remained similarly unchanged (P=0.170). For the femto-LASIK and PRK-MMC groups, the safety indices were 1.01±0.05 and 1.01±0.14 (P=0.949), respectively, and the efficacy indices were 0.99±0.07 and 0.93±0.22 (P=0.192), respectively. Comparing CS, only CS18 showed a significantly greater decrease in the femto-LASIK group compared with the PRK-MMC group (P=0.016). Intergroup differences were not statistically significant in other spatial frequencies. Changes in the ocular and corneal higher order aberrations were not statistically different between the two groups except ocular coma, which increased in the femto-LASIK group (P=0.041). Femto-LASIK improves UDVA better than PRK-MMC in high myopia. However, because of increased coma, the quality of vision is reduced. In other words, visual acuity outcome is better with femto-LASIK and visual quality outcome is better with PRK-MMC.

  20. Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity.

    PubMed

    Kaido, Minako; Toda, Ikuko; Oobayashi, Tomoo; Kawashima, Motoko; Katada, Yusaku; Tsubota, Kazuo

    2016-01-01

    To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23-43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20-49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05). Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.

  1. Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity

    PubMed Central

    Kaido, Minako

    2016-01-01

    Purpose To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE). Methods Twenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23–43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20–49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio. Results The baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05), Conclusions Protecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE. PMID:27045760

  2. Visual disability rates in a ten-year cohort of patients with anterior visual pathway meningiomas.

    PubMed

    Bor-Shavit, Elite; Hammel, Naama; Nahum, Yoav; Rappaport, Zvi Harry; Stiebel-Kalish, Hadas

    2015-01-01

    To examine the visual outcome of anterior visual pathway meningioma (AVPM) patients followed for at least one year. Data were collected on demographics, clinical course and management. Visual disability was classified at the first and last examination as follows: I--no visual disability; II--mild visual defect in one eye; III--mild visual defect in both eyes; IV--loss of driver's license; V--legally blind. Eight-one AVPM patients had their tumor originate in the clinoid process in 23 (28%), sphenoid-wing area in 18 (22%), cavernous sinus in 15 (19%), tuberculum sellae in 8 (10%), and mixed in 17 (21%). On last examination, 46 patients (57%) had good visual acuity in one or both eyes (Class I or II) and 17 (21%) were mildly affected in both eyes. The rate of Class IV disability was 16%, and Class V disability was 6%. Attention needs to be addressed to the considerable proportion of patients with AVPM (22% in this study) who may lose their driver's license or become legally blind. Occupational therapists should play an important role in the multidisciplinary management of those patients to help them adapt to their new physical and social situation. Anterior visual pathway meningiomas (AVPMs) are commonly not life-threatening but they can lead to profound visual disability, especially when the tumor originates in the tuberculum sellae and cavernous sinus. Particular attention should be paid to visual acuity and visual field deficits, as these can profoundly affect the patient's quality of life including ability to drive and activities of daily living. The interdisciplinary management of patients with AVPM should include the neurosurgeon, neuro-ophthalmologist and occupational therapist. Also, early intervention by the occupational therapist can help patients adapt to their current physical and social situation and return to everyday tasks more rapidly.

  3. Visual acuity and fatty acid status of term infants fed human milk and formulas with and without docosahexaenoate and arachidonate from egg yolk lecithin.

    PubMed

    Carlson, S E; Ford, A J; Werkman, S H; Peeples, J M; Koo, W W

    1996-05-01

    Preterm infants fed formulas with docosahexaenoic acid (DHA, 22:6n-3) during the interval equivalent to the last intrauterine trimester and beyond have higher circulating DHA and transiently higher visual acuity compared with infants fed formulas containing linolenic acid. In term infants several nonrandomized studies of infants receiving DHA from human milk suggest a relationship between DHA status and acuity, but the evidence for a cause-and-effect relationship is mixed. In the present study, term infants were randomly assigned to a standard term formula (n = 20) or the same formula with egg yolk lecithin to provide DHA (0.1%) and arachidonic acid (AA, 20:4n-6, 0.43%) (n = 19) at levels reported in milk of American women. A third group of infants was breast fed for > or = 3 mo (n = 19). Grating visual acuity (Teller Acuity Card procedure) and plasma and red blood cell (RBC) phosphatidylcholine (PC) and phosphatidylethanolamine (PE) DHA and AA were determined at corrected ages of 2, 4, 6, 9 (acuity only), and 12 mo past term = 40 wk postmenstrual age (PMA). At 2 mo breast-fed infants and infants fed the supplemented formula had higher grating acuity than term infants fed standard formula. As in preterm infants, the increase was transient. Plasma PC DHA and AA and RBC PE AA increased by 2 mo in supplemented infants, but RBC PE DHA in supplemented infants was not higher than in controls until 4 mo and beyond. Despite normal intrauterine accumulation of DHA and AA, infants fed formula with 2% linolenic acid and 0.1% DHA had better 2-mo visual acuity than infants fed formula with 2% linolenic acid.

  4. Objective evaluation of the visual acuity in human eyes

    NASA Astrophysics Data System (ADS)

    Rosales, M. A.; López-Olazagasti, E.; Ramírez-Zavaleta, G.; Varillas, G.; Tepichín, E.

    2009-08-01

    Traditionally, the quality of the human vision is evaluated by a subjective test in which the examiner asks the patient to read a series of characters of different sizes, located at a certain distance of the patient. Typically, we need to ensure a subtended angle of vision of 5 minutes, which implies an object of 8.8 mm high located at 6 meters (normal or 20/20 visual acuity). These characters constitute what is known as the Snellen chart, universally used to evaluate the spatial resolution of the human eyes. The mentioned process of identification of characters is carried out by means of the eye - brain system, giving an evaluation of the subjective visual performance. In this work we consider the eye as an isolated image-forming system, and show that it is possible to isolate the function of the eye from that of the brain in this process. By knowing the impulse response of the eye´s system we can obtain, in advance, the image of the Snellen chart simultaneously. From this information, we obtain the objective performance of the eye as the optical system under test. This type of results might help to detect anomalous situations of the human vision, like the so called "cerebral myopia".

  5. Are blind people more likely to accept free cataract surgery? A study of vision-related quality of life and visual acuity in Kenya.

    PubMed

    Briesen, Sebastian; Roberts, Helen; Ilako, Dunera; Karimurio, Jefitha; Courtright, Paul

    2010-01-01

    To determine possible differences in visual acuity, socio-demographic factors and vision-related Quality of Life (QoL) between people accepting and people refusing sponsored cataract surgery. Three hundred and fifty seven local residents with visually impairing cataract, presenting at screening sites in Kwale District, Kenya were clinically assessed and interviewed. The World Health Organization (WHO) QoL-questionnaire WHO/Prevention of Blindness and Deafness Visual Functioning Questionnaire 20 (PBD-VFQ20) was used to determine the vision-related QoL. A standardized questionnaire asked for socio-demographic data and prior cataract surgery in one eye. After interview, patients were offered free surgery. Primary outcome was the mean QoL-score between acceptors and non-acceptors. Secondary outcomes were visual acuity and socio-demographic factors and their contribution to QoL-scores and the decision on acceptance or refusal. Fifty nine people (16.5%) refused and 298 accepted cataract surgery. Vision-related QoL was poorer in people accepting than in those refusing (mean score 51.54 and 43.12 respectively). People with poor visual acuity were only slightly more likely to accept surgery than people with better vision; the strongest predictors of acceptance were the QoL-score and gender. Men were twice as likely to accept compared to women. Of people who accepted surgery, 73.8% had best eye vision of 20/200 or better. In this population, visual acuity was of limited use to predict a person's decision to accept or refuse cataract surgery. QoL-scores provide further insight into which individuals will agree to surgery and it might be useful to adapt the QoL-questions for field use. Gender inequities remain a matter of concern with men being more likely to get sight-restoring surgery.

  6. Brief Report: The Relationship between Visual Acuity, the Embedded Figures Test and Systemizing in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Brosnan, Mark J.; Gwilliam, Lucy R.; Walker, Ian

    2012-01-01

    Enhanced performance upon the Embedded Figures Test (EFT) in individuals with autism spectrum disorder (ASD) has informed psychological theories of the non-social aspects that characterise ASD. The Extreme Male Brain theory of autism proposes that enhanced visual acuity underpins greater attention to detail (assessed by the EFT) which is a…

  7. Association of Visual Impairment and All-Cause 10-Year Mortality Among Indigenous Australian Individuals Within Central Australia: The Central Australian Ocular Health Study.

    PubMed

    Ng, Soo Khai; Kahawita, Shyalle; Andrew, Nicholas Howard; Henderson, Tim; Craig, Jamie Evan; Landers, John

    2018-05-01

    It is well established from different population-based studies that visual impairment is associated with increased mortality rate. However, to our knowledge, the association of visual impairment with increased mortality rate has not been reported among indigenous Australian individuals. To assess the association between visual impairment and 10-year mortality risk among the remote indigenous Australian population. Prospective cohort study recruiting indigenous Australian individuals from 30 remote communities located within the central Australian statistical local area over a 36-month period between July 2005 and June 2008. The data were analyzed in January 2017. Visual acuity, slitlamp biomicroscopy, and fundus examination were performed on all patients at recruitment. Visual impairment was defined as a visual acuity of less than 6/12 in the better eye. Mortality rate and mortality cause were obtained at 10 years, and statistical analyses were performed. Hazard ratios for 10-year mortality with 95% confidence intervals are presented. One thousand three hundred forty-seven patients were recruited from a total target population number of 2014. The mean (SD) age was 56 (11) years, and 62% were women. The total all-cause mortality was found to be 29.3% at 10 years. This varied from 21.1% among those without visual impairment to 48.5% among those with visual impairment. After adjustment for age, sex, and the presence of diabetes and hypertension, those with visual impairment were 40% more likely to die (hazard ratio, 1.40; 95% CI, 1.16-1.70; P = .001) during the 10-year follow-up period compared with those with normal vision. Bilateral visual impairment among remote indigenous Australian individuals was associated with 40% higher 10-year mortality risk compared with those who were not visually impaired. Resource allocation toward improving visual acuity may therefore aid in closing the gap in mortality outcomes between indigenous and nonindigenous Australian

  8. Association between visual impairment and patient-reported visual disability at different stages of cataract surgery.

    PubMed

    Acosta-Rojas, E Ruthy; Comas, Mercè; Sala, Maria; Castells, Xavier

    2006-10-01

    To evaluate the association between visual impairment (visual acuity, contrast sensitivity, stereopsis) and patient-reported visual disability at different stages of cataract surgery. A cohort of 104 patients aged 60 years and over with bilateral cataract was assessed preoperatively, after first-eye surgery (monocular pseudophakia) and after second-eye surgery (binocular pseudophakia). Partial correlation coefficients (PCC) and linear regression models were calculated. In patients with bilateral cataracts, visual disability was associated with visual acuity (PCC = -0.30) and, to a lesser extent, with contrast sensitivity (PCC = 0.16) and stereopsis (PCC = -0.09). In monocular and binocular pseudophakia, visual disability was more strongly associated with stereopsis (PCC = -0.26 monocular and -0.51 binocular) and contrast sensitivity (PCC = 0.18 monocular and 0.34 binocular) than with visual acuity (PCC = -0.18 monocular and -0.18 binocular). Visual acuity, contrast sensitivity and stereopsis accounted for between 17% and 42% of variance in visual disability. The association of visual impairment with patient-reported visual disability differed at each stage of cataract surgery. Measuring other forms of visual impairment independently from visual acuity, such as contrast sensitivity or stereopsis, could be important in evaluating both needs and outcomes in cataract surgery. More comprehensive assessment of the impact of cataract on patients should include measurement of both visual impairment and visual disability.

  9. Meta-analysis of dietary essential fatty acids and long-chain polyunsaturated fatty acids as they relate to visual resolution acuity in healthy preterm infants.

    PubMed

    SanGiovanni, J P; Parra-Cabrera, S; Colditz, G A; Berkey, C S; Dwyer, J T

    2000-06-01

    To derive combined estimates of visual resolution acuity differences between healthy preterm infants consuming different compositions and ratios of essential fatty acids (EFAs) and docosahexaenoic acid (DHA), an omega-3 (n-3) long-chain polyunsaturated fatty acid (LCPUFA). Electronic biomedical reference database (Medline and Health Star from 1965 to July 1999) searches with index terms omega-3, n-3, infant, vision, acuity, and human. Current review article, monograph, and book chapter bibliography/reference section hand searches. A total of 5 original articles and 4 review chapters were reviewed for details on study design, conduct, and outcome. Four prospective trials of EFA/LCPUFA supplementation were included in these analyses. For behaviorally based outcomes, there were 2 randomized comparisons each at visual-evoked potential), there were 2 randomized comparisons each at visual resolution acuity between groups of infants who received a source of dietary EFAs/LCPUFAs and groups who did not was computed and then analyzed with the DerSimonian and Laird random-effects method. Analysis of the randomized comparisons (DHA-supplemented formula vs DHA-free formula) showed significant differences in visual resolution acuity at 2 and 4 months of age. Combined estimates of behaviorally based visual resolution

  10. SMARTPHONE-BASED DILATED FUNDUS PHOTOGRAPHY AND NEAR VISUAL ACUITY TESTING AS INEXPENSIVE SCREENING TOOLS TO DETECT REFERRAL WARRANTED DIABETIC EYE DISEASE.

    PubMed

    Toy, Brian C; Myung, David J; He, Lingmin; Pan, Carolyn K; Chang, Robert T; Polkinhorne, Alison; Merrell, Douglas; Foster, Doug; Blumenkranz, Mark S

    2016-05-01

    To compare clinical assessment of diabetic eye disease by standard dilated examination with data gathered using a smartphone-based store-and-forward teleophthalmology platform. 100 eyes of 50 adult patients with diabetes from a health care safety-net ophthalmology clinic. All patients underwent comprehensive ophthalmic examination. Concurrently, a smartphone was used to estimate near visual acuity and capture anterior and dilated posterior segment photographs, which underwent masked, standardized review. Quantitative comparison of clinic and smartphone-based data using descriptive, kappa, Bland-Altman, and receiver operating characteristic analyses was performed. Smartphone visual acuity was successfully measured in all eyes. Anterior and posterior segment photography was of sufficient quality to grade in 96 and 98 eyes, respectively. There was good correlation between clinical Snellen and smartphone visual acuity measurements (rho = 0.91). Smartphone-acquired fundus photographs demonstrated 91% sensitivity and 99% specificity to detect moderate nonproliferative and worse diabetic retinopathy, with good agreement between clinic and photograph grades (kappa = 0.91 ± 0.1, P < 0.001; AUROC = 0.97, 95% confidence interval, 0.93-1). The authors report a smartphone-based telemedicine system that demonstrated sensitivity and specificity to detect referral-warranted diabetic eye disease as a proof-of-concept. Additional studies are warranted to evaluate this approach to expanding screening for diabetic retinopathy.

  11. Reduced response cluster size in early visual areas explains the acuity deficit in amblyopia.

    PubMed

    Huang, Yufeng; Feng, Lixia; Zhou, Yifeng

    2017-05-03

    Focal visual stimulation typically results in the activation of a large portion of the early visual cortex. This spread of activity is attributed to long-range lateral interactions. Such long-range interactions may serve to stabilize a visual representation or to simply modulate incoming signals, and any associated dysfunction in long-range activation may reduce sensitivity to visual information in conditions such as amblyopia. We sought to measure the dispersion of cortical activity following local visual stimulation in a group of patients with amblyopia and matched normal. Twenty adult anisometropic amblyopes and 10 normal controls participated in this study. Using a multifocal stimulation, we simultaneously measured cluster sizes to multiple stimulation points in the visual field. We found that the functional MRI (fMRI) response cluster size that corresponded to the fellow eye was significantly larger as opposed to that corresponding to the amblyopic eye and that the fMRI response cluster size at the two more central retinotopic locations correlated with amblyopia acuity deficit. Our results suggest that the amblyopic visual cortex has a diminished long-range communication as evidenced by significantly smaller cluster of activity as measured with fMRI. These results have important implications for models of amblyopia and approaches to treatment.

  12. Visual acuity, self-reported vision and falls in the EPIC-Norfolk Eye study.

    PubMed

    Yip, Jennifer L Y; Khawaja, Anthony P; Broadway, David; Luben, Robert; Hayat, Shabina; Dalzell, Nichola; Bhaniani, Amit; Wareham, Nicholas; Khaw, Kay-Tee; Foster, Paul J

    2014-03-01

    To examine the relationship between visual acuity (VA) and self-reported vision (SRV) in relation to falls in 8317 participants of the European Prospective Investigation into Cancer-Norfolk Eye study. All participants completed a health questionnaire that included a question regarding SRV and questions regarding the number of falls in the past year. Distance VA was measured using a logMAR chart for each eye. Poor SRV was defined as those reporting fair or poor distance vision. The relationship between VA and SRV and self-rated falls was analysed by logistic regression, adjusting for age, sex, physical activity, body mass index, chronic disease, medication use and grip strength. Of 8317 participants, 26.7% (95% CI 25.7% to 27.7%) had fallen in the past 12 months. Worse VA and poorer SRV were associated with one or more falls in multivariable analysis (OR for falls=1.31, 95% CI 1.04 to 1.66 and OR=1.32, 95% CI 1.09 to 1.61, respectively). Poorer SRV was significantly associated with falls even after adjusting for VA (OR=1.28, 95% CI 1.05 to 1.57). SRV was associated with falls independently of VA and could be used as a simple proxy measure for other aspects of visual function to detect people requiring vision-related falls interventions.

  13. Reliability and Normative Data for the Dynamic Visual Acuity Test for Vestibular Screening.

    PubMed

    Riska, Kristal M; Hall, Courtney D

    2016-06-01

    The purpose of this study was to determine reliability of computerized dynamic visual acuity (DVA) testing and to determine reference values for younger and older adults. A primary function of the vestibular system is to maintain gaze stability during head motion. The DVA test quantifies gaze stabilization with the head moving versus stationary. Commercially available computerized systems allow clinicians to incorporate DVA into their assessment; however, information regarding reliability and normative values of these systems is sparse. Forty-six healthy adults, grouped by age, with normal vestibular function were recruited. Each participant completed computerized DVA testing including static visual acuity, minimum perception time, and DVA using the NeuroCom inVision System. Testing was performed by two examiners in the same session and then repeated at a follow-up session 3 to 14 days later. Intraclass correlation coefficients (ICCs) were used to determine inter-rater and test-retest reliability. ICCs for inter-rater reliability ranged from 0.323 to 0.937 and from 0.434 to 0.909 for horizontal and vertical head movements, respectively. ICCs for test-retest reliability ranged from 0.154 to 0.856 and from 0.377 to 0.9062 for horizontal and vertical head movements, respectively. Overall, raw scores (left/right DVA and up/down DVA) were more reliable than DVA loss scores. Reliability of a commercially available DVA system has poor-to-fair reliability for DVA loss scores. The use of a convergence paradigm and not incorporating the forced choice paradigm may contribute to poor reliability.

  14. Validation of an automated tractography method for the optic radiations as a biomarker of visual acuity in neurofibromatosis-associated optic pathway glioma.

    PubMed

    de Blank, Peter; Fisher, Michael J; Gittleman, Haley; Barnholtz-Sloan, Jill S; Badve, Chaitra; Berman, Jeffrey I

    2018-01-01

    Fractional anisotropy (FA) of the optic radiations has been associated with vision deficit in multiple intrinsic brain pathologies including NF1 associated optic pathway glioma, but hand-drawn regions of interest used in previous tractography methods limit consistency of this potential biomarker. We created an automated method to identify white matter tracts in the optic radiations and compared this method to previously reported hand-drawn tractography. Automated tractography of the optic radiation using probabilistic streamline fiber tracking between the lateral geniculate nucleus of the thalamus and the occipital cortex was compared to the hand-drawn method between regions of interest posterior to Meyer's loop and anterior to tract branching near the calcarine cortex. Reliability was assessed by two independent raters in a sample of 20 healthy child controls. Among 50 children with NF1-associated optic pathway glioma, the association of FA and visual acuity deficit was compared for both tractography methods. Hand-drawn tractography methods required 2.6±0.9min/participant; automated methods were performed in <1min of operator time for all participants. Cronbach's alpha was 0.83 between two independent raters for FA in hand-drawn tractography, but repeated automated tractography resulted in identical FA values (Cronbach's alpha=1). On univariate and multivariate analyses, FA was similarly associated with visual acuity loss using both methods. Receiver operator characteristic curves of both multivariate models demonstrated that both automated and hand-drawn tractography methods were equally able to distinguish normal from abnormal visual acuity. Automated tractography of the optic radiations offers a fast, reliable and consistent method of tract identification that is not reliant on operator time or expertise. This method of tract identification may be useful as DTI is developed as a potential biomarker for visual acuity. Copyright © 2017 Elsevier Inc. All rights

  15. Using the Freiburg Acuity and Contrast Test to measure visual performance in USAF personnel after PRK.

    PubMed

    Dennis, Richard J; Beer, Jeremy M A; Baldwin, J Bruce; Ivan, Douglas J; Lorusso, Frank J; Thompson, William T

    2004-07-01

    Photorefractive keratectomy (PRK) may be an alternative to spectacle and contact lens wear for United States Air Force (USAF) aircrew and may offer some distinct advantages in operational situations. However, any residual corneal haze or scar formation from PRK could exacerbate the disabling effects of a bright glare source on a complex visual task. The USAF recently completed a longitudinal clinical evaluation of the long-term effects of PRK on visual performance, including the experiment described herein. After baseline data were collected, 20 nonflying active duty USAF personnel underwent PRK. Visual performance was then measured at 6, 12, and 24 months after PRK. Visual acuity (VA) and contrast sensitivity (CS) data were collected by using the Freiburg Acuity and Contrast Test (FrACT), with the subject viewing half of the runs through a polycarbonate windscreen. Experimental runs were completed under 3 glare conditions: no glare source and with either a broadband or a green laser (532-nm) glare annulus (luminance approximately 6090 cd/m) surrounding the Landolt C stimulus. Systematic effects of PRK on VA relative to baseline were not identified. However, VA was almost 2 full Snellen lines worse with the laser glare source in place versus the broadband glare source. A significant drop-off was observed in CS performance after PRK under conditions of no glare and broadband glare; this was the case both with and without the windscreen. As with VA, laser glare disrupted CS performance significantly and more than broadband glare did. PRK does not appear to have affected VA, but the changes in CS might represent a true decline in visual performance. The greater disruptive effects from laser versus broadband glare may be a result of increased masking from coherent spatial noise (speckle) surrounding the laser stimulus.

  16. Visual function at 11 years of age in preterm-born children with and without fetal brain sparing.

    PubMed

    Kok, Joke H; Prick, Liesbeth; Merckel, Elly; Everhard, Yolande; Verkerk, Gijs J Q; Scherjon, Sicco A

    2007-06-01

    We have demonstrated earlier an accelerated maturation of the visual evoked potential in the first year of life in preterm infants with antenatal brain sparing. We have now assessed visual functioning at 11 years of age in the same cohort and compared the groups with and without brain sparing. One hundred sixteen survivors included in a study on the outcome of preterm infants born at <33 weeks' gestation with and without fetal brain sparing and admitted to the NICU were followed extensively. Ninety-eight infants (85%) were again assessed at 11 years of age. Data were available for fetal Doppler measurements indicating brain sparing, neonatal cerebral ultrasound scanning, and developmental outcome in the first 5 years. Mean birth weight was 1303 g; mean gestational age was 29.8 weeks. The infants were divided into 2 groups with and without brain sparing. Visual functioning was estimated by measuring visual acuity, visual fields, eye position, and binocular function and by visual motor tests. Six percent of the children were found to have a visual acuity of <0.8, 12% had strabismus, and 14% to 46% showed abnormal results on the visual motor tests. No statistical differences were found between the 2 groups. However, children with severe cerebral ultrasound diagnoses in the neonatal period were found to have significantly more abnormalities on visual functioning and lower scores on visual motor tests than children without these morbidities. Children with fetal brain sparing do not demonstrate a different development of their visual functioning at late school age. However, an abnormal cerebral ultrasound in the neonatal period is associated with impaired visual function in later life.

  17. The correlation between visual acuity and color vision as an indicator of the cause of visual loss.

    PubMed

    Almog, Yehoshua; Nemet, Arie

    2010-06-01

    To explore the correlation between visual acuity (VA) and color vision and to establish a guide for the diagnosis of the cause of visual loss based on this correlation. Retrospective comparative evaluation of a diagnostic test. A total of 259 patients with visual impairment caused by 1 of 4 possible disease categories were included. Patients were divided into 4 groups according to the etiology of visual loss: 1) optic neuropathies, 2) macular diseases, 3) media opacities, and 4) amblyopia. The best-corrected VA was established and a standard Ishihara 15 color plates was tested and correlated to the VA in every group separately. Correlation between the VA and the color vision along the different etiologies was evaluated. Frequency of each combination of color vision and VA in every disease category was established. VA is correlated with color vision in all 4 disease categories. For the same degree of VA loss, patients with optic neuropathy are most likely and patients with amblyopia are the least expected to have a significant color vision loss. Patients with optic neuropathy had considerably worse average color vision (6.7/15) compared to patients in the other 3 disease categories: 11.1/15 (macular diseases), 13.2/15 (media opacities), and 13.4/15 (amblyopia). Diseases of the optic nerve affect color vision earlier and more profoundly than other diseases. When the cause of visual loss is uncertain, the correlation between the severity of color vision and VA loss can imply the possible etiology of the visual loss. Copyright 2010 Elsevier Inc. All rights reserved.

  18. A morphological study of amblyopic eyes in children failing to achieve normal visual acuity after electronically monitored long-term occlusion treatment.

    PubMed

    Kuhli-Hattenbach, Claudia; Koss, Michael Janusz; Kohnen, Thomas; Fronius, Maria

    2015-11-01

    To search for morphological abnormalities in compliant unilaterally amblyopic children with poor occlusion treatment outcomes, for the first time with electronically recorded patching dosage. We included school children with remaining interocular logMAR (logarithm of the minimum angle of resolution) difference ≥ 0.3 after patching time of more than 22 months and 1300 h total in a previous prospective study. Six patients with a mean age of 11.19 years were included. Four patients had anisometropic amblyopia and two patients had a mixed strabismic and anisometropic amblyopia. Best-corrected visual acuity, cycloplegic refraction, dilated fundus examination, optic disc morphology and macular thickness using optical coherence tomography (OCT), retinal visual acuity, color perception, and the presence of a relative afferent pupillary defect (RAPD) were assessed. Paired t tests were performed to compare optic disc values and macular thickness of the amblyopic eyes to those of the fellow eyes. Average (± SD) logMAR VA in the amblyopic eyes was 0.42 (±0.23) with a remaining average interocular difference (IOD) of 0.51 (± 0.23), despite electronically monitored occlusion treatment of more than 1300 h. All patients presented with hyperopia and a significantly different mean spherical equivalent of + 4.73 (± 2.73) D in the amblyopic eye compared with the fellow eye (p = 0.02). A statistically significant difference in macular thickness was found between amblyopic and fellow eyes, with amblyopic eyes having an increased average thickness (p = 0.0062) and total volume (p = 0.0091) of the macula. One patient had familial hereditary primary macrodisc in both eyes. Our results provide evidence that average macular thickness and total macular volume tended to be increased among these compliant amblyopic children with unsatisfactory occlusion treatment outcomes. Further studies are warranted to evaluate whether morphological changes may have an impact on the

  19. Six-Year Incidence of Blindness and Visual Impairment in Kenya: The Nakuru Eye Disease Cohort Study

    PubMed Central

    Bastawrous, Andrew; Mathenge, Wanjiku; Wing, Kevin; Rono, Hillary; Gichangi, Michael; Weiss, Helen A.; Macleod, David; Foster, Allen; Burton, Matthew J.; Kuper, Hannah

    2016-01-01

    Purpose To describe the cumulative 6-year incidence of visual impairment (VI) and blindness in an adult Kenyan population. The Nakuru Posterior Segment Eye Disease Study is a population-based sample of 4414 participants aged ≥50 years, enrolled in 2007–2008. Of these, 2170 (50%) were reexamined in 2013–2014. Methods The World Health Organization (WHO) and US definitions were used to calculate presenting visual acuity classifications based on logMAR visual acuity tests at baseline and follow-up. Detailed ophthalmic and anthropometric examinations as well as a questionnaire, which included past medical and ophthalmic history, were used to assess risk factors for study participation and vision loss. Cumulative incidence of VI and blindness, and factors associated with these outcomes, were estimated. Inverse probability weighting was used to adjust for nonparticipation. Results Visual acuity measurements were available for 2164 (99.7%) participants. Using WHO definitions, the 6-year cumulative incidence of VI was 11.9% (95%CI [confidence interval]: 10.3–13.8%) and blindness was 1.51% (95%CI: 1.0–2.2%); using the US classification, the cumulative incidence of blindness was 2.70% (95%CI: 1.8–3.2%). Incidence of VI increased strongly with older age, and independently with being diabetic. There are an estimated 21 new cases of VI per year in people aged ≥50 years per 1000 people, of whom 3 are blind. Therefore in Kenya we estimate that there are 92,000 new cases of VI in people aged ≥50 years per year, of whom 11,600 are blind, out of a total population of approximately 4.3 million people aged 50 and above. Conclusions The incidence of VI and blindness in this older Kenyan population was considerably higher than in comparable studies worldwide. A continued effort to strengthen the eye health system is necessary to support the growing unmet need in an aging and growing population. PMID:27820953

  20. Six-Year Incidence of Blindness and Visual Impairment in Kenya: The Nakuru Eye Disease Cohort Study.

    PubMed

    Bastawrous, Andrew; Mathenge, Wanjiku; Wing, Kevin; Rono, Hillary; Gichangi, Michael; Weiss, Helen A; Macleod, David; Foster, Allen; Burton, Matthew J; Kuper, Hannah

    2016-11-01

    To describe the cumulative 6-year incidence of visual impairment (VI) and blindness in an adult Kenyan population. The Nakuru Posterior Segment Eye Disease Study is a population-based sample of 4414 participants aged ≥50 years, enrolled in 2007-2008. Of these, 2170 (50%) were reexamined in 2013-2014. The World Health Organization (WHO) and US definitions were used to calculate presenting visual acuity classifications based on logMAR visual acuity tests at baseline and follow-up. Detailed ophthalmic and anthropometric examinations as well as a questionnaire, which included past medical and ophthalmic history, were used to assess risk factors for study participation and vision loss. Cumulative incidence of VI and blindness, and factors associated with these outcomes, were estimated. Inverse probability weighting was used to adjust for nonparticipation. Visual acuity measurements were available for 2164 (99.7%) participants. Using WHO definitions, the 6-year cumulative incidence of VI was 11.9% (95%CI [confidence interval]: 10.3-13.8%) and blindness was 1.51% (95%CI: 1.0-2.2%); using the US classification, the cumulative incidence of blindness was 2.70% (95%CI: 1.8-3.2%). Incidence of VI increased strongly with older age, and independently with being diabetic. There are an estimated 21 new cases of VI per year in people aged ≥50 years per 1000 people, of whom 3 are blind. Therefore in Kenya we estimate that there are 92,000 new cases of VI in people aged ≥50 years per year, of whom 11,600 are blind, out of a total population of approximately 4.3 million people aged 50 and above. The incidence of VI and blindness in this older Kenyan population was considerably higher than in comparable studies worldwide. A continued effort to strengthen the eye health system is necessary to support the growing unmet need in an aging and growing population.

  1. Visual functions in amblyopia as determinants of response to treatment.

    PubMed

    Singh, Vinita; Agrawal, Siddharth

    2013-01-01

    To describe the visual functions in amblyopia as determinants of response to treatment. Sixty-nine patients with unilateral and bilateral amblyopia (114 amblyopic eyes) 3 to 15 years old (mean age: 8.80 ± 2.9 years), 40 males (58%) and 29 females (42%), were included in this study. All patients were treated by conventional occlusion 6 hours per day for mild to moderate amblyopia (visual acuity 0.70 or better) and full-time for 4 weeks followed by 6 hours per day for severe amblyopia (visual acuity 0.8 or worse). During occlusion, near activities requiring hand-eye coordination were advised. The follow-up examination was done at 3 and 6 months. Improvement in visual acuity was evaluated on the logMAR chart and correlated with the visual functions. Statistical analysis was done using Wilcoxon rank sum test (Mann-Whitney U test) and Kruskal-Wallis analysis. There was a statistically significant association of poor contrast sensitivity with the grade of amblyopia (P < .001). The grade of amblyopia (P < .01), accommodation (P < .01), stereopsis (P = .01), and mesopic visual acuity (P < .03) were found to have a correlation with response to amblyopia therapy. The grade of amblyopia (initial visual acuity) and accommodation are strong determinants of response to amblyopia therapy, whereas stereopsis and mesopic visual acuity have some value as determinants. Copyright 2013, SLACK Incorporated.

  2. Myopic Maculopathy and Optic Disc Changes in Highly Myopic Young Asian Eyes and Impact on Visual Acuity.

    PubMed

    Koh, Victor; Tan, Colin; Tan, Pei Ting; Tan, Marcus; Balla, Vinay; Nah, Gerard; Cheng, Ching-Yu; Ohno-Matsui, Kyoko; Tan, Mellisa M H; Yang, Adeline; Zhao, Paul; Wong, Tien Yin; Saw, Seang-Mei

    2016-04-01

    To determine the prevalence and risk factors of myopic maculopathy and specific optic disc and macular changes in highly myopic eyes of young Asian adults and their impact on visual acuity. Prospective cross-sectional study. In total, 593 highly myopic (spherical equivalent refraction [SER] less than -6.00 diopters [D]) and 156 emmetropic (SER between -1.00 and +1.00 D) male participants from a population-based survey were included. All participants underwent standardized medical interviews, ophthalmic examination, and color fundus photographs. These photographs were graded systematically to determine the presence of optic disc and macular lesions. Myopic maculopathy was classified based on the International Classification of Myopic Maculopathy. The mean age was 21.1 ± 1.2 years. The mean SER for the highly myopic and emmetropic group was -8.87 ± 2.11 D and 0.40 ± 0.39 D, respectively (P < .001). Compared to emmetropic eyes, highly myopic eyes were significantly more likely to have optic disc tilt, peripapillary atrophy (PPA), posterior staphyloma, chorioretinal atrophy, and myopic maculopathy (all P < .001). The main findings included PPA (98.3%), disc tilt (22.0%), posterior staphyloma (32.0%), and chorioretinal atrophy (8.3%). Myopic maculopathy was present in 8.3% of highly myopic eyes and was associated with older age (odds ratio [OR] 1.66; 95% CI: 1.22, 2.26), reduced choroidal thickness (OR 0.99; 95% CI: 0.98, 0.99), and increased axial length (AL) (OR 1.52; 95% CI: 1.06, 2.19). The presence of disc tilt, posterior staphyloma, and chorioretinal atrophy were associated with reduced visual acuity. Our study showed that myopia-related changes of the optic disc and macula were common in highly myopic eyes even at a young age. The risk factors for myopic maculopathy include increased age, longer AL, and reduced choroidal thickness. Some of these changes were associated with reduced central visual function. Copyright © 2016 Elsevier Inc. All rights

  3. Correlation between spectral-domain OCT findings and visual acuity in X-linked retinoschisis.

    PubMed

    Yang, Hyun Seung; Lee, Jung Bok; Yoon, Young Hee; Lee, Joo Yong

    2014-05-08

    To investigate the tomographic characteristics of the outer retina and choroid and their relationship with visual acuity in X-linked juvenile retinoschisis (XLRS) patients using spectral-domain optical coherence tomography (SD-OCT). In this retrospective, observational, case-control study, we analyzed 20 eyes of 10 patients with XLRS using SD-OCT. The clinical and tomographic features of the outer retina, including the external limiting membrane (ELM), inner segment/outer segment (IS/OS) junction, cone cell outer segment tips (COST) line, photoreceptor outer segment (PROS) length, and choroid, were evaluated. As controls, 40 age-, sex-, and refraction-matched healthy eyes (1:2 matched) were randomly selected and imaged in parallel. The most prevalent area of abnormality in the outer retina layer of our patients was the outer plexiform layer (OPL; 60% of all affected eyes) and COST line (75% of all affected eyes). On average, the subfoveal choroid and PROS lengths were 35 μm thicker and 19 μm thinner, respectively, in XLRS patients (P = 0.084 and P < 0.001, respectively). A dominant IS/OS junction, COST line defects, and PROS length were related to patient best-corrected visual acuity (BCVA; P = 0.029, P = 0.001, and P < 0.001, respectively) by univariate analysis. Cone cell outer segment tips line defect and PROS length were the only factors related to BCVA in multivariate analysis (P = 0.028 and 0.003, respectively). Outer plexiform layer and photoreceptor microstructure defects are frequent in XLRS patients. Cone cell outer segment tips line defects and shortened PROS lengths as well as other photoreceptor microstructure defects may be closely related to poor vision in XLRS.

  4. The Use of Dynamic Visual Acuity as a Functional Test of Gaze Stabilization Following Space Flight

    NASA Technical Reports Server (NTRS)

    Peters, B. T.; Mulavara, A. P.; Brady, R.; Miller, C. A.; Richards, J. T.; Warren, L. E.; Cohen, H. S.; Bloomberg, J. J.

    2006-01-01

    After prolonged exposure to a given gravitational environment the transition to another is accompanied by adaptations in the sensorimotor subsystems, including the vestibular system. Variation in the adaptation time course of these subsystems, and the functional redundancies that exist between them make it difficult to accurately assess the functional capacity and physical limitations of astro/cosmonauts using tests on individual subsystems. While isolated tests of subsystem performance may be the only means to address where interventions are required, direct measures of performance may be more suitable for assessing the operational consequences of incomplete adaptation to changes in the gravitational environment. A test of dynamic visual acuity (DVA) is currently being used in the JSC Neurosciences Laboratory as part of a series of measures to assess the efficacy of a countermeasure to mitigate postflight locomotor dysfunction. In the current protocol, subjects visual acuity is determined using Landolt ring optotypes presented sequentially on a computer display. Visual acuity assessments are made both while standing and while walking at 1.8 m/s on a motorized treadmill. The use of a psychophysical threshold detection algorithm reduces the required number of optotype presentations and the results can be presented immediately after the test. The difference between the walking and standing acuity measures provides a metric of the change in the subject s ability to maintain gaze fixation on the visual target while walking. This functional consequence is observable regardless of the underlying subsystem most responsible for the change. Data from 15 cosmo/astronauts have been collected following long-duration (approx. 6 months) stays in space using a visual target viewing distance of 4.0 meters. An investigation of the group mean shows a change in DVA soon after the flight that asymptotes back to baseline approximately one week following their return to earth. The

  5. Quality of life and visual acuity outcomes in the Registry in Glaucoma Outcomes Research study.

    PubMed

    Coleman, Anne L; Lum, Flora C; Gliklich, Richard E; Velentgas, Priscilla; Su, Zhaohui

    2016-01-01

    The RiGOR study evaluated the association of treatment and patient-reported outcomes for open-angle glaucoma patients. The Glaucoma Symptom Scale (National Eye Institute-Visual Function Questionnaire (NEI-VFQ) and visual acuity (VA) were collected as quality of life measures. The proportion of patients with improvement of at least two lines of vision was highest in the incisional surgery group (14.2% compared with 9.9% for laser surgery and 10.9% for additional medication). No clinically relevant differences were seen in benefit for the laser surgery or incisional surgery groups compared with additional medications for the Glaucoma Symptom Scale or NEI-VFQ measures or subscales. Differences in quality of life by race need to be explored in further studies.

  6. Repeatability of Monocular Acuity Testing in Adults with and without Down Syndrome.

    PubMed

    Ravikumar, Ayeswarya; Benoit, Julia S; Morrison, Kelsie B; Marsack, Jason D; Anderson, Heather A

    2018-03-01

    Individuals with Down syndrome may experience greater difficulty reliably performing visual acuity (VA) tests because of intellectual disability and limitations in visual quality. This study evaluated the repeatability of acuity (Bailey-Lovie [BL] and HOTV) in subjects with and without Down syndrome. High-contrast VA was measured in both eyes of 30 subjects with Down syndrome (mean, 30 years; range, 18 to 50 years) and 24 control subjects without Down syndrome (mean, 29 years; range, 18 to 50 years). In the Down syndrome group, 23 subjects performed BL, and 7 subjects performed HOTV. All control subjects performed both BL and HOTV, but for HOTV analysis, only seven age-matched control subjects were included. For each eye, subjects performed VA three times on different charts (computer controlled, single-line display) until five total letters were missed on each chart. A repeated-measure ANOVA was used to compare the acuity measures between groups. The average logMAR VA for subjects with Down syndrome was approximately six lines worse than the control subjects (BL: Down syndrome = right eye: 0.51 ± 0.16, left eye: 0.53 ± 0.18; control = right eye: -0.06 ± 0.06, left eye: -0.06 ± 0.08, P < .0001; HOTV: Down syndrome = right eye: 0.47 ± 0.19, left eye: 0.46 ± 0.16; control: right eye = -0.11 ± 0.09, left eye: -0.07 ± 0.07, P < .001). Bailey-Lovie VA repeatability (1.96 * Sw * √2) was 0.13 logMAR (6.5 letters) for Down syndrome and 0.09 logMAR (4.5 letters) for control subjects. HOTV VA repeatability was 0.16 logMAR (eight letters) for both Down syndrome and control subjects. Despite poorer acuity in individuals with Down syndrome, repeatability of VA measurements was comparable to control subjects for both BL and HOTV techniques.

  7. Visual function affects prosocial behaviors in older adults.

    PubMed

    Teoli, Dac A; Smith, Merideth D; Leys, Monique J; Jain, Priyanka; Odom, J Vernon

    2016-02-01

    Eye-related pathological conditions such as glaucoma, diabetic retinopathy, and age-related macular degeneration commonly lead to decreased peripheral/central field, decreased visual acuity, and increased functional disability. We sought to answer if relationships exist between measures of visual function and reported prosocial behaviors in an older adult population with eye-related diagnoses. The sample consisted of adults, aged ≥ 60 years old, at an academic hospital's eye institute. Vision ranged from normal to severe impairment. Medical charts determined the visual acuities, ocular disease, duration of disease (DD), and visual fields (VF). Measures of giving help were via validated questionnaires on giving formal support (GFS) and giving informal support; measures of help received were perceived support (PS) and informal support received (ISR). ISR had subscales: tangible support (ISR-T), emotional support (ISR-E), and composite (ISR-C). Visual acuities of the better and worse seeing eyes were converted to LogMAR values. VF information converted to a 4-point rating scale of binocular field loss severity. DD was in years. Among 96 participants (mean age 73.28; range 60-94), stepwise regression indicated a relationship of visual variables to GFS (p < 0.05; Multiple R (2) = 0.1679 with acuity-better eye, VF rating, and DD), PS (p < 0.05; Multiple R (2) = 0.2254 with acuity-better eye), ISR-C (p < 0.05; Multiple R (2) = 0.041 with acuity-better eye), and ISR-T (p < 0.05; Multiple R (2) = 0.1421 with acuity-better eye). The findings suggest eye-related conditions can impact levels and perceptions of support exchanges. Our data reinforces the importance of visual function as an influence on prosocial behavior in older adults.

  8. Femtosecond laser-assisted LASIK versus PRK for high myopia: comparison of 18-month visual acuity and quality.

    PubMed

    Hashemi, Hassan; Ghaffari, Reza; Miraftab, Mohammad; Asgari, Soheila

    2017-08-01

    To compare 18-month outcomes between femtosecond laser-assisted LASIK (femto-LASIK) and photorefractive keratectomy with mitomycin-C (PRK-MMC) for myopia of more than 7.0 D in terms of visual acuity and quality. In this comparative nonrandomized clinical trial, 60 eyes from 30 patients (30 eyes in each group) were enrolled. The two procedures were compared in terms of 18-month changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent, ocular and corneal higher order aberrations (HOAs), and contrast sensitivity (CS). Mean myopia was -8.65 ± 1.51 and -8.04 ± 1.70 D (P = 0.149) and mean ablation depth was 109.37 ± 9.07 and 105.09 ± 12.59 µm (P = 0.138), in the femto-LASIK and PRK-MMC groups, respectively. Baseline parameters were not significantly different between the two groups (all P > 0.05). At 18 months postoperatively, 75 % in the femto-LASIK, versus 57.1 % in the PRK-MMC group, had 20/20 UDVA (P = 0.017). CDVA remained similarly unchanged in both groups (P = 0.616). No case had residual refractive error more than 1.0 D in the femto-LASIK group, while 33.5 % in the other group had more than 1.0 D residual error (P = 0.390). Changes in corneal HOA were not significantly different between the two groups (P = 0.260). Cases in the femto-LASIK group showed more increase in ocular HOA (P = 0.032) and coma (P = 0.083, power = 72 %). CS remained similarly unchanged in all spatial frequencies in both groups (all P > 0.05). Although femto-LASIK induces more HOA compared to PRK-MMC, considering outcomes in terms of 20/20 UDVA, residual refractive error, and CS stability, femto-LASIK provides more favorable results than PRK-MMC in high myopia.

  9. One year study on the integrative intervention of acupressure and interactive multimedia for visual health in school children.

    PubMed

    Yeh, Mei-Ling; Chen, Hsing-Hsia; Chung, Yu-Chu

    2012-12-01

    This study used a larger sample size, added a long-term observation of the effect of intervention, and provided an integrated intervention of acupressure and interactive multimedia of visual health instruction for school children. The short- and long-term effects of the interventions were then evaluated by visual health knowledge, visual acuity, and refractive error. A repeated pretest-posttest controlled trial was used with two experimental groups and one control group. Four elementary schools in northern Taiwan. 287 School children with visual impairment in fourth grade were recruited. One experimental group received the integrative intervention of acupressure and interactive multimedia of visual health instruction (ACIMU), and another received auricular acupressure (AC) alone; whereas a control group received no intervention. Two 10-week interventions were separately given in the fall and spring semesters. The short- and long-term effects of the interventions were then evaluated by visual health knowledge, visual acuity, and refractive error. During the school year the visual health knowledge was significantly higher in the ACIMU group than the control group (p<0.001). A significant difference in the changing visual acuity was in the three groups (p<0.001), with the improvement in the ACIMU group. No difference in the refractive error was found between any two groups (p>0.05). This study demonstrated that a long-term period of acupressure is required to improve school children's visual health. School children receiving the intervention of acupressure combined with interactive multimedia had better improvement of visual health and related knowledge than others. Further study is suggested in which visual health and preventative needs can be established for early childhood. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Is it really important to form a big bubble in DALK to enhance the visual acuity?

    PubMed

    Acar, Banu Torun; Vural, Ece Turan; Acar, Suphi

    2012-09-01

    The aim of this study was to investigate the prognosis of visual acuity (VA) in the patients with keratoconus, who underwent deep anterior lamellar keratoplasty (DALK) with a successful big bubble or lamellar dissection. Sixty-eight eyes of 60 patients with keratoconus, who underwent DALK using the big-bubble technique, were enrolled in this retrospective comparative study. The VA and refractive errors were assessed before the operation and, thereafter, at months 1, 3, 6, and 12 after the operation (1) in the patients who achieved a big-bubble formation, and in those who required layer-by-layer lamellar dissection (2) to reach the Descemet membrane. Successful big bubble was achieved in 50 eyes (73.5 %) (group 1), and lamellar dissection was performed in 18 eyes (26.5 %) (group 2). The mean follow-up period was 22.4±6.2 months in group 1 and 23.7±7.8 months in group 2 (P=0.562). Although best-corrected visual acuity (BCVA) values observed at months 1 and 3 were significantly higher in group 1 than in group 2 (P=0.016 and P=0.024, respectively), there was no statistically significant difference between the two groups for BCVA values observed at months 6 and 12 (P=0.412 and P=0.528, respectively). Although the visual recovery was delayed in the early postoperative follow-up because of residual stroma in lamellar dissection, the final results were comparable between the achievement of big-bubble formation and lamellar dissection.

  11. [Epidemiological survey of visual impairment in Funing County, Jiangsu].

    PubMed

    Yang, M; Zhang, J F; Zhu, R R; Kang, L H; Qin, B; Guan, H J

    2017-07-11

    Objective: To investigate the prevalence of visual impairment and factors associated with visual impairment among people aged 50 years and above in Funing County, Jiangsu Province. Methods: Cross-sectional study. Random cluster sampling was used in selecting individuals aged ≥50 years in 30 clusters, and 5 947 individuals received visual acuity testing and eye examination. Stata 13.0 software was used to analyze the data. Multivariate logistic regression was used to detect possible factors of visual impairment such as age, gender and education. Statistical significance was defined as P< 0.05. Results: A total of 6 145 persons aged 50 years and above were enumerated, and 5 947 (96.8%) participants were examined. Based on the criteria of World Health Organization (WHO) visual impairment classification and presenting visual acuity, 138 persons were diagnosed as blindness, and 1 405 persons were diagnosed as low vision. The prevalence of blindness and low vision was 2.32% and 23.63%, respectively. And the prevalence of visual impairment was 25.95%. Based on the criteria of WHO visual impairment classification and best-corrected visual acuity, 92 persons were diagnosed as blindness, and 383 persons were diagnosed as low vision. The prevalence of blindness and low vision was 1.55% and 6.44%, respectively. And the prevalence of visual impairment was 7.99%. Concerning presenting visual acuity and best-corrected visual acuity, the prevalence of blindness and low vision was higher in old people, females and less educated persons. Cataract (46.63%) was the leading cause of blindness. Uncorrected refractive error (36.51%) was also a main cause of visual impairment. Conclusion: The prevalence of visual impairment is higher in old people, females and less educated persons in Funing County, Jiangsu Province. Cataract is still the leading cause of visual impairment. (Chin J Ophthalmol, 2017, 53: 502-508) .

  12. [Epidemiological Study of Poor Visual Acuity among Schoolchildren in Bonin Islands].

    PubMed

    Ito, Misae; Shimizu, Kimiya; Kawamorita, Takushi; Shoji, Nobuyuki

    2016-04-01

    To investigate the change in uncorrected visual acuity (UCVA) among schoolchildren in Bonin Islands. UCVA of schoolchildren aged 6 to 14 years, was collected from reports of School Health Examination Surveys conducted from 1981 to 2012. The proportion of schoolchildren with poor UCVA in the Bonin Islands was compared with those in metropolitan Tokyo. The results in Bonin Islands were also divided into two groups, before- and after-1996 when terrestrial television broadcasting service has been started, and the data of those two groups were compared. The proportion of schoolchildren with poor UCVA in Bonin Islands was lower than that in Tokyo. Among the residents of Bonin Islands, the proportion of schoolchildren with UCVA of < 1.0 was higher in the after-1996 group than in the before- 1996 group, with a clear increase in schoolchildren with poor UCVA after 1996 (p < 0.01, Fisher's exact test), examined among the 4th grade of elementary school or above. After 1996, 26.6% of first graders at a public junior high school had poor UCVA of < 0.7, whereas before 1996 no such case could be detected. The present study revealed that the proportions of schoolchildren with poor UCVA in Bonin Islands was lower than that in Tokyo; but in the residents of Bonin Islands after 1996, the proportion of the schoolchildren with poor UCVA increased.

  13. Macular Morphology and Visual Acuity in the Second Year of the Comparison of Age-Related Macular Degeneration Treatments Trials.

    PubMed

    Sharma, Sumit; Toth, Cynthia A; Daniel, Ebenezer; Grunwald, Juan E; Maguire, Maureen G; Ying, Gui-Shuang; Huang, Jiayan; Martin, Daniel F; Jaffe, Glenn J

    2016-04-01

    To describe the association between morphologic features on fundus photography (FP), fluorescein angiography (FA), and optical coherence tomography (OCT) and visual acuity (VA) in the second year of the Comparison of Age-related Macular Degeneration Treatments Trials (CATT). Prospective cohort study within a randomized clinical trial. Participants in the CATT. Study eye eligibility required angiographic and OCT evidence of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and VA between 20/25 and 20/320. Treatment was assigned randomly to ranibizumab or bevacizumab with 3 different dosing regimens over a 2-year period. Fluid type, location, and thickness; retina and subretinal tissue complex thickness on OCT; size and lesion composition on FP and FA; and VA. Among 1185 CATT participants, 993 (84%) had fluid on OCT at baseline and completed 2 years of follow-up. At 2 years, intraretinal fluid (IRF), subretinal fluid (SRF), sub-retinal pigment epithelium (RPE) fluid, and subretinal tissue complex thickness decreased in all treatment groups. Ranibizumab monthly was best able to resolve each type of fluid. Eyes with SRF in the foveal center on OCT had better mean VA than eyes with no SRF (72.8 vs. 66.6 letters; P = 0.006). Eyes with IRF in the foveal center had worse mean VA than eyes without IRF (59.9 vs. 70.9 letters; P < 0.0001). Eyes with retinal thickness <120 μm had worse VA compared with eyes with retinal thickness 120 to 212 and >212 μm (59.4 vs. 71.3 vs. 70.3 letters; P < 0.0001). At 2 years, the mean VA (letters) of eyes varied substantially by the type of subfoveal pathology on FP and FA: 70.6 for no pathology; 74.1 for fluid only; 73.3 for CNV or pigment epithelial (RPE) detachment; 68.4 for nongeographic atrophy; and 62.9 for geographic atrophy, hemorrhage, RPE tear, or scar (P < 0.0001). The associations between VA and morphologic features identified through year 1 were maintained or strengthened during year 2. Eyes

  14. Prevalence of Visual Impairment among 4- to 6-years-old Children in Khon Kaen City Municipality, Thailand.

    PubMed

    Wongwai, Phanthipha; Anupongongarch, Pacharapan; Suwannaraj, Sirinya; Asawaphureekorn, Somkiat

    2016-08-01

    To evaluate the prevalence of visual impairment of children aged four to six years in Khon Kaen City Municipality, Thailand. The visual acuity test was performed on 1,286 children in kindergarten schools located in Khon Kaen Municipality. The first test of visual acuity was done by trained teachers and the second test by the pediatric ophthalmologist. The prevalence of visual impairment of both tests was recorded including sensitivity, specificity, likelihood ratio, and predictive value of the test by teachers. The causes of visual impairment were also recorded. There were 39 children with visual impairment from the test by the teacher and 12 children from the test by the ophthalmologist. Myopia is the single cause of visual impairment. Mean spherical equivalence is 1.375 diopters (SD = 0.53). Median spherical equivalence is 1.375 diopters (minimum = 0.5, maximum =4). The detection of visual impairment by trained teachers had a sensitivity of 1.00 (95% CI 0.76-1.00), specificity of 0.98 (95% CI 0.97-0.99), likelihood ratio for a positive test 44.58 (95% CI 30.32-65.54), likelihood ratio for a negative test 0.04 (95% CI 0.003-0.60), positive predictive value of 0.31 (95% CI 0.19-0.47), and negative predictive value of 1.00 (95% CI 0.99-1.00). The prevalence of visual impairment among children aged four to six year old is 0.9%. Trained teachers can be examiners for screening purpose.

  15. Effects of Reduced Acuity and Stereo Acuity on Saccades and Reaching Movements in Adults With Amblyopia and Strabismus.

    PubMed

    Niechwiej-Szwedo, Ewa; Goltz, Herbert C; Colpa, Linda; Chandrakumar, Manokaraananthan; Wong, Agnes M F

    2017-02-01

    Our previous work has shown that amblyopia disrupts the planning and execution of visually-guided saccadic and reaching movements. We investigated the association between the clinical features of amblyopia and aspects of visuomotor behavior that are disrupted by amblyopia. A total of 55 adults with amblyopia (22 anisometropic, 18 strabismic, 15 mixed mechanism), 14 adults with strabismus without amblyopia, and 22 visually-normal control participants completed a visuomotor task while their eye and hand movements were recorded. Univariate and multivariate analyses were performed to assess the association between three clinical predictors of amblyopia (amblyopic eye [AE] acuity, stereo sensitivity, and eye deviation) and seven kinematic outcomes, including saccadic and reach latency, interocular saccadic and reach latency difference, saccadic and reach precision, and PA/We ratio (an index of reach control strategy efficacy using online feedback correction). Amblyopic eye acuity explained 28% of the variance in saccadic latency, and 48% of the variance in mean saccadic latency difference between the amblyopic and fellow eyes (i.e., interocular latency difference). In contrast, for reach latency, AE acuity explained only 10% of the variance. Amblyopic eye acuity was associated with reduced endpoint saccadic (23% of variance) and reach (22% of variance) precision in the amblyopic group. In the strabismus without amblyopia group, stereo sensitivity and eye deviation did not explain any significant variance in saccadic and reach latency or precision. Stereo sensitivity was the best clinical predictor of deficits in reach control strategy, explaining 23% of total variance of PA/We ratio in the amblyopic group and 12% of variance in the strabismus without amblyopia group when viewing with the amblyopic/nondominant eye. Deficits in eye and limb movement initiation (latency) and target localization (precision) were associated with amblyopic acuity deficit, whereas changes in

  16. Effect of Yellow-Tinted Lenses on Visual Attributes Related to Sports Activities

    PubMed Central

    Kohmura, Yoshimitsu; Murakami, Shigeki; Aoki, Kazuhiro

    2013-01-01

    The purpose of this study was to clarify the effect of colored lenses on visual attributes related to sports activities. The subjects were 24 students (11 females, 13 males; average age 21.0 ±1.2 years) attending a sports university. Lenses of 5 colors were used: colorless, light yellow, dark yellow, light gray, and dark gray. For each lens, measurements were performed in a fixed order: contrast sensitivity, dynamic visual acuity, depth perception, hand-eye coordination and visual acuity and low-contrast visual acuity. The conditions for the measurements of visual acuity and low-contrast visual acuity were in the order of Evening, Evening+Glare, Day, and Day+Glare. There were no significant differences among lenses in dynamic visual acuity and depth perception. For hand-eye coordination, time was significantly shorter with colorless than dark gray lenses. Contrast sensitivity was significantly higher with colorless, light yellow, and light gray lenses than with dark yellow and dark gray lenses. The low-contrast visual acuity test in the Day+Glare condition showed no significant difference among the lenses. In the Evening condition, low-contrast visual acuity was significantly higher with colorless and light yellow lenses than with dark gray lenses, and in the Evening+Glare condition, low-contrast visual acuity was significantly higher with colorless lenses than with the other colors except light yellow. Under early evening conditions and during sports activities, light yellow lenses do not appear to have an adverse effect on visual attributes. PMID:23717352

  17. Myopia prevention, near work, and visual acuity of college students: integrating the theory of planned behavior and self-determination theory.

    PubMed

    Chan, Derwin King-Chung; Fung, Ying-Ki; Xing, Suxuan; Hagger, Martin S

    2014-06-01

    There has been little research examining the psychological antecedents of safety-oriented behavior aimed at reducing myopia risk. This study utilizes self-determination theory (SDT) and the theory of planned behavior (TPB) to understand the role of motivational and social-cognitive factors on individuals' near-work behavior. Adopting a prospective design, undergraduate students (n = 107) completed an initial questionnaire based on SDT in week 1, a second questionnaire containing measures of TPB variables in week 2, and objective measures of reading distance and visual acuity in week 6. The data were analyzed by variance-based structural equation modeling. The results showed that perceived autonomy support and autonomous motivation from SDT significantly predicted attitude, subjective norm, and perceived behavioral control from the TPB. These social-cognitive factors were significantly associated with intention and intention significantly predicted reading distance. The relationships in the model held when controlling for visual acuity. In conclusion, the integrated model of SDT and the TPB may help explain myopia-preventive behaviors.

  18. Visual Outcomes of Parapapillary Uveal Melanomas Following Proton Beam Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thariat, Juliette, E-mail: jthariat@gmail.com; Grange, Jean-Daniel; Mosci, Carlo

    Purpose: In parapapillary melanoma patients, radiation-induced optic complications are frequent and visual acuity is often compromised. We investigated dose-effect relationships for the optic nerve with respect to visual acuity after proton therapy. Methods and Materials: Of 5205 patients treated between 1991 and 2014, those treated using computed tomography (CT)-based planning to 52 Gy (prescribed dose, not accounting for relative biologic effectiveness correction of 1.1) in 4 fractions, with minimal 6-month follow-up and documented initial and last visual acuity, were included. Deterioration of ≥0.3 logMAR between initial and last visual acuity results was reported. Results: A total of 865 consecutive patients weremore » included. Median follow-up was 69 months, mean age was 61.7 years, tumor abutted the papilla in 35.1% of patients, and tumor-to-fovea distance was ≤3 mm in 74.2% of patients. Five-year relapse-free survival rate was 92.7%. Visual acuity was ≥20/200 in 72.6% of patients initially and 47.2% at last follow-up. A wedge filter was used in 47.8% of the patients, with a positive impact on vision and no impact on relapse. Glaucoma, radiation-induced optic neuropathy, maculopathy were reported in 17.9%, 47.5%, and 33.6% of patients, respectively. On multivariate analysis, age, diabetes, thickness, initial visual acuity and percentage of macula receiving 26 Gy were predictive of visual acuity. Furthermore, patients irradiated to ≥80% of their papilla had better visual acuity when limiting the 50% (30-Gy) and 20% (12-Gy) isodoses to ≤2 mm and 6 mm of optic nerve length, respectively. Conclusions: A personalized proton therapy plan with optic nerve and macular sparing can be used efficiently with good oncological and functional results in parapapillary melanoma patients.« less

  19. Visual function and quality of life among visually impaired and cataract operated adults. The Pakistan National Blindness and Visual Impairment Survey.

    PubMed

    Taylor, Amy E; Shah, Shaheen P; Gilbert, Clare E; Jadoon, Mohammad Z; Bourne, Rupert R A; Dineen, Brendan; Johnson, Gordon J; Khan, Mohammad D

    2008-01-01

    To assess visual functioning and quality of life in a representative sample of normally sighted, visually impaired and cataract operated individuals aged >or= 30 years in Pakistan. As part of the Pakistan National Blindness and Visual Impairment Survey, visual functioning (VF) and quality of life (QOL) questionnaires were administered to participants with presenting visual acuity less than 6/60 in either eye, aphakes/pseudophakes and a phakic sample with normal acuity (>or= 6/12 both eyes). Of 16,507 adults included in the survey, 2329 questionnaires were administered. There were strong correlations between visual acuity and VF/QOL. Mean VF and median QOL scores in normally sighted phakic individuals were 81.1 and 88.9, respectively, but were only 34.8 and 64.9 in blind unoperated individuals. In the cataract operated population overall mean VF and median QOL scores were 49.3 and 75.0. Both VF and QOL scores were lower in operated individuals than unoperated individuals (p < 0.001). Among operated individuals, rural dwelling and illiteracy were associated with lower VF and QOL scores (p all < 0.02). Although in multivariable analysis bilateral pseudophakes had similar VF scores to bilateral aphakes they had significantly better QOL scores (p = 0.001). Cataract surgery in Pakistan has not led to VF and QOL scores equivalent to those in unoperated individuals with the same levels of visual acuity. The higher proportion of intraocular lens surgery in recent years is likely to improve QOL following cataract surgery. Further focus is needed on rural and illiterate populations, to ensure that they achieve comparable VF/QOL outcomes following surgery.

  20. [Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province: the China Nine-Province Survey].

    PubMed

    Ge, Jian; He, Mingguang; Zhao, Jialiang; Fang, Min; Ellwein, Leon B; He, Ning; Yang, Mei; Wang, Yu; Gao, Xuecheng

    2014-03-01

    To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province, China. It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5 531 individuals aged 50 years or above in Yangxi County from September 2006 to January 2007. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated using village registers followed by door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. Five thousands five hundreds and thirty-one individuals were enumerated and 4 589 persons were examined, the response rate was 82.97%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 2.38% (109/4 589) and 9.44% (433/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 2.68% (123/4 589) and 18.15% (833/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 1 239.34, P < 0.01) , female (χ(2) = 37.88, P < 0.01) and illiterate (trend χ(2) = 235.11, P < 0.01) persons. Cataract was the first leading cause of blindness and visual impairment. The prevalence of blindness and moderate and severe visual impairment is higher among older adults aged 50 years or above in Yangxi County. Cataract remains as the first leading cause of blindness and visual impairment.

  1. Visual acuity, refractive error, and endothelial cell density six months after Descemet stripping and automated endothelial keratoplasty (DSAEK).

    PubMed

    Koenig, Steven B; Covert, Douglas J; Dupps, William J; Meisler, David M

    2007-07-01

    To evaluate visual acuity, refractive outcomes, and endothelial cell density 6 months after Descemet stripping and automated endothelial keratoplasty (DSAEK). We performed an institutional review board-approved prospective study of a surgical case series of 34 patients at 2 institutions undergoing DSAEK for Fuchs endothelial dystrophy, pseudophakic bullous keratopathy, or aphakic bullous keratopathy with or without simultaneous phacoemulsification and intraocular lens implantation. Clinical outcomes, including best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, and refractive astigmatism and topographic or keratometric astigmatism, were assessed at the 6-month postoperative examination and compared with preoperative values with paired Student t tests. The change in endothelial cell density from the eye bank examination to 6 months after transplantation was similarly evaluated. BSCVA averaged 20/99 preoperatively and 20/42 postoperatively (P < 0.0001). After DSAEK, 30 (88.2%) of 34 patients showed improved BSCVA, and 21 (61.8%) of the 34 patients achieved a BSCVA of 20/40 or better. For patients not undergoing simultaneous phacoemulsification and intraocular lens implantation, a hyperopic shift in refraction of 1.19 +/- 1.32 D was noted. Refractive astigmatism, topographic astigmatism, and keratometry showed no statistically significant change. Endothelial cell density of donor corneas averaged 2826 +/- 370 cells/mm, whereas the mean postoperative density was 1396 +/- 440 cells/mm. This finding corresponded to an average loss of 1426 cells/mm (50% loss; P = 0.0001). The first half of cases experienced an average cell loss of 1674 cells/mm (59% loss) compared with 1181 (41% loss) in the second half of cases (P = 0.005). Three (9%) of 34 grafts experienced iatrogenic graft failure and required reoperation with new donor tissue. Also, 9 (27%) of 34 grafts experienced dislocation in the early postoperative period and required repositioning

  2. Comparison of visual function between phakic eyes and pseudophakic eyes with a monofocal intraocular lens.

    PubMed

    Hayashi, Ken; Yoshida, Motoaki; Manabe, Shin-ichi; Hayashi, Hideyuki

    2010-01-01

    To compare all-distance visual acuity and contrast visual acuity with and without glare (glare visual acuity) between phakic eyes with a clear lens and pseudophakic eyes with a monofocal intraocular lens. Hayashi Eye Hospital, Fukuoka, Japan. This study comprised phakic), pseudophakic eyes in 4 age groups (40s, 50s, 60s, 70s). Corrected visual acuity from far to near, contrast visual acuity, and glare visual acuity were examined. The mean corrected intermediate and near visual acuities were significantly better in phakic eyes than in pseudophakic eyes in patients in their 40s and 50s (Pvisual acuity was similar. In the 60s and 70s age groups, there was no statistically significant difference in corrected visual acuity at any distance. The region of accommodation at which eyes achieved a corrected visual acuity of 20/29 or 20/40 was greater in phakic eyes than in pseudophakic eyes in the 40s and 50s age groups (Pvisual acuity or glare visual acuity. In patients in their 40s and 50s, the region of accommodation in phakic eyes was greater than in pseudophakic eyes; the region was similar in patients in their 60s and 70s. Because contrast sensitivity with and without glare was similar at all ages, visual function appeared to be comparable in patients 60 years and older. Copyright 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  3. A randomized trial of atropine vs patching for treatment of moderate amblyopia: follow-up at age 10 years.

    PubMed

    Repka, Michael X; Kraker, Raymond T; Beck, Roy W; Holmes, Jonathan M; Cotter, Susan A; Birch, Eileen E; Astle, William F; Chandler, Danielle L; Felius, Joost; Arnold, Robert W; Tien, D Robbins; Glaser, Stephen R

    2008-08-01

    To determine the visual acuity outcome at age 10 years for children younger than 7 years when enrolled in a treatment trial for moderate amblyopia. In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40-20/100) were randomized to patching or atropine eyedrops for 6 months. Two years after enrollment, a subgroup of 188 children entered long-term follow-up. Treatment after 6 months was at the discretion of the investigator; 89% of children were treated. Visual acuity at age 10 years with the electronic Early Treatment Diabetic Retinopathy Study test. Patching and atropine eyedrops produce comparable improvement in visual acuity that is maintained through age 10 years. The mean amblyopic eye acuity, measured in 169 patients, at age 10 years was 0.17 logMAR (logarithm of the minimum angle of resolution) (approximately 20/32), and 46% of amblyopic eyes had an acuity of 20/25 or better. Age younger than 5 years at entry into the randomized trial was associated with a better visual acuity outcome (P < .001). Mean amblyopic and sound eye visual acuities at age 10 years were similar in the original treatment groups (P = .56 and P = .80, respectively). At age 10 years, the improvement of the amblyopic eye is maintained, although residual amblyopia is common after treatment initiated at age 3 years to younger than 7 years. The outcome is similar regardless of initial treatment with atropine or patching.

  4. A study of static, kinetic, and dynamic visual acuity in 102 Japanese professional baseball players

    PubMed Central

    Hoshina, Kohji; Tagami, Yuichi; Mimura, Osamu; Edagawa, Hiroshi; Matsubara, Masao; Nakayama, Teiichi

    2013-01-01

    Background It seemed that visual functions might have some effects on the performance of baseball players. We measured static, kinetic, and dynamic visual acuity (SVA, KVA, and DVA, respectively) of Japanese professional baseball players to ascertain whether there would be any difference in SVA, KVA, and DVA among player groups stratified according to their performance level. Methods The subjects were 102 male professional baseball players with a mean age of 26 years who were members of a Japanese professional baseball club from 2000 to 2009. They were stratified into three groups according to their performance level: A (players who were on the roster of the top-level team all the time throughout the study period), B (players who were on the roster of the top-level team sometimes but not all the time), and C (players who were never on the roster of the top-level team). They were interviewed for the use of corrective visual aids, and examined for SVA, KVA, and DVA. The measurements of these parameters were compared among groups A, B, and C. We also investigated and analyzed the association of KVA or DVA with player position (pitchers or fielders) and with hand dominance for batting. KVA was compared between the pitchers and the fielders because they each require different playing skills. DVA was compared between the right-handed and the left-handed batters. Results There was no statistically significant difference among groups A, B, and C. There was a statistically significant difference in KVA between the pitchers and the fielders (t-test; P < 0.05) There was no statistically significant difference in DVA between the right-handed and the left-handed batters. Conclusions There was no significant difference in the examined visual functions among player groups with different performance levels. PMID:23569356

  5. Comparison of distance and near visual acuity in patients with vision loss due to cataract.

    PubMed

    Mercado, Carmel L; Doroslovački, Pavle; Wang, Jiangxia; Siddiqui, Aazim A; Kolker, Andrew F; Kolker, Richard J

    2017-02-01

    The purpose of this study was to assess whether there is a disparity in distance and near best-corrected visual acuity (BCVA) in cataract eyes. 102 patients with cataract (N = 121 eyes) were seen in clinic between January and November 2013 at the Wilmer Eye Institute Comprehensive Eye Service. An age-related macular degeneration (ARMD) group (N = 27 eyes) was also identified for comparison. Distance and near BCVA were measured as part of the standard ophthalmic evaluation. Snellen measurements were converted to their LogMAR equivalents for statistical analysis. Near was better than distance BCVA with mean difference of 1.38 lines (P < 0.001) in the cataract eyes. This disparity was not seen in the ARMD eyes. Near-distance BCVA disparity is a statistically significant finding seen with cataracts. This may have further implications in patients with both cataract and ARMD as the presence of disparity may suggest a cataract etiology playing a greater role in vision loss. This comparison may be useful for surgical prognostication and as a quick triage tool in conjunction with, or in place of, a potential acuity meter and dilated near-pinhole test.

  6. Effect of Using High Signal-to-Noise Image Intensifier Tubes on Night Vision Goggle (NVG) Aided Visual Acuity

    DTIC Science & Technology

    2006-05-01

    tubes utilizing thin- filmed technology allowing for a higher SNR, and the F4949G goggles were tested. Twelve participants tested each goggle under six...LogMAR Visual Acuity as a Function of Illumination, Contrast, and NVG ........ 37 Repeated Measures Within-Subjects Analysis of Variance...auto-gated power supply and thin- filmed technology. The Pinnacle’sTM thin- filmed technology gave the image intensifier tube an increase in the signal-to

  7. Long-term visual outcomes in extremely low-birth-weight children (an American Ophthalmological Society thesis).

    PubMed

    Spencer, Rand

    2006-01-01

    The goal is to analyze the long-term visual outcome of extremely low-birth-weight children. This is a retrospective analysis of eyes of extremely low-birth-weight children on whom vision testing was performed. Visual outcomes were studied by analyzing acuity outcomes at >/=36 months of adjusted age, correlating early acuity testing with final visual outcome and evaluating adverse risk factors for vision. Data from 278 eyes are included. Mean birth weight was 731g, and mean gestational age at birth was 26 weeks. 248 eyes had grating acuity outcomes measured at 73 +/- 36 months, and 183 eyes had recognition acuity testing at 76 +/- 39 months. 54% had below normal grating acuities, and 66% had below normal recognition acuities. 27% of grating outcomes and 17% of recognition outcomes were acuity testing was predictive of abnormal grating (P < .0001) and recognition (P = .0001) acuity testing at >/=3 years of age. A slower-than-normal rate of early visual development was predictive of abnormal grating acuity (P < .0001) and abnormal recognition acuity (P < .0001) at >/=3 years of age. Eyes diagnosed with maximal retinopathy of prematurity in zone I had lower acuity outcomes (P = .0002) than did those with maximal retinopathy of prematurity in zone II/III. Eyes of children born at acuity than did those of children born at >28 weeks gestational age. Eyes of children with poorer general health after premature birth had a 5.3 times greater risk of abnormal recognition acuity. Long-term visual development in extremely low-birth-weight infants is problematic and associated with a high risk of subnormal acuity. Early acuity testing is useful in identifying children at greatest risk for long-term visual abnormalities. Gestational age at birth of

  8. LONG-TERM VISUAL OUTCOMES IN EXTREMELY LOW-BIRTH-WEIGHT CHILDREN (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

    PubMed Central

    Spencer, Rand

    2006-01-01

    Purpose The goal is to analyze the long-term visual outcome of extremely low-birth-weight children. Methods This is a retrospective analysis of eyes of extremely low-birth-weight children on whom vision testing was performed. Visual outcomes were studied by analyzing acuity outcomes at ≥36 months of adjusted age, correlating early acuity testing with final visual outcome and evaluating adverse risk factors for vision. Results Data from 278 eyes are included. Mean birth weight was 731g, and mean gestational age at birth was 26 weeks. 248 eyes had grating acuity outcomes measured at 73 ± 36 months, and 183 eyes had recognition acuity testing at 76 ± 39 months. 54% had below normal grating acuities, and 66% had below normal recognition acuities. 27% of grating outcomes and 17% of recognition outcomes were ≤20/200. Abnormal early grating acuity testing was predictive of abnormal grating (P < .0001) and recognition (P = .0001) acuity testing at ≥3 years of age. A slower-than-normal rate of early visual development was predictive of abnormal grating acuity (P < .0001) and abnormal recognition acuity (P < .0001) at ≥3 years of age. Eyes diagnosed with maximal retinopathy of prematurity in zone I had lower acuity outcomes (P = .0002) than did those with maximal retinopathy of prematurity in zone II/III. Eyes of children born at ≤28 weeks gestational age had 4.1 times greater risk for abnormal recognition acuity than did those of children born at >28 weeks gestational age. Eyes of children with poorer general health after premature birth had a 5.3 times greater risk of abnormal recognition acuity. Conclusions Long-term visual development in extremely low-birth-weight infants is problematic and associated with a high risk of subnormal acuity. Early acuity testing is useful in identifying children at greatest risk for long-term visual abnormalities. Gestational age at birth of ≤ 28 weeks was associated with a higher risk of an abnormal long-term outcome. PMID

  9. Visual Outcomes in Pediatric Optic Pathway Glioma After Conformal Radiation Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Awdeh, Richard M.; Kiehna, Erin N.; Drewry, Richard D.

    Purpose: To assess visual outcome prospectively after conformal radiation therapy (CRT) in children with optic pathway glioma. Methods and Materials: We used CRT to treat optic pathway glioma in 20 children (median age 9.3 years) between July 1997 and January 2002. We assessed changes in visual acuity using the logarithm of the minimal angle of resolution after CRT (54 Gy) with a median follow-up of 24 months. We included in the study children who underwent chemotherapy (8 patients) or resection (9 patients) before CRT. Results: Surgery played a major role in determining baseline (pre-CRT) visual acuity (better eye: P=.0431; worsemore » eye: P=.0032). The visual acuity in the worse eye was diminished at baseline (borderline significant) with administration of chemotherapy before CRT (P=.0726) and progression of disease prior to receiving CRT (P=.0220). In the worse eye, improvement in visual acuity was observed in patients who did not receive chemotherapy before CRT (P=.0289). Conclusions: Children with optic pathway glioma initially treated with chemotherapy prior to receiving radiation therapy have decreased visual acuity compared with those who receive primary radiation therapy. Limited surgery before radiation therapy may have a role in preserving visual acuity.« less

  10. Effect of Graft Thickness on Visual Acuity After Descemet Stripping Endothelial Keratoplasty: A Systematic Review and Meta-Analysis.

    PubMed

    Wacker, Katrin; Bourne, William M; Patel, Sanjay V

    2016-03-01

    To assess the relationship between graft thickness and best-corrected visual acuity (BCVA) after Descemet stripping endothelial keratoplasty (DSEK). Systematic review and meta-analysis. PubMed, EMBASE, Web of Science, and conference abstracts were searched for studies published up to October 2015 with standard systematic review methodology. Eligibility criteria included studies evaluating graft thickness in primary DSEK and visual outcomes. There were no restrictions to study design, study population, or language. Correlation coefficients were pooled using random-effects models. Of 480 articles and conference abstracts, 31 met inclusion criteria (2214 eyes) after full-text review. Twenty-three studies assessed correlations between BCVA and graft thickness, and 8 studies used different statistical methods. All associations were reported dimensionless. Studies generally had small sample sizes and were heterogeneous, especially with respect to data and analysis quality (P = .02). Most studies did not measure BCVA in a standardized manner. The pooled correlation coefficient for graft thickness vs BCVA was 0.20 (95% CI, 0.14-0.26) for 17 studies without data concerns; this did not include 7 studies (815 eyes) that used different statistical methods and did not find significant associations. There is insufficient evidence that graft thickness is clinically important with respect to BCVA after DSEK, with meta-analysis suggesting a weak relationship. Although well-designed longitudinal studies with standardized measurements of visual acuity and graft thickness are necessary to better characterize this relationship, current evidence suggests that graft thickness is not important for surgical planning. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Predictors of visual outcomes following Boston type 1 keratoprosthesis implantation.

    PubMed

    Ahmad, Sumayya; Akpek, Esen K; Gehlbach, Peter L; Dunlap, Karen; Ramulu, Pradeep Y

    2015-04-01

    To identify predictors of visual outcomes following Boston type 1 Keratoprosthesis (KPro) implantation. Retrospective chart review. Data regarding preoperative clinical and demographic characteristics and postoperative course were collected. Fifty-nine eyes of 59 adult patients who underwent KPro implantation between January 2006 and March 2012 at a single tertiary care center. Preoperative factors associated with all-cause and glaucoma-related loss of visual acuity from the best postoperative visual acuity noted. Fifty-two of 59 eyes (88%) achieved improved vision post implantation, with 7 eyes failing to gain vision as a result of pre-existing glaucoma (n = 4) or retino-choroidal disease (n = 3). Twenty-one eyes (21/52, 40%) maintained their best-ever visual acuity at last visit (mean follow-up period was 37.8 months). The likelihood of maintaining best-ever vision was 71% at 1 year, 59% at 2 years, and 48% at 3 years. Primary KPro implantation was associated with a higher likelihood of losing best-ever vision as compared to KPro implantation as a repeat corneal procedure (hazard ratio [HR] = 3.06; P = 006). The main reasons for postimplantation vision loss was glaucoma (12/31, 39%), and the risk of glaucomatous visual acuity loss was 15% at 2 years and 27% at 3 years. Prior trabeculectomy was associated with a higher rate of vision loss from glaucoma (HR = 3.25, P = .04). Glaucoma is the primary reason for loss of visual acuity after KPro implantation. Conditions necessitating primary KPro surgery are associated with more frequent all-cause vision loss. Prospective trials are necessary to better determine which clinical features best predict KPro success. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Association between changes in visual acuity and vision-related quality of life in Japanese patients with low vision.

    PubMed

    Yanagisawa, Mieko; Kato, Satoshi; Kunimatsu, Shiho; Kobayashi, Megumi; Ochiai, Makiko

    2011-01-01

    To investigate the association between vision-related quality of life (VRQOL) and changes in visual acuity (VA). We examined the VA in 100 patients for > 1 year and evaluated the degree of its impact on VRQOL using the National Eye Institute Visual Function (VF) Questionnaire (VFQ-25; Japanese version). Before determining VFQ-25, we monitored the changes in VA in these patients for 1 year and classified them into the following two groups depending on VA changes. Patients exhibiting a decline of > 3 steps in VA, as assessed by the logarithm of the minimum angle of resolution scale, were placed in the 'decline' group (47.0%) and patients exhibiting no change in VA were placed in the 'no change' group (53.0%). We compared the VFQ-25 scores between both groups in all patients with glaucoma (GLA) and macular degeneration (MD). The total score of the decline was 34.9 ± 13.6 and that of the no change group was 44.6 ± 13.9: the difference in the scores between both groups was statistically significant (p = 0.006). Similar results were obtained for patients with GLA and MD (p = 0.007 and 0.003, respectively). VRQOL differed between patients with constant VA and those with reduced VA, even though VA values were equal at a certain time point. Copyright © 2010 S. Karger AG, Basel.

  13. OPTICAL COHERENCE TOMOGRAPHY BASELINE PREDICTORS FOR INITIAL BEST-CORRECTED VISUAL ACUITY RESPONSE TO INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT IN EYES WITH DIABETIC MACULAR EDEMA: The CHARTRES Study.

    PubMed

    Santos, Ana R; Costa, Miguel Â; Schwartz, Christian; Alves, Dalila; Figueira, João; Silva, Rufino; Cunha-Vaz, Jose G

    2018-06-01

    To identify baseline optical coherence tomography morphologic characteristics predicting the visual response to anti-vascular endothelial growth factor therapy in diabetic macular edema. Sixty-seven patients with diabetic macular edema completed a prospective, observational study (NCT01947881-CHARTRES). All patients received monthly intravitreal injections of Lucentis for 3 months followed by PRN treatment and underwent best-corrected visual acuity measurements and spectral domain optical coherence tomography at Baseline, Months 1, 2, 3, and 6. Visual treatment response was characterized as good (≥10 letters), moderate (5-10 letters), and poor (<5 or letters loss). Spectral domain optical coherence tomography images were graded before and after treatment by a certified Reading Center. One month after loading dose, 26 patients (38.80%) were identified as good responders, 19 (28.35%) as Moderate and 22 (32.83%) as poor responders. There were no significant best-corrected visual acuity and central retinal thickness differences at baseline (P = 0.176; P = 0.573, respectively). Ellipsoid zone disruption and disorganization of retinal inner layers were good predictors for treatment response, representing a significant risk for poor visual recovery to anti-vascular endothelial growth factor therapy (odds ratio = 10.96; P < 0.001 for ellipsoid zone disruption and odds ratio = 7.05; P = 0.034 for disorganization of retinal inner layers). Damage of ellipsoid zone, higher values of disorganization of retinal inner layers, and central retinal thickness decrease are good predictors of best-corrected visual acuity response to anti-vascular endothelial growth factor therapy.

  14. The Auckland Optotypes: An open-access pictogram set for measuring recognition acuity.

    PubMed

    Hamm, Lisa M; Yeoman, Janice P; Anstice, Nicola; Dakin, Steven C

    2018-03-01

    When measuring recognition acuity in a research setting, the most widely used symbols are the Early Treatment of Diabetic Retinopathy Study (ETDRS) set of 10 Sloan letters. However, the symbols are not appropriate for patients unfamiliar with letters, and acuity for individual letters is variable. Alternative pictogram sets are available, but are generally comprised of fewer items. We set out to develop an open-access set of 10 pictograms that would elicit more consistent estimates of acuity across items than the ETDRS letters from visually normal adults. We measured monocular acuity for individual uncrowded optotypes within a newly designed set (The Auckland Optotype [TAO]), the ETDRS set, and Landolt Cs. Eleven visually normal adults were assessed on regular and vanishing formats of each set. Inter-optotype reliability and ability to detect subtle differences between participants were assessed using intraclass correlations (ICC) and fractional rank precision (FRP). The TAO vanishing set showed the strongest performance (ICC = 0.97, FRP = 0.90), followed by the other vanishing sets (Sloan ICC = 0.88, FRP = 0.74; Landolt ICC = 0.86, FRP = 0.80). Within the regular format, TAO again outperformed the existing sets (TAO ICC = 0.77, FRP = 0.75; Sloan ICC = 0.65, FRP = 0.64; Landolt ICC = 0.48, FRP = 0.63). For adults with normal visual acuity, the new optotypes (in both regular and vanishing formats) are more equally legible and sensitive to subtle individual differences than their Sloan counterparts. As this set does not require observers to be able to name Roman letters, and is freely available to use and modify, it may have wide application for measurement of acuity.

  15. Half-Fluence Photodynamic Therapy for Chronic Central Serous Chorioretinopathy: Predisposing Factors for Visual Acuity Outcomes.

    PubMed

    Matušková, Veronika; Vysloužilová, Daniela; Uher, Michal

    2017-12-18

    Central serous chorioretinopathy (CSC) is characterised by a serous detachment of the neurosensory retina in the macula. Chronic CSC tends to affect older individuals with a less favourable visual outcome. Photodynamic therapy (PDT) with verteporfin is a possible therapeutic approach in cases of CSC with no tendency for spontaneous resorption. PDT has shown good anatomic and functional results in treating chronic CSC. For the purpose of diminishing side effects, modifications of the standard protocol were used. This is a retrospective study of 32 eyes with CSC of 32 patients treated by half-fluence PDT. The patients underwent complete ophthalmology examination. On optical coherence tomography (OCT) we measured central retinal thickness (CRT), the outer nuclear layer (ONL), presence of subfoveolar detachment of retinal pigment epithelium (PED), disturbance of external limiting membrane (ELM), morphological changes in the inner segment/outer segment (IS/OS) line and retinal pigment epithelium (RPE) atrophy. We evaluated at baseline, 3 and 12 months after PDT. The mean BCVA at baseline was 0.41 ± 0.23 log MAR, the mean BCVA at 3 months was 0.24 ± 0.20 and at the end of the follow-up it was 0.23 ± 0.200. We observed statistically significant improvements of visual acuity after 3 and 12 months (p < 0.001, Wilcoxon test). The mean central retinal thickness at baseline was 373 ± 87 µm, the mean CRT after 3 months was 234 ± 42 µm and after 12 months 223 ± 39 µm. A significant reduction from baseline was seen after 3 months and 12 months (p < 0.001, Wilcoxon test). Baseline ONL reached 80 ± 27 µm, after 3 months it was 78 ± 20 and after 12 months it was 74 ± 20 µm. We observed a statistically significant change in diminishing the amount of PED after PDT after 3 months and after 12 months (p = 0.021, McNemar's test). We observed that in patients with RPE ablation, there is lower chance for the restitution of the IS

  16. Change in vision, visual disability, and health after cataract surgery.

    PubMed

    Helbostad, Jorunn L; Oedegaard, Maria; Lamb, Sarah E; Delbaere, Kim; Lord, Stephen R; Sletvold, Olav

    2013-04-01

    Cataract surgery improves vision and visual functioning; the effect on general health is not established. We investigated if vision, visual functioning, and general health follow the same trajectory of change the year after cataract surgery and if changes in vision explain changes in visual disability and general health. One-hundred forty-eight persons, with a mean (SD) age of 78.9 (5.0) years (70% bilateral surgery), were assessed before and 6 weeks and 12 months after surgery. Visual disability and general health were assessed by the CatQuest-9SF and the Short Formular-36. Corrected binocular visual acuity, visual field, stereo acuity, and contrast vision improved (P < 0.001) from before to 6 weeks after surgery, with further improvements of visual acuity evident up to 12 months (P = 0.034). Cataract surgery had an effect on visual disability 1 year later (P < 0.001). Physical and mental health improved after surgery (P < 0.01) but had returned to presurgery level after 12 months. Vision changes did not explain visual disability and general health 6 weeks after surgery. Vision improved and visual disability decreased in the year after surgery, whereas changes in general health and visual functioning were short-term effects. Lack of associations between changes in vision and self-reported disability and general health suggests that the degree of vision changes and self-reported health do not have a linear relationship.

  17. The Auckland Cataract Study: 2 year postoperative assessment of aspects of clinical, visual, corneal topographic and satisfaction outcomes

    PubMed Central

    Thompson, A M; Sachdev, N; Wong, T; Riley, A F; Grupcheva, C N; McGhee, C N

    2004-01-01

    Aim: To assess clinical, visual, computerised corneal topographic, and subjective satisfaction with visual acuity, in a cohort of subjects 2 years after phacoemulsification surgery in a public hospital in New Zealand. Methods: Prospective study of a representative sample of 97 subjects (20%) randomly selected from 480 subjects in the original Auckland Cataract Study (ACS) cohort. The clinical assessment protocol was identical to the ACS and included an extensive questionnaire to enable direct comparisons to be made between the two groups. Results: The study population was predominantly female (66%) with a mean age of 76.3 (SD 9.9) years. New systemic and ocular disease affected 18.4% and 10.3% of subjects respectively, and 10.3% required referral to either a general practitioner (2.1%) or ophthalmologist (8.2%). Mean best spectacle corrected visual acuity (BSCVA) was 0.2 (0.2) logMAR units (6/9 Snellen equivalent), with mean spherical equivalent −0.37 (1.01) dioptres (D) and astigmatism −1.07 (0.70) D 2 years postoperatively, compared to mean BSCVA 0.1 (0.2) logMAR units (6/7.5 Snellen equivalent), spherical equivalent −0.59 (1.07) D, and astigmatism −1.14 (0.77) D 4 weeks after surgery. 94.9% of subjects retained a BSCVA of 6/12 or better, irrespective of pre-existing ocular disease. The overall posterior capsule opacification (PCO) rate was 20.4% and this was visually insignificant in all but 3.1% of eyes that had already undergone Nd:YAG posterior capsulotomy. Orbscan II elevation technology demonstrated corneal stability 2 years after uncomplicated phacoemulsification. Although corneal astigmatism was eliminated in approximately half of the subjects 1 month postoperatively, astigmatism showed a tendency to regress towards the preoperative level with local corneal thickening at the site of incision 2 years after cataract surgery. Of fellow eyes, 61.2% had undergone cataract surgery. Overall, 75.3% of subjects were moderately to very satisfied with their

  18. [Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Shuangcheng City of Heilongjiang Province: the China Nine-Province Survey].

    PubMed

    Zhang, Liqiong; Cui, Hao; Zhao, Jialiang; Ellwein, Leon B; Li, Zhijian; Li, Mingsheng; Yu, Nannan; Wang, Yu; Gao, Xuecheng

    2014-03-01

    To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Shuangcheng City of Heilongjiang Province, China. It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5 841 individuals aged 50 years or above in 28 basic sample units in Shuangcheng City from September to December 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. Five thousands four hundreds and eighty-one individuals were enumerated and 5 047 persons were examined, the response rate was 92.08%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 1.72% (87/5 047) and 4.69% (237/5 047) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.90% (96/5 047) and 7.23% (365/5 047) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2)=674.44, P < 0.01), female (χ(2)=39.61, P < 0.01) and illiterate (trend χ(2)=142.82, P < 0.01) persons. Cataract (52.70%) was still the first leading cause of blindness and visual impairment. The percentage of the retinal diseases, including age-related macular degeneration, high myopic retinopathy and diabetic retinopathy was 11.31% among the eyes with blindness and moderate and severe visual

  19. Simulating visibility under reduced acuity and contrast sensitivity.

    PubMed

    Thompson, William B; Legge, Gordon E; Kersten, Daniel J; Shakespeare, Robert A; Lei, Quan

    2017-04-01

    Architects and lighting designers have difficulty designing spaces that are accessible to those with low vision, since the complex nature of most architectural spaces requires a site-specific analysis of the visibility of mobility hazards and key landmarks needed for navigation. We describe a method that can be utilized in the architectural design process for simulating the effects of reduced acuity and contrast on visibility. The key contribution is the development of a way to parameterize the simulation using standard clinical measures of acuity and contrast sensitivity. While these measures are known to be imperfect predictors of visual function, they provide a way of characterizing general levels of visual performance that is familiar to both those working in low vision and our target end-users in the architectural and lighting-design communities. We validate the simulation using a letter-recognition task.

  20. Simulating Visibility Under Reduced Acuity and Contrast Sensitivity

    PubMed Central

    Thompson, William B.; Legge, Gordon E.; Kersten, Daniel J.; Shakespeare, Robert A.; Lei, Quan

    2017-01-01

    Architects and lighting designers have difficulty designing spaces that are accessible to those with low vision, since the complex nature of most architectural spaces requires a site-specific analysis of the visibility of mobility hazards and key landmarks needed for navigation. We describe a method that can be utilized in the architectural design process for simulating the effects of reduced acuity and contrast on visibility. The key contribution is the development of a way to parameterize the simulation using standard clinical measures of acuity and contrast sensitivity. While these measures are known to be imperfect predictors of visual function, they provide a way of characterizing general levels of visual performance that is familiar to both those working in low vision and our target end-users in the architectural and lighting design communities. We validate the simulation using a letter recognition task. PMID:28375328

  1. Visual functions and disability in diabetic retinopathy patients.

    PubMed

    Shrestha, Gauri Shankar; Kaiti, Raju

    2014-01-01

    This study was undertaken to find correlations between visual functions and visual disabilities in patients with diabetic retinopathy. A cross-sectional study was carried out among 38 visually impaired diabetic retinopathy subjects at the Low Vision Clinic of B.P. Koirala Lions Centre for Ophthalmic Studies, Kathmandu. The subjects underwent assessment of distance and near visual acuity, objective and subjective refraction, contrast sensitivity, color vision, and central and peripheral visual fields. The visual disabilities of each subject in their daily lives were evaluated using a standard questionnaire. Multiple regression analysis between visual functions and visual disabilities index was assessed. The majority of subjects (42.1%) were of the age group 60-70 years. Best corrected visual acuity was found to be 0.73±0.2 in the better eye and 0.93±0.27 in the worse eye, which was significantly different at p=0.002. Visual disability scores were significantly higher for legibility of letters (1.2±0.3) and sentences (1.4±0.4), and least for clothing (0.7±0.3). Visual disability index for legibility of letters and sentences was significantly correlated with near visual acuity and peripheral visual field. Contrast sensitivity was also significantly correlated with the visual disability index, and total scores. Impairment of near visual acuity, contrast sensitivity, and peripheral visual field correlated significantly with different types of visual disability. Hence, these clinical tests should be an integral part of the visual assessment of diabetic eyes. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  2. Poorer Visual Acuity Is Associated with Declines in Cognitive Performance Across Multiple Cognitive Domains: The Maine-Syracuse Longitudinal Study.

    PubMed

    Dearborn, Peter J; Elias, Merrill F; Sullivan, Kevin J; Sullivan, Cara E; Robbins, Michael A

    2018-06-21

    Prior studies have found associations between visual acuity (VA) and cognitive function. However, these studies used a limited range of cognitive measures and did not control for cardiovascular disease risk factors (CVD-RFs) and baseline function. The primary objective of this study was to analyze the associations of VA and cognitive performance using a thorough neuropsychological test battery. This study used community-dwelling sample data across the sixth (2001-2006) and seventh (2006-2010) waves of the Maine-Syracuse Longitudinal Study (n=655). Wave 6 VA as measured by the Snellen Eye Test was the primary predictor of wave 6 and wave 7 Global cognitive performance, Visual-Spatial Organization and Memory, Verbal Episodic Memory, Working Memory, Scanning and Tracking, and Executive Function. Additionally, VA was used to predict longitudinal changes in wave 7 cognitive performance (wave 6 performance adjusted). We analyzed these relationships with multiple linear and logistic regression models adjusted for age, sex, education, ethnicity, depressive symptoms, physical function deficits in addition to CVD-RFs, chronic kidney disease, homocysteine, continuous systolic blood pressure, and hypertension status. Adjusted for demographic covariates and CVD-RFs, poorer VA was associated with concurrent and approximate 5-year declines in Global cognitive function, Visual-Spatial Organization and Memory, and Verbal Episodic Memory. VA may be used in combination with other screening measures to determine risk for cognitive decline. (JINS, 2018, 24, 1-9).

  3. Distinct Circuits for Recovery of Eye Dominance and Acuity in Murine Amblyopia.

    PubMed

    Stephany, Céleste-Élise; Ma, Xiaokuang; Dorton, Hilary M; Wu, Jie; Solomon, Alexander M; Frantz, Michael G; Qiu, Shenfeng; McGee, Aaron W

    2018-05-24

    Degrading vision by one eye during a developmental critical period yields enduring deficits in both eye dominance and visual acuity. A predominant model is that "reactivating" ocular dominance (OD) plasticity after the critical period is required to improve acuity in amblyopic adults. However, here we demonstrate that plasticity of eye dominance and acuity are independent and restricted by the nogo-66 receptor (ngr1) in distinct neuronal populations. Ngr1 mutant mice display greater excitatory synaptic input onto both inhibitory and excitatory neurons with restoration of normal vision. Deleting ngr1 in excitatory cortical neurons permits recovery of eye dominance but not acuity. Reciprocally, deleting ngr1 in thalamus is insufficient to rectify eye dominance but yields improvement of acuity to normal. Abolishing ngr1 expression in adult mice also promotes recovery of acuity. Together, these findings challenge the notion that mechanisms for OD plasticity contribute to the alterations in circuitry that restore acuity in amblyopia. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. The effect of astigmatism axis on visual acuity.

    PubMed

    Mimouni, Michael; Nemet, Achia; Pokroy, Russell; Sela, Tzahi; Munzer, Gur; Kaiserman, Igor

    2017-05-11

    To evaluate the effect of astigmatism axis on uncorrected distance visual acuity (UDVA) in emmetropic eyes that underwent laser refractive surgery. This retrospective study included patients who underwent laser in situ keratomileusis or photorefractive keratectomy between January 2000 and December 2015 at the Care-Vision Laser Centers, Tel Aviv, Israel. Eyes with a 3-month postoperative spherical equivalent between -0.5 D and 0.5 D were included in this study. Eyes with ocular comorbidities and planned ametropia were excluded. Study eyes were divided into 3 groups according to the steep astigmatic axis: with the rule (WTR) (60-120), oblique (31-59 or 121-149), and against the rule (ATR) (0-30 or 150-180). The UDVA of these 3 groups was compared. The oblique group was divided into oblique ATR and oblique WTR, which were compared with each other. A total of 17,416 consecutive eyes of 8,708 patients were studied. The WTR eyes (n = 10,651) had significantly better UDVA (logMAR 0.01 ± 0.08) than the oblique (n = 3,141, logMAR 0.02 ± 0.09) and ATR eyes (n = 3,624, logMAR 0.02 ± 0.10) (p<0.001). The oblique WTR group had significantly better UDVA than the oblique ATR group (p<0.001). The UDVA of the oblique and ATR groups was similar. Stepwise multiple regression analysis showed that the group accounted for 15% of the UDVA variance (p = 0.04). The astigmatic axis has a small but significant effect on UDVA in emmetropic eyes; WTR was better than oblique and ATR astigmatism. Therefore, when correcting astigmatism, it may be preferable to err towards WTR astigmatism.

  5. A Comparison of Patched HOTV Visual Acuity and Photoscreening

    ERIC Educational Resources Information Center

    Leman, Rachel; Clausen, Michelle M.; Bates, Janice; Stark, Lee; Arnold, Koni K.; Arnold, Robert W.

    2006-01-01

    Early detection of significant vision problems in children is a high priority for pediatricians and school nurses. Routine vision screening is a necessary part of that detection and has traditionally involved acuity charts. However, photoscreening in which "red eye" is elicited to show whether each eye is focusing may outperform routine acuity…

  6. Correlation between observation task performance and visual acuity, contrast sensitivity and environmental light in a simulated maritime study.

    PubMed

    Koefoed, Vilhelm F; Assmuss, Jörg; Høvding, Gunnar

    2018-03-25

    To examine the relevance of visual acuity (VA) and index of contrast sensitivity (ICS) as predictors for visual observation task performance in a maritime environment. Sixty naval cadets were recruited to a study on observation tasks in a simulated maritime environment under three different light settings. Their ICS were computed based on contrast sensitivity (CS) data recorded by Optec 6500 and CSV-1000E CS tests. The correlation between object identification distance and VA/ICS was examined by stepwise linear regression. The object detection distance was significantly correlated to the level of environmental light (p < 0.001), but not to the VA or ICS recorded in the test subjects. Female cadets had a significantly shorter target identification range than the male cadets. Neither CS nor VA were found to be significantly correlated to observation task performance. This apparent absence of proven predictive value of visual parameters for observation tasks in a maritime environment may presumably be ascribed to the normal and uniform visual capacity in all our study subjects. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  7. Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness After Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Rosenberg, M. J. F.; Kreutzberg, G. A.; Peters, B. T.; Reschke, M. F.

    2017-01-01

    Gravity transitions cause changes in the vestibulo-occular reflex (VOR), which manifests as poor gaze control, a decrement in dynamic visual acuity (the ability to maintain gaze while in motion), both of which are caused by retinal slip. Retinal slip, the inability to keep an image focused on the retina, can drive or worsen sensory conflict, resulting in motion sickness (MS). Currently 100% of returning crewmembers report MS symptoms, which might affect their ability to perform mission critical tasks immediately after landing. Reschke et al. (2007) demonstrate that stroboscopic vision goggles improve motion sickness onset and symptom severity in motion sickness driven by retinal slip.

  8. Correlation of visual performance with quality of life and intraocular aberrometric profile in patients implanted with rotationally asymmetric multifocal IOLs.

    PubMed

    Ramón, María L; Piñero, David P; Pérez-Cambrodí, Rafael J

    2012-02-01

    To examine the visual performance of a rotationally asymmetric multifocal intraocular lens (IOL) by correlating the defocus curve of the IOL-implanted eye with the intraocular aberrometric profile and impact on the quality of life. A prospective, consecutive, case series study including 26 eyes from 13 patients aged between 50 and 83 years (mean: 65.54±7.59 years) was conducted. All patients underwent bilateral cataract surgery with implantation of a rotationally asymmetric multifocal IOL (Lentis Mplus LS-312 MF30, Oculentis GmbH). Distance and near visual acuity outcomes, intraocular aberrations, defocus curve, and quality of life (assessed using the National Eye Institute Visual Functioning Questionnaire-25) were evaluated postoperatively (mean follow-up: 6.42±2.24 months). A significant improvement in distance visual acuity was found postoperatively (P<.01). Mean postoperative logMAR distance-corrected near visual acuity was 0.19±0.12 (∼20/30). Corrected distance visual acuity and near visual acuity of 20/20 or better were achieved by 30.8% and 7.7% of eyes, respectively. Of all eyes, 96.2% had a postoperative addition between 0 and 1.00 diopter (D). The defocus curve showed two peaks of maximum visual acuity (0 and 3.00 D of defocus), with an acceptable range of intermediate vision. LogMAR visual acuity corresponding to near defocus was directly correlated with some higher order intraocular aberrations (r⩾0.44, P⩽.04). Some difficulties evaluated with the quality of life test correlated directly with near and intermediate visual acuity (r⩾0.50, P⩽.01). The Lentis Mplus multifocal IOL provides good distance, intermediate, and near visual outcomes; however, the induced intraocular aberrometric profile may limit the potential visual benefit. Copyright 2012, SLACK Incorporated.

  9. Temporal order and processing acuity of visual, auditory, and tactile perception in developmentally dyslexic young adults.

    PubMed

    Laasonen, M; Service, E; Virsu, V

    2001-12-01

    We studied the temporal acuity of 16 developmentally dyslexic young adults in three perceptual modalities. The control group consisted of 16 age- and IQ-matched normal readers. Two methods were used. In the temporal order judgment (TOJ) method, the stimuli were spatially separate fingertip indentations in the tactile system, tone bursts of different pitches in audition, and light flashes in vision. Participants indicated which one of two stimuli appeared first. To test temporal processing acuity (TPA), the same 8-msec nonspeech stimuli were presented as two parallel sequences of three stimulus pulses. Participants indicated, without order judgments, whether the pulses of the two sequences were simultaneous or nonsimultaneous. The dyslexic readers were somewhat inferior to the normal readers in all six temporal acuity tasks on average. Thus, our results agreed with the existence of a pansensory temporal processing deficit associated with dyslexia in a language with shallow orthography (Finnish) and in well-educated adults. The dyslexic and normal readers' temporal acuities overlapped so much, however, that acuity deficits alone would not allow dyslexia diagnoses. It was irrelevant whether or not the acuity task required order judgments. The groups did not differ in the nontemporal aspects of our experiments. Correlations between temporal acuity and reading-related tasks suggested that temporal acuity is associated with phonological awareness.

  10. Atropine vs patching for treatment of moderate amblyopia: follow-up at 15 years of age of a randomized clinical trial.

    PubMed

    Repka, Michael X; Kraker, Raymond T; Holmes, Jonathan M; Summers, Allison I; Glaser, Stephen R; Barnhardt, Carmen N; Tien, David R

    2014-07-01

    Initial treatment for amblyopia of the fellow eye with patching and atropine sulfate eyedrops improves visual acuity. Long-term data on the durability of treatment benefit are needed. To report visual acuity at 15 years of age among patients who were younger than 7 years when enrolled in a treatment trial for moderate amblyopia. In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40 to 20/100) were randomly assigned to patching (minimum of 6 h/d) or atropine sulfate eyedrops, 1% (1 drop daily), for 6 months. Treatment after 6 months was at the discretion of the investigator. Two years after enrollment, an unselected subgroup of 188 children were enrolled into long-term follow-up. Initial treatment with patching or atropine with subsequent treatment at investigator discretion. Visual acuity at 15 years of age with the electronic Early Treatment Diabetic Retinopathy Study test in amblyopic and fellow eyes. Mean visual acuity in the amblyopic eye measured in 147 participants at 15 years of age was 0.14 logMAR (approximately 20/25); 59.9% of amblyopic eyes had visual acuity of 20/25 or better and 33.3%, 20/20 or better. Mean interocular acuity difference (IOD) at 15 years of age was 0.21 logMAR (2.1 lines); 48.3% had an IOD of 2 or more lines and 71.4%, 1 or more lines. Treatment (other than spectacles) was prescribed for 9 participants (6.1%) aged 10 to 15 years. Mean IOD was similar at examinations at 10 and 15 years of age (2.0 and 2.1 logMAR lines, respectively; P = .39). Better visual acuity at the 15-year examination was achieved in those who were younger than 5 years at the time of entry into the randomized clinical trial (mean logMAR, 0.09) compared with those aged 5 to 6 years (mean logMAR, 0.18; P < .001). When we compared subgroups based on original treatment with atropine or patching, no significant differences were observed in visual acuity of amblyopic and fellow eyes at 15 years of age (P = .44 and P = .43

  11. Visual functions and disability in diabetic retinopathy patients

    PubMed Central

    Shrestha, Gauri Shankar; Kaiti, Raju

    2013-01-01

    Purpose This study was undertaken to find correlations between visual functions and visual disabilities in patients with diabetic retinopathy. Method A cross-sectional study was carried out among 38 visually impaired diabetic retinopathy subjects at the Low Vision Clinic of B.P. Koirala Lions Centre for Ophthalmic Studies, Kathmandu. The subjects underwent assessment of distance and near visual acuity, objective and subjective refraction, contrast sensitivity, color vision, and central and peripheral visual fields. The visual disabilities of each subject in their daily lives were evaluated using a standard questionnaire. Multiple regression analysis between visual functions and visual disabilities index was assessed. Result The majority of subjects (42.1%) were of the age group 60–70 years. Best corrected visual acuity was found to be 0.73 ± 0.2 in the better eye and 0.93 ± 0.27 in the worse eye, which was significantly different at p = 0.002. Visual disability scores were significantly higher for legibility of letters (1.2 ± 0.3) and sentences (1.4 ± 0.4), and least for clothing (0.7 ± 0.3). Visual disability index for legibility of letters and sentences was significantly correlated with near visual acuity and peripheral visual field. Contrast sensitivity was also significantly correlated with the visual disability index, and total scores. Conclusion Impairment of near visual acuity, contrast sensitivity, and peripheral visual field correlated significantly with different types of visual disability. Hence, these clinical tests should be an integral part of the visual assessment of diabetic eyes. PMID:24646899

  12. [Examinations with the Cardiff Acuity Test].

    PubMed

    Gräf, M; Becker, R; Neff, A; Kaufmann, H

    1996-08-01

    Recently, a new preferential looking (PL) test has been presented for measuring visual acuity in infants and young children (Cardiff Acuity Test, CAT). The PL target is a schematic vanishing picture composed of isoluminant lines with different spatial orientations. Fifty-three healthy children (4-34 months, group 1), 28 (4-35 months) children at risk for amblyopia due to strabismus (group 2), 19 healthy subjects, and 157 patients (group 3) were tested with the CAT. In group 2 the CAT was compared with the fixation preference test. In group 3 the CAT was compared with a recognition test (Landolt C test). In group 1 the interocular difference of the CAT data was a maximum of 1 dB (70% 0 dB, 30% 1 dB, 1/3 so-called octave). Thus, an interocular difference of > 1 dB was considered to be suggestive of monocular or asymmetrical visual impairment. The maximum value 6/6 was frequently achieved (RE 44%, LE 36%, > 18 months RE 57%, LE 46%). In group 2 only 20% of the monolateral strabismic children showed an interocular difference > 1 dB in the CAT. In group 3 we found significant correlations between the CAT and Landolt acuity. A ratio of about 1.7/1 between CAT and Landolt acuity remained constant in cataract eyes as compared to healthy eyes. In amblyopic eyes due to strabismus this ratio was 3.7/1. Thus, amblyopia was underestimated with the CAT. Without limiting the examination distance, interocular differences > 1 dB in the CAT occurred in 52% of the strabismic amblyopic patients (potential sensitivity). At a distance of 1 m this rate decreased to 22% (real sensitivity). In conclusion, the CAT definitely lacks sensitivity for strabismic amblyopia. The data suggest that the real sensitivity could be improved by using higher spatial frequencies. The use of familiar shapes instead of gratings such as PL targets affects cooperation favorably in 12- to 36-month-old children.

  13. Refractive aim and visual outcome after phacoemulsification: A 2-year review from a Tertiary Private Eye Hospital in Sub-Saharan Africa.

    PubMed

    Oderinlo, O; Hassan, A O; Oluyadi, F O; Ogunro, A O; Okonkwo, O N; Ulaikere, M O; Ashano, O

    2017-02-01

    To review the short-term visual outcome of phacoemulsification in adults with uncomplicated cataracts in Eye Foundation Hospital, Lagos, Nigeria. A retrospective review of records of patients that had phacoemulsification between January 2012 and December 2013 in Eye Foundation Hospital, Lagos, Nigeria, was done. Preoperative visual acuity, refractive aim, intraoperative complications, postoperative unaided, and best-corrected visual acuity at 1 and 3 months were analyzed. Only eyes of adults that had phacoemulsification for uncomplicated cataracts were included in the study, all pediatric cataracts and eyes with ocular comorbidities were excluded. Common ocular comorbidities excluded were corneal opacity/corneal scar, glaucoma, uveitis, pseudo exfoliation syndrome, moderate and severe nonproliferative diabetic retinopathy, macula edema, proliferative diabetic retinopathy, eye trauma, age-related macular degeneration, previous corneal surgery, glaucoma surgery, and previous or simultaneous vitreoretinal surgery. A total of 157 eyes of 119 patients who met the inclusion criteria were analyzed. There were 60 (50.4%) females and 59 (49.6%) males, with age range from 31 to 91 years and a mean of 65.3 ± 11.10 years. Only eyes with available data were analyzed at 1 and 3 months postoperatively. In 112 eyes (85.7%), the refractive aim was met, 21 eyes (14.3%) did not meet their refractive aim, 20 eyes (12.7%) were excluded, the refractive aim could not be determined from the records as surgeons did not specify, and in 4 eyes, the required information was missing from the case files. An unaided visual acuity of 6/18 and better was achieved in 134 eyes (85.4%) at 1 month and 126 eyes (85.9%) at 3 months whereas best-corrected vision of 6/18 and better was achieved by 145 eyes (92.4%) at 1 month and 146 eyes (98.0%) at 3 months. Surgical outcomes after phacoemulsification are comparable with international benchmarks for good outcomes, with 85.4% of eyes achieving within 1 D

  14. Evaluating the interdependence of aging-related changes in visual and auditory acuity, balance, and cognitive functioning.

    PubMed

    Hofer, Scott M; Berg, Stig; Era, Pertti

    2003-06-01

    High proportions of shared age-related variance are found among measures of perceptual acuity, balance, muscle strength, and cognitive capabilities in age-heterogeneous, cross-sectional studies. Reliance on cross-sectional studies is problematic, however, because associations may arise from age-related mean trends. Narrow age-cohort samples provide an alternative basis for testing hypotheses regarding associations among rates of change. Cross-domain associations were evaluated in combined 75-year-old cohort samples from Denmark, Finland, and Sweden. In general, no consistent associations were found across sensory, balance, strength, and cognitive domains. These findings indicate that the effects of aging on sensory acuity, balance, and cognitive functioning are likely to be largely independent, multidimensional, and complex at the level of the individual.

  15. Local and non-local deficits in amblyopia: acuity and spatial interactions.

    PubMed

    Bonneh, Yoram S; Sagi, Dov; Polat, Uri

    2004-12-01

    Amblyopic vision is thought to be limited by abnormal long-range spatial interactions, but their exact mode of action and relationship to the main amblyopic deficit in visual acuity is largely unknown. We studied this relationship in a group (N=59) of anisometropic (N=21) and strabismic (or combined, N=38) subjects, using (1) a single and multi-pattern (crowded) computerized static Tumbling-E test with scaled spacing of two pattern widths (TeVA), in addition to an optotype (ETDRS chart) acuity test (VA) and (2) contrast detection of Gabor patches with lateral flankers (lateral masking) along the horizontal and vertical axes as well as in collinear and parallel configurations. By correlating the different measures of visual acuity and contrast suppression, we found that (1) the VA of the strabismic subjects could be decomposed into two uncorrelated components measured in TeVA: acuity for isolated patterns and acuity reduction due to flanking patterns. The latter comprised over 60% of the VA magnitude, on the average and accounted for over 50% of its variance. In contrast, a slight reduction in acuity was found in the anisometropic subjects, and the acuity for a single pattern could account for 70% of the VA variance. (2) The lateral suppression (contrast threshold elevation) in a parallel configuration along the horizontal axis was correlated with the VA (R2=0.7), as well as with the crowding effect (TeVA elevation, R2=0.5) for the strabismic group. Some correlation with the VA was also found for the collinear configuration in the anisometropic group, but less suppression and no correlation were found for all the vertical configurations in all the groups. The results indicate the existence of a specific non-local component of the strabismic deficit, in addition to the local acuity deficit in all amblyopia types. This deficit might reflect long-range lateral inhibition, or alternatively, an inaccurate and scattered top-down attentional selection mechanism.

  16. Long-term visual acuity, retention and complications observed with the type-I and type-II Boston keratoprostheses in an Irish population.

    PubMed

    Duignan, E S; Ní Dhubhghaill, S; Malone, C; Power, W

    2016-08-01

    To evaluate the outcomes of the type-I and type-II Boston keratoprostheses in a single Irish centre. A retrospective chart review of keratoprosthesis implantations carried out in our institution from November 2002 to March 2014 was performed. All procedures were performed by a single surgeon (WP). Thirty-four keratoprosthesis implantations were carried out in 31 patients with a mean follow-up of 42±31 months (range 2-110 months). Seventeen patients were female (54.8%) and 14 were male (45.2%). The majority of keratoprostheses implanted were type-I (31/34, 91.2%), and three were type-II (3/34, 8.8%). Twenty-nine patients (85.3%) had an improvement in distance best-corrected visual acuity (BCVA) from baseline. Fifty per cent (17/34) of patients had a best-ever BCVA of at least 6/12. Eighteen patients (64.3%) retained a BCVA of at least 6/60 at 1 year. Over the course of follow-up, six keratoprostheses were explanted from six eyes of five patients, one of which was a type-II keratoprosthesis. Twenty-six patients (76.5%) developed postoperative complications. Complications included retroprosthetic membrane (18 patients, 52.9%), an exacerbation or new diagnosis of glaucoma (6 patients, 17.6%), endophthalmitis (5 patients, 14.7%) and retinal detachment (2 patients, 5.9%). These data demonstrate excellent visual acuity and retention outcomes in a cohort with a long follow-up period in a single centre. Complications remain a considerable source of morbidity. These outcomes provide further evidence for the long-term stability of type-I and type-II Boston keratoprostheses in the management of patients in whom a traditional graft is likely to fail. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Motor skills of children with unilateral visual impairment in the Infant Aphakia Treatment Study.

    PubMed

    Celano, Marianne; Hartmann, E Eugenie; DuBois, Lindreth G; Drews-Botsch, Carolyn

    2016-02-01

    To assess motor functioning in children aged 4 years 6 months enrolled in the Infant Aphakia Treatment Study, and to determine contributions of visual acuity and stereopsis to measured motor skills. One hundred and four children (53% female) with unilateral aphakia randomized to intraocular lens or contact lens treatment were evaluated at 4 years 6 months (age range 4y 6mo-4y 11mo) for monocular recognition visual acuity, motor skills, and stereopsis by a traveling examiner masked to treatment condition. Motor skills were assessed with the Movement Assessment Battery for Children--Second Edition (MABC-2). Visual acuity was operationalized as log10 of the minimum angle of resolution (logMAR) value for treated eye, best logMAR value for either eye, and intraocular logMAR difference. Student's t-tests showed no significant differences in MABC-2 scores between the intraocular lens and contact lens groups. The mean total score was low (6.43; 18th centile) compared with the normative reference group. Motor functioning was not related to visual acuity in the treated eye or to intraocular logMAR difference, but was predicted in a regression model by the better visual acuity of either eye (usually the fellow eye), even after accounting for the influence of age at surgery, examiner, orthotropic ocular alignment, and stereopsis. Children with unilateral congenital cataract may have delayed motor functioning at 4 years 6 months, which may adversely affect their social and academic functioning. © 2015 Mac Keith Press.

  18. Relation between Approximate Number System Acuity and Mathematical Achievement: The Influence of Fluency

    PubMed Central

    Wang, Li; Sun, Yuhua; Zhou, Xinlin

    2016-01-01

    Previous studies have observed inconsistent relations between the acuity of the Approximate Number System (ANS) and mathematical achievement. In this paper, we hypothesize that the relation between ANS acuity and mathematical achievement is influenced by fluency; that is, the mathematical achievement test covering a greater expanse of mathematical fluency may better reflect the relation between ANS acuity and mathematics skills. We explored three types of mathematical achievement tests utilized in this study: Subtraction, graded, and semester-final examination. The subtraction test was designed to measure the mathematical fluency. The graded test was more fluency-based than the semester-final examination, but both involved the same mathematical knowledge from the class curriculum. A total of 219 fifth graders from primary schools were asked to perform all three tests, then given a numerosity comparison task, a visual form perception task (figure matching), and a series of other tasks to assess general cognitive processes (mental rotation, non-verbal matrix reasoning, and choice reaction time). The findings were consistent with our expectations. The relation between ANS acuity and mathematical achievement was particularly clearly reflected in the participants’ performance on the visual form perception task, which supports the domain-general explanations for the underlying mechanisms of the relation between ANS acuity and math achievement. PMID:28066291

  19. Effect of Cellular Mobile Phone Use and Cetrizine on Hand-Eye Coordination and Visual Acuity.

    PubMed

    Gawit, Kalpita Ganpat; Tiwari, Smita Anand; Kasabe, Gauri Hari; Deshpande, Pradeep Kisanrao; Ghongane, Balasaheb Baburao

    2017-09-01

    Cellular mobile phones are a major cause of distraction especially while driving. The aggressive and inappropriate use of cellular mobile phones has increased the risk of accidents. Similar alerts are available in literature for certain substances and drugs (e.g. second generation anti H1 drug -Cetirizine) which also derange psychomotor performance and parameters of alertness. This study measured variations in hand-eye coordination and visual acuity due to use of cellular mobile phone in comparison to that of commonly used antihistaminic drug viz., single dose Cetirizine 10 mg. It was a single blind, single dose, interventional study, 100 healthy human volunteers divided into two groups. Baseline readings of all volunteers were noted. Group-I (n=50) was Cetirizine group (10mg orally stat), Group -II (n=50) Cellular mobile phone user group. Alertness was tested on hand- steadiness tester (Reaction Time Index = RTI) and on Flicker-fusion apparatus (visual acuity - Critical Flicker Fusion Frequency per second= CFFF/sec). Baseline readings of all volunteers were noted before intervention. Baseline was compared with readings at three hour post-intervention and was analysed by paired t-test. Inter-group comparison of parameters was also done and was analysed by unpaired t-test. The baseline RTI (95.46±41.74, 85.11±39.05) and CFF low and high (40.07±9.970, 40.76±9.309 and 40.42±9.035, 40.48±9.863) respectively, in Cetirizine group and Mobile user group were comparable. The RTI increased significantly (116.4±51.46, 102.8±49.26) in both the groups after intervention. However, there is no significant change in CFF intensity from baseline in either group post-intervention. Concurrent use of mobile phone while performing tasks, showed significant impairment of hand-steadiness which was comparable to that produced by single dose Cetirizine 10 mg and this may be one of the factors contributing to their close association with road traffic accidents.

  20. The risk of newly developed visual impairment in treated normal-tension glaucoma: 10-year follow-up.

    PubMed

    Choi, Yun Jeong; Kim, Martha; Park, Ki Ho; Kim, Dong Myung; Kim, Seok Hwan

    2014-12-01

    To investigate the risk and risk factors for newly developed visual impairment in treated patients with normal-tension glaucoma (NTG) followed up on for 10 years. Patients with NTG, who did not have visual impairment at the initial diagnosis and had undergone intraocular pressure (IOP)-lowering treatment for more than 7 years, were included on the basis of a retrospective chart review. Visual impairment was defined as either low vision (0.05 [20/400] ≤ visual acuity (VA) <0.3 [20/60] and/or 10 degrees ≤ central visual field (VF) <20 degrees) or blindness (VA <0.05 [20/400] and/or central VF <10 degrees) by World Health Organization (WHO) criteria. To investigate the risk and risk factors for newly developed visual impairment, Kaplan-Meier survival analysis and generalized linear mixed effects models were utilized. During the 10.8 years mean follow-up period, 20 eyes of 16 patients were diagnosed as visual impairment (12 eyes as low vision, 8 as blindness) among 623 eyes of 411 patients. The cumulative risk of visual impairment in at least one eye was 2.8% at 10 years and 8.7% at 15 years. The risk factors for visual impairment from treated NTG were worse VF mean deviation (MD) at diagnosis and longer follow-up period. The risk of newly developed visual impairment in the treated patients with NTG was relatively low. Worse VF MD at diagnosis and longer follow-up period were associated with development of visual impairment. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  1. On Using Vernier Acuity to Assess Magnocellular Sensitivity

    ERIC Educational Resources Information Center

    Skottun, Bernt C.; Skoyles, John R.

    2010-01-01

    A recent study [Keri, S., & Benedek, G. (2009). Visual pathway deficit in female fragile x premutation carriers: A potential endophenotype. "Brain and Cognition", 69, 291-295] has found Vernier acuity deficiencies together with contrast sensitivity defects consistent with a magnocellular deficit in female fragile x premutation carriers. This may…

  2. Visual Acuity Change over 12 Months in the Prospective Progression of Atrophy Secondary to Stargardt Disease (ProgStar) Study: ProgStar Report Number 6.

    PubMed

    Kong, Xiangrong; Strauss, Rupert W; Cideciyan, Artur V; Michaelides, Michel; Sahel, José-Alain; Munoz, Beatriz; Ahmed, Mohamed; Ervin, Ann M; West, Sheila K; Cheetham, Janet K; Scholl, Hendrik P N

    2017-11-01

    To estimate the yearly rate of change of best-corrected visual acuity (BCVA) and the risk of loss 1 line or more over 1 year and to identify risk factors for BCVA loss in patients with Stargardt disease (STGD1). Multicenter, prospective cohort study. Two hundred fifty-nine patients (489 eyes) with molecularly confirmed STGD1 enrolled at 9 centers in the United States and Europe. Participants were followed up every 6 months, and data at the baseline and 6- and 12-month visits were analyzed. Best-corrected visual acuity was measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Standardized reporting forms were used to collect participants' characteristics and clinical observations. Linear mixed effects models were used to estimate the rate of BCVA loss. Linear models with generalized estimating equations were used to identify risk factors for BCVA loss of 1 line or more over 1 year. Change in BCVA over 1 year. Cross-sectional analysis at baseline showed that earlier symptom onset and longer duration since onset was associated with worse BCVA. Longitudinal analysis showed no overall significant change of BCVA within 12 months, but the rate of BCVA change was significantly different by baseline BCVA (P < 0.001). The BCVA of eyes with baseline BCVA of 20/25 or better declined at a rate of 2.8 ETDRS letters per year (P = 0.10), eyes with baseline BCVA between 20/25 and 20/70 declined at a rate of 2.3 ETDRS letters per year (P = 0.002), eyes with baseline BCVA between 20/70 and 20/200 declined at a rate of 0.8 ETDRS letters per year (P = 0.08), and eyes with baseline BCVA worse than 20/200 showed a significant improvement of 2.3 ETDRS letters per year (P < 0.001). Overall, 12.9% of eyes lost 1 line or more, and the risk of such BCVA loss was different by baseline BCVA level (P = 0.016). Smoking and vitamin A use was not associated significantly with baseline BCVA, nor with rate of BCVA loss over 1 year. Change in BCVA in STGD1 patients over a

  3. Grating acuity at different luminances in wild-type mice and in mice lacking rod or cone function.

    PubMed

    Schmucker, Christine; Seeliger, Mathias; Humphries, Pete; Biel, Martin; Schaeffel, Frank

    2005-01-01

    The mouse eye has become an important model in vision research. However, it is not known how visual acuity changes with luminance. Therefore, grating acuity of mice was measured at different luminances in an automated optomotor paradigm. Furthermore, mutant mice lacking either rods (RHO-/- and CNGB1-/-) or cones (CNGA3-/-), or both, were studied to determine the rod and cone contribution to visual acuity. Freely ranging individual mice were automatically tracked at a 25-Hz sampling rate with a self-programmed video system in a large rotating optomotor drum. The drum had a square-wave grating inside with adjustable spatial frequency. The angular speed of the mice with respect to the center of the drum and the angular orientation of the snout-tail body axis were analyzed. In addition, the motor activity of the wild-type mice was recorded at different luminances. The optomotor drum provided reliable data on visual input to the mouse's behavior and was convenient to use, since the experimenter's had only to place the mice individually in a Perspex cylinder. Optomotor grating acuity of the wild-type mice was limited to 0.3 to 0.4 cyc/deg. Maximum optomotor responses were obtained at 0.1 to 0.2 cyc/deg. The importance of visual input declined monotonically with decreasing luminance (30 cd/m2, 100%; 0.1 cd/m2, 76.4%; 0.005 cd/m2, 45.9%; and darkness, -9%). Mice lacking functional rods were able to resolve gratings up to 0.1 cyc/deg at 30 cd/m2. Surprisingly, mice lacking functional cones had an optomotor acuity that was similar to the wild-type. Double-knockout mice without rods and cones had no detectable grating acuity. Because the visual system of the mouse is more responsive at bright luminances, experiments in which visual input is important should be performed in photopic conditions (30 cd/m2 or even more). Apparently, spatial vision is governed by the rod system, which is not saturated in the mesopic or low photopic range. Mice lacking both rods and cones have no

  4. Evaluating refraction and visual acuity with the Nidek autorefractometer AR-360A in a randomized population-based screening study.

    PubMed

    Stoor, Katri; Karvonen, Elina; Liinamaa, Johanna; Saarela, Ville

    2017-11-30

    The evaluation of visual acuity (VA) and refraction in the Northern Finland Birth Cohort Eye study was performed using the Nidek AR-360A autorefractometer. The accuracy of the method for this population-based screening study was assessed. Measurements of the refractive error were obtained from the right eyes of 1238 subjects (mean age 47), first objectively with the AR-360A and then subjectively by an optometrist. Agreement with the subjective refraction was calculated for sphere, cylinder, mean spherical equivalent (MSE), cylindrical vectors J 45 and J 0 and presbyopic correction (add). Visual acuity (VA) was measured using an ETDRS chart and the autorefractometer. The refractive error measured with the AR-360A was higher than the subjective refraction performed by the optometrist for sphere (0.007 D ± 0.24 D p = 0.30) and also for cylinder (-0.16 D ± 0.20 D p < 0.0005). The bias between the measurements of MSE, J 45 and J 0 was low: -0.07 D ± 0.22 D (p = 0.002), 0.01 D ± 0.43 D (p = 0.25) and -0.01 D ± 0.42 D (p = 0.43), respectively. The amount of add measured by the autorefractometer was higher than the subjective 0.35 D ± 0.29 D (p < 0.0005). There was a statistically significant correlation between VA (p < 0.0005) and the difference between the subjective and objective refraction. In 99.2% of the measurements, visual values were within one decimal line of each other. The Nidek AR-360A autorefractometer is an accurate tool for determining the refraction and VA in a clinical screening trial. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  5. Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration.

    PubMed

    Roh, Miin; Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W; Jackson, Mary Lou

    2018-01-01

    Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL.

  6. One-year outcomes of AquaLase cataract surgery.

    PubMed

    Yoo, Sonia H; Bhatt, Anand B

    2007-01-01

    The authors report surgical experience and clinical outcomes up to 1 year postoperatively in patients who underwent cataract surgery with the AquaLase liquefaction device (Alcon Laboratories, Fort Worth, TX). The device is a handpiece option for use with Alcon's Infiniti Vision System that uses heated balanced saline solution micropulses to liquefy lenticular material. Twenty-seven eyes of 23 patients underwent cataract extraction with the use of the AquaLase liquefaction device. The average age of participants was 68 years, and the average nuclear sclerotic grade was 1.96 on a 4-point scale. Outcomes were judged by metrics such as visual acuity, inflammation, endothelial cell count, and postoperative posterior capsule opacification. At 30 days postoperatively, 78% of eyes had a best-corrected visual acuity of 20/20. Visual acuity was 20/25 or better 1 year postoperatively in 88% of patients without complications except conversion to ultrasound phacoemulsification for two dense cataracts.

  7. Visual functioning and quality of life among the older people in Hong Kong.

    PubMed

    Leung, Jason C S; Kwok, Timothy C Y; Chan, Dicken C C; Yuen, Kay W K; Kwok, Anthony W L; Choy, Dicky T K; Lau, Edith M C; Leung, P C

    2012-08-01

    This study aimed to examine the association of visual functioning and health-related quality of life (HRQOL) among the older community in Hong Kong. This study used the baseline examination of a cohort study MrOs and MsOs (a large study for osteoporosis in men and women). This study was set in the Hong Kong community. A total of 4000 ambulatory community-dwelling Chinese men and women aged 65 years or above participated in this study. Health-related quality of life was assessed by Medical Outcomes Study Short Form-12 (SF-12), with physical component summary (PCS) and mental component summary (MCS) scores. Demographics, medical history, mental status, and quality of life were obtained from face-to-face interviews, using standard structured questionnaire. Visual functions (i.e., binocular visual acuity, contrast sensitivity, and stereopsis) were assessed by different visual tests after refraction corrections. Different visual functions were tested simultaneously in multiple ordinal logistic regression models. Better binocular visual acuity, contrast sensitivity, and stereopsis were associated with higher PCS. Visual acuity and contrast sensitivity was associated with PCS after adjustment of different visual functions and sex, age, education level, cognitive status, and history of diabetes in multivariate analysis, (OR = 0.73, 95% CI = 0.54 0.98) for low vision (≤6/24) compared with ≥6/9 in visual acuity and (OR = 1.34, 95% CI = 1.09 1.64) for contrast sensitivity row b 5-8 (best) compared with 0-1 (worst). MCS was only associated with visual acuity and contrast sensitivity, but no association was found after adjustment. Apparent association was found between visual functions and HRQOL among older community in Hong Kong. In addition to visual acuity, contrast sensitivity is also important, so eye care should also cover. Copyright © 2011 John Wiley & Sons, Ltd.

  8. Relating Standardized Visual Perception Measures to Simulator Visual System Performance

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Sweet, Barbara T.

    2013-01-01

    Human vision is quantified through the use of standardized clinical vision measurements. These measurements typically include visual acuity (near and far), contrast sensitivity, color vision, stereopsis (a.k.a. stereo acuity), and visual field periphery. Simulator visual system performance is specified in terms such as brightness, contrast, color depth, color gamut, gamma, resolution, and field-of-view. How do these simulator performance characteristics relate to the perceptual experience of the pilot in the simulator? In this paper, visual acuity and contrast sensitivity will be related to simulator visual system resolution, contrast, and dynamic range; similarly, color vision will be related to color depth/color gamut. Finally, we will consider how some characteristics of human vision not typically included in current clinical assessments could be used to better inform simulator requirements (e.g., relating dynamic characteristics of human vision to update rate and other temporal display characteristics).

  9. Influence of different types of astigmatism on visual acuity.

    PubMed

    Remón, Laura; Monsoriu, Juan A; Furlan, Walter D

    To investigate the change in visual acuity (VA) produced by different types of astigmatism (on the basis of the refractive power and position of the principal meridians) on normal accommodating eyes. The lens induced method was employed to simulate a set of 28 astigmatic blur conditions on different healthy emmetropic eyes. Additionally, 24 values of spherical defocus were also simulated on the same eyes for comparison. VA was measured in each case and the results, expressed in logMAR units, were represented against of the modulus of the dioptric power vector (blur strength). LogMAR VA varies in a linear fashion with increasing astigmatic blur, being the slope of the line dependent on the accommodative demand in each type of astigmatism. However, in each case, we found no statistically significant differences between the three axes investigated (0°, 45°, 90°). Non-statistically significant differences were found either for the VA achieved with spherical myopic defocus (MD) and mixed astigmatism (MA). VA with simple hyperopic astigmatism (SHA) was higher than with simple myopic astigmatism (SMA), however, in this case non conclusive results were obtained in terms of statistical significance. The VA achieved with imposed compound hyperopic astigmatism (CHA) was highly influenced by the eye's accommodative response. VA is correlated with the blur strength in a different way for each type of astigmatism, depending on the accommodative demand. VA is better when one of the focal lines lie on the retina irrespective of the axis orientation; accommodation favors this situation. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  10. Prevalence and Causes of Visual Impairment and Blindness in Shanxi Province, China.

    PubMed

    Li, Tong; Du, Liping; Du, Lingzhen

    2015-01-01

    To estimate the prevalence and causes of visual impairment and blindness in Shanxi Province, China. Data were obtained from the Second National Sampling Survey of Disability conducted in 2006. Blindness and visual impairment were defined as best corrected visual acuity <3/60 and <6/18, respectively, in the better-seeing eye. Standardized ophthalmologic examinations were administered to participants aged 0-80 years in 2006. Visual acuity (VA) was measured using a Standard Logarithmic Visual Acuity E chart (Snellen) for subjects aged 7 years and older. Participants younger than 7 years were examined using special experiments or the Childhood Graphical Visual Chart. The prevalence of visual impairment and blindness in Shanxi was estimated to be 0.6% (466/75,016) among persons up to 80 years old. The prevalence in rural areas (0.7%; 351/48,137) was significantly higher than that in urban areas (0.4%; 115/26,879) and was higher in females (0.8%; 298/36,933) than in males (0.4%; 168/38,083). The most common cause of visual impairment and blindness was cataract (44.9%), followed by retinopathy and choroidopathy (12.5%), hereditary and developmental disorders (10.3%), corneal disease (5.2%), and refractive error (4.9%). Prevalences of visual impairment and blindness in women and in rural areas were higher than in men and urban areas, and increased with age. Cataract was the most prevalent cause of visual impairment and blindness. Based on the findings from this study, we suggest that provision of support and welfare services should be organized.

  11. Correctable and non-correctable visual impairment among young males: a 12-year prevalence study of the Military Service in Poland.

    PubMed

    Nowak, Michal S; Gos, Roman; Jurowski, Piotr; Smigielski, Janusz

    2009-07-01

    To evaluate the prevalence of correctable and non-correctable visual impairment in a representative sample of young males commissioned for Military Service in Poland. Data concerning vision status was retrospectively reviewed in 969 subjects of European Caucasian origin, most of whom live and have lived in Poland. They were selected from the original database comprising 105017 subjects examined in the period 1993-2004. Based on the age of subjects they were divided into two groups; group I aged 18-24 and group II aged 25-34 years. Visual impairment was defined as distance visual acuity of <20/40 in one or both eyes. Non-correctable impairment was defined as that which was not eliminated by refractive correction. A total of 1938 eyes of 969 white males were examined. There was statistically significant association between rates of visual impairment and increasing age (p < 0.001). Visual impairment was found in 128 (13.2%) subjects in at least one eye. Non-correctable visual impairment was found in 12 (1.2%) subjects. Amblyopia was the main cause, accounting for eight cases (66.67%). Correctable visual impairment was found in the remaining 116 (12.0%) patients. Among them myopia was the most common refractive error and accounted for 75.8%. Differences between age-specific rates of refractive errors were statistically significant (p = 0.003). Appropriate refractive correction improves visual acuity in most subjects presenting with visual impairment. There was a relatively low prevalence of non-correctable visual impairment in a population of young adults in Poland, and this was mainly due to amblyopia.

  12. Forty-five years of keratoprosthesis study and application at the Filatov Institute: a retrospective analysis of 1 060 cases

    PubMed Central

    Iakymenko, Stanislav

    2013-01-01

    AIM To present results of the keratoprosthesis method used at The Filatov Institute of Eye Diseases and Tissue Therapy. METHODS A retrospective case series analysis was used to describe the development of new types of keratoprostheses and methods of implantation as well as different ways of leukoma strengthening. RESULTS Keratoprosthesis was performed in 1 060 eyes of 1 040 patients with leukomas of different etiology: burns, 725 eyes (68.4%); trauma, 120 eyes (11.3%); keratitis and ocular pemphigoid, 108 eyes (10.2%); and bullous keratopathy, 107 eyes (10.1%). Visual acuity before keratoprosthesis consisted of light perception in 962 eyes (92%), and 98 eyes (8%) had minimal visual acuity (1/200-1/50). Both eyes were blind (visual acuity less than 1/200) in 955 patients (91.8%). The period of blindness varied from 1 to 52 years. As a result of keratoprosthesis, visual acuity of ≥1/200 was restored in 1 023 of 1 060 eyes (96.5%). Visual acuity of 20/200-20/20 was achieved in 716 eyes (67.5%). At the last follow-up visit visual acuity of ≥1/200 was preserved in 806 eyes (76%), visual acuity of 20/200-20/20 was measured in 583 of 1 060 eyes (55%) and good keratoprosthesis fixation in the cornea was achieved in 986 of 1 060 eyes (93%). The minimal follow-up was 12 months (range, 12 months to 37 years, median 5 years). CONCLUSION Our techniques of keratoprosthesis effectively restore vision in patients with leukomas that cannot be treated by optical corneal grafting. PMID:23826536

  13. Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice

    PubMed Central

    Yusifov, Rashad

    2018-01-01

    Abstract For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162–P182] SC-raised mice. This was indeed the case: 40–50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice. PMID:29379877

  14. Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice.

    PubMed

    Hosang, Leon; Yusifov, Rashad; Löwel, Siegrid

    2018-01-01

    For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162-P182] SC-raised mice. This was indeed the case: 40-50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice.

  15. Cerebral Visual Impairment in Children: A Longitudinal Case Study of Functional Outcomes beyond the Visual Acuities

    ERIC Educational Resources Information Center

    Lam, Fook Chang; Lovett, Fiona; Dutton, Gordon N.

    2010-01-01

    Damage to the areas of the brain that are responsible for higher visual processing can lead to severe cerebral visual impairment (CVI). The prognosis for higher cognitive visual functions in children with CVI is not well described. We therefore present our six-year follow-up of a boy with CVI and highlight intervention approaches that have proved…

  16. Visual function, driving safety, and the elderly.

    PubMed

    Keltner, J L; Johnson, C A

    1987-09-01

    The authors have conducted a survey of the Departments of Motor Vehicles in all 50 states, the District of Columbia, and Puerto Rico requesting information about the visual standards, accidents, and conviction rates for different age groups. In addition, we have reviewed the literature on visual function and traffic safety. Elderly drivers have a greater number of vision problems that affect visual acuity and/or peripheral visual fields. Although the elderly are responsible for a small percentage of the total number of traffic accidents, the types of accidents they are involved in (e.g., failure to yield the right-of-way, intersection collisions, left turns onto crossing streets) may be related to peripheral and central visual field problems. Because age-related changes in performance occur at different rates for various individuals, licensing of the elderly driver should be based on functional abilities rather than age. Based on information currently available, we can make the following recommendations: (1) periodic evaluations of visual acuity and visual fields should be performed every 1 to 2 years in the population over age 65; (2) drivers of any age with multiple accidents or moving violations should have visual acuity and visual fields evaluated; and (3) a system should be developed for physicians to report patients with potentially unsafe visual function. The authors believe that these recommendations may help to reduce the number of traffic accidents that result from peripheral visual field deficits.

  17. Perceived Visual Distortions in Juvenile Amblyopes During/Following Routine Amblyopia Treatment.

    PubMed

    Piano, Marianne E F; Bex, Peter J; Simmers, Anita J

    2016-08-01

    To establish the point prevalence of perceived visual distortions (PVDs) in amblyopic children; the association between severity of PVDs and clinical parameters of amblyopia; and the relationship between PVDs and amblyopia treatment outcomes. Perceived visual distortions were measured using a 16-point dichoptic alignment paradigm in 148 visually normal children (aged, 9.18 ± 2.51 years), and 82 amblyopic children (aged, 6.33 ± 1.48 years) receiving or following amblyopia treatment. Global distortion (GD; vector sum of mean-centered individual alignment error between physical and perceived target location) and Global uncertainty (GU; SD of GD over two experiment runs) were compared to age-matched control data, and correlated against clinical parameters of amblyopia (type, monocular visual acuity, pretreatment interocular acuity difference, refractive error, age at diagnosis, motor fusion, stereopsis, near angle of deviation) and amblyopia treatment outcomes (refractive adaption duration, treatment duration, occlusion dosage, posttreatment interocular acuity difference, number of lines improvement). Point prevalence of PVDs in amblyopes was 56.1%. Strabismic amblyopes experienced more severe distortions than anisometropic or microtropic amblyopes (GD Kruskal Wallis H = 16.89, P < 0.001; GU Kruskal Wallis H = 15.31, P < 0.001). Perceived visual distortions severity moderately correlated with the strength of binocular function, (e.g., log stereoacuity [GD rho = 0.419, P < 0.001; GU rho = 0.384, P < 0.001)], and strongly with near angle of deviation (GD rho = 0.578, P < 0.001; GU rho = 0.384, P < 0.001). There was no relationship between severity of PVDs and amblyopia treatment outcomes, or the amblyopic visual acuity deficit. Perceived visual distortions persisted in more than one-half of treated amblyopic cases whose treatment was deemed successful. Perceived visual distortions are common symptoms of amblyopia and are correlated with binocular (stereoacuity, angle

  18. Development and testing of an automated computer tablet-based method for self-testing of high and low contrast near visual acuity in ophthalmic patients.

    PubMed

    Aslam, Tariq M; Parry, Neil R A; Murray, Ian J; Salleh, Mahani; Col, Caterina Dal; Mirza, Naznin; Czanner, Gabriela; Tahir, Humza J

    2016-05-01

    Many eye diseases require on-going assessment for optimal management, creating an ever-increasing burden on patients and hospitals that could potentially be reduced through home vision monitoring. However, there is limited evidence for the utility of current applications and devices for this. To address this, we present a new automated, computer tablet-based method for self-testing near visual acuity (VA) for both high and low contrast targets. We report on its reliability and agreement with gold standard measures. The Mobile Assessment of Vision by intERactIve Computer (MAVERIC) system consists of a calibrated computer tablet housed in a bespoke viewing chamber. Purpose-built software automatically elicits touch-screen responses from subjects to measure their near VA for either low or high contrast acuity. Near high contrast acuity was measured using both the MAVERIC system and a near Landolt C chart in one eye for 81 patients and low contrast acuity using the MAVERIC system and a 25 % contrast near EDTRS chart in one eye of a separate 95 patients. The MAVERIC near acuity was also retested after 20 min to evaluate repeatability. Repeatability of both high and low contrast MAVERIC acuity measures, and their agreement with the chart tests, was assessed using the Bland-Altman comparison method. One hundred and seventy-three patients (96 %) completed the self- testing MAVERIC system without formal assistance. The resulting MAVERIC vision demonstrated good repeatability and good agreement with the gold-standard near chart measures. This study demonstrates the potential utility of the MAVERIC system for patients with ophthalmic disease to self-test their high and low contrast VA. The technique has a high degree of reliability and agreement with gold standard chart based measurements.

  19. Vestibular rehabilitation outcomes in chronic vertiginous patients through computerized dynamic visual acuity and Gaze stabilization test.

    PubMed

    Badaracco, Carlo; Labini, Francesca Sylos; Meli, Annalisa; De Angelis, Ezio; Tufarelli, Davide

    2007-09-01

    To evaluate the efficiency of the rehabilitative protocols in patients with labyrinthine hypofunction, focusing on computerized dynamic visual acuity test (DVAt) and Gaze stabilization test (GST) specifically evaluating the vestibulo-oculomotor reflex (VOR) changes due to vestibular rehabilitation. Consecutive sample study. Day hospital in Ears, Nose, and Throat Rehabilitation Unit. Thirty-two patients with chronic dizziness with a mean age of 60.74 years. Patients performed one cycle of 12 daily rehabilitation sessions (2 h each) consisting of exercises aimed at improving VOR gain. The rehabilitation program included substitutional and/or habitudinal exercises, exercises on a stability platform, and exercises on a moving footpath with rehabilitative software. Dizziness Handicap Inventory and Activities-specific Balance Confidence Scale. Computerized dynamic posturography, computerized DVAt, and GST. The patients significantly improved in all the tests. Vestibular rehabilitation improved the quality of life by reducing the handicap index and improving the ability in everyday tasks. The recovery of the vestibular-ocular reflex and vestibular-spinal reflex efficiency was objectively proven by instrumental testing. The DVAt and the GST allow to objectively quantify the fixation ability at higher frequencies and speeds (main VOR function). Moreover, these new parameters permit to completely evaluate vestibular rehabilitation outcomes, adding new information to the generally used tests that only assess vestibulospinal reflex.

  20. Visual acuity, contrast sensitivity, and range performance with compressed motion video

    NASA Astrophysics Data System (ADS)

    Bijl, Piet; de Vries, Sjoerd C.

    2010-10-01

    Video of visual acuity (VA) and contrast sensitivity (CS) test charts in a complex background was recorded using a CCD color camera mounted on a computer-controlled tripod and was fed into real-time MPEG-2 compression/decompression equipment. The test charts were based on the triangle orientation discrimination (TOD) test method and contained triangle test patterns of different sizes and contrasts in four possible orientations. In a perception experiment, observers judged the orientation of the triangles in order to determine VA and CS thresholds at the 75% correct level. Three camera velocities (0, 1.0, and 2.0 deg/s, or 0, 4.1, and 8.1 pixels/frame) and four compression rates (no compression, 4 Mb/s, 2 Mb/s, and 1 Mb/s) were used. VA is shown to be rather robust to any combination of motion and compression. CS, however, dramatically decreases when motion is combined with high compression ratios. The measured thresholds were fed into the TOD target acquisition model to predict the effect of motion and compression on acquisition ranges for tactical military vehicles. The effect of compression on static performance is limited but strong with motion video. The data suggest that with the MPEG2 algorithm, the emphasis is on the preservation of image detail at the cost of contrast loss.

  1. Visual Acuity Is Correlated with the Area of the Foveal Avascular Zone in Diabetic Retinopathy and Retinal Vein Occlusion.

    PubMed

    Balaratnasingam, Chandrakumar; Inoue, Maiko; Ahn, Seungjun; McCann, Jesse; Dhrami-Gavazi, Elona; Yannuzzi, Lawrence A; Freund, K Bailey

    2016-11-01

    To determine if the area of the foveal avascular zone (FAZ) is correlated with visual acuity (VA) in diabetic retinopathy (DR) and retinal vein occlusion (RVO). Cross-sectional study. Ninety-five eyes of 66 subjects with DR (65 eyes), branch retinal vein occlusion (19 eyes), and central retinal vein occlusion (11 eyes). Structural optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) and OCT angiography (OCTA; Avanti, Optovue RTVue XR) data from a single visit were analyzed. FAZ area, point thickness of central fovea, central 1-mm subfield thickness, the occurrence of intraretinal cysts, ellipsoid zone disruption, and disorganization of retinal inner layers (DRIL) length were measured. VA was also recorded. Correlations between FAZ area and VA were explored using regression models. Main outcome measure was VA. Mean age was 62.9±13.2 years. There was no difference in demographic and OCT-derived anatomic measurements between branch retinal vein occlusion and central retinal vein occlusion groups (all P ≥ 0.058); therefore, data from the 2 groups were pooled together to a single RVO group for further statistical comparisons. Univariate and multiple regression analysis showed that the area of the FAZ was significantly correlated with VA in DR and RVO (all P ≤ 0.003). The relationship between FAZ area and VA varied with age (P = 0.026) such that for a constant FAZ area, an increase in patient age was associated with poorer vision (rise in logarithm of the minimum angle of resolution visual acuity). Disruption of the ellipsoid zone was significantly correlated with VA in univariate and multiple regression analysis (both P < 0.001). Occurrence of intraretinal cysts, DRIL length, and lens status were significantly correlated with VA in the univariate regression analysis (P ≤ 0.018) but not the multiple regression analysis (P ≥ 0.210). Remaining variables evaluated in this study were not predictive of VA (all P ≥ 0.225). The area of the FAZ is

  2. Effectiveness of the addition of citicoline to patching in the treatment of amblyopia around visual maturity: A randomized controlled trial

    PubMed Central

    Pawar, Prachee Vasant; Mumbare, Sachin S; Patil, Mrunal Suresh; Ramakrishnan, Seema

    2014-01-01

    Aim: To study the effectiveness of the addition of citicoline to patching in the treatment of amblyopia in the age group of 4-13 years. Materials and Methods: A randomized controlled trial, which included patients who were randomly divided into two groups. Both the groups received patching therapy till plateau was achieved in phase 1 of the study. Then in phase 2, group I received citicoline plus patching and group II continued to receive only patching. Outcome Measures: Outcome was measured by the visual acuity in logMAR every month in phase 1 till plateau was achieved and then for 12 months in phase 2. Results: No significant difference was found in the mean visual acuities in these two groups in phase 1 till plateau was reached. In phase 2, for the initial four months, there was no significant difference in the visual acuities in these two groups, at the respective intervals. However, five months onward, up to 12 months, there was a significant difference in the visual acuities in these groups. The result was the same in younger patients (< seven years of age) as well as in older patients (> seven years of age). In phase 2, the mean proportional improvement in group I was significantly more than that in group II, at two months and onward, at the respective intervals. Conclusion: The improvement in visual acuity with citicoline plus patching was significantly more than that with patching alone, in one year of treatment. PMID:24618483

  3. [Survey on avoidable blindness and visual impairment in Panama].

    PubMed

    López, Maritza; Brea, Ileana; Yee, Rita; Yi, Rodolfo; Carles, Víctor; Broce, Alberto; Limburg, Hans; Silva, Juan Carlos

    2014-12-01

    Determine prevalence of blindness and visual impairment in adults aged ≥ 50 years in Panama, identify their main causes, and characterize eye health services. Cross-sectional population study using standard Rapid Assessment of Avoidable Blindness methodology. Fifty people aged ≥ 50 years were selected from each of 84 clusters chosen through representative random sampling of the entire country. Visual acuity was assessed using a Snellen chart; lens and posterior pole status were assessed by direct ophthalmoscopy. Cataract surgery coverage was calculated and its quality assessed, along with causes of visual acuity < 20/60 and barriers to access to surgical treatment. A total of 4 125 people were examined (98.2% of the calculated sample). Age- and sex-adjusted prevalence of blindness was 3.0% (95% CI: 2.3-3.6). The main cause of blindness was cataract (66.4%), followed by glaucoma (10.2%). Cataract (69.2%) was the main cause of severe visual impairment and uncorrected refractive errors were the main cause of moderate visual impairment (60.7%). Surgical cataract coverage in individuals was 76.3%. Of all eyes operated for cataract, 58.0% achieved visual acuity ≤ 20/60 with available correction. Prevalence of blindness in Panama is in line with average prevalence found in other countries of the Region. This problem can be reduced, since 76.2% of cases of blindness and 85.0% of cases of severe visual impairment result from avoidable causes.

  4. The association between higher education and approximate number system acuity

    PubMed Central

    Lindskog, Marcus; Winman, Anders; Juslin, Peter

    2014-01-01

    Humans are equipped with an approximate number system (ANS) supporting non-symbolic numerosity representation. Studies indicate a relationship between ANS-precision (acuity) and math achievement. Whether the ANS is a prerequisite for learning mathematics or if mathematics education enhances the ANS remains an open question. We investigated the association between higher education and ANS acuity with university students majoring in subjects with varying amounts of mathematics (mathematics, business, and humanities), measured either early (First year) or late (Third year) in their studies. The results suggested a non-significant trend where students taking more mathematics had better ANS acuity and a significant improvement in ANS acuity as a function of study length that was mainly confined to the business students. The results provide partial support for the hypothesis that education in mathematics can enhance the ANS acuity. PMID:24904478

  5. The association between higher education and approximate number system acuity.

    PubMed

    Lindskog, Marcus; Winman, Anders; Juslin, Peter

    2014-01-01

    Humans are equipped with an approximate number system (ANS) supporting non-symbolic numerosity representation. Studies indicate a relationship between ANS-precision (acuity) and math achievement. Whether the ANS is a prerequisite for learning mathematics or if mathematics education enhances the ANS remains an open question. We investigated the association between higher education and ANS acuity with university students majoring in subjects with varying amounts of mathematics (mathematics, business, and humanities), measured either early (First year) or late (Third year) in their studies. The results suggested a non-significant trend where students taking more mathematics had better ANS acuity and a significant improvement in ANS acuity as a function of study length that was mainly confined to the business students. The results provide partial support for the hypothesis that education in mathematics can enhance the ANS acuity.

  6. RETENTION OF HIGH TACTILE ACUITY THROUGHOUT THE LIFESPAN IN BLINDNESS

    PubMed Central

    Legge, Gordon E.; Madison, Cindee; Vaughn, Brenna N.; Cheong, Allen M.Y.; Miller, Joseph C.

    2009-01-01

    Previous studies of tactile acuity on the fingertip using passive touch have demonstrated an age-related decline in spatial resolution for both sighted and blind subjects. We have re-examined this age dependence with two newly designed tactile-acuity charts requiring active exploration of the test symbols. One chart used dot patterns similar to Braille and the other used embossed Landolt rings. Groups of blind Braille readers and sighted subjects, ranging in age from 12 to 85 years, were tested in two experiments. We replicated previous findings for sighted subjects by showing an age related decrease in tactile acuity by nearly 1% per year. Surprisingly, the blind subjects retained high acuity into old age showing no age-related decline. For the blind subjects, tactile acuity did not correlate with braille reading speed, the amount of daily reading, or the age at which braille was learned. We conclude that when measured with active touch, blind subjects retain high tactile acuity into old age, unlike their aging sighted peers. We propose that blind people's use of active touch in daily activities, not specifically Braille reading, results in preservation of tactile acuity across the lifespan. PMID:19064491

  7. Lrit1, a Retinal Transmembrane Protein, Regulates Selective Synapse Formation in Cone Photoreceptor Cells and Visual Acuity.

    PubMed

    Ueno, Akiko; Omori, Yoshihiro; Sugita, Yuko; Watanabe, Satoshi; Chaya, Taro; Kozuka, Takashi; Kon, Tetsuo; Yoshida, Satoyo; Matsushita, Kenji; Kuwahara, Ryusuke; Kajimura, Naoko; Okada, Yasushi; Furukawa, Takahisa

    2018-03-27

    In the vertebrate retina, cone photoreceptors play crucial roles in photopic vision by transmitting light-evoked signals to ON- and/or OFF-bipolar cells. However, the mechanisms underlying selective synapse formation in the cone photoreceptor pathway remain poorly understood. Here, we found that Lrit1, a leucine-rich transmembrane protein, localizes to the photoreceptor synaptic terminal and regulates the synaptic connection between cone photoreceptors and cone ON-bipolar cells. Lrit1-deficient retinas exhibit an aberrant morphology of cone photoreceptor pedicles, as well as an impairment of signal transmission from cone photoreceptors to cone ON-bipolar cells. Furthermore, we demonstrated that Lrit1 interacts with Frmpd2, a photoreceptor scaffold protein, and with mGluR6, an ON-bipolar cell-specific glutamate receptor. Additionally, Lrit1-null mice showed visual acuity impairments in their optokinetic responses. These results suggest that the Frmpd2-Lrit1-mGluR6 axis regulates selective synapse formation in cone photoreceptors and is essential for normal visual function. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Psychological distress and visual functioning in relation to vision-related disability in older individuals with cataracts.

    PubMed

    Walker, J G; Anstey, K J; Lord, S R

    2006-05-01

    To determine whether demographic, health status and psychological functioning measures, in addition to impaired visual acuity, are related to vision-related disability. Participants were 105 individuals (mean age=73.7 years) with cataracts requiring surgery and corrected visual acuity in the better eye of 6/24 to 6/36 were recruited from waiting lists at three public out-patient ophthalmology clinics. Visual disability was measured with the Visual Functioning-14 survey. Visual acuity was assessed using better and worse eye logMAR scores and the Melbourne Edge Test (MET) for edge contrast sensitivity. Data relating to demographic information, depression, anxiety and stress, health care and medication use and numbers of co-morbid conditions were obtained. Principal component analysis revealed four meaningful factors that accounted for 75% of the variance in visual disability: recreational activities, reading and fine work, activities of daily living and driving behaviour. Multiple regression analyses determined that visual acuity variables were the only significant predictors of overall vision-related functioning and difficulties with reading and fine work. For the remaining visual disability domains, non-visual factors were also significant predictors. Difficulties with recreational activities were predicted by stress, as well as worse eye visual acuity, and difficulties with activities of daily living were associated with self-reported health status, age and depression as well as MET contrast scores. Driving behaviour was associated with sex (with fewer women driving), depression, anxiety and stress scores, and MET contrast scores. Vision-related disability is common in older individuals with cataracts. In addition to visual acuity, demographic, psychological and health status factors influence the severity of vision-related disability, affecting recreational activities, activities of daily living and driving.

  9. Changes in Keratocyte Density and Visual Function Five Years After Laser In Situ Keratomileusis: Femtosecond Laser Versus Mechanical Microkeratome.

    PubMed

    McLaren, Jay W; Bourne, William M; Maguire, Leo J; Patel, Sanjay V

    2015-07-01

    To determine the effects of keratocyte loss on optical properties and vision after laser in situ keratomileusis (LASIK) with the flap created with a femtosecond laser or a mechanical microkeratome. Randomized clinical paired-eye study. Both eyes of 21 patients received LASIK for myopia or myopic astigmatism. One eye of each patient was randomized by ocular dominance to flap creation with a femtosecond laser and the other eye to flap creation with a mechanical microkeratome. Before LASIK and at 1, 3, and 6 months and 1, 3, and 5 years after LASIK, keratocyte density was measured using confocal microscopy, and high-contrast visual acuity and anterior corneal wavefront aberrations were measured by standard methods. At each visit, all variables were compared between methods of creating the flap and to the same variable before treatment using paired tests with Bonferroni correction for multiple comparisons. Keratocyte density in the flap decreased by 20% during the first year after LASIK and remained low through 5 years (P < .001). High-order wavefront aberrations increased and uncorrected visual acuity improved immediately after surgery, but these variables did not change further to 5 years. There were no differences in any variables between treatments. A sustained reduction in keratocyte density does not affect vision or optical properties of the cornea through 5 years after LASIK. The method of creating a LASIK flap does not influence the changes in keratocyte density in the flap. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Changes in Keratocyte Density and Visual Function Five Years after Laser in situ Keratomileusis: Femtosecond Laser vs Mechanical Microkeratome

    PubMed Central

    McLaren, Jay W.; Bourne, William M.; Maguire, Leo J.; Patel, Sanjay V.

    2015-01-01

    Purpose To determine the effects of keratocyte loss on optical properties and vision after laser in situ keratomileusis (LASIK) with the flap created with a femtosecond laser or a mechanical microkeratome. Design Randomized clinical paired-eye study. Methods Both eyes of 21 patients received LASIK for myopia or myopic astigmatism. One eye of each patient was randomized by ocular dominance to flap creation with a femtosecond laser and the other eye to flap creation with a mechanical microkeratome. Before LASIK and at 1, 3, 6 months and 1, 3, and 5 years after LASIK, keratocyte density was measured by using confocal microscopy, and high-contrast visual acuity and anterior corneal wavefront aberrations were measured by standard methods. At each visit, all variables were compared between methods of creating the flap and to the same variable before treatment by using paired tests with Bonferroni correction for multiple comparisons. Results Keratocyte density in the flap decreased by 20% during the first year after LASIK and remained low through 5 years (p<0.001). High-order wavefront aberrations increased and uncorrected visual acuity improved immediately after surgery but these variables did not change further to five years. There were no differences in any variables between treatments. Conclusions A sustained reduction in keratocyte density does not affect vision or optical properties of the cornea through 5 years after LASIK. The method of creating a LASIK flap does not influence the changes in keratocyte density in the flap. PMID:25868758

  11. Long-term visual outcomes and patient satisfaction following bilateral implantation of trifocal intraocular lenses

    PubMed Central

    Ganesh, Sri; Brar, Sheetal; Pawar, Archana

    2017-01-01

    Purpose To study the long-term visual and refractive outcomes and evaluate patient satisfaction after bilateral implantation of trifocal intraocular lenses (IOLs). Setting Nethradhama Superspeciality Eye Hospital, Bangalore. Design Prospective, nonrandomized study. Methods Eligible patients undergoing bilateral phacoemulsification with trifocal IOL implantation were included. Follow-up examinations were conducted at day 1, 1 week, 1 month, 6 months, and 12 months. Postoperatively, 1 month onward evaluation of uncorrected and distance-corrected far and near visual acuity; reading acuity and reading speeds (using Salzburg Reading Desk) at 70, 80, and 90 cm; contrast sensitivity; defocus curves; and patient satisfaction was carried out. Results Fifty eyes from 25 patients with a mean age of 58±13.44 years were included. All eyes showed significant improvement in spherical equivalent, uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, and corrected near visual acuity at 1 month compared to preoperative values (P<0.05), with no significant change in these parameters thereafter until the last follow-up (P>0.05). At 12 months, mean uncorrected reading acuities and reading speeds at 70, 80, and 90 cm were in the range of 0.09–0.04 logMAR units and 153.6–169.0 words per minute, respectively, with significantly better results at 80 cm. Five eyes underwent YAG laser capsulotomy for early posterior capsule opacification (PCO) at a mean follow-up of 7.2±2.9 months. Contrast sensitivity scores at 12 months were comparable to 1 month (P>0.05 for all spatial frequencies). All patients reported good tolerance and 100% independence from spectacles for all activities. Conclusion Trifocal IOLs provided excellent unaided vision at all distances. Reading performance was good through the complete intermediate distance range. PCO occurrence and subsequent YAG capsulotomy did not affect the long-term visual outcomes. PMID:28860693

  12. Evaluation of visual acuity measurements after autorefraction vs manual refraction in eyes with and without diabetic macular edema.

    PubMed

    Sun, Jennifer K; Qin, Haijing; Aiello, Lloyd Paul; Melia, Michele; Beck, Roy W; Andreoli, Christopher M; Edwards, Paul A; Glassman, Adam R; Pavlica, Michael R

    2012-04-01

    To compare visual acuity (VA) scores after autorefraction vs manual refraction in eyes of patients with diabetes mellitus and a wide range of VAs. The letter score from the Electronic Visual Acuity (EVA) test from the electronic Early Treatment Diabetic Retinopathy Study was measured after autorefraction (AR-EVA score) and after manual refraction (MR-EVA score), which is the research protocol of the Diabetic Retinopathy Clinical Research Network. Testing order was randomized, study participants and VA examiners were masked to refraction source, and a second EVA test using an identical supplemental manual refraction (MR-EVAsuppl score) was performed to determine test-retest variability. In 878 eyes of 456 study participants, the median MR-EVA score was 74 (Snellen equivalent, approximately 20/32). The spherical equivalent was often similar for manual refraction and autorefraction (median difference, 0.00; 5th-95th percentile range, -1.75 to 1.13 diopters). However, on average, the MR-EVA scores were slightly better than the AR-EVA scores, across the entire VA range. Furthermore, the variability between the AR-EVA scores and the MR-EVA scores was substantially greater than the test-retest variability of the MR-EVA scores (P < .001). The variability of differences was highly dependent on the autorefractor model. Across a wide range of VAs at multiple sites using a variety of autorefractors, VA measurements tend to be worse with autorefraction than manual refraction. Differences between individual autorefractor models were identified. However, even among autorefractor models that compare most favorably with manual refraction, VA variability between autorefraction and manual refraction is higher than the test-retest variability of manual refraction. The results suggest that, with current instruments, autorefraction is not an acceptable substitute for manual refraction for most clinical trials with primary outcomes dependent on best-corrected VA.

  13. Association of visual sensory function and higher order visual processing skills with incident driving cessation

    PubMed Central

    Huisingh, Carrie; McGwin, Gerald; Owsley, Cynthia

    2017-01-01

    Background Many studies on vision and driving cessation have relied on measures of sensory function, which are insensitive to the higher order cognitive aspects of visual processing. The purpose of this study was to examine the association between traditional measures of visual sensory function and higher order visual processing skills with incident driving cessation in a population-based sample of older drivers. Methods Two thousand licensed drivers aged ≥70 were enrolled and followed-up for three years. Tests for central vision and visual processing were administered at baseline and included visual acuity, contrast sensitivity, sensitivity in the driving visual field, visual processing speed (Useful Field of View (UFOV) Subtest 2 and Trails B), and spatial ability measured by the Visual Closure Subtest of the Motor-free Visual Perception Test. Participants self-reported the month and year of driving cessation and provided a reason for cessation. Cox proportional hazards models were used to generate crude and adjusted hazard ratios with 95% confidence intervals between visual functioning characteristics and risk of driving cessation over a three-year period. Results During the study period, 164 participants stopped driving which corresponds to a cumulative incidence of 8.5%. Impaired contrast sensitivity, visual fields, visual processing speed (UFOVand Trails B), and spatial ability were significant risk factors for subsequent driving cessation after adjusting for age, gender, marital status, number of medical conditions, and miles driven. Visual acuity impairment was not associated with driving cessation. Medical problems (63%), specifically musculoskeletal and neurological problems, as well as vision problems (17%) were cited most frequently as the reason for driving cessation. Conclusion Assessment of cognitive and visual functioning can provide useful information about subsequent risk of driving cessation among older drivers. In addition, a variety of

  14. Visual acuity and contrast sensitivity are two important factors affecting vision-related quality of life in advanced age-related macular degeneration

    PubMed Central

    Selivanova, Alexandra; Shin, Hyun Joon; Miller, Joan W.; Jackson, Mary Lou

    2018-01-01

    Purpose Vision loss from age-related macular degeneration (AMD) has a profound effect on vision-related quality of life (VRQoL). The pupose of this study is to identify clinical factors associated with VRQoL using the Rasch- calibrated NEI VFQ-25 scales in bilateral advanced AMD patients. Methods We retrospectively reviewed 47 patients (mean age 83.2 years) with bilateral advanced AMD. Clinical assessment included age, gender, type of AMD, high contrast visual acuity (VA), history of medical conditions, contrast sensitivity (CS), central visual field loss, report of Charles Bonnet Syndrome, current treatment for AMD and Rasch-calibrated NEI VFQ-25 visual function and socioemotional function scales. The NEI VFQ visual function scale includes items of general vision, peripheral vision, distance vision and near vision-related activity while the socioemotional function scale includes items of vision related-social functioning, role difficulties, dependency, and mental health. Multiple regression analysis (structural regression model) was performed using fixed item parameters obtained from the one-parameter item response theory model. Results Multivariate analysis showed that high contrast VA and CS were two factors influencing VRQoL visual function scale (β = -0.25, 95% CI-0.37 to -0.12, p<0.001 and β = 0.35, 95% CI 0.25 to 0.46, p<0.001) and socioemontional functioning scale (β = -0.2, 95% CI -0.37 to -0.03, p = 0.023, and β = 0.3, 95% CI 0.18 to 0.43, p = 0.001). Central visual field loss was not assoicated with either VRQoL visual or socioemontional functioning scale (β = -0.08, 95% CI-0.28 to 0.12,p = 0.44 and β = -0.09, 95% CI -0.03 to 0.16, p = 0.50, respectively). Conclusion In patients with vision impairment secondary to bilateral advanced AMD, high contrast VA and CS are two important factors affecting VRQoL. PMID:29746512

  15. Neural Retinal Disorganization as a Robust Marker of Visual Acuity in Current and Resolved Diabetic Macular Edema

    PubMed Central

    Radwan, Salma H.; Soliman, Ahmed Z.; Lammer, Jan; Lin, Michael M.; Prager, Sonja G.; Silva, Paolo S.; Aiello, Lloyd Bryce; Aiello, Lloyd Paul

    2015-01-01

    Despite treatment advances, diabetic eye disease remains a leading cause of visual acuity (VA) loss worldwide. No methods to prospectively determine which patients will gain or lose vision exist, limiting individualized risk assessment and management. We investigated whether noninvasive, readily obtainable spectral domain optical coherence tomography parameters were correlated with VA in eyes with current or resolved center-involved diabetic macular edema (DME). Images were evaluated for disorganization of the retinal inner layers (DRIL), cysts, epiretinal membranes, microaneurysms, subretinal fluid, and outer layer disruption/reflectivity. DRIL affecting ≥50% of the 1-mm central retinal zone was associated with worse VA in all eyes, eyes with current edema, and eyes with resolved edema. Furthermore, early 4-month change in DRIL extent predicted VA change from baseline to 1 year. These data suggest that DRIL is a robust predictor of VA in eyes with present or previous DME and more highly correlated with VA than other widely used measures, such as retinal thickness. If further studies confirm DRIL as a predictive biomarker of future VA, physicians would gain a new tool of substantial clinical and investigative importance that could significantly change the approach to ophthalmic counseling and therapeutic management in patients with diabetes. PMID:25633419

  16. Refractive errors and cataract as causes of visual impairment in Brazil.

    PubMed

    Eduardo Leite Arieta, Carlos; Nicolini Delgado, Alzira Maria; José, Newton Kara; Temporini, Edméia Rita; Alves, Milton Ruiz; de Carvalho Moreira Filho, Djalma

    2003-02-01

    To identify the main causes of visual impairment (VA years of age examined in "Cataract Free Zone" projects sponsored by the University of Campinas from 1986 to 1995. A retrospective review of the ophthalmic forms used for 60,404 patients examined in 74 Cataract Projects was performed. Through mass media information, adults of the target region or city were asked to self-test their vision. Patients with VA visual acuity test. Using Snellen charts, visual acuity testing was done by trained auxiliaries and medical students. The positive cases were then examined by ophthalmologists Criteria were established for the classification of the diagnoses and statistical analysis was performed. After the self-test of visual acuity, 60,404 patients came to have their visual acuity tested; 11,462 (18.97%) cases were considered positive and were submitted to complete eye examination; 5447 (42.7%) received spectacles for vision improvement, and 2704 (23.59%) had cataract surgery done. Other important causes of visual impairment were senile macular degeneration (5.4%) and glaucoma (4.02%). The main causes of visual impairment were non-corrected refractive errors and senile cataract. Ophthalmic community-based campaigns to serve the older population are recommended in order to detect and treat the identified cases and to indicate possible changes in the health care system.

  17. One-year visual outcome of small incision lenticule extraction (SMILE) surgery in high myopic eyes: retrospective cohort study

    PubMed Central

    Wu, Wenjing; Wang, Yan; Zhang, Hui; Zhang, Jiamei; Li, Hua; Dou, Rui

    2016-01-01

    Objective To determine whether the long-term visual outcome of small incision lenticule extraction (SMILE) surgery is consistent with the short-term results in high myopic eyes. Design Retrospective cohort study; data collected from 8 August 2011 to 31 August 2015. Setting Single refractive surgery centre. Participants A total of 156 eyes were studied: 65 eyes of 39 subjects (22 female/17 male) in the high myopic group (manifest refraction spherical equivalent (MRSE) ≥−6.0 D), and 91 eyes of 54 subjects (29 female/25 male) in the control group (MRSE <−6.0 D). The inclusion criteria were subjects who had follow-ups after 1 day, 1 week, 1 month, 3, 6 months and 1 year with the manifest refraction, uncorrected and corrected distance visual acuity (UDVA/CDVA). There were no statistically significant differences between the two groups in the subjects' gender, age, or cylindrical dioptre, preoperatively (p=0.835, p=0.055, p=0.341, respectively). Primary and secondary outcome measures UDVA, refractive stability, safety index (postoperative CDVA/preoperative CDVA), and predictability (the percentage of eyes within ±0.50 D). Results In both groups, the 1-year UDVA and safety index were significantly better than results at 1 day (high myopic group: p=0.035, p<0.001; control group: p<0.016, p<0.001); the 1-year predictability showed no significant difference with the short-term results (p=1.00 in both groups). In the high myopic eyes, the 1-year MRSE was significantly worse than the short-term result (p=0.048). To correct it, the added magnitude (D) for the high myopic eyes may equal 0.13×Attempted SE (D)−0.66 D. However, the postoperative MRSE showed no differences from 1 day to 1 year (p=0.612) in the control group. Conclusions The 1-year visual outcomes were better than the short-term results after the SMILE surgery on the visual acuity and safety. However, the high myopic eyes suffered a significant regression at 1 year, which may be

  18. Blindness and Visual Impairment in an Urban West African Population: The Tema Eye Survey

    PubMed Central

    Budenz, Donald L.; Bandi, Jagadeesh R.; Barton, Keith; Nolan, Winifred; Herndon, Leon; Whiteside-de Vos, Julia; Hay-Smith, Graham; Kim, Hanna; Tielsch, James

    2012-01-01

    Objective To determine the prevalence, etiologies, and risk factors of blindness and visual impairment among persons age 40 years and older residing in an urban West African location. Design Population-based cross-sectional study. Participants Five thousand six hundred and three participants residing in Tema, Ghana. Methods Proportionate random cluster sampling was used to select participants age 40 and over living in the city of Tema. Presenting distance visual acuity was measured at 4 and 1 meters using a reduced Logarithm of the Minimum Angle of Resolution (logMAR) tumbling E chart and then with trial frame based on autorefraction. A screening examination was performed in the field on all participants. Complete clinical examination by an ophthalmologist was performed on participants with best corrected visual acuity < 20/40 or failure of any screening test. Main Outcome Measures Age- and gender-specific prevalence, causes, and risk factors for blindness (visual acuity in the better eye of < 20/400, World Health Organization definition) and visual impairment (visual acuity in the better eye of < 20/40). Results Six thousand eight hundred and six eligible participants were identified of which 5603 (82.3%) participated in the study. The mean age (±standard deviation) of participants was 52.7±10.9. The prevalence of visual impairment was 17.1% and blindness was 1.2%. After refraction and spectacle correction, the prevalence of visual impairment and blindness decreased to 6.7% and 0.75% respectively, suggesting that refractive error is the major correctable etiology of visual impairment and blindness in this population. Of 65 subjects having visual acuity < 20/400, 22 (34%) were correctable with refraction, 21 to the level of visual impairment, and one to normal. The remaining 43 (66%) had underlying pathology (19 cataract, 9 glaucoma, 3 non-glaucomatous optic neuropathy, 3 corneal opacities, 3 retinal disease, 5 undetermined) that prevented refractive correction

  19. Crowding in central vision in normally sighted and visually impaired [corrected] children aged 4 to 8 years: the influence of age and test design.

    PubMed

    Huurneman, Bianca; Boonstra, F Nienke; Cillessen, Antonius H N; van Rens, Ger; Cox, Ralf F A

    2012-06-01

    To investigate crowding ratios in children with a visual impairment due to ocular disease (n = 58) and normally sighted children (n = 75) aged 4 to 8 years using several variants of two clinically available tests with different optotype spacing (fixed or proportional to the optotype size). Crowding ratios, calculated by dividing the single acuity by the linear acuity, were measured binocularly with the C-test and the LH line chart. Ratios >1.00 indicate crowding. The charts with fixed spacing revealed significantly higher crowding ratios for visually impaired children than normally sighted children (both for measurements at 40 cm and 5 m). The age-related reduction of the crowding ratios seen in normally sighted children when tested with near-vision charts with fixed spacing was not present in the visually impaired group. Visually impaired children with nystagmus showed higher crowding ratios than visually impaired children without nystagmus. The chart with proportional intersymbol spacing (ISS) did not reveal differences between the normally sighted and visually impaired children; nor did it show group, age, or nystagmus effects. Visually impaired children showed higher crowding ratios than normally sighted children when measured with charts with fixed ISS. This study illustrates that test design and target/flanker interference as a manifestation of crowding are critical issues to bear in mind when assessing crowding ratios in children.

  20. The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery: report 2, relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture

    PubMed Central

    Day, A C; Donachie, P H J; Sparrow, J M; Johnston, R L

    2015-01-01

    Purpose To describe the relationships of axial length with ocular copathology, preoperative visual acuity, and posterior capsule rupture rates in patients undergoing cataract surgery. Design The Royal College of Ophthalmologists' National Ophthalmology Database (NOD) study. Methods Anonymised data on 180 114 eyes from 127 685 patients undergoing cataract surgery between August 2006 and November 2010 were collected prospectively from 28 sites. Data parameters included: demographics, biometry, ocular copathology, visual acuity measurements, and surgical complications including posterior capsule rupture, or vitreous loss or both (PCR). Results Consultant surgeons performed a higher proportion of operations on eyes whose axial length were at the extremes. Glaucoma and age related macular degeneration were more common in eyes with shorter axial lengths, whilst previous vitrectomy was associated with longer axial lengths. Eyes with brunescent or white cataracts or amblyopia were more common at both axial length extremes. Preoperative visual acuities were similar for eyes with axial length measurements up to approximately 28 mm and worse for eyes with longer axial length measurements. PCR rates showed little change with axial length (overall mean 1.95%, 95% CI: 1.89 to 2.01%), except for a borderline increase in eyes with axial length <20.0 mm where rates were 3.6% (95% CI: 2.0 to 6.3%). The likelihood of PCR in eyes with axial length <20.0 mm was 1.88 times higher than those of ≥20.0 mm (P=0.0373). Conclusion Rates of ocular comorbidities vary by axial length. PCR rates in eyes with very short or long axial lengths were lower than expected. PMID:26493034

  1. Merging Psychophysical and Psychometric Theory to Estimate Global Visual State Measures from Forced-Choices

    NASA Astrophysics Data System (ADS)

    Massof, Robert W.; Schmidt, Karen M.; Laby, Daniel M.; Kirschen, David; Meadows, David

    2013-09-01

    Visual acuity, a forced-choice psychophysical measure of visual spatial resolution, is the sine qua non of clinical visual impairment testing in ophthalmology and optometry patients with visual system disorders ranging from refractive error to retinal, optic nerve, or central visual system pathology. Visual acuity measures are standardized against a norm, but it is well known that visual acuity depends on a variety of stimulus parameters, including contrast and exposure duration. This paper asks if it is possible to estimate a single global visual state measure from visual acuity measures as a function of stimulus parameters that can represent the patient's overall visual health state with a single variable. Psychophysical theory (at the sensory level) and psychometric theory (at the decision level) are merged to identify the conditions that must be satisfied to derive a global visual state measure from parameterised visual acuity measures. A global visual state measurement model is developed and tested with forced-choice visual acuity measures from 116 subjects with no visual impairments and 560 subjects with uncorrected refractive error. The results are in agreement with the expectations of the model.

  2. Crowded letter and crowded picture logMAR acuity in children with amblyopia: a quantitative comparison.

    PubMed

    O'Boyle, Cathy; Chen, Sean I; Little, Julie-Anne

    2017-04-01

    Clinically, picture acuity tests are thought to overestimate visual acuity (VA) compared with letter tests, but this has not been systematically investigated in children with amblyopia. This study compared VA measurements with the LogMAR Crowded Kay Picture test to the LogMAR Crowded Keeler Letter acuity test in a group of young children with amblyopia. 58 children (34 male) with amblyopia (22 anisometropic, 18 strabismic and 18 with both strabismic/anisometropic amblyopia) aged 4-6 years (mean=68.7, range=48-83 months) underwent VA measurements. VA chart testing order was randomised, but the amblyopic eye was tested before the fellow eye. All participants wore up-to-date refractive correction. The Kay Picture test significantly overestimated VA by 0.098 logMAR (95% limits of agreement (LOA), 0.13) in the amblyopic eye and 0.088 logMAR (95% LOA, 0.13) in the fellow eye, respectively (p<0.001). No interactions were found from occlusion therapy, refractive correction or type of amblyopia on VA results (p>0.23). For both the amblyopic and fellow eyes, Bland-Altman plots demonstrated a systematic and predictable difference between Kay Picture and Keeler Letter charts across the range of acuities tested (Keeler acuity: amblyopic eye 0.75 to -0.05 logMAR; fellow eye 0.45 to -0.15 logMAR). Linear regression analysis (p<0.00001) and also slope values close to one (amblyopic 0.98, fellow 0.86) demonstrate that there is no proportional bias. The Kay Picture test consistently overestimated VA by approximately 0.10 logMAR when compared with the Keeler Letter test in young children with amblyopia. Due to the predictable difference found between both crowded logMAR acuity tests, it is reasonable to adjust Kay Picture acuity thresholds by +0.10 logMAR to compute expected Keeler Letter acuity scores. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. The contributions of numerical acuity and non-numerical stimulus features to the development of the number sense and symbolic math achievement.

    PubMed

    Starr, Ariel; DeWind, Nicholas K; Brannon, Elizabeth M

    2017-11-01

    Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comparison judgments, has been shown to be predictive of mathematical ability. However, recent findings suggest that stimulus controls in these tasks are often insufficiently implemented, and the proposal has been made that alternative visual features or inhibitory control capacities may actually explain this relation. Here, we use a novel mathematical algorithm to parse the relative influence of numerosity from other visual features in nonsymbolic numerical discrimination and to examine the strength of the relations between each of these variables, including inhibitory control, and mathematical ability. We examined these questions developmentally by testing 4-year-old children, 6-year-old children, and adults with a nonsymbolic numerical comparison task, a symbolic math assessment, and a test of inhibitory control. We found that the influence of non-numerical features decreased significantly over development but that numerosity was a primary determinate of decision making at all ages. In addition, numerical acuity was a stronger predictor of math achievement than either non-numerical bias or inhibitory control in children. These results suggest that the ability to selectively attend to number contributes to the maturation of the number sense and that numerical acuity, independent of inhibitory control, contributes to math achievement in early childhood. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Visual Processing Deficits in Children with Slow RAN Performance

    ERIC Educational Resources Information Center

    Stainthorp, Rhona; Stuart, Morag; Powell, Daisy; Quinlan, Philip; Garwood, Holly

    2010-01-01

    Two groups of 8- to 10-year-olds differing in rapid automatized naming speed but matched for age, verbal and nonverbal ability, phonological awareness, phonological memory, and visual acuity participated in four experiments investigating early visual processing. As low RAN children had significantly slower simple reaction times (SRT) this was…

  5. Community screening for visual impairment in older people.

    PubMed

    Clarke, Emily L; Evans, Jennifer R; Smeeth, Liam

    2018-02-20

    Visual problems in older people are common and frequently under-reported. The effects of poor vision in older people are wide reaching and include falls, confusion and reduced quality of life. Much of the visual impairment in older ages can be treated (e.g. cataract surgery, correction of refractive error). Vision screening may therefore reduce the number of older people living with sight loss. The objective of this review was to assess the effects on vision of community vision screening of older people for visual impairment. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 10); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 23 November 2017. We included randomised controlled trials (RCTs) that compared vision screening alone or as part of a multi-component screening package as compared to no vision screening or standard care, on the vision of people aged 65 years or over in a community setting. We included trials that used self-reported visual problems or visual acuity testing as the screening tool. We used standard methods expected by Cochrane. We graded the certainty of the evidence using GRADE. Visual outcome data were available for 10,608 people in 10 trials. Four trials took place in the UK, two in Australia, two in the United States and two in the Netherlands. Length of follow-up ranged from one to five years. Three of these studies were cluster-randomised trials whereby general practitioners or family physicians were randomly allocated to undertake vision screening or no vision screening. All studies were funded by government agencies. Overall we judged the studies to be at low risk of bias and only downgraded the certainty of the evidence (GRADE) for imprecision.Seven trials compared vision screening as part of a multi-component screening versus no screening. Six of these studies used self

  6. Effects of Binaural Sensory Aids on the Development of Visual Perceptual Abilities in Visually Handicapped Infants. Final Report, April 15, 1982-November 15, 1982.

    ERIC Educational Resources Information Center

    Hart, Verna; Ferrell, Kay

    Twenty-four congenitally visually handicapped infants, aged 6-24 months, participated in a study to determine (1) those stimuli best able to elicit visual attention, (2) the stability of visual acuity over time, and (3) the effects of binaural sensory aids on both visual attention and visual acuity. Ss were dichotomized into visually handicapped…

  7. The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study.

    PubMed

    Premsenthil, Mallika; Manju, Rose; Thanaraj, Asokumaran; Rahman, Syed Alwi Syed Abdul; Kah, Tan Aik

    2013-04-19

    To screen for visual impairment in Malaysian preschool children. Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test. The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9). The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group.

  8. Effect of ocular transverse chromatic aberration on detection acuity for peripheral vision.

    PubMed

    Cheney, Frank; Thibos, Larry; Bradley, Arthur

    2015-01-01

    We examined the effect of transverse chromatic aberration (TCA) on detection acuity for white-light interference fringes seen in Maxwellian view at various orientations and locations in the visual field. A circular patch (3.5° diameter, 3.2 log Trolands) of nominally high-contrast fringes was produced on the retina by a commercial instrument (the Lotmar Visometer, Haag Streit) mounted on a gimbal for controlled positioning of the stimulus in the visual field from 0° to 35° eccentricity. Detection acuity for white light fringes for all meridians and eccentricities ≥15° was maximum when fringes were oriented parallel to the visual meridian line. This meridional effect disappeared when a narrow-band filter was used to eliminate TCA. The meridional effect also disappeared when the interferometric stimulator was displaced laterally to align the instrument with the eye's local achromatic axis. Modelling confirmed that TCA is the major factor responsible for white-light meridional bias, with minor contribution arising from higher-order monochromatic aberrations and neural factors. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

  9. The changing pattern of cataract surgery indications: a 5-year study of 2 cataract surgery databases.

    PubMed

    Lundström, Mats; Goh, Pik-Pin; Henry, Ype; Salowi, Mohamad A; Barry, Peter; Manning, Sonia; Rosen, Paul; Stenevi, Ulf

    2015-01-01

    The aim of this study was to describe changes over time in the indications and outcomes of cataract surgery and to discuss optimal timing for the surgery. Database study. Patients who had undergone cataract extraction in the Netherlands, Sweden, or Malaysia from 2008 through 2012. We analyzed preoperative, surgical, and postoperative data from 2 databases: the European Registry of Quality Outcomes for Cataract and Refractive Surgery (EUREQUO) and the Malaysian National Cataract Registry. The EUREQUO contains complete data from the national cataract registries in the Netherlands and Sweden. Preoperative and postoperative corrected distance visual acuity, preoperative ocular comorbidity in the surgery eye, and capsule complications during surgery. There were substantial differences in indication for surgery between the 3 national data sets. The percentage of eyes with a preoperative best-corrected visual acuity of 20/200 or worse varied from 7.1% to 72%. In all 3 data sets, the visual thresholds for cataract surgery decreased over time by 6% to 28% of the baseline values. The frequency of capsule complications varied between the 3 data sets, from 1.1% to 3.7% in 2008 and from 0.6% to 2.7% in 2012. An increasing postoperative visual acuity was also seen for all 3 data sets. A high frequency of capsule complication was related significantly to poor preoperative visual acuity, and a high frequency of decreased visual acuity after surgery was related significantly to excellent preoperative visual acuity. The 5-year trend in all 3 national data sets showed decreasing visual thresholds for surgery, decreasing surgical complication rates, and increasing visual outcomes regardless of the initial preoperative visual level. Cataract surgery on eyes with poor preoperative visual acuity was related to surgical complications, and cataract surgery on eyes with excellent preoperative visual acuity was related to adverse visual results. Copyright © 2015 American Academy of

  10. A comprehensive assessment of visual impairment in a population of older Americans. The SEE Study. Salisbury Eye Evaluation Project.

    PubMed

    Rubin, G S; West, S K; Muñoz, B; Bandeen-Roche, K; Zeger, S; Schein, O; Fried, L P

    1997-03-01

    The Salisbury Eye Evaluation Project is a longitudinal study of risk factors for age-related eye diseases and the impact of eye disease and visual impairment on physical disability. In this article, the authors report the prevalence of visual impairment in their population and explore the relations among the various measures of visual function. A population-based sample of 2520 residents of Salisbury, Maryland, between the ages of 65 and 84 years were enrolled in the study. Twenty-six percent of participants were black. Vision tests included best-corrected Early Treatment Diabetic Retinopathy Study acuity, Pelli-Robson contrast sensitivity with and without glare, Randot stereoacuity, and 60 degrees Humphrey visual fields. Visual function decreased linearly with age for the acuity, contrast sensitivity, glare, and visual field tests. Stereoacuity remained constant into the mid-70s and declined at an accelerating rate thereafter. Black participants had lower contrast sensitivity, reduced stereoacuity, and worse visual fields, at all ages compared to white participants; however, white participants were more sensitive to glare. The overall prevalence of visual acuity impairment in blacks was 5.6% versus 3.0% for whites, using the traditional United States definition (worse than 20/40 to better than 20/200) and 3.3% for blacks versus 1.6% for whites, using the World Health Organization definition (worse than 20/60 to 20/400). Acuity was correlated moderately with contrast sensitivity, stereoacuity, and visual fields (Spearman rho = 0.50, 0.35, and 0.34, respectively). The correlation between acuity and glare sensitivity was low (rho = 0.12). Many aspects of visual function, not just acuity, decline with age. Black participants have more visual impairement than do white participants for all tests except glare sensitivity. The prevalence of visual acuity impairement in the Salisbury Eye Evaluation population is lower than that reported by other studies using similar test

  11. [Visual outcomes four years after small incision lenticule extraction (SMILE) surgery on highly myopic eyes [French version

    PubMed

    Burazovitch, J; Naguzeswski, D; Beuste, T; Guillard, M

    2017-09-01

    To determine whether the visual outcomes of the refractive surgery technique, small incision lenticule extraction (SMILE), are stable, effective, and predictable for high myopia over a four-year period. This is a retrospective study. The data were collected between March 2012 and July 2016. Two hundred and forty-eight patients participated in the study; that is, 496 eyes: 140 eyes of 70 patients (52 women/18 men) were classified in the highly myopic group (refraction measured in spherical equivalent [RMSE]>-6D), and 356 eyes of 178 patients (98 women/80 men) in the control group (RMSE≤-6D). Follow-up tests were conducted immediately post-operatively (D+1), after three months, after one year, and after four years. Refraction, uncorrected visual acuity (UCVA), and best visual corrected acuity (BCVA) were measured. The highly myopic group (HMG) contained more women, and astigmatism was higher for this group than for the control group (CG). These are BCVA, refractive stability, the index of safety (SI: BCVA preoperatively D+1/BCVA postoperatively), and predictability (the percentage of eyes within±0.5 D of the target). In both groups, UCVA was better after the fourth year than it was immediately after the procedure (HMG: P=0.001; CG: P=0.001). Although it differed at one year (P=0.01), the groups' refractive stability tended to converge over four years (P=0.138). Both groups' SI was identical in the four follow-up tests (P=0.734 at D+1; P=0.07 at M+1; P=0.160 at M3 and Y1; and P=0.274 at Y4). For the HMG, SI stability was attained after three months (1.00±0.1); whereas it was attained after one month (0.91±0.11) for the CG. Four years after the surgery, we observed that 87 % of the operated eyes in the HMG were within 0.5 D of the target. SMILE is a good refractive surgery technique for treating high myopia. It yields stable, safe, effective, and predictable results over four years. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Visual impairment and spectacle use in schoolchildren in rural and urban regions in Beijing.

    PubMed

    Guo, Yin; Liu, Li Juan; Xu, Liang; Lv, Yan Yun; Tang, Ping; Feng, Yi; Meng, Lei; Jonas, Jost B

    2014-01-01

    To determine prevalence and associations of visual impairment and frequency of spectacle use among grade 1 and grade 4 students in Beijing. This school-based, cross-sectional study included 382 grade 1 children (age 6.3 ± 0.5 years) and 299 grade 4 children (age 9.4 ± 0.7 years) who underwent a comprehensive eye examination including visual acuity, noncycloplegic refractometry, and ocular biometry. Presenting visual acuity (mean 0.04 ± 0.17 logMAR) was associated with younger age (p = 0.002), hyperopic refractive error (p<0.001), and male sex (p = 0.03). Presenting visual impairment (presenting visual acuity ≤20/40 in the better eye) was found in 44 children (prevalence 6.64 ± 1.0% [95% confidence interval (CI) 4.74, 8.54]). Mean best-corrected visual acuity (right eyes -0.02 ± 0.04 logMAR) was associated with more hyperopic refractive error (p = 0.03) and rural region of habitation (p<0.001). The prevalence of best-corrected visual impairment (best-corrected visual acuity ≤20/40 in the better eye) was 2/652 (0.30 ± 0.21% [95% CI 0.00, 0.72]). Undercorrection of refractive error was present in 53 children (7.99 ± 1.05%) and was associated with older age (p = 0.003; B 0.53; OR 1.71 [95% CI 1.20, 2.42]), myopic refractive error (p = 0.001; B -0.72; OR 0.49 [95% CI 0.35, 0.68]), and longer axial length (p = 0.002; B 0.74; OR 2.10 [95% CI 1.32, 3.32]). Spectacle use was reported for 54 children (8.14 ± 1.06%). Mean refractive error of the worse eyes of these children was -2.09 ± 2.88 D (range -7.38 to +7.25 D). Factors associated with presenting visual impairment were older age, myopic refractive error, and higher maternal education level. Despite a prevalence of myopia of 33% in young schoolchildren in Greater Beijing, prevalence of best-corrected visual impairment (0.30% ± 0.21%), presenting visual impairment (6.64% ± 1.0%), and undercorrection of refractive error (7.99% ± 1.05%) were relatively low.

  13. Predicting individual contrast sensitivity functions from acuity and letter contrast sensitivity measurements

    PubMed Central

    Thurman, Steven M.; Davey, Pinakin Gunvant; McCray, Kaydee Lynn; Paronian, Violeta; Seitz, Aaron R.

    2016-01-01

    Contrast sensitivity (CS) is widely used as a measure of visual function in both basic research and clinical evaluation. There is conflicting evidence on the extent to which measuring the full contrast sensitivity function (CSF) offers more functionally relevant information than a single measurement from an optotype CS test, such as the Pelli–Robson chart. Here we examine the relationship between functional CSF parameters and other measures of visual function, and establish a framework for predicting individual CSFs with effectively a zero-parameter model that shifts a standard-shaped template CSF horizontally and vertically according to independent measurements of high contrast acuity and letter CS, respectively. This method was evaluated for three different CSF tests: a chart test (CSV-1000), a computerized sine-wave test (M&S Sine Test), and a recently developed adaptive test (quick CSF). Subjects were 43 individuals with healthy vision or impairment too mild to be considered low vision (acuity range of −0.3 to 0.34 logMAR). While each test demands a slightly different normative template, results show that individual subject CSFs can be predicted with roughly the same precision as test–retest repeatability, confirming that individuals predominantly differ in terms of peak CS and peak spatial frequency. In fact, these parameters were sufficiently related to empirical measurements of acuity and letter CS to permit accurate estimation of the entire CSF of any individual with a deterministic model (zero free parameters). These results demonstrate that in many cases, measuring the full CSF may provide little additional information beyond letter acuity and contrast sensitivity. PMID:28006065

  14. Association of Baseline Visual Acuity and Retinal Thickness With 1-Year Efficacy of Aflibercept, Bevacizumab, and Ranibizumab for Diabetic Macular Edema.

    PubMed

    Wells, John A; Glassman, Adam R; Jampol, Lee M; Aiello, Lloyd Paul; Antoszyk, Andrew N; Baker, Carl W; Bressler, Neil M; Browning, David J; Connor, Crystal G; Elman, Michael J; Ferris, Frederick L; Friedman, Scott M; Melia, Michele; Pieramici, Dante J; Sun, Jennifer K; Beck, Roy W

    2016-02-01

    Comparisons of the relative effect of 3 anti-vascular endothelial growth factor agents to treat diabetic macular edema warrant further assessment. To provide additional outcomes from a randomized trial evaluating 3 anti-vascular endothelial growth factor agents for diabetic macular edema within subgroups based on baseline visual acuity (VA) and central subfield thickness (CST) as evaluated on optical coherence tomography. Post hoc exploratory analyses were conducted of randomized trial data on 660 adults with diabetic macular edema and decreased VA (Snellen equivalent, approximately 20/32 to 20/320). The original study was conducted between August 22, 2012, and August 28, 2013. Analysis was conducted from January 7 to June 2, 2015. Repeated 0.05-mL intravitreous injections of 2.0 mg of aflibercept (224 eyes), 1.25 mg of bevacizumab (218 eyes), or 0.3 mg of ranibizumab (218 eyes) as needed per protocol. One-year VA and CST outcomes within prespecified subgroups based on both baseline VA and CST thresholds, defined as worse (20/50 or worse) or better (20/32 to 20/40) VA and thicker (≥400 µm) or thinner (250 to 399 µm) CST. In the subgroup with worse baseline VA (n = 305), irrespective of baseline CST, aflibercept showed greater improvement than bevacizumab or ranibizumab for several VA outcomes. In the subgroup with better VA and thinner CST at baseline (61-73 eyes across 3 treatment groups), VA outcomes showed little difference between groups; mean change was +7.2, +8.4, and +7.6 letters in the aflibercept, bevacizumab, and ranibizumab groups, respectively. However, in the subgroup with better VA and thicker CST at baseline (31-43 eyes), there was a suggestion of worse VA outcomes in the bevacizumab group; mean change from baseline to 1 year was +9.5, +5.4, and +9.5 letters in the aflibercept, bevacizumab, and ranibizumab groups, respectively, and VA letter score was greater than 84 (approximately 20/20) in 21 of 33 (64%), 7 of 31 (23%), and 21 of 43 (49

  15. Changes in Retinal Microvasculature and Visual Acuity After Antivascular Endothelial Growth Factor Therapy in Retinal Vein Occlusion.

    PubMed

    Winegarner, Andrew; Wakabayashi, Taku; Fukushima, Yoko; Sato, Tatsuhiko; Hara-Ueno, Chikako; Busch, Caleb; Nishiyama, Issei; Shiraki, Nobuhiko; Sayanagi, Kaori; Nishida, Kentaro; Sakaguchi, Hirokazu; Nishida, Kohji

    2018-06-01

    To investigate the changes in the retinal microvasculature during the course of anti-VEGF therapy in eyes with macular edema due to retinal vein occlusion (RVO) and their association with visual outcomes. The vessel density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were quantitatively measured by optical coherence tomography angiography (OCTA) in 48 consecutive eyes with RVO before and 1, 3, 6, 9, and 12 months after anti-VEGF therapy. Anti-VEGF therapy was performed either with ranibizumab or aflibercept following a pro re nata (PRN) regimen. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA were assessed. The BCVA improved significantly at 12 months (P < 0.001). Better BCVA at 12 months was significantly associated with a better VD in the SCP and DCP both at baseline (R2 = 0.524, P < 0.001 and R2 = 0.457, P < 0.001, respectively) and at 12 months (R2 = 0.521, P < 0.001 and R2 = 0.662, P < 0.001, respectively). Overall, both VD and FAZ did not change significantly during the 12 months. However, the progression of nonperfusion was observed in the SCP in 6 (13%) eyes and in the DCP in 10 (21%) eyes. The number of macular edema recurrence was significantly associated with a decrease in the VD (P = 0.006 [SCP] and P < 0.001 [DCP]) and less visual gain (P = 0.02) after treatment. Anti-VEGF therapy maintains retinal perfusion in most patients with RVO. Preserving retinal perfusion is crucial for better visual outcomes.

  16. Longterm visual prognosis in Usher syndrome types 1 and 2.

    PubMed

    Sadeghi, André M; Eriksson, Kristina; Kimberling, William J; Sjöström, Anders; Möller, Claes

    2006-08-01

    To estimate the age at diagnosis of retinitis pigmentosa and to determine visual acuity deterioration, visual field impairment and the frequency of cataracts in Usher syndrome types 1 and 2. We carried out a retrospective study of 328 affected subjects with Usher syndrome types 1 and 2. Study subjects were divided into seven different age groups by decade. Data were analysed using descriptive statistics, general linear model anova and survival analysis. Retinitis pigmentosa was diagnosed significantly earlier in subjects with Usher syndrome type 1 than in those with type 2. Visual acuity was significantly more impaired in affected subjects with Usher syndrome type 1 than in those with type 2 from 50 years of age onwards. Survival analysis revealed a significant difference in visual field loss (visual field categories. Cataract was found to be generally more common in Usher syndrome type 1 than type 2. Progressive loss of visual acuity and visual field begins to be substantial between the second and third decades of life in both Usher types. The rate of degeneration varies between individuals in both groups. The data are useful for the counselling of affected subjects with Usher syndrome types 1 and 2.

  17. Visual neuroscience before the neuron.

    PubMed

    Wade, Nicholas J

    2004-01-01

    Visual neuroscience is considered to be a contemporary concern, based in large part on relating characteristics of neural functioning to visual experience. It presupposes a detailed knowledge of neural activity for which the neuron doctrine is a fundamental tenet. However, long before either the neuron doctrine had been advanced or the nerve cell had been described, attempts were made to estimate the dimensions of nerve fibres from measures of visual resolution. In the seventeenth century, the microscopes of Hooke and van Leeuwenhoek were unable to resolve structures as small as nerves adequately. However, it was not Hooke's microscope that led to an estimate of the dimensions of nerve fibres but his experiments on the limits of visual resolution. Hooke determined that a separation of one minute of arc was the minimum that could normally be seen. Descartes had earlier speculated that the retina consisted of the terminations of fibres of the optic nerve, and that their size defined the limits of what could be seen. Estimates of the diameters of nerve fibres were made on the basis of human visual acuity by Porterfield in 1738; he calculated the diameters of nerve fibres in the retina as one 7200th part of an inch (0.0035 mm), based on the resolution of one minute of arc as the minimum visible. In the same year, Jurin questioned the reliability of such estimates because of variations in visual resolution with different stimuli. The measurement of visual acuity was refined by Mayer in 1755, with dots, gratings, and grids used as stimuli. In the 1830s, Treviranus fused the microscopic and acuity approaches to determine the dimensions of nerve fibres. His indirect estimates of the dimensions of retinal fibres were close to those derived from microscopic observation. However, the suggestion that the retina consisted of terminations of nerve fibres influenced his detailed illustrations of its microscopic structure. Contrary to the situation that obtained after the

  18. Effect of anterior capsule contraction on visual function after cataract surgery.

    PubMed

    Hayashi, Ken; Hayashi, Hideyuki

    2007-11-01

    To examine the effect of contraction of the anterior capsule opening after cataract surgery on visual acuity and contrast sensitivity. Hayashi Eye Hospital, Fukuoka, Japan. Thirty-two eyes of 32 consecutive patients who showed marked contraction of the anterior capsule opening after implantation of an intraocular lens were recruited. The area of the anterior capsule opening was measured by Scheimpflug videophotography before and after neodymium:YAG (Nd:YAG) laser anterior capsulotomy and was correlated with visual acuity and contrast sensitivity. After Nd:YAG laser anterior capsulotomy, the mean area of the anterior capsule opening increased significantly from 8.2 mm(2) to 18.0 mm(2) (P<.0001). Contrast sensitivity at most visual angles also improved significantly after Nd:YAG anterior capsulotomy, although visual acuity did not. The area of the anterior capsule opening before anterior capsulotomy was correlated significantly with contrast sensitivity but not with visual acuity, whereas there was no correlation between the opening area after anterior capsulotomy and visual acuity or contrast sensitivity. Contraction of the anterior capsule opening after cataract surgery significantly diminished contrast sensitivity in proportion to the opening area but did not markedly worsen visual acuity. Neodymium:YAG laser anterior capsulotomy improved contrast sensitivity.

  19. Association Between Vessel Density and Visual Acuity in Patients With Diabetic Retinopathy and Poorly Controlled Type 1 Diabetes.

    PubMed

    Dupas, Bénédicte; Minvielle, Wilfried; Bonnin, Sophie; Couturier, Aude; Erginay, Ali; Massin, Pascale; Gaudric, Alain; Tadayoni, Ramin

    2018-05-10

    Capillary dropout is a hallmark of diabetic retinopathy, but its role in visual loss remains unclear. To examine how macular vessel density is correlated with visual acuity (VA) in patients younger than 40 years who have type 1 diabetes without macular edema but who have diabetic retinopathy requiring panretinal photocoagulation. Retrospective cohort study of VA and optical coherence tomography angiography data collected from consecutive patients during a single visit to Lariboisière Hospital, a tertiary referral center in Paris, France. The cohort included 22 eyes of 22 patients with type 1 diabetes without macular edema but with bilateral rapidly progressive diabetic retinopathy that was treated with panretinal photocoagulation between August 15, 2015, and December 30, 2016. Eyes were classified into 2 groups by VA: normal (logMAR, 0; Snellen equivalent, 20/20) and decreased (logMAR, >0; Snellen equivalent, <20/20). The control group included 12 eyes from age-matched healthy participants with normal vision. Visual acuity and mean vessel density in 4 retinal vascular plexuses: the superficial vascular plexus and the deep capillary complex, which comprises the intermediate capillary plexus and the deep capillary plexus. Of the 22 participants, 11 (50%) were men, mean (SD) age was 30 (6) years, and mean (SD) hemoglobin A1c level was 8.9% (1.6%). Of the 22 eyes with diabetic retinopathy, 13 (59%) had normal VA and 9 (41%) had decreased VA (mean [SD]: logMAR, 0.12 [0.04]; Snellen equivalent, 20/25). Mean [SE] vessel density was lower for eyes with diabetic retinopathy and normal VA compared with the control group in the superficial vascular plexus (44.1% [0.9%] vs 49.1% [0.9%]; difference, -5.0% [1.3%]; 95% CI, -7.5% to -2.4%; P < .001), in the deep capillary complex (44.3% [1.2%] vs 50.6% [1.3%]; difference, -6.3% [1.8%]; 95% CI, -9.9% to -2.7%; P = .001), in the intermediate capillary plexus (43.8% [1.2%] vs 49.3% [1.2%]; difference, -5.5% [1.7%]; 95% CI

  20. Visual function after strontium-90 plaque irradiation in patients with age-related subfoveal choroidal neovascularization.

    PubMed

    Jaakkola, A; Heikkonen, J; Tarkkanen, A; Immonen, I

    1999-02-01

    To report 2-year visual and angiographic results in eyes treated with strontium plaque irradiation for subfoveal choroidal neovascular membranes (CNVM) in age-related macular degeneration. Twenty eyes with recent subfoveal CNVM were treated with local irradiation. The impact of the treatment on visual function was evaluated by visual acuity, contrast sensitivity and reading speed testing. At 12 months visual acuity had improved or remained the same in 9/ 20 eyes (45%). At 24 months visual acuity was stable in 5/18 eyes (28%). Eyes with signs of CNVM regression (13/18, 72%) lost a mean of 3.3 lines, but eyes with recurrent CNVM lost a mean of 5.1 lines of vision. The mean contrast sensitivity was better in the irradiated eyes than in the fellow eyes with late age-related macular degeneration at 24 months. Six of 17 irradiated eyes (35%) could read at least some words at 24 months. Visual function decreases in patients treated with strontium irradiation, but less in eyes showing regression of the CNVM than in eyes with further growth of the CNVM.

  1. Association Between Adherence to Glasses Wearing During Amblyopia Treatment and Improvement in Visual Acuity.

    PubMed

    Maconachie, Gail D E; Farooq, Shegufta; Bush, Glen; Kempton, Julie; Proudlock, Frank A; Gottlob, Irene

    2016-12-01

    Occlusion dose monitors have helped establish that better adherence to occlusion is associated with improved visual outcomes in patients undergoing amblyopia treatment. However, the role of adherence to glasses wearing is unknown. To establish the feasibility and reliability of objectively monitoring adherence to glasses wearing using age-based norms, establish the association between adherence to glasses wearing and improvement in visual acuity (VA) after optical treatment and occlusion therapy, and analyze the effect of age, sex, refractive errors, type of amblyopia, and adherence to glasses wearing on improvement in VA. A prospective, observational, nonmasked, cohort study was conducted between June 8, 2008, and June 30, 2013, among patients at a pediatric ophthalmology clinic of a tertiary care hospital who were newly diagnosed with anisometropic and/or strabismic amblyopia and had not undergone previous treatment. The study consisted of a glasses phase (18 weeks) and a patching phase (glasses and occlusion for 10 hours per day for 12 weeks). Reliability of the glasses monitors was assessed by comparing diary entries and monitor recordings in adults. Objective monitoring of glasses wearing and occlusion. Adherence to glasses wearing (hours per day) and effect on VA. Among 20 children with anisometropia (mean [SD] age, 6.20 [2.16] years; 11 boys and 9 girls) and 20 with strabismic or mixed amblyopia (mean [SD] age, 4.90 [1.36] years; 10 boys and 10 girls), adherence to glasses wearing was successfully monitored in all but 1 patient. Agreement between diaries and monitored times wearing glasses in adults was high (intraclass correlation coefficient, 1.00; 95% CI, 0.999-1.00). Median (SD) adherence to glasses wearing was 70% (25.3%). A moderate correlation was observed between adherence to glasses wearing and percentage improvement in VA during the glasses phase (r = 0.462; P = .003). Multiple regression revealed that age (β = -0.535; P = .001

  2. Visual Function in Carriers of X-linked Retinitis Pigmentosa

    PubMed Central

    Comander, Jason; Weigel-DiFranco, Carol; Sandberg, Michael A.; Berson, Eliot L.

    2015-01-01

    Purpose To determine the frequency and severity of visual function loss in female carriers of X-linked retinitis pigmentosa (XLRP). Design Case series. Participants XLRP carriers with cross-sectional data (n = 242) and longitudinal data (n = 34, median follow-up: 16 years, follow-up range: 3–37 years). Half of the carriers were from RPGR- or RP2-genotyped families. Methods Retrospective medical records review. Main Outcome Measures Visual acuities, visual field areas, final dark adaptation thresholds, and full-field ERGs to 0.5 Hz and 30 Hz flashes. Results In genotyped families, 40% of carriers showed a baseline abnormality on at least one of the three psychophysical tests. There was a wide range of function among carriers; for example 3 of 121 (2%) of genotyped carriers were legally blind due to poor visual acuity, some as young as 35 years of age. Visual fields were less affected than visual acuity. In all carriers, the average ERG amplitude to 30 Hz flashes was about 50% of normal, and the average exponential rate of amplitude loss over time was half that of XLRP males (3.7%/year vs 7.4%/year, respectively). Among obligate carriers with affected fathers and/or sons, 53 of 55 (96%) had abnormal baseline ERGs. Some carriers who initially had completely normal fundi in both eyes went on to develop moderately decreased vision, though not legal blindness. Among carriers with RPGR mutations, those with mutations in ORF15, compared to those in exons 1–14, had worse final dark adaptation thresholds and lower 0.5 Hz and 30 Hz ERG amplitudes. Conclusions Most carriers of XLRP had mildly or moderately reduced visual function but rarely became legally blind. In most cases, obligate carriers could be identified by ERG testing. Carriers of RPGR ORF15 mutations tended to have worse visual function than carriers of RPGR exon 1–14 mutations. Since XLRP carrier ERG amplitudes and decay rates over time were on average half of those of affected males, these observations were

  3. Dry-eye screening by using a functional visual acuity measurement system: the Osaka Study.

    PubMed

    Kaido, Minako; Uchino, Miki; Yokoi, Norihiko; Uchino, Yuichi; Dogru, Murat; Kawashima, Motoko; Komuro, Aoi; Sonomura, Yukiko; Kato, Hiroaki; Kinoshita, Shigeru; Tsubota, Kazuo

    2014-05-06

    We determined whether functional visual acuity (VA) parameters and a dry eyes (DEs) symptoms questionnaire could predict DEs in a population of visual terminal display (VDT) users. This prospective study included 491 VDT users from the Osaka Study. Subjects with definite DE, diagnosed with the presence of DE symptoms, tear abnormality (Schirmer test ≤ 5 mm or tear breakup time [TBUT] ≤ 5 seconds), and conjunctivocorneal epithelial damage (total staining score of ≥3 points), or probable DE, diagnosed with the presence of two of them, were assigned to a DE group, and the remainder to a non-DE group. Functional VA was assessed, and DE questionnaires were administered. We assessed whether univariate and discriminant analyses could determine to which group a subject belonged. Sensitivity and specificity were assessed. Of 491 subjects, 320 and 171 were assigned to the DE and non-DE groups, respectively. No significant differences were observed between DE and non-DE groups in Schirmer test value and epithelial damage, but TBUT value (3.1 ± 1.5 vs. 5.9 ± 3.0 seconds). The sensitivity and specificity of single test using functional VA parameters were 59% and 49% in functional VA, 60% and 50% in visual maintenance ratio, and 83% and 30% in frequency of blinking, respectively. According to a discriminant analysis using a combination of functional VA parameters and a DE questionnaire, six variables were selected for the discriminant equation, of which area under the curve (AUC) was 0.735. Sensitivity and specificity of diagnoses predicted by the discriminant equation were 85.9% and 45.6%, respectively. The discriminant equation obtained using functional VA measurement combined with a symptoms questionnaire may suggest the possibility for the first step screening of DE with unstable tear film. Since the questionnaire has an overall poor sensitivity and specificity, further amelioration may be necessary for the actual utilization of this screening tool. Copyright 2014

  4. Spontaneous Resolution of Long-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement.

    PubMed

    Parikakis, Efstratios A; Chatziralli, Irini P; Peponis, Vasileios G; Karagiannis, Dimitrios; Stratos, Aimilianos; Tsiotra, Vasileia A; Mitropoulos, Panagiotis G

    2014-01-01

    To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT). The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS) junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

  5. Clinical Profile and Visual Outcome of Ocular Bartonellosis in Malaysia

    PubMed Central

    Tan, Chai Lee; Fhun, Lai Chan; Abdul Gani, Nor Hasnida; Muhammed, Julieana; Tuan Jaafar, Tengku Norina

    2017-01-01

    Background. Ocular bartonellosis can present in various ways, with variable visual outcome. There is limited data on ocular bartonellosis in Malaysia. Objective. We aim to describe the clinical presentation and visual outcome of ocular bartonellosis in Malaysia. Materials and Methods. This was a retrospective review of patients treated for ocular bartonellosis in two ophthalmology centers in Malaysia between January 2013 and December 2015. The diagnosis was based on clinical features, supported by a positive Bartonella spp. serology. Results. Of the 19 patients in our series, females were predominant (63.2%). The mean age was 29.3 years. The majority (63.2%) had unilateral involvement. Five patients (26.3%) had a history of contact with cats. Neuroretinitis was the most common presentation (62.5%). Azithromycin was the antibiotic of choice (42.1%). Concurrent systemic corticosteroids were used in approximately 60% of cases. The presenting visual acuity was worse than 6/18 in approximately 60% of eyes; on final review, 76.9% of eyes had a visual acuity better than 6/18. Conclusion. Ocular bartonellosis tends to present with neuroretinitis. Azithromycin is a viable option for treatment. Systemic corticosteroids may be considered in those with poor visual acuity on presentation. PMID:28265290

  6. Small fruit flies sacrifice temporal acuity to maintain contrast sensitivity.

    PubMed

    Currea, John P; Smith, Joshua L; Theobald, Jamie C

    2018-06-05

    Holometabolous insects, like fruit flies, grow primarily during larval development. Scarce larval feeding is common in nature and generates smaller adults. Despite the importance of vision to flies, eye size scales proportionately with body size, and smaller eyes confer poorer vision due to smaller optics. Variable larval feeding, therefore, causes within-species differences in visual processing, which have gone largely unnoticed due to ad libitum feeding in the lab that results in generally large adults. Do smaller eyes have smaller ommatidial lenses, reducing sensitivity, or broader inter-ommatidial angles, reducing acuity? And to what extent might neural processes adapt to these optical challenges with temporal and spatial summation? To understand this in the fruit fly, we generated a distribution of body lengths (1.67-2.34 mm; n = 24) and eye lengths (0.33-0.44 mm; n = 24), resembling the distribution of wild-caught flies, by removing larvae from food during their third instar. We find smaller eyes (0.19 vs.0.07 mm 2 ) have substantially fewer (978 vs. 540, n = 45) and smaller ommatidia (222 vs. 121 μm 2 ;n = 45) separated by slightly wider inter-ommatidial angles (4.5 vs.5.5°; n = 34). This corresponds to a greater loss in contrast sensitivity (<50%) than spatial acuity (<20%). Using a flight arena and psychophysics paradigm, we find that smaller flies lose little spatial acuity (0.126 vs. 0.118CPD; n = 45), and recover contrast sensitivity (2.22 for both; n = 65) by sacrificing temporal acuity (26.3 vs. 10.8Hz; n = 112) at the neural level. Therefore, smaller flies sacrifice contrast sensitivity to maintain spatial acuity optically, but recover contrast sensitivity, almost completely, by sacrificing temporal acuity neurally. Copyright © 2018. Published by Elsevier Ltd.

  7. The screening of visual impairment among preschool children in an urban population in Malaysia; the Kuching pediatric eye study: a cross sectional study

    PubMed Central

    2013-01-01

    Background To screen for visual impairment in Malaysian preschool children. Methods Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test. Results The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9). Conclusion The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group. PMID:23601160

  8. Five-Year Incidence of Visual Impairment in Middle-Aged Iranians: The Shahroud Eye Cohort Study.

    PubMed

    Hashemi, Hassan; Mehravaran, Shiva; Emamian, Mohammad Hassan; Fotouhi, Akbar

    2017-02-01

    To study the 5-year incidence of visual impairment and its causes and risk factors, in the middle-aged Iranian sample of the Shahroud Eye Cohort Study (ShECS). Data from subjects who had participated in both phases of the ShECS were used to determine age- and sex-specific incidence rates of visual impairment using the World Health Organization (WHO) definitions for bilateral low vision (visual acuity, VA, >0.5 and ≤1.3 LogMAR in the better eye) and blindness (VA worse than 1.3 LogMAR in the better eye). Risk ratios (RR) and 95% confidence intervals (CIs) were calculated using multivariable log-binomial regression. Of the 5079 ShECS I survivors, 4737 (93.3%) completed the 5-year follow-up. Their mean age at baseline was 50.9 ± 6.2 years, and 58.9% were female. The incidence of visual impairment was 1.12% (95% CI 0.82-1.42%) by presenting VA and 0.19% (95% CI 0.07-0.32%) by best-corrected VA; leading causes of the former were uncorrected refractive error (81.3%) and diabetic retinopathy (15.1%). In the multivariable model, risk factors for incident visual impairment by presenting VA were older age (RR 1.05, p = 0.044), lower education (RR 0.89, p = 0.002), and diabetes (RR 3.74, p < 0.001). This is the first incidence study of visual impairment in a middle-aged Iranian population. Since age is a major risk factor, the number of visually impaired is expected to increase as the population ages, and less treatable causes such as diabetic retinopathy begin to surface. Measures for tackling uncorrected refractive error and enhancing diabetes screening and preventive programs are recommended.

  9. Dry Eye Symptoms, Patient-Reported Visual Functioning, and Health Anxiety Influencing Patient Satisfaction After Cataract Surgery.

    PubMed

    Szakáts, Ildikó; Sebestyén, Margit; Tóth, Éva; Purebl, György

    2017-06-01

    To evaluate how patient satisfaction after cataract surgery is associated with postoperative visual acuity, visual functioning, dry eye signs and symptoms, health anxiety, and depressive symptoms. Fifty-four patients (mean age: 68.02 years) were assessed 2 months after uneventful phacoemulsification; 27 were unsatisfied with their postoperative results and 27 were satisfied. They completed the following questionnaires: Visual Function Index-14 (VF-14), Ocular Surface Disease Index (OSDI), Shortened Health Anxiety Inventory (SHAI), and Shortened Beck Depression Inventory. Testing included logarithm of the Minimum Angle of Resolution (logMAR) uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), dry eye tests (tear meniscus height and depth measured by spectral optical coherence tomography, tear film break-up time (TBUT), ocular surface staining, Schirmer 1 test, and meibomian gland dysfunction grading). Postoperative UCVA, BCVA, and the dry eye parameters - except TBUT - showed no statistically significant difference between the two groups (p > 0.130). However, the VF-14 scores, the OSDI scores, and the SHAI scores were significantly worse in the unsatisfied patient group (p < 0.002). No significant correlations were found between visual acuity measures and visual functioning (r < 0.170, p > 0.05). However, the VF-14 scores correlated with the OSDI scores (r = -0.436, p < 0.01) and the OSDI scores correlated with the SHAI scores (r = 0.333, p < 0.05). Multiple logistic regression revealed an adjusted association between patient satisfaction and dry eye symptoms (odds ratio = 1.46, 95% CI = 1.02-2.09, p = 0.038) and visual functioning (odds ratio = 0.78, 95% CI = 0.60-1.0, p = 0.048). Our results suggest that patient-reported visual functioning, dry eye symptoms, and health anxiety are more closely associated with patients' postoperative satisfaction than with the objective clinical measures of visual acuity or the signs of dry eye.

  10. Individual differences in non-verbal number acuity correlate with maths achievement.

    PubMed

    Halberda, Justin; Mazzocco, Michèle M M; Feigenson, Lisa

    2008-10-02

    Human mathematical competence emerges from two representational systems. Competence in some domains of mathematics, such as calculus, relies on symbolic representations that are unique to humans who have undergone explicit teaching. More basic numerical intuitions are supported by an evolutionarily ancient approximate number system that is shared by adults, infants and non-human animals-these groups can all represent the approximate number of items in visual or auditory arrays without verbally counting, and use this capacity to guide everyday behaviour such as foraging. Despite the widespread nature of the approximate number system both across species and across development, it is not known whether some individuals have a more precise non-verbal 'number sense' than others. Furthermore, the extent to which this system interfaces with the formal, symbolic maths abilities that humans acquire by explicit instruction remains unknown. Here we show that there are large individual differences in the non-verbal approximation abilities of 14-year-old children, and that these individual differences in the present correlate with children's past scores on standardized maths achievement tests, extending all the way back to kindergarten. Moreover, this correlation remains significant when controlling for individual differences in other cognitive and performance factors. Our results show that individual differences in achievement in school mathematics are related to individual differences in the acuity of an evolutionarily ancient, unlearned approximate number sense. Further research will determine whether early differences in number sense acuity affect later maths learning, whether maths education enhances number sense acuity, and the extent to which tertiary factors can affect both.

  11. The neural correlates of learned motor acuity

    PubMed Central

    Yang, Juemin; Caffo, Brian; Mazzoni, Pietro; Krakauer, John W.

    2014-01-01

    We recently defined a component of motor skill learning as “motor acuity,” quantified as a shift in the speed-accuracy trade-off function for a task. These shifts are primarily driven by reductions in movement variability. To determine the neural correlates of improvement in motor acuity, we devised a motor task compatible with magnetic resonance brain imaging that required subjects to make finely controlled wrist movements under visual guidance. Subjects were imaged on day 1 and day 5 while they performed this task and were trained outside the scanner on intervening days 2, 3, and 4. The potential confound of performance changes between days 1 and 5 was avoided by constraining movement time to a fixed duration. After training, subjects showed a marked increase in success rate and a reduction in trial-by-trial variability for the trained task but not for an untrained control task, without changes in mean trajectory. The decrease in variability for the trained task was associated with increased activation in contralateral primary motor and premotor cortical areas and in ipsilateral cerebellum. A global nonlocalizing multivariate analysis confirmed that learning was associated with increased overall brain activation. We suggest that motor acuity is acquired through increases in the number of neurons recruited in contralateral motor cortical areas and in ipsilateral cerebellum, which could reflect increased signal-to-noise ratio in motor output and improved state estimation for feedback corrections, respectively. PMID:24848466

  12. Retropupillary fixation of iris-claw lens in visual rehabilitation of aphakic eyes.

    PubMed

    Jayamadhury, G; Potti, Sudhakar; Kumar, K Vinaya; Kumar, R Madhu; Divyansh Mishra, K C; Nambula, Srinivasa Rao

    2016-10-01

    Surgical outcome of retropupillary fixation of iris claw lens. To evaluate the various indications, intra and post-operative complications, and visual outcome of retropupillary fixation of iris claw lens in aphakic eyes. The study design is a retrospective study at a tertiary eye care center. Review of medical records of 61 aphakic eyes of 61 patients, who were rehabilitated with retropupillary fixation of an iris claw lens, with a follow-up duration of at least 1 year. Data analysis was performed using paired t-test and Chi-square test. Mean preoperative uncorrected visual acuity was 1.66 ± 0.3 LogMAR and postoperative acuity at 1 year was 0.53 ± 0.5 LogMAR (P = 0.00001). Preoperative distant best-corrected visual acuity was 0.30 ± 0.48 LogMAR and postoperative acuity at 1 year was 0.27 ± 0.46 LogMAR (P = 0.07). Mean preoperative astigmatism was 1.43 ± 1.94 D and postoperatively was 1.85 ± 2.16 D (P = 0.0127). Mean endothelial cell count was 2353.52 ± 614 cells/mm2 preoperatively which decreased to 2200 ± 728 cells/mm2 at 1 year follow-up (P = 0.006). There was no significant difference in central macular thickness and intraocular pressure pre and post-surgery. Complications included ovalization of pupil in 9.83%, hypotony in 1.63%, toxic anterior segment syndrome in 1.63%, cystoid macular edema in 11.47%, epiretinal membrane in 3.27%, and iris atrophy in 6.55%. Iris claw is a safe and an effective method of rehabilitating aphakic eyes.

  13. Improvement of visual acuity in children with anisometropic amblyopia treated with rotated prisms combined with near activity

    PubMed Central

    Lin, Chao-Chyun; Chen, Po-Liang

    2013-01-01

    AIM To evaluate the efficacy of a new modality for improving visual acuity (VA) in pediatric patients with anisometropic amblyopia. METHODS Retrospective and interventional case series. Medical records of 360 children with anisometropic amblyopia treated with a modality that included rotated prisms, lenses, and near activities from January 2008 to January 2012 were analyzed. Characteristics such as improvement of VA and contrast sensitivity in amblyopic eyes and resolution of amblyopia (VA ≤0.1logMAR or a difference of ≤2 lines in logMAR between the eyes) were assessed. RESULTS Among the patients, the mean VA of the amblyopic eyes improved from 0.48logMAR (SD=0.16) to 0.12logMAR (SD=0.16) and the mean VA improvement was 0.36logMAR (SD=0.10, P<0.001). Resolution of amblyopia was achieved in 233 of 360 patients (64.72%). The mean time for resolution of amblyopia was 8.05 weeks (SD=4.83) or 14.14 sessions (SD=8.76). Among the study group, refraction error did not change significantly after treatment (P=0.437). We found that better baseline VA may be related to success and shorten the time to amblyopic resolution. CONCLUSION VA and contrast sensitivity improved with rotated prisms, correcting lenses, and near activities in children with anisometropic amblyopia. The VA improvement by this modality was comparable to other methods. However, the time to resolution of amblyopia was shorter with this method than with other modalities. Rotated prisms combined with near acuity could provide an alternative treatment in children with anisometropic amblyopia who can't tolerant traditional therapy method like patching. PMID:23991384

  14. Are Individual Differences in Reading Speed Related to Extrafoveal Visual Acuity and Crowding?

    PubMed Central

    Frömer, Romy; Dimigen, Olaf; Niefind, Florian; Krause, Niels; Kliegl, Reinhold; Sommer, Werner

    2015-01-01

    Readers differ considerably in their speed of self-paced reading. One factor known to influence fixation durations in reading is the preprocessing of words in parafoveal vision. Here we investigated whether individual differences in reading speed or the amount of information extracted from upcoming words (the preview benefit) can be explained by basic differences in extrafoveal vision—i.e., the ability to recognize peripheral letters with or without the presence of flanking letters. Forty participants were given an adaptive test to determine their eccentricity thresholds for the identification of letters presented either in isolation (extrafoveal acuity) or flanked by other letters (crowded letter recognition). In a separate eye-tracking experiment, the same participants read lists of words from left to right, while the preview of the upcoming words was manipulated with the gaze-contingent moving window technique. Relationships between dependent measures were analyzed on the observational level and with linear mixed models. We obtained highly reliable estimates both for extrafoveal letter identification (acuity and crowding) and measures of reading speed (overall reading speed, size of preview benefit). Reading speed was higher in participants with larger uncrowded windows. However, the strength of this relationship was moderate and it was only observed if other sources of variance in reading speed (e.g., the occurrence of regressive saccades) were eliminated. Moreover, the size of the preview benefit—an important factor in normal reading—was larger in participants with better extrafoveal acuity. Together, these results indicate a significant albeit moderate contribution of extrafoveal vision to individual differences in reading speed. PMID:25789812

  15. Ten-year all-cause mortality and its association with vision among Indigenous Australians within Central Australia: the Central Australian Ocular Health Study.

    PubMed

    Liu, Ebony; Ng, Soo K; Kahawita, Shyalle; Andrew, Nicholas H; Henderson, Tim; Craig, Jamie E; Landers, John

    2017-05-01

    No studies to date have explored the association of vision with mortality in Indigenous Australians. We aimed to determine the 10-year all-cause mortality and its associations among Indigenous Australians living in Central Australia. Prospective observational cohort study. A total of 1257 (93.0%) of 1347 patients from The Central Australian Ocular Health Study, over the age of 40 years, were available for follow-up during a 10-year period. All-cause mortality and its associations with visual acuity, age and gender were analysed. All-cause mortality. All-cause mortality was 29.3% at the end of 10 years. Mortality increased as age of recruitment increased: 14.2% (40-49 years), 22.6% (50-59 years), 50.3% (60 years or older) (χ = 59.15; P < 0.00001). Gender was not associated with mortality as an unadjusted variable, but after adjustment with age and visual acuity, women were 17.0% less likely to die (t = 2.09; P = 0.037). Reduced visual acuity was associated with increased mortality rate (5% increased mortality per one line of reduced visual acuity; t = 4.74; P < 0.0001) after adjustment for age, sex, diabetes and hypertension. The 10-year all-cause mortality rate of Indigenous Australians over the age of 40 years and living in remote communities of Central Australia was 29.3%. This is more than double that of the Australian population as a whole. Mortality was significantly associated with visual acuity at recruitment. Further work designed to better understand this association is warranted and may help to reduce this disparity in the future. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  16. Five-year study of ocular injuries due to fireworks in India.

    PubMed

    Malik, Archana; Bhala, Soniya; Arya, Sudesh K; Sood, Sunandan; Narang, Subina

    2013-08-01

    To study the demographic profile, cause, type and severity of ocular injuries, their complications and final visual outcome following fireworks around the time of Deepawali in India. Case records of patients who presented with firework-related injuries during 2005-2009 at the time of Deepawali were reviewed. Data with respect to demographic profile of patients, cause and time of injury, time of presentation and types of intervention were analyzed. Visual acuity at presentation and final follow-up, anterior and posterior segment findings, and any diagnostic and surgical interventions carried out were noted. One hundred and one patients presented with firework-related ocular injuries, of which 77.5 % were male. The mean age was 17.60 ± 11.9 years, with 54 % being ≤14 years of age. The mean time of presentation was 8.9 h. Seventeen patients had open globe injury (OGI) and 84 had closed globe injury (CGI). Fountains were the most common cause of CGI and bullet bombs were the most common cause of OGI. Mean log MAR visual acuity at presentation was 0.64 and 1.22 and at last follow-up was 0.09 and 0.58 for CGI and OGI, respectively (p < 0.05). Patients with CGI had a better visual outcome. Three patients with OGI developed permanent blindness. Factors associated with poor visual outcome included poor initial visual acuity, OGI, intraocular foreign body (IOFB), retinal detachment and development of endophthalmitis. Firework injuries were seen mostly in males and children. Poor visual outcome was associated with poor initial visual acuity, OGI, IOFB, retinal detachment and development of endophthalmitis, while most patients with CGI regained good vision.

  17. [Surgical solution to vitreous floaters visual problem].

    PubMed

    Martínez-Sanz, F; Velarde, J I; Casuso, P; Fernández-Cotero, J N

    2009-05-01

    To evaluate the role of 25 gauge pars-plana vitrectomy (25G-PPV), after a careful patient selection, when we find highly annoying vitreous floaters and to question if this is an ethical therapeutic option. A retrospective study of eight eyes (seven patients) aged 58+/-14 years old (range 42-78) high myopes and pseudophakes who underwent 25G-PPV. Clinical data and visual acuity were studied at six to twelve months follow-up. Health-related functioning and quality of life was measured with the 39-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-39). No complications were observed. All patients were satisfied. Safety at third month was 100% and 37.5% improved one or more lines of visual acuity. Vitreous floaters can be often undervaluated by ophthalmologists, resulting in no intervention. Conventional 20 gauge PPV after a carefully examination can be an effective option for some authors. 25G-PPV incorporates also advantages as the early recovery, with little complications in pseudophakic eyes.

  18. Association of disease-specific causes of visual impairment and 10-year mortality amongst Indigenous Australians: the Central Australian Ocular Health Study.

    PubMed

    Estevez, José; Kaidonis, Georgia; Henderson, Tim; Craig, Jamie E; Landers, John

    2018-01-01

    Visual impairment significantly impairs the length and quality of life, but little is known of its impact in Indigenous Australians. To investigate the association of disease-specific causes of visual impairment with all-cause mortality. A retrospective cohort analysis. A total of 1347 Indigenous Australians aged over 40 years. Participants visiting remote medical clinics underwent clinical examinations including visual acuity, subjective refraction and slit-lamp examination of the anterior and posterior segments. The major ocular cause of visual impairment was determined. Patients were assessed periodically in these remote clinics for the succeeding 10 years after recruitment. Mortality rates were obtained from relevant departments. All-cause 10-year mortality and its association with disease-specific causes of visual impairment. The all-cause mortality rate for the entire cohort was 29.3% at the 10-year completion of follow-up. Of those with visual impairment, the overall mortality rate was 44.9%. The mortality rates differed for those with visual impairment due to cataract (59.8%), diabetic retinopathy (48.4%), trachoma (46.6%), 'other' (36.2%) and refractive error (33.4%) (P < 0.0001). Only those with visual impairment from diabetic retinopathy were any more likely to die during the 10 years of follow-up when compared with those without visual impairment (HR 1.70; 95% CI, 1.00-2.87; P = 0.049). Visual impairment was associated with all-cause mortality in a cohort of Indigenous Australians. However, diabetic retinopathy was the only ocular disease that significantly increased the risk of mortality. Visual impairment secondary to diabetic retinopathy may be an important predictor of mortality. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  19. The United Kingdom Diabetic Retinopathy Electronic Medical Record Users Group, Report 1: baseline characteristics and visual acuity outcomes in eyes treated with intravitreal injections of ranibizumab for diabetic macular oedema.

    PubMed

    Egan, Catherine; Zhu, Haogang; Lee, Aaron; Sim, Dawn; Mitry, Danny; Bailey, Clare; Johnston, Robert; Chakravarthy, Usha; Denniston, Alastair; Tufail, Adnan; Khan, Rehna; Mahmood, Sajjad; Menon, Geeta; Akerele, Toks; Downey, Louise; McKibbin, Martin; Varma, Atul; Lobo, Aires; Wilkinson, Elizabeth; Fitt, Alan; Brand, Christopher; Tsaloumas, Marie; Mandal, Kaveri; Kumar, Vineeth; Natha, Salim; Crabb, David

    2017-01-01

    To describe baseline characteristics and visual outcome for eyes treated with ranibizumab for diabetic macular oedema (DMO) from a multicentre database. Structured clinical data were anonymised and extracted from an electronic medical record from 19 participating UK centres: age at first injection, ETDRS visual acuity (VA), number of injections, ETDRS diabetic retinopathy (DR) and maculopathy grade at baseline and visits. The main outcomes were change in mean VA from baseline, number of injections and clinic visits and characteristics affecting VA change and DR grade. Data from 12 989 clinic visits was collated from baseline and follow-up for 3103 eyes. Mean age at first treatment was 66 years. Mean VA (letters) for eyes followed at least 2 years was 51.1 (SD=19.3) at baseline, 54.2 (SD: 18.6) and 52.5 (SD: 19.4) at 1 and 2 years, respectively. Mean visual gain was five letters. The proportion of eyes with VA of 72 letters or better was 25% (baseline) and 33% (1 year) for treatment naïve eyes. Eyes followed for at least 6 months received a mean of 3.3 injections over a mean of 6.9 outpatient visits in 1 year. In a large cohort of eyes with DMO treated with ranibizumab injections in the UK, 33% of patients achieved better than or equal to 6/12 in the treated eye at 12 months compared with 25% at baseline. The mean visual gain was five letters. Eyes with excellent VA at baseline maintain good vision at 18 months. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Perceptual visual dysfunction, physical impairment and quality of life in Bangladeshi children with cerebral palsy.

    PubMed

    Mitry, D; Williams, C; Northstone, K; Akter, A; Jewel, J; Khan, N; Muhit, M; Gilbert, C E; Bowman, R

    2016-09-01

    Cerebral palsy (CP) is the most common cause of motor disability in children and is often accompanied by sensory and/or cognitive impairment. The aim of this study was to characterise visual acuity impairment, perceptual visual dysfunction (PVD) and physical disability in a community-based sample of Bangladeshi children with CP and to assess the impact of these factors on the quality of life of the children. A key informant study was used to recruit children with CP from Sirajganj district. Gross Motor Function Classification System (GMFCS) levels and visual impairment were assessed by a physiotherapist and an optometrist, respectively. Assessments of visual perception were performed and standardised questionnaires were administered to each child's main carer to elicit indicators of PVD and parent-reported health-related quality of life. A generalised linear regression analysis was conducted to assess the determinants of the quality of life scores. 180 children were recruited. The median age was 8 years (IQR: 6-11 years); 112 (62%) were male; 57 (32%) had visual acuity impairment and 95 (53%) had some parent-reported PVD. In analyses adjusted for age, sex, GMFCS and acuity impairment, visual attention (p<0.001) and recognition/navigation (p<0.001) were associated with total health-related quality of life, and there were similar trends for total PVD score (p=0.006) and visual search (p=0.020). PVD is an important contributor in reducing quality of life in children with CP, independent of motor disability and acuity impairment. Better characterisation of PVD is important to help design interventions for affected children, which may improve their quality of life. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  1. Four-year visual outcomes after photorefractive keratectomy in pilots with low-moderate myopia.

    PubMed

    Moon, Chan Hee

    2016-02-01

    The photorefractive keratectomy (PRK) is approved for Air Force pilots in several nations. The occupational environments of pilots in the Air Force are unique, including extremely high altitude, low oxygen tension, high ultraviolet light exposure and high G-force load. The short-term efficacy and safety of PRK for pilots are documented. However, the study for long-term visual and refractive outcomes of PRK in pilots is limited. To investigate the long-term visual and refractive outcomes in a 4-year follow-up period after PRK in pilots with low to moderate myopia. Thirty-eight eyes of 20 subjects that underwent PRK and recruited to Air Force pilot were evaluated preoperatively and at 3, 6, 12, 24, and 48 months postoperatively. The mean patient age was 21.42±0.75 years. The mean preoperative manifest refraction spherical equivalent (SE) was -1.51±1.15 diopters (D). At 4 years postoperatively, the mean SE was -0.29±0.51, 89.5% of eyes achieved 20/20 or better Snellen uncorrected visual acuity, 71.1% of eyes were within ±0.50 D of emmetropia. The refraction stabilised by 6 months and was maintained up to the 4-year follow-up stage. PRK for pilots with low to moderate myopia is safe and effective in the long term. High-altitude environmental stress exposure has no effect on the refractive stability after PRK. ROKAF-ASMC-2015-IRB-002. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Visual outcomes in children in Malawi following retinopathy of severe malaria.

    PubMed

    Beare, N A V; Southern, C; Kayira, K; Taylor, T E; Harding, S P

    2004-03-01

    To investigate whether retinal changes in children with severe malaria affect visual acuity 1 month after systemic recovery. All children with severe malaria admitted to a research ward in Malawi during one malaria season were examined by direct and indirect ophthalmoscopy. Visual acuity was tested in those attending follow up by Cardiff cards, Sheridan-Gardiner single letters, or Snellen chart. 96 (68%) children attended follow up, of whom 83 (86%) had visual acuity measured. Cardiff cards were used in 47 (57%) children, and Sheridan-Gardiner letters or Snellen chart in 29 (35%). There was no significant difference in the mean logMAR visual acuity between groups with or without macular whitening (0.14 versus 0.16, p = 0.55). There was no trend for worse visual acuity with increasing severity of macular whitening (p = 0.52) including patients in whom the fovea was involved (p = 0.32). Six (4.2%) children had cortical blindness after cerebral malaria, and all six had other neurological sequelae. Ophthalmoscopy during the acute illness revealed no abnormalities in four of these children. Retinal changes in severe malaria, in particular macular whitening, do not appear to affect visual acuity at 1 month. This supports the hypothesis that retinal whitening is due to reversible intracellular oedema in response to relative hypoxia, caused by sequestered erythrocytes infected by Plasmodium falciparum. Impaired visual functioning after cerebral malaria is not attributable to retinal changes and appears to be a cortical phenomenon.

  3. Spatial acuity of the body surface over the life span.

    PubMed

    Stevens, J C; Choo, K K

    1996-01-01

    Spatial acuity over 13 regions of the body was assessed cross-sectionally in 122 male and female subjects between 8 and 87 years of age. Of two measures, the primary one was a threshold for detecting a gap between two points (a refinement of the conventional two-point threshold). The secondary one was a threshold of point localization in 7 of these 13 body regions. The two measures yielded similar pictures of body acuity and age-related changes in acuity, and they agreed in essentials with an early acuity map dating back to Weber in 1835, as cited and confirmed experimentally by Weinstein (1968). To this acuity map, the present study added the dimension of age. The main finding was that aging is much harder on some body regions than on others. Declining acuity with age was found to characterize all regions to one degree or another, but the hands and feet turned out to be far more vulnerable than the more central regions, including the very acute lip and tongue. Deterioration of acuity in the great toe (averaging 400% between youth and advanced age) and fingertip (averaging 130%) may adversely affect such diverse activities as braille reading, grasping, and maintaining balance. The acuity map determined by gap discrimination was essentially the same for males and females; however, males gave significantly smaller localization thresholds than females. In two body regions tested (fingertip and upper lip), children significantly outperformed young adults at gap discrimination.

  4. Visual Acuity Change Over 24 Months and its Association With Foveal Phenotype and Genotype in Individuals With Stargardt Disease: ProgStar Study Report No. 10.

    PubMed

    Kong, Xiangrong; Fujinami, Kaoru; Strauss, Rupert W; Munoz, Beatriz; West, Sheila K; Cideciyan, Artur V; Michaelides, Michel; Ahmed, Mohamed; Ervin, Ann-Margret; Schönbach, Etienne; Cheetham, Janet K; Scholl, Hendrik P N

    2018-06-14

    Limited data from prospective studies are available to understand the natural history of ABCA4-related Stargardt disease (STGD1). Such data are important for determining appropriate outcome measures for future STGD1 trials. To estimate the rate of loss of best-corrected visual acuity (BCVA) during 2 years and to estimate the associations of BCVA loss with foveal phenotype and genotype in patients with STGD1. This multicenter prospective cohort study included 259 participants (489 study eyes) with molecularly confirmed STGD1 who were 6 years or older. The participants were enrolled at 9 centers in the United States and Europe and were followed up every 6 months for 2 years. Baseline BCVA and presence and type of foveal lesion (determined via fundus autofluorescence images) and genotype (classified into 4 groups based on the number and pathogenicity of ABCA4 mutations). Rate of BCVA change per year. The mean (SD) age was 33 (15) years. Of 259 the participants, 141 (54%) were female, and 222 (85%) were white. The overall rate of BCVA loss was 0.55 (95% CI, 0.20-0.90) letters per year during the 2 years. Eyes with baseline BCVA worse than 20/200 showed an improvement of 0.65 (95% CI, 0.1-1.2) letters per year. At baseline, the mean BCVA for eyes without foveal lesion was 20/32, and their BCVA change rate over time was 0.1 (95% CI, -1.2 to 1.35) letters per year (P = .89). Eyes with a foveal lesion but having BCVA of 20/70 or better at baseline lost BCVA at a rate of 3 (95% CI, 1.5-4.4) letters per year (P < .001). Genotype was neither associated with baseline BCVA nor with the rate of BCVA change during the follow-up. A clinically small BCVA loss was observed during 2 years, and the change rate varied depending on baseline BCVA. Eyes without lesion in the fovea had better BCVA at baseline and showed minimal change of BCVA throughout 2 years. Eyes with no or modest acuity impairment but with a foveal lesion at baseline had the fastest loss rate. For trials of

  5. The New Zealand National Eye Bank: survival and visual outcome 1 year after penetrating keratoplasty.

    PubMed

    Patel, Hussain Y; Ormonde, Sue; Brookes, Nigel H; Moffatt, S Louise; Sherwin, Trevor; Pendergrast, David G C; McGhee, Charles N J

    2011-07-01

    To identify potential donor, recipient, surgical, and postoperative factors that may influence survival and visual outcome of penetrating keratoplasty (PKP). As part of a prospective longitudinal study, the electronic records of the New Zealand National Eye Bank were analyzed for the 10-year period from 1994-2003. Both univariate and multivariate analysis was performed. During the study period, the New Zealand National Eye Bank supplied 1820 corneas for PKP and 1629 (90%) had 1-year follow-up data. Overall, the 1-year survival rate was 87% (n = 1429). Donor factors including age, donor source, cause of death, death-to-preservation interval, endothelial cell density, donor lens status, and storage duration, were not significantly associated with decreased survival. The leading cause of PKP failure was irreversible rejection (7%, n = 114). Independent risk factors identified for decreased PKP survival were: 1 or more episodes of reversible rejection, active inflammation at PKP, preexisting corneal vascularization, intraoperative complications, small graft size (≤ 7.25 mm), large graft size (≥ 8.5 mm), preoperative glaucoma, and a preoperative diagnosis of regraft or trauma. A best-corrected Snellen visual acuity of 6/12 or better was achieved in 60% of eyes [mean: 6/15 (logarithm of the minimum angle of resolution 0.40)]. Keratoconus and Fuchs endothelial dystrophy were the diagnoses with best survival and visual outcome, whereas, bullous keratopathy, trauma or noninfective keratitis were associated with poorer visual outcome. Several independent risk factors were identified that significantly influenced PKP first year survival outcome. This information is valuable to patients and surgeons with respect to determining prognosis and clinical decision making.

  6. [Case of pediatric chronic myeloid leukemia with bilateral visual loss onset].

    PubMed

    Hara, Yusuke; Kamura, Yumi; Oikawa, Aki; Shichino, Hiroyuki; Mugishima, Hideo; Goto, Hiroshi

    2010-05-01

    Chronic myeloid leukemia (CML) during childhood is rare, and only been a few cases showed visual disturbances as an initial symptom. We report a pediatric CML case diagnosed by bilateral visual loss. An 11-year-old boy complained of visual loss in both eyes. His best corrected visual acuity was 0.5 in the right eye and 0.2 in the left. Fundus examination showed disc swelling, dilated and tortuous retinal veins and multiple elevated retinal lesions with hemorrhages of various size from one-forth to four disc diameters in both eyes. He was diagnosed as having CML by leucocytosis and systematic work-up including Philadelphia chromosome-positive, BCR-ABL kinase domain in peripheral blood and bone marrow. The ocular findings improved after treatment with hydroxyurea, leukocytaphresis and imatinib. His best corrected visual acuity improved to 0.7 in both eyes. Recent leukemia therapy including imatinib is effective not only for ocular lesions but also to induce hematological remission in childhood CML.

  7. Effect of light-emitting diode colour temperature on magnifier reading performance of the visually impaired.

    PubMed

    Wolffsohn, James S; Palmer, Eshmael; Rubinstein, Martin; Eperjesi, Frank

    2012-09-01

    As light-emitting diodes become more common as the light source for low vision aids, the effect of illumination colour temperature on magnifier reading performance was investigated. Reading ability (maximum reading speed, critical print size, threshold near visual acuity) using Radner charts and subjective preference was assessed for 107 participants with visual impairment using three stand magnifiers with light emitting diode illumination colour temperatures of 2,700 K, 4,500 K and 6,000 K. The results were compared with distance visual acuity, prescribed magnification, age and the primary cause of visual impairment. Reading speed, critical print size and near visual acuity were unaffected by illumination colour temperature (p > 0.05). Reading metrics decreased with worsening acuity and higher levels of prescribed magnification but acuity was unaffected by age. Each colour temperature was preferred and disliked by a similar number of patients and was unrelated to distance visual acuity, prescribed magnification and age (p > 0.05). Patients had better near acuity (p = 0.002), critical print size (p = 0.034) and maximum reading speed (p < 0.001), and the improvement in near from distance acuity was greater (p = 0.004) with their preferred rather than least-liked colour temperature illumination. A range of colour temperature illuminations should be offered to all visually impaired individuals prescribed with an optical magnifier for near tasks to optimise subjective and objective benefits. © 2012 The Authors. Clinical and Experimental Optometry © 2012 Optometrists Association Australia.

  8. Effects of Mild Hypercapnia During Head-Down Bed Rest on Ocular Structures, Cerebral Blood Flow, aud Visual Acuity in Healthy Human Subjects

    NASA Technical Reports Server (NTRS)

    Laurie, S. S.; Taibbi, G.; Lee, S. M. C.; Martin, D. S.; Zanello, S.; Ploutz-Snyder, R.; Hu, X.; Stenger, M. B.; Vizzeri, G.

    2014-01-01

    The cephalad fluid shift induced by microgravity has been hypothesized to cause an elevation in intracranial pressure (ICP) and contribute to the development of the Visual Impairment/Intracranial Pressure (VIIP) syndrome, as experienced by some astronauts during long-duration space flight. Elevated ambient partial pressure of carbon dioxide (PCO2) on ISS may also raise ICP and contribute to VIIP development. We seek to determine if the combination of mild CO2 exposure, similar to that occurring on the International Space Station, with the cephalad fluid shift induced by head-down tilt, will induce ophthalmic and cerebral blood flow changes similar to those described in the VIIP syndrome. We hypothesize that mild hypercapnia in the head-down tilt position will increase choroidal blood volume and cerebral blood flow, raise intraocular pressure (IOP), and transiently reduce visual acuity as compared to the seated or the head-down tilt position without elevated CO2, respectively.

  9. Contralateral Bias of High Spatial Frequency Tuning and Cardinal Direction Selectivity in Mouse Visual Cortex

    PubMed Central

    Zeitoun, Jack H.; Kim, Hyungtae

    2017-01-01

    Binocular mechanisms for visual processing are thought to enhance spatial acuity by combining matched input from the two eyes. Studies in the primary visual cortex of carnivores and primates have confirmed that eye-specific neuronal response properties are largely matched. In recent years, the mouse has emerged as a prominent model for binocular visual processing, yet little is known about the spatial frequency tuning of binocular responses in mouse visual cortex. Using calcium imaging in awake mice of both sexes, we show that the spatial frequency preference of cortical responses to the contralateral eye is ∼35% higher than responses to the ipsilateral eye. Furthermore, we find that neurons in binocular visual cortex that respond only to the contralateral eye are tuned to higher spatial frequencies. Binocular neurons that are well matched in spatial frequency preference are also matched in orientation preference. In contrast, we observe that binocularly mismatched cells are more mismatched in orientation tuning. Furthermore, we find that contralateral responses are more direction-selective than ipsilateral responses and are strongly biased to the cardinal directions. The contralateral bias of high spatial frequency tuning was found in both awake and anesthetized recordings. The distinct properties of contralateral cortical responses may reflect the functional segregation of direction-selective, high spatial frequency-preferring neurons in earlier stages of the central visual pathway. Moreover, these results suggest that the development of binocularity and visual acuity may engage distinct circuits in the mouse visual system. SIGNIFICANCE STATEMENT Seeing through two eyes is thought to improve visual acuity by enhancing sensitivity to fine edges. Using calcium imaging of cellular responses in awake mice, we find surprising asymmetries in the spatial processing of eye-specific visual input in binocular primary visual cortex. The contralateral visual pathway is

  10. Sudden visual loss after cardiac resynchronization therapy device implantation.

    PubMed

    De Vitis, Luigi A; Marchese, Alessandro; Giuffrè, Chiara; Carnevali, Adriano; Querques, Lea; Tomasso, Livia; Baldin, Giovanni; Maestranzi, Gisella; Lattanzio, Rosangela; Querques, Giuseppe; Bandello, Francesco

    2017-03-10

    To report a case of sudden decrease in visual acuity possibly due to a cardiogenic embolism in a patient who underwent cardiac resynchronization therapy (CRT) device implantation. A 62-year-old man with severe left ventricular systolic dysfunction and a left bundle branch block was referred to our department because of a sudden decrease in visual acuity. Nine days earlier, he had undergone cardiac transapical implantation of a CRT device, which was followed, 2 days later, by an inflammatory reaction. The patient underwent several general and ophthalmologic examinations, including multimodal imaging. At presentation, right eye (RE) best-corrected visual acuity (BCVA) was counting fingers and RE pupil was hyporeactive. Fundus examination revealed white-centered hemorrhagic dots suggestive of Roth spots. Fluorescein angiography showed delay in vascular perfusion during early stage, late hyperfluorescence of the macula and optic disk, and peripheral perivascular leakage. The first visual field test showed complete loss of vision RE and a normal left eye. Due to suspected giant cell arteritis, temporal artery biopsy was performed. Thirty minutes after the procedure, an ischemic stroke with right hemisyndrome and aphasia occurred. The RE BCVA worsened to hands motion. Four months later, RE BCVA did not improve, despite improvement in fluorescein angiography inflammatory sign. We report a possible cardiogenic embolism secondary to undiagnosed infective endocarditis causing monocular visual loss after CRT device implantation. It remains unclear how the embolus caused severe functional damage without altering the retinal anatomical structure.

  11. Patching vs Atropine to Treat Amblyopia in Children Aged 7 to 12 Years: A Randomized Trial

    PubMed Central

    2008-01-01

    Objective To compare patching with atropine eye drops in the treatment of moderate amblyopia (20/40 -20/100) in children age 7 to 12 years. Methods In a randomized multi-center clinical trial, 193 children with amblyopia were randomized to weekend atropine or patching 2 hours per day of the sound eye. Main Outcome Measure Masked assessment of amblyopic eye visual acuity using the EETDRS testing protocol at 17 weeks. Results At 17 weeks, visual acuity had improved from baseline by an average of 7.6 letters in the atropine group and 8.6 letters in the patching group. The mean difference (patching minus atropine) between groups adjusted for baseline acuity was 1.2 letters (ends of complementary 1-sided 95% confidence intervals for noninferiority = -0.7 and +3.1 letters). Based on the confidence intervals this difference met the pre-specified definition for equivalence (ends of confidence intervals <5 letters). Amblyopic eye visual acuity was 20/25 or better in 15 subjects (17%) in the atropine group and 20 subjects (24%) in the patching group (difference = 7%, 95% confidence interval = -3% to 17%). Conclusions Treatment with atropine or patching leads to similar degrees of improvement in 7 to 12 year old children with moderate amblyopia. About 1 in 5 achieves 20/25 or better visual acuity in the amblyopic eye. Application to Clinical Practice Treatment of older children with unilateral amblyopia. PMID:19064841

  12. Visual abilities in two raptors with different ecology.

    PubMed

    Potier, Simon; Bonadonna, Francesco; Kelber, Almut; Martin, Graham R; Isard, Pierre-François; Dulaurent, Thomas; Duriez, Olivier

    2016-09-01

    Differences in visual capabilities are known to reflect differences in foraging behaviour even among closely related species. Among birds, the foraging of diurnal raptors is assumed to be guided mainly by vision but their foraging tactics include both scavenging upon immobile prey and the aerial pursuit of highly mobile prey. We studied how visual capabilities differ between two diurnal raptor species of similar size: Harris's hawks, Parabuteo unicinctus, which take mobile prey, and black kites, Milvus migrans, which are primarily carrion eaters. We measured visual acuity, foveal characteristics and visual fields in both species. Visual acuity was determined using a behavioural training technique; foveal characteristics were determined using ultra-high resolution spectral-domain optical coherence tomography (OCT); and visual field parameters were determined using an ophthalmoscopic reflex technique. We found that these two raptors differ in their visual capacities. Harris's hawks have a visual acuity slightly higher than that of black kites. Among the five Harris's hawks tested, individuals with higher estimated visual acuity made more horizontal head movements before making a decision. This may reflect an increase in the use of monocular vision. Harris's hawks have two foveas (one central and one temporal), while black kites have only one central fovea and a temporal area. Black kites have a wider visual field than Harris's hawks. This may facilitate the detection of conspecifics when they are scavenging. These differences in the visual capabilities of these two raptors may reflect differences in the perceptual demands of their foraging behaviours. © 2016. Published by The Company of Biologists Ltd.

  13. Efficiency of electronically monitored amblyopia treatment between 5 and 16 years of age: new insight into declining susceptibility of the visual system.

    PubMed

    Fronius, Maria; Cirina, Licia; Ackermann, Hanns; Kohnen, Thomas; Diehl, Corinna M

    2014-10-01

    The notion of a limited, early period of plasticity of the visual system has been challenged by more recent research demonstrating functional enhancement even into adulthood. In amblyopia ("lazy eye") it is still unclear to what extent the reduced effect of treatment after early childhood is due to declining plasticity or lower compliance with prescribed patching. The aim of this study was to determine the dose-response relationship and treatment efficiency from acuity gain and electronically recorded patching dose rates, and to infer from these parameters on a facet of age dependence of functional plasticity related to occlusion for amblyopia. The Occlusion Dose Monitor was used to record occlusion in 27 participants with previously untreated strabismic and/or anisometropic amblyopia aged between 5.4 and 15.8 (mean 9.2) years during 4months of conventional treatment. Group data showed improvement of acuity throughout the age span, but significantly more in patients younger than 7years despite comparable patching dosages. Treatment efficiency declined with age, with the most pronounced effects before the age of 7years. Thus, electronic recording allowed this first quantitative insight into occlusion treatment spanning the age range from within to beyond the conventional age for patching. Though demonstrating improvement in over 7year old patients, it confirmed the importance of early detection and treatment of amblyopia. Treatment efficiency is presented as a tool extending insight into age-dependent functional plasticity of the visual system, and providing a basis for comparisons of effects of patching vs. emerging alternative treatment approaches for amblyopia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Changes in Visual Function Following Optical Treatment of Astigmatism-Related Amblyopia

    PubMed Central

    Harvey, Erin M.; Dobson, Velma; Miller, Joseph M.; Donaldson, Candice E.

    2009-01-01

    Effects of optical correction on best-corrected grating acuity (vertical (V), horizontal (H), oblique (O)), vernier acuity (V, H, O), contrast sensitivity (1.5, 6.0, and 18.0 cy/deg spatial frequency, V and H), and stereoacuity were evaluated prospectively in 4- to 13-year-old astigmats and a non-astigmatic age-matched control group. Measurements made at baseline (eyeglasses dispensed for astigmats), 6 weeks, and 1 year showed greater improvement in astigmatic than non-astigmatic children for all measures. Treatment effects occurred by 6 weeks, and did not differ by cohort (< 8 vs. 8 years), but astigmatic children did not attain normal levels of visual function. PMID:18261760

  15. Sporadic Visual Acuity Loss in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT)

    PubMed Central

    Kim, Benjamin J.; Ying, Gui-Shuang; Huang, Jiayan; Levy, Nicole E.; Maguire, Maureen G.

    2014-01-01

    Purpose To evaluate transient, large visual acuity (VA) decreases, termed sporadic vision loss, during anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD). Design Cohort within a randomized clinical trial. Methods Setting Comparison of AMD Treatments Trials (CATT). Study Population 1185 CATT patients. Main Outcome Measures incidence of sporadic vision loss and odds ratio (OR) for association with patient and ocular factors. Sporadic vision loss was a decline of ≥ 15 letters from the previous visit, followed by a return at the next visit to no more than 5 letters worse than the visit before the VA loss. Results There were 143 sporadic vision loss events in 122/1185 (10.3%) patients. Mean VA at two years for those with and without sporadic vision loss was 58.5 (~20/63) and 68.4 (~20/40) letters, respectively (P < 0.001). Among patients treated pro re nata, no injection was given for 27.6% (27/98) of sporadic vision loss events. Multivariate analysis demonstrated that baseline predictors for sporadic vision loss included worse baseline VA (OR 2.92, 95%CI:1.65–5.17 for ≤ 20/200 compared with ≥ 20/40), scar (OR 2.21, 95%CI:1.22–4.01), intraretinal foveal fluid on optical coherence tomography (OR 1.80, 95%CI:1.11–2.91), and medical history of anxiety (OR 1.90, 95%CI:1.12–3.24) and syncope (OR 2.75, 95%CI:1.45–5.22). Refraction decreased the likelihood of sporadic vision loss (OR 0.62, 95%CI:0.42–0.91). Conclusions Approximately 10% of CATT patients had sporadic vision loss. Baseline predictors included AMD-related factors and factors independent of AMD. These data are relevant for clinicians in practice and those involved in clinical trials. PMID:24727261

  16. Sporadic visual acuity loss in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT).

    PubMed

    Kim, Benjamin J; Ying, Gui-Shuang; Huang, Jiayan; Levy, Nicole E; Maguire, Maureen G

    2014-07-01

    To evaluate transient, large visual acuity (VA) decreases, termed sporadic vision loss, during anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration (AMD). Cohort within a randomized clinical trial. setting: Comparison of Age-Related Macular Degeneration Treatments Trials (CATT). study population: Total of 1185 CATT patients. main outcome measures: Incidence of sporadic vision loss and odds ratio (OR) for association with patient and ocular factors. Sporadic vision loss was a decline of ≥15 letters from the previous visit, followed by a return at the next visit to no more than 5 letters worse than the visit before the VA loss. There were 143 sporadic vision loss events in 122 of 1185 patients (10.3%). Mean VA at 2 years for those with and without sporadic vision loss was 58.5 (∼20/63) and 68.4 (∼20/40) letters, respectively (P < .001). Among patients treated pro re nata, no injection was given for 27.6% (27/98) of sporadic vision loss events. Multivariate analysis demonstrated that baseline predictors for sporadic vision loss included worse baseline VA (OR 2.92, 95% confidence interval [CI]:1.65-5.17 for ≤20/200 compared with ≥20/40), scar (OR 2.21, 95% CI:1.22-4.01), intraretinal foveal fluid on optical coherence tomography (OR 1.80, 95% CI:1.11-2.91), and medical history of anxiety (OR 1.90, 95% CI:1.12-3.24) and syncope (OR 2.75, 95% CI:1.45-5.22). Refraction decreased the likelihood of sporadic vision loss (OR 0.62, 95%CI: 0.42-0.91). Approximately 10% of CATT patients had sporadic vision loss. Baseline predictors included AMD-related factors and factors independent of AMD. These data are relevant for clinicians in practice and those involved in clinical trials. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Visual outcomes in children in Malawi following retinopathy of severe malaria

    PubMed Central

    Beare, N A V; Southern, C; Kayira, K; Taylor, T E; Harding, S P

    2004-01-01

    Aim: To investigate whether retinal changes in children with severe malaria affect visual acuity 1 month after systemic recovery. Methods: All children with severe malaria admitted to a research ward in Malawi during one malaria season were examined by direct and indirect ophthalmoscopy. Visual acuity was tested in those attending follow up by Cardiff cards, Sheridan-Gardiner single letters, or Snellen chart. Results: 96 (68%) children attended follow up, of whom 83 (86%) had visual acuity measured. Cardiff cards were used in 47 (57%) children, and Sheridan-Gardiner letters or Snellen chart in 29 (35%). There was no significant difference in the mean logMAR visual acuity between groups with or without macular whitening (0.14 versus 0.16, p = 0.55). There was no trend for worse visual acuity with increasing severity of macular whitening (p = 0.52) including patients in whom the fovea was involved (p = 0.32). Six (4.2%) children had cortical blindness after cerebral malaria, and all six had other neurological sequelae. Ophthalmoscopy during the acute illness revealed no abnormalities in four of these children. Conclusion: Retinal changes in severe malaria, in particular macular whitening, do not appear to affect visual acuity at 1 month. This supports the hypothesis that retinal whitening is due to reversible intracellular oedema in response to relative hypoxia, caused by sequestered erythrocytes infected by Plasmodium falciparum. Impaired visual functioning after cerebral malaria is not attributable to retinal changes and appears to be a cortical phenomenon. PMID:14977760

  18. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia.

    PubMed

    Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

    2016-02-01

    To present and evaluate a new screening protocol for amblyopia in preschool children. Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.

  19. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia

    PubMed Central

    Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

    2016-01-01

    Aim To present and evaluate a new screening protocol for amblyopia in preschool children. Methods Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. Results 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. Conclusion The ZAPS study used the most discriminative VA test with optotypes in lines as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia. PMID:26935612

  20. Effect of Bevacizumab vs Aflibercept on Visual Acuity Among Patients With Macular Edema Due to Central Retinal Vein Occlusion

    PubMed Central

    Scott, Ingrid U.; Ip, Michael S.; Blodi, Barbara A.; Oden, Neal L.; Awh, Carl C.; Kunimoto, Derek Y.; Marcus, Dennis M.; Wroblewski, John J.; King, Jacqueline

    2017-01-01

    Importance Studies have established the efficacy and safety of aflibercept for the treatment of macular edema due to central retinal vein occlusion. Bevacizumab is used off-label to treat this condition despite the absence of supporting data. Objective To investigate whether bevacizumab is noninferior to aflibercept for the treatment of macular edema secondary to central retinal or hemiretinal vein occlusion. Design, Setting, and Participants The SCORE2 randomized noninferiority clinical trial was conducted at 66 private practice or academic centers in the United States, and included 362 patients with macular edema due to central retinal or hemiretinal vein occlusion who were randomized 1:1 to receive aflibercept or bevacizumab. The first participant was randomized on September 17, 2014, and the last month 6 visit occurred on May 6, 2016. Analyses included data available as of December 30, 2016. Interventions Eyes were randomized to receive intravitreal injection of bevacizumab (1.25 mg; n = 182) or aflibercept (2.0 mg; n = 180) every 4 weeks through month 6. Main Outcomes and Measures The primary outcome was mean change in visual acuity (VA) letter score (VALS) from the randomization visit to the 6-month follow-up visit, based on the best-corrected electronic Early Treatment Diabetic Retinopathy Study VALS (scores range from 0-100; higher scores indicate better VA). The noninferiority margin was 5 letters, and statistical testing for noninferiority was based on a 1-sided 97.5% confidence interval. Results Among 362 randomized participants (mean [SD] age, 69 [12] years; 157 [43.4%] women; mean [SD] VALS at baseline, 50.3 [15.2] [approximate Snellen VA 20/100]), 348 (96.1%) completed the month 6 follow-up visit. At month 6, the mean VALS was 69.3 (a mean increase from baseline of 18.6) in the bevacizumab group and 69.3 (a mean increase from baseline of 18.9) in the aflibercept group (model-based estimate of between-group difference, −0.14; 97.5% CI, −3

  1. Spatial contrast sensitivity vision loss in children with cortical visual impairment.

    PubMed

    Good, William V; Hou, Chuan; Norcia, Anthony M

    2012-11-19

    Although cortical visual impairment (CVI) is the leading cause of bilateral vision impairment in children in Western countries, little is known about the effects of CVI on visual function. The aim of this study was to compare visual evoked potential measures of contrast sensitivity and grating acuity in children with CVI with those of age-matched typically developing controls. The swept parameter visual evoked potential (sVEP) was used to measure contrast sensitivity and grating acuity in 34 children with CVI at 5 months to 5 years of age and in 16 age-matched control children. Contrast thresholds and spatial frequency thresholds (grating acuities) were derived by extrapolating the tuning functions to zero amplitude. These thresholds and maximal suprathreshold response amplitudes were compared between groups. Among 34 children with CVI, 30 had measurable but reduced contrast sensitivity with a median threshold of 10.8% (range 5.0%-30.0% Michelson), and 32 had measurable but reduced grating acuity with median threshold 0.49 logMAR (9.8 c/deg, range 5-14 c/deg). These thresholds were significantly reduced, compared with age-matched control children. In addition, response amplitudes over the entire sweep range for both measures were significantly diminished in children with CVI compared with those of control children. Our results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI. The substantial degree of loss in contrast sensitivity suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.

  2. The Nigerian national blindness and visual impairment survey: Rationale, objectives and detailed methodology

    PubMed Central

    Dineen, Brendan; Gilbert, Clare E; Rabiu, Mansur; Kyari, Fatima; Mahdi, Abdull M; Abubakar, Tafida; Ezelum, Christian C; Gabriel, Entekume; Elhassan , Elizabeth; Abiose, Adenike; Faal, Hannah; Jiya, Jonathan Y; Ozemela, Chinenyem P; Lee, Pak Sang; Gudlavalleti, Murthy VS

    2008-01-01

    Background Despite having the largest population in Africa, Nigeria has no accurate population based data to plan and evaluate eye care services. A national survey was undertaken to estimate the prevalence and determine the major causes of blindness and low vision. This paper presents the detailed methodology used during the survey. Methods A nationally representative sample of persons aged 40 years and above was selected. Children aged 10–15 years and individuals aged <10 or 16–39 years with visual impairment were also included if they lived in households with an eligible adult. All participants had their height, weight, and blood pressure measured followed by assessment of presenting visual acuity, refractokeratomery, A-scan ultrasonography, visual fields and best corrected visual acuity. Anterior and posterior segments of each eye were examined with a torch and direct ophthalmoscope. Participants with visual acuity of < = 6/12 in one or both eyes underwent detailed examination including applanation tonometry, dilated slit lamp biomicroscopy, lens grading and fundus photography. All those who had undergone cataract surgery were refracted and best corrected vision recorded. Causes of visual impairment by eye and for the individual were determined using a clinical algorithm recommended by the World Health Organization. In addition, 1 in 7 adults also underwent a complete work up as described for those with vision < = 6/12 for constructing a normative data base for Nigerians. Discussion The field work for the study was completed in 30 months over the period 2005–2007 and covered 305 clusters across the entire country. Concurrently persons 40+ years were examined to form a normative data base. Analysis of the data is currently underway. Conclusion The methodology used was robust and adequate to provide estimates on the prevalence and causes of blindness in Nigeria. The survey would also provide information on barriers to accessing services, quality of life of

  3. Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Abouaf, Lucie; Girard, Nicolas; Claude Bernard University, Lyon

    2012-03-01

    Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM. Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were comparedmore » with Wilcoxon's signed rank test. Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision. Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.« less

  4. Visual function at altitude under night vision assisted conditions.

    PubMed

    Vecchi, Diego; Morgagni, Fabio; Guadagno, Anton G; Lucertini, Marco

    2014-01-01

    Hypoxia, even mild, is known to produce negative effects on visual function, including decreased visual acuity and sensitivity to contrast, mostly in low light. This is of special concern when night vision devices (NVDs) are used during flight because they also provide poor images in terms of resolution and contrast. While wearing NVDs in low light conditions, 16 healthy male aviators were exposed to a simulated altitude of 12,500 ft in a hypobaric chamber. Snellen visual acuity decreased in normal light from 28.5 +/- 4.2/20 (normoxia) to 37.2 +/- 7.4/20 (hypoxia) and, in low light, from 33.8 +/- 6.1/20 (normoxia) to 42.2 +/- 8.4/20 (hypoxia), both at a significant level. An association was found between blood oxygen saturation and visual acuity without significance. No changes occurred in terms of sensitivity to contrast. Our data demonstrate that mild hypoxia is capable of affecting visual acuity and the photopic/high mesopic range of NVD-aided vision. This may be due to several reasons, including the sensitivity to hypoxia of photoreceptors and other retinal cells. Contrast sensitivity is possibly preserved under NVD-aided vision due to its dependency on the goggles' gain.

  5. Blindness enhances tactile acuity and haptic 3-D shape discrimination.

    PubMed

    Norman, J Farley; Bartholomew, Ashley N

    2011-10-01

    This study compared the sensory and perceptual abilities of the blind and sighted. The 32 participants were required to perform two tasks: tactile grating orientation discrimination (to determine tactile acuity) and haptic three-dimensional (3-D) shape discrimination. The results indicated that the blind outperformed their sighted counterparts (individually matched for both age and sex) on both tactile tasks. The improvements in tactile acuity that accompanied blindness occurred for all blind groups (congenital, early, and late). However, the improvements in haptic 3-D shape discrimination only occurred for the early-onset and late-onset blindness groups; the performance of the congenitally blind was no better than that of the sighted controls. The results of the present study demonstrate that blindness does lead to an enhancement of tactile abilities, but they also suggest that early visual experience may play a role in facilitating haptic 3-D shape discrimination.

  6. Effect of a modified optic edge design on visual function: textured-edge versus round-anterior, slope-side edge.

    PubMed

    Hayashi, Ken; Hayashi, Hideyuki

    2004-08-01

    To compare the impairment in visual function caused by glare with 2 acrylic intraocular lenses (IOLs) with different modified optic edges. Hayashi Eye Hospital, Fukuoka, Japan. Fifty-four patients had implantation of an IOL with a textured edge (Alcon MA60AC) in 1 eye and an IOL with a round-anterior, sloped-sided edge (AMO AR40e) in the opposite eye. Visual acuity was measured at 5 contrast visual targets (100%, 25%, 10%, 5%, and 2.5%) (contrast visual acuity) under photopic and mesopic conditions with and without a glare source approximately 1 month after surgery using the Contrast Sensitivity Accurate Tester (Menicon CAT-2000). The mean mesopic contrast visual acuity at moderate- to low-contrast visual targets was significantly worse in the presence of a glare source in both groups, whereas photopic contrast visual acuity did not change significantly. There were no significant differences between the 2 groups in the mean visual acuity or in photopic or mesopic lighting contrast visual acuity with and without a glare source. Furthermore, there was no significant difference in loss of contrast visual acuity in the presence of glare. Mesopic contrast sensitivity with both acrylic IOLs was impaired significantly in the presence of glare, but the impairment of contrast sensitivity from glare was approximately the same between eyes with a textured-edge IOL and eyes with a round-anterior, sloped-sided edge IOL.

  7. Comparison of visual and refractive outcomes after bilateral implantation of toric intraocular lenses with or without a multifocal component.

    PubMed

    Hayashi, Ken; Masumoto, Miki; Takimoto, Minehiro

    2015-01-01

    To compare visual outcomes between patients with a multifocal toric intraocular lens (IOL) and those with a monofocal toric IOL. Hayashi Eye Hospital, Fukuoka, Japan. Prospective case-control series. Eyes with preoperative corneal astigmatism between 0.75 diopter (D) and 2.82 D scheduled for implantation of a diffractive multifocal toric IOL (Restor SND1T) or monofocal toric IOL (Acrysof SN6AT) were recruited. Three months postoperatively, visual acuity at various distances, contrast visual acuity, and refractive outcomes were examined. Each group comprised 66 eyes (33 patients). Postoperatively, the mean refractive astigmatism decreased to 0.71 D in the multifocal group and 0.74 D in the monofocal group. The mean monocular and binocular uncorrected and corrected near visual acuity at 0.3 m and intermediate visual acuity at 0.5 m were significantly better in the multifocal group than in the monofocal group (P≤.0011). The uncorrected and corrected visual acuities at other distances were similar between groups except at 1.0 m. Binocular photopic and mesopic contrast visual acuities at high to moderate contrasts did not differ significantly between groups; however, acuities at low contrasts were worse in the multifocal group (P≤.0429). Diffractive multifocal toric IOL implantation decreased refractive astigmatism to an acceptable range in eyes with moderate corneal astigmatism and provided useful visual acuity (≥20/40) at any distance and significantly better near and intermediate visual acuity than a monofocal toric IOL. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Unhealthy behaviours and risk of visual impairment: The CONSTANCES population-based cohort.

    PubMed

    Merle, Bénédicte M J; Moreau, Gwendoline; Ozguler, Anna; Srour, Bernard; Cougnard-Grégoire, Audrey; Goldberg, Marcel; Zins, Marie; Delcourt, Cécile

    2018-04-26

    Unhealthy behaviours are linked to a higher risk of eye diseases, but their combined effect on visual function is unknown. We aimed to examine the individual and combined associations of diet, physical activity, smoking and alcohol consumption with visual impairment among French adults. 38 903 participants aged 18-73 years from the CONSTANCES nationwide cohort (2012-2016) with visual acuity measured and who completed, lifestyle, medical and food frequency questionnaires were included. Visual impairment was defined as a presenting visual acuity <20/40 in the better eye. After full multivariate adjustment, the odds for visual impairment increased with decreasing diet quality (p for trend = 0.04), decreasing physical activity (p for trend = 0.02) and increasing smoking pack-years (p for trend = 0.03), whereas no statistically significant association with alcohol consumption was found. Combination of several unhealthy behaviours was associated with increasing odds for visual impairment (p for trend = 0.0002), with a fully-adjusted odds ratio of 1.81 (95% CI 1.18 to 2.79) for participants reporting 2 unhealthy behaviours and 2.92 (95% CI 1.60 to 5.32) for those reporting 3 unhealthy behaviours. An unhealthy lifestyle including low/intermediate diet quality, low physical activity and heavy smoking was associated with visual impairment in this large population-based study.

  9. Functional Multijoint Position Reproduction Acuity in Overhead-Throwing Athletes

    PubMed Central

    Tripp, Brady L; Uhl, Timothy L; Mattacola, Carl G; Srinivasan, Cidambi; Shapiro, Robert

    2006-01-01

    Context: Baseball players rely on the sensorimotor system to uphold the balance between upper extremity stability and mobility while maintaining athletic performance. However, few researchers have studied functional multijoint measures of sensorimotor acuity in overhead-throwing athletes. Objective: To compare sensorimotor acuity between 2 high-demand functional positions and among planes of motion within individual joints and to describe a novel method of measuring sensorimotor function. Design: Single-session, repeated-measures design. Setting: University musculoskeletal research laboratory. Patients or Other Participants: Twenty-one National Collegiate Athletic Association Division I baseball players (age = 20.8 ± 1.5 years, height = 181.3 ± 5.1 cm, mass = 87.8 ± 9.1 kg) with no history of upper extremity injury or central nervous system disorder. Main Outcome Measure(s): We measured active multijoint position reproduction acuity in multiple planes using an electromagnetic tracking device. Subjects reproduced 2 positions: arm cock and ball release. We calculated absolute and variable error for individual motions at the scapulothoracic, glenohumeral, elbow, and wrist joints and calculated overall joint acuity with 3-dimensional variable error. Results: Acuity was significantly better in the arm-cock position compared with ball release at the scapulothoracic and glenohumeral joints. We observed significant differences among planes of motion within the scapulothoracic and glenohumeral joints at ball release. Scapulothoracic internal rotation and glenohumeral horizontal abduction and rotation displayed less acuity than other motions. Conclusions: We established the reliability of a functional measure of upper extremity sensorimotor system acuity in baseball players. Using this technique, we observed differences in acuity between 2 test positions and among planes of motion within the glenohumeral and scapulothoracic joints. Clinicians may consider these

  10. INCREASED VISUAL BEHAVIOR IN LOW VISION CHILDREN.

    ERIC Educational Resources Information Center

    BARRAGA, NATALIE

    TEN PAIRS OF BLIND CHILDREN AGED SIX TO 13 YEARS WHO HAD SOME VISION WERE MATCHED BY PRETEST SCORES ON A TEST OF VISUAL DISCRIMINATION. A CRITERION GROUP, DESIGNATED THE PRINT COMPARISON GROUP, HAD SLIGHLY HIGHER RECORDED DISTANCE ACUITIES AND USED VISION AS THE PRIMARY MEANS OF LEARNING. PAIRS OF EXPERIMENTAL SUBJECTS DAILY RECEIVED 45 MINUTES OF…

  11. Refractive errors, visual impairment, and the use of low-vision devices in albinism in Malawi.

    PubMed

    Schulze Schwering, M; Kumar, N; Bohrmann, D; Msukwa, G; Kalua, K; Kayange, P; Spitzer, M S

    2015-04-01

    This study focuses on the refractive implications of albinism in Malawi, which is mostly associated with the burden of visual impairment. The main goal was to describe the refractive errors and to analyze whether patients with albinism in Malawi, Sub-Saharan Africa, benefit from refraction. Age, sex, refractive data, uncorrected and best-corrected visual acuity (UCVA, BCVA), colour vision, contrast sensitivity, and the prescription of sunglasses and low vision devices were collected for a group of 120 albino individuals with oculocutaneous albinism (OCA). Refractive errors were evaluated objectively and subjectively by retinoscopy, and followed by cycloplegic refraction to reconfirm the results. Best-corrected visual acuity (BCVA) was also assessed binocularly. One hundred and twenty albino subjects were examined, ranging in age from 4 to 25 years (median 12 years), 71 (59 %) boys and 49 (41 %) girls. All exhibited horizontal pendular nystagmus. Mean visual acuity improved from 0.98 (0.33) logMAR to 0.77 (0.15) logMAR after refraction (p < 0.001). The best improvement of VA was achieved in patients with mild to moderate myopia. Patients with albinism who were hyperopic more than +1.5 D hardly improved from refraction. With the rule (WTR) astigmatism was more present (37.5 %) than against the rule (ATR) astigmatism (3.8 %). Patients with astigmatism less than 1.5 D improved in 15/32 of cases (47 %) by 2 lines or more. Patients with astigmatism equal to or more than 1.5 D in any axis improved in 26/54 of cases (48 %) by 2 lines or more. Refraction improves visual acuity of children with oculocutaneous albinism in a Sub-Saharan African population in Malawi. The mean improvement was 2 logMAR units.

  12. Correction of Refractive Errors in Rhesus Macaques (Macaca mulatta) Involved in Visual Research

    PubMed Central

    Mitchell, Jude F; Boisvert, Chantal J; Reuter, Jon D; Reynolds, John H; Leblanc, Mathias

    2014-01-01

    Macaques are the most common animal model for studies in vision research, and due to their high value as research subjects, often continue to participate in studies well into old age. As is true in humans, visual acuity in macaques is susceptible to refractive errors. Here we report a case study in which an aged macaque demonstrated clear impairment in visual acuity according to performance on a demanding behavioral task. Refraction demonstrated bilateral myopia that significantly affected behavioral and visual tasks. Using corrective lenses, we were able to restore visual acuity. After correction of myopia, the macaque's performance on behavioral tasks was comparable to that of a healthy control. We screened 20 other male macaques to assess the incidence of refractive errors and ocular pathologies in a larger population. Hyperopia was the most frequent ametropia but was mild in all cases. A second macaque had mild myopia and astigmatism in one eye. There were no other pathologies observed on ocular examination. We developed a simple behavioral task that visual research laboratories could use to test visual acuity in macaques. The test was reliable and easily learned by the animals in 1 d. This case study stresses the importance of screening macaques involved in visual science for refractive errors and ocular pathologies to ensure the quality of research; we also provide simple methodology for screening visual acuity in these animals. PMID:25427343

  13. Correction of refractive errors in rhesus macaques (Macaca mulatta) involved in visual research.

    PubMed

    Mitchell, Jude F; Boisvert, Chantal J; Reuter, Jon D; Reynolds, John H; Leblanc, Mathias

    2014-08-01

    Macaques are the most common animal model for studies in vision research, and due to their high value as research subjects, often continue to participate in studies well into old age. As is true in humans, visual acuity in macaques is susceptible to refractive errors. Here we report a case study in which an aged macaque demonstrated clear impairment in visual acuity according to performance on a demanding behavioral task. Refraction demonstrated bilateral myopia that significantly affected behavioral and visual tasks. Using corrective lenses, we were able to restore visual acuity. After correction of myopia, the macaque's performance on behavioral tasks was comparable to that of a healthy control. We screened 20 other male macaques to assess the incidence of refractive errors and ocular pathologies in a larger population. Hyperopia was the most frequent ametropia but was mild in all cases. A second macaque had mild myopia and astigmatism in one eye. There were no other pathologies observed on ocular examination. We developed a simple behavioral task that visual research laboratories could use to test visual acuity in macaques. The test was reliable and easily learned by the animals in 1 d. This case study stresses the importance of screening macaques involved in visual science for refractive errors and ocular pathologies to ensure the quality of research; we also provide simple methodology for screening visual acuity in these animals.

  14. Association Between Depression and Functional Vision Loss in Persons 20 Years of Age or Older in the United States, NHANES 2005–2008

    PubMed Central

    Zhang, Xinzhi; Bullard, Kai McKeever; Cotch, Mary Frances; Wilson, M. Roy; Rovner, Barry W.; McGwin, Gerald; Owsley, Cynthia; Barker, Lawrence; Crews, John E.; Saaddine, Jinan B.

    2013-01-01

    Importance This study provides further evidence from a national sample to generalize the relationship between depression and vision loss to adults across the age spectrum. Better recognition of depression among people reporting reduced ability to perform routine activities of daily living due to vision loss is warranted. Objectives To estimate, in a national survey of US adults 20 years of age or older, the prevalence of depression among adults reporting visual function loss and among those with visual acuity impairment. The relationship between depression and vision loss has not been reported in a nationally representative sample of US adults. Previous studies have been limited to specific cohorts and predominantly focused on the older population. Design The National Health and Nutrition Examination Survey (NHANES) 2005–2008. Setting A cross-sectional, nationally representative sample of adults, with prevalence estimates weighted to represent the civilian, noninstitutionalized US population. Participants A total of 10 480 US adults 20 years of age or older. Main Outcome Measures Depression, as measured by the 9-item Patient Health Questionnaire depression scale, and vision loss, as measured by visual function using a questionnaire and by visual acuity at examination. Results In 2005–2008, the estimated crude prevalence of depression (9-item Patient Health Questionnaire score of ≥10) was 11.3% (95% CI, 9.7%–13.2%) among adults with self-reported visual function loss and 4.8% (95% CI, 4.0%–5.7%) among adults without. The estimated prevalence of depression was 10.7% (95% CI, 8.0%–14.3%) among adults with presenting visual acuity impairment (visual acuity worse than 20/40 in the better-seeing eye) compared with 6.8% (95% CI, 5.8%–7.8%) among adults with normal visual acuity. After controlling for age, sex, race/ethnicity, marital status, living alone or not, education, income, employment status, health insurance, body mass index, smoking, binge drinking

  15. A preliminary investigation of lumbar tactile acuity in yoga practitioners.

    PubMed

    Flaherty, Mary; Connolly, Martin

    2014-01-01

    Tactile acuity in the back relates to voluntary lumbo-pelvic control and is lower in chronic low back pain (CLBP) patients. Two-point discrimination (TPD) thresholds are higher, indicating decreased tactile acuity in patients with CLBP. Yoga has been shown to help relieve CLBP. This study investigated the hypothesis that regular practitioners of yoga have increased tactile acuity (i.e., lower TPD thresholds) when compared to matched controls who regularly perform gym-based (resistance training or aerobic-type) exercise. Tactile acuity in the low back was assessed using TPD in 16 long-term practitioners of yoga (5 Ashtanga, 5 Bikram, and 6 Iyengar practitioners) and 16 age- and gender-matched healthy controls who exercise (with weights and aerobic exercise). The yoga practitioners' TPD was lower than that of the exercisers, indicating greater tactile acuity in the low back. While there was no difference between the TPD of the practitioners of different yoga styles, the TPD of the Ashtanga yoga participants were significantly lower than those of the exercisers. The yogis whose main reasons to practice yoga were for "meditation or increased mindfulness" and for "well-being" showed a nonsignificant trend of higher tactile acuity than those who did yoga for "physical exercise." There was no association between TPD threshold and cumulative amount of yoga practice in terms of hours per week and years of experience. However, increased hours of exercise per week correlated with higher TPD. The findings suggest that there may be a relationship between yoga practice and enhanced tactile acuity in the low back.

  16. Visual outcome and efficacy of conjunctival autograft, harvested from the body of pterygium in pterygium excision.

    PubMed

    Bhandari, Vipul; Rao, Chandan Latha; Ganesh, Sri; Brar, Sheetal

    2015-01-01

    To evaluate the efficacy of conjunctival autograft after the pterygium excision with fibrin adhesive using conjunctiva over the pterygium. This prospective study included 25 eyes of 25 patients with a mean age of 40±10 years, who underwent the pterygium excision with conjunctival autograft derived from the body of the pterygium and attached using fibrin glue. The mean follow-up period was 6 months. On all postoperative visits, changes in uncorrected visual acuity, corrected distance visual acuity, astigmatism, complications, and the evidence of recurrence were recorded. At the end of mean follow-up, uncorrected visual acuity and corrected distance visual acuity improved by one or two lines in all eyes treated. Mean astigmatism reduced significantly from a preoperative value from 2.308D to 1.248D postoperatively (P<0.026). Minor postoperative complications such as congestion, chemosis, and subconjunctival hemorrhage were seen, which resolved with time. No major sight-threatening or graft-related complications were detected. There was no evidence of recurrence during a follow-up period of 6 months. Self-conjunctival autograft following the pterygium excision appears to be a feasible, safe, and effective alternative method for management of pterygium. It also preserves the superior conjunctiva for future surgeries. However, longer follow-up is required to study the long-term outcomes, especially the incidence of recurrence.

  17. The Impact of Early Visual Deprivation on Spatial Hearing: A Comparison between Totally and Partially Visually Deprived Children

    PubMed Central

    Cappagli, Giulia; Finocchietti, Sara; Cocchi, Elena; Gori, Monica

    2017-01-01

    The specific role of early visual deprivation on spatial hearing is still unclear, mainly due to the difficulty of comparing similar spatial skills at different ages and to the difficulty in recruiting young blind children from birth. In this study, the effects of early visual deprivation on the development of auditory spatial localization have been assessed in a group of seven 3–5 years old children with congenital blindness (n = 2; light perception or no perception of light) or low vision (n = 5; visual acuity range 1.1–1.7 LogMAR), with the main aim to understand if visual experience is fundamental to the development of specific spatial skills. Our study led to three main findings: firstly, totally blind children performed overall more poorly compared sighted and low vision children in all the spatial tasks performed; secondly, low vision children performed equally or better than sighted children in the same auditory spatial tasks; thirdly, higher residual levels of visual acuity are positively correlated with better spatial performance in the dynamic condition of the auditory localization task indicating that the more residual vision the better spatial performance. These results suggest that early visual experience has an important role in the development of spatial cognition, even when the visual input during the critical period of visual calibration is partially degraded like in the case of low vision children. Overall these results shed light on the importance of early assessment of spatial impairments in visually impaired children and early intervention to prevent the risk of isolation and social exclusion. PMID:28443040

  18. Causes of severe visual impairment and blindness in children attending schools for the visually handicapped in the Czech Republic.

    PubMed

    Kocur, I; Kuchynka, P; Rodný, S; Baráková, D; Schwartz, E C

    2001-10-01

    To describe the causes of severe visual impairment and blindness in children in schools for the visually handicapped in the Czech Republic in 1998. Pupils attending all 10 primary schools for the visually handicapped were examined. A modified WHO/PBL eye examination record for children with blindness and low vision was used. 229 children (146 males and 83 females) aged 6-15 years were included in the study: 47 children had severe visual impairment (20.5%) (visual acuity in their better eye less than 6/60), and 159 were blind (69.5%) (visual acuity in their better eye less than 3/60). Anatomically, the most affected parts of the eye were the retina (124, 54.2%), optic nerve (35, 15.3%), whole globe (25, 10.9%), lens (20, 8.7%), and uvea (12, 5.2%). Aetiologically (timing of insult leading to visual loss), the major cause of visual impairment was retinopathy of prematurity (ROP) (96, 41.9 %), followed by abnormalities of unknown timing of insult (97, 42.4%), and hereditary disease (21, 9.2%). In 90 children (40%), additional disabilities were present: mental disability (36, 16%), physical handicap (16, 7%), and/or a combination of both (19, 8%). It was estimated that 127 children (56%) suffer from visual impairment caused by potentially preventable and/or treatable conditions (for example, ROP, cataract, glaucoma). Establishing a study group for comprehensive evaluation of causes of visual handicap in children in the Czech Republic, as well as for detailed analysis of present practice of screening for ROP was recommended.

  19. A new computer program for mass screening of visual defects in preschool children.

    PubMed

    Briscoe, D; Lifshitz, T; Grotman, M; Kushelevsky, A; Vardi, H; Weizman, S; Biedner, B

    1998-04-01

    To test the effectiveness of a PC computer program for detecting vision disorders which could be used by non-trained personnel, and to determine the prevalence of visual impairment in a sample population of preschool children in the city of Beer-Sheba, Israel. 292 preschool children, aged 4-6 years, were examined in the kindergarten setting, using the computer system and "gold standard" tests. Visual acuity and stereopsis were tested and compared using Snellen type symbol charts and random dot stereograms respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and kappa test were evaluated. A computer pseudo Worth four dot test was also performed but could not be compared with the standard Worth four dot test owing to the inability of many children to count. Agreement between computer and gold standard tests was 83% and 97.3% for visual acuity and stereopsis respectively. The sensitivity of the computer stereogram was only 50%, but it had a specificity of 98.9%, whereas the sensitivity and specificity of the visual acuity test were 81.5% and 83% respectively. The positive predictive value of both tests was about 63%. 27.7% of children tested had a visual acuity of 6/12 or less and stereopsis was absent in 28% using standard tests. Impairment of fusion was found in 5% of children using the computer pseudo Worth four dot test. The computer program was found to be stimulating, rapid, and easy to perform. The wide availability of computers in schools and at home allow it to be used as an additional screening tool by non-trained personnel, such as teachers and parents, but it is not a replacement for standard testing.

  20. Visual disability, visual function, and myopia among rural chinese secondary school children: the Xichang Pediatric Refractive Error Study (X-PRES)--report 1.

    PubMed

    Congdon, Nathan; Wang, Yunfei; Song, Yue; Choi, Kai; Zhang, Mingzhi; Zhou, Zhongxia; Xie, Zhenling; Li, Liping; Liu, Xueyu; Sharma, Abhishek; Wu, Bin; Lam, Dennis S C

    2008-07-01

    To evaluate visual acuity, visual function, and prevalence of refractive error among Chinese secondary-school children in a cross-sectional school-based study. Uncorrected, presenting, and best corrected visual acuity, cycloplegic autorefraction with refinement, and self-reported visual function were assessed in a random, cluster sample of rural secondary school students in Xichang, China. Among the 1892 subjects (97.3% of the consenting children, 84.7% of the total sample), mean age was 14.7 +/- 0.8 years, 51.2% were female, and 26.4% were wearing glasses. The proportion of children with uncorrected, presenting, and corrected visual disability (< or = 6/12 in the better eye) was 41.2%, 19.3%, and 0.5%, respectively. Myopia < -0.5, < -2.0, and < -6.0 D in both eyes was present in 62.3%, 31.1%, and 1.9% of the subjects, respectively. Among the children with visual disability when tested without correction, 98.7% was due to refractive error, while only 53.8% (414/770) of these children had appropriate correction. The girls had significantly (P < 0.001) more presenting visual disability and myopia < -2.0 D than did the boys. More myopic refractive error was associated with worse self-reported visual function (ANOVA trend test, P < 0.001). Visual disability in this population was common, highly correctable, and frequently uncorrected. The impact of refractive error on self-reported visual function was significant. Strategies and studies to understand and remove barriers to spectacle wear are needed.

  1. Hypnosis and Osteopathic Manipulative Treatment for Visual Disorders During Pregnancy: A Case Report.

    PubMed

    Russo, Giancarlo; Remonato, Alessandro; Remonato, Roberto; Zanier, Emiliano

    2017-01-01

    Context • Pregnancy causes physiological alterations to the visual system, particularly in relation to retinal vascularization, with a consequent increase of intraocular pressure, and to the lacrimal fluid, with a consequent ocular dryness, which both can lead to a reduction in visual acuity. Numerous case reports refer to the employment of hypnotic treatment in cases of myopia, but the literature does not report any case of decreased visual acuity postpartum that was treated with hypnosis. Objective • For women with visual disorders that had appeared during pregnancy or were preexisting, the study intended to evaluate the benefits of treatment of the diaphragm by hypnotherapy and osteopathy to modify intracorporeal pressure and restore the women's visual function. Design • The research team performed a case study. Setting • The setting was a private osteopathic clinic. Participant • The participant was a 35-y-old woman lacking visual acuity postpartum. Intervention • The study took place during a period of 1 d. The participant first took part in a hypnotherapy session, the first intervention, and then participated in an osteopathic session, the second intervention. Outcome Measures • For the first evaluation of visual function at baseline, 3 tests were performed: (1) a visual acuity test; (2) a cover test for near and distance vision; and (3) a test for near point convergence. The visual function evaluation (all 3 tests) occurred after the 2 types of treatment (T1, T2). Finally, a visual function evaluation (all 3 tests) occurred at a follow-up session 1 mo after the end of treatment (T3). Results • The intervention produced a significant improvement in visual acuity, due to the multidisciplinary approach of treatment with hypnotherapy and osteopathy, and achieved a result that was maintained in the medium term. Conclusions • Hypnosis and osteopathy produced a significant improvement in visual acuity and the result was maintained in the medium

  2. Dysflective cones: Visual function and cone reflectivity in long-term follow-up of acute bilateral foveolitis.

    PubMed

    Tu, Joanna H; Foote, Katharina G; Lujan, Brandon J; Ratnam, Kavitha; Qin, Jia; Gorin, Michael B; Cunningham, Emmett T; Tuten, William S; Duncan, Jacque L; Roorda, Austin

    2017-09-01

    Confocal adaptive optics scanning laser ophthalmoscope (AOSLO) images provide a sensitive measure of cone structure. However, the relationship between structural findings of diminished cone reflectivity and visual function is unclear. We used fundus-referenced testing to evaluate visual function in regions of apparent cone loss identified using confocal AOSLO images. A patient diagnosed with acute bilateral foveolitis had spectral-domain optical coherence tomography (SD-OCT) (Spectralis HRA + OCT system [Heidelberg Engineering, Vista, CA, USA]) images indicating focal loss of the inner segment-outer segment junction band with an intact, but hyper-reflective, external limiting membrane. Five years after symptom onset, visual acuity had improved from 20/80 to 20/25, but the retinal appearance remained unchanged compared to 3 months after symptoms began. We performed structural assessments using SD-OCT, directional OCT (non-standard use of a prototype on loan from Carl Zeiss Meditec) and AOSLO (custom-built system). We also administered fundus-referenced functional tests in the region of apparent cone loss, including analysis of preferred retinal locus (PRL), AOSLO acuity, and microperimetry with tracking SLO (TSLO) (prototype system). To determine AOSLO-corrected visual acuity, the scanning laser was modulated with a tumbling E consistent with 20/30 visual acuity. Visual sensitivity was assessed in and around the lesion using TSLO microperimetry. Complete eye examination, including standard measures of best-corrected visual acuity, visual field tests, color fundus photos, and fundus auto-fluorescence were also performed. Despite a lack of visible cone profiles in the foveal lesion, fundus-referenced vision testing demonstrated visual function within the lesion consistent with cone function. The PRL was within the lesion of apparent cone loss at the fovea. AOSLO visual acuity tests were abnormal, but measurable: for trials in which the stimulus remained completely

  3. Attention and Visual Motor Integration in Young Children with Uncorrected Hyperopia.

    PubMed

    Kulp, Marjean Taylor; Ciner, Elise; Maguire, Maureen; Pistilli, Maxwell; Candy, T Rowan; Ying, Gui-Shuang; Quinn, Graham; Cyert, Lynn; Moore, Bruce

    2017-10-01

    Among 4- and 5-year-old children, deficits in measures of attention, visual-motor integration (VMI) and visual perception (VP) are associated with moderate, uncorrected hyperopia (3 to 6 diopters [D]) accompanied by reduced near visual function (near visual acuity worse than 20/40 or stereoacuity worse than 240 seconds of arc). To compare attention, visual motor, and visual perceptual skills in uncorrected hyperopes and emmetropes attending preschool or kindergarten and evaluate their associations with visual function. Participants were 4 and 5 years of age with either hyperopia (≥3 to ≤6 D, astigmatism ≤1.5 D, anisometropia ≤1 D) or emmetropia (hyperopia ≤1 D; astigmatism, anisometropia, and myopia each <1 D), without amblyopia or strabismus. Examiners masked to refractive status administered tests of attention (sustained, receptive, and expressive), VMI, and VP. Binocular visual acuity, stereoacuity, and accommodative accuracy were also assessed at near. Analyses were adjusted for age, sex, race/ethnicity, and parent's/caregiver's education. Two hundred forty-four hyperopes (mean, +3.8 ± [SD] 0.8 D) and 248 emmetropes (+0.5 ± 0.5 D) completed testing. Mean sustained attention score was worse in hyperopes compared with emmetropes (mean difference, -4.1; P < .001 for 3 to 6 D). Mean Receptive Attention score was worse in 4 to 6 D hyperopes compared with emmetropes (by -2.6, P = .01). Hyperopes with reduced near visual acuity (20/40 or worse) had worse scores than emmetropes (-6.4, P < .001 for sustained attention; -3.0, P = .004 for Receptive Attention; -0.7, P = .006 for VMI; -1.3, P = .008 for VP). Hyperopes with stereoacuity of 240 seconds of arc or worse scored significantly worse than emmetropes (-6.7, P < .001 for sustained attention; -3.4, P = .03 for Expressive Attention; -2.2, P = .03 for Receptive Attention; -0.7, P = .01 for VMI; -1.7, P < .001 for VP). Overall, hyperopes with better near visual function generally performed similarly to

  4. The Best Colors for Audio-Visual Materials for More Effective Instruction.

    ERIC Educational Resources Information Center

    Start, Jay

    A number of variables may affect the ability of students to perceive, and learn from, instructional materials. The objectives of the study presented here were to determine the projected color that provided the best visual acuity for the viewer, and the necessary minimum exposure time for achieving maximum visual acuity. Fifty…

  5. Geographic Variation in the Use of Low-Acuity Pediatric Emergency Medical Services.

    PubMed

    Gregory, Emily F; Chamberlain, James M; Teach, Stephen J; Engstrom, Ryan; Mathison, David J

    2017-02-01

    The aim of this study was to examine geographic variation in pediatric low-acuity emergency medical services (EMS) use in Washington, DC. This cross-sectional analysis of low-acuity EMS transports evaluated arrivals at 2 emergency departments and included 93% of pediatric transports in Washington, DC, during the study period. Low-acuity classification was defined as a triage emergency severity index of 4 or 5 not resulting in transfer, admission, or death. Logistic regression compared low-acuity visits arriving via EMS with all other low-acuity visits. Home zip code represented geographic location. Covariates included patient age, sex, race/ethnicity, hour of emergency department arrival, and insurance status. There were 45,454 low-acuity visits among children aged 0 to 17 years. Of these, 3304 (7.3%) arrived via EMS. The mean age was 5.6 (±5.0) years. Most were African American (84.3%) and had Medicaid insurance (87.3%). Geographic variation predicted EMS use. Adjusted odds ratios (ORs) of using EMS varied from 1.11 to 2.54 when compared with the lowest EMS use zip code. Odds of EMS use were higher among those with public insurance (adjusted OR [adj OR], 1.71; 95% confidence interval [CI], 1.46-2.00) and those with evening and overnight arrivals (evening arrival, adj OR of 1.65 and 95% CI of 1.47-1.86; overnight arrival, adj OR of 2.98 and 95% CI of 2.43-3.65). After adjusting for known covariates, residential zip code was associated with low-acuity EMS activation, stressing the importance of geographic variation in EMS use. Providing alternate means of transportation, or targeted education to certain residential areas, may decrease unnecessary EMS activation.

  6. Food and Drug Administration study update. One-year results from 671 patients with the 3M multifocal intraocular lens.

    PubMed

    Lindstrom, R L

    1993-01-01

    The clinical evaluation of the Food and Drug Administration study of the 3M diffractive multifocal intraocular lens (IOL) is presented here to demonstrate the results of 1-year postoperative data accumulated for 671 patients, the first of whom received the implant in 1987. Patients were selected for study if they had absence of preoperative pathology, were at least 60 years of age, and had a reasonable postoperative prognosis. Extensive evaluations took place at 4 to 6 months and 12 to 14 months after surgery, including five different visual acuity measurements and contrast sensitivity. All testing was completed on both eyes. Data from the fellow eye served as a control when implanted with a monofocal IOL. Overall uncorrected distance visual acuity at 1 year after surgery shows 57% patients with 20/40 or better acuity. In this same group, 78% achieved J3 or better near vision, which improved to 82% in the best case group. Uncorrected visual acuity of 20/40 or better and J3 or better was achieved by 50% of best case multifocal IOL patients, compared with 26% of the monofocal best case comparison group. Measurements of contrast sensitivity consistently document a small loss, which is considered clinically insignificant. Statistical analysis of satisfaction ratings shows that predictors of satisfaction include uncorrected distance acuity, final near acuity, and fellow eye spherical equivalent. This multifocal lens appears to work very well for most patients, with more than half having functional uncorrected distance and near vision. The study showed several considerations that are important for optimizing clinical performance and patient satisfaction: patient selection, realistic expectations, accurate biometry, and adequate control of surgical procedures.

  7. The occurrence of visual and cognitive impairment, and eye diseases in the super-elderly in Japan: a cross-sectional single-center study.

    PubMed

    Fukuoka, Hideki; Nagaya, Masahiro; Toba, Kenji

    2015-10-29

    The current state of eye diseases and treatments in the elderly as well as the relationships between dementia and systemic diseases remain unclear. Therefore, this study evaluated the prevalence of eye diseases, visual impairment, cognitive impairment, and falls (which are an important health issue and are considered one of the Geriatric Giants) in super-elderly people in Japan. The subjects were 31 elderly people (62 eyes; mean age: 84.6 ± 8.8 years; age range 61-98 years) who were admitted to a geriatric health services facility. Eye treatment status, systemic diseases, dementia, and recent falls were investigated. Eye examinations including vision and intraocular pressure measurement, and slit-lamp biomicroscopy were conducted. Mean best corrected visual acuity (logMAR) was 0.51 ± 0.56, and mean intraocular pressure was 13.7 ± 3.5 mmHg. Approximately half of the subjects exhibited excavation of the optic nerve head including cataracts and glaucoma. Ten subjects had visual impairment (i.e., visual acuity of the eye with the better vision <20/40). The mean Hasegawa dementia scale scores between the visually impaired and non-visually impaired groups were 10.2 ± 6 and 16 ± 8 points, respectively (p < 0.05). Furthermore, 70% of subjects with visual impairment experienced a fall in the past year compared to 48% of those without visual impairment, although the difference was not significant. Regarding systemic diseases, there were 6, 5, and 15 cases of diabetes, hyperlipidemia, and hypertension, respectively. There was no significant difference between these systemic diseases and visual function after adjusted for age and gender. The percentages of patients with age-related eye diseases and poor visual acuity in a geriatric health services facility were extremely high. Compared to those without visual impairment, those with visual impairment had lower dementia scores and a higher rate of falls.

  8. Clinical Outcomes after Keraring Implantation for Keratoconus Management in Patients Older Than 40 Years: A Retrospective, Interventional, Cohort Study.

    PubMed

    Gatzioufas, Zisis; Khine, Aye; Elalfy, Mohamed; Guber, Ivo; McLintock, Cameron; Sabatino, Francesco; Hamada, Samer; Lake, Damian

    2018-06-01

    Intracorneal ring segment implantation is an effective and safe method of visual improvement in patients with keratoconus. The aim of our study was to evaluate the long-term clinical outcomes after Keraring implantation for keratoconus in patients older than 40 years. Eleven eyes from 11 patients with keratoconus who underwent femtosecond laser-assisted Keraring implantation for keratoconus were included in this retrospective study. The uncorrected visual acuity (UCVA), corrected visual acuity, keratometric readings, central corneal thickness and thinnest corneal pachymetry were evaluated preoperatively and 6 months after the Keraring implantation. UCVA, BCVA and keratometric readings improved at 6 months postoperatively. Our data showed significant keratometric amelioration and visual improvement after Keraring implantation for keratoconus in patients older than 40 years at 6 months postoperatively.

  9. UV-blocking spectacle lens protects against UV-induced decline of visual performance.

    PubMed

    Liou, Jyh-Cheng; Teng, Mei-Ching; Tsai, Yun-Shan; Lin, En-Chieh; Chen, Bo-Yie

    2015-01-01

    Excessive exposure to sunlight may be a risk factor for ocular diseases and reduced visual performance. This study was designed to examine the ability of an ultraviolet (UV)-blocking spectacle lens to prevent visual acuity decline and ocular surface disorders in a mouse model of UVB-induced photokeratitis. Mice were divided into 4 groups (10 mice per group): (1) a blank control group (no exposure to UV radiation), (2) a UVB/no lens group (mice exposed to UVB rays, but without lens protection), (3) a UVB/UV400 group (mice exposed to UVB rays and protected using the CR-39™ spectacle lens [UV400 coating]), and (4) a UVB/photochromic group (mice exposed to UVB rays and protected using the CR-39™ spectacle lens [photochromic coating]). We investigated UVB-induced changes in visual acuity and in corneal smoothness, opacity, and lissamine green staining. We also evaluated the correlation between visual acuity decline and changes to the corneal surface parameters. Tissue sections were prepared and stained immunohistochemically to evaluate the structural integrity of the cornea and conjunctiva. In blank controls, the cornea remained undamaged, whereas in UVB-exposed mice, the corneal surface was disrupted; this disruption significantly correlated with a concomitant decline in visual acuity. Both the UVB/UV400 and UVB/photochromic groups had sharper visual acuity and a healthier corneal surface than the UVB/no lens group. Eyes in both protected groups also showed better corneal and conjunctival structural integrity than unprotected eyes. Furthermore, there were fewer apoptotic cells and less polymorphonuclear leukocyte infiltration in corneas protected by the spectacle lenses. The model established herein reliably determines the protective effect of UV-blocking ophthalmic biomaterials, because the in vivo protection against UV-induced ocular damage and visual acuity decline was easily defined.

  10. Visual performance after the implantation of a new trifocal intraocular lens

    PubMed Central

    Vryghem, Jérôme C; Heireman, Steven

    2013-01-01

    Purpose To evaluate the subjective and objective visual results after the implantation of a new trifocal diffractive intraocular lens. Methods A new trifocal diffractive intraocular lens was designed combining two superimposed diffractive profiles: one with +1.75 diopters (D) addition for intermediate vision and the other with +3.50 D addition for near vision. Fifty eyes of 25 patients that were operated on by one surgeon are included in this study. The uncorrected and best distance-corrected monocular and binocular, near, intermediate, and distance visual acuities, contrast sensitivity, and defocus curves were measured 6 months postoperatively. In addition to the standard clinical follow-up, a questionnaire evaluating individual satisfaction and quality of life was submitted to the patients. Results The mean age of patients at the time of surgery was 70 ± 10 years. The mean uncorrected and corrected monocular distance visual acuity (VA) were LogMAR 0.06 ± 0.10 and LogMAR 0.00 ± 0.08, respectively. The outcomes for the binocular uncorrected distance visual acuity were almost the same (LogMAR −0.04 ± 0.09). LogMAR −010 ± 0.15 and 0.02 ± 0.06 were measured for the binocular uncorrected intermediate and near VA, respectively. The distance-corrected visual acuity was maintained in mesopic conditions. The contrast sensitivity was similar to that obtained after implantation of a bifocal intraocular lens and did not decrease in mesopic conditions. The binocular defocus curve confirms good VA even in the intermediate distance range, with a moderate decrease of less than LogMAR 0.2 at −1.5 D, with respect to the best distance VA at 0 D defocus. Patient satisfaction was high. No discrepancy between the objective and subjective outcomes was evidenced. Conclusion The introduction of a third focus in diffractive multifocal intraocular lenses improves the intermediate vision with minimal visual discomfort for the patient. PMID:24124348

  11. Clinical profile and aetiology of optic neuritis in Hospital Universiti Sains Malaysia--5 years review.

    PubMed

    Ismail, Shatriah; Wan Hazabbah, Wan Hitam; Muhd-Nor, Nor-Idahriani; Daud, Jakiyah; Embong, Zunaina

    2012-04-01

    Although few studies concerning optic neuritis (ON) in Asian countries have been reported, there is no report about ON in Malaysia particularly within the Malay population. We aimed to determine the clinical manifestation, visual outcome and aetiology of ON in Malays, and discussed the literature of ON studies in other Asian populations. This was a retrospective study involving 31 consecutive patients (41 eyes) with ON treated at Hospital Universiti Sains Malaysia commencing from July 2005 till January 2010 with a period of follow-up ranging from 18-60 months. The clinical features, laboratory results, possible aetiology, and visual acuity after one year were analysed. Females were the predominant group. The age of the patients ranged between 3-55 years and peaked between 21-30 years old. 67.7% of the patients had unilateral involvement. Pain on ocular movement was observed in 31.7% of the affected eyes. 73.3% of 41 involved eyes showed visual acuity equal 6/60 or worse on presentation. Paracentral scotoma was the most common visual field defect noted. Optic disc papillitis proved more widespread compared to the retrobulbar type of ON. The aetiology was idiopathic in more than 50%, while the risk of multiple sclerosis was extremely low (3.2%) in our series. 66.0% demonstrating visual acuity improved to 6/12 or better at one year after the attack. 16.1% showed evidence of recurrence during follow-up. In conclusion, the clinical profile and aetiology of ON in Malay patients are comparable to other ON studies reported by other Asian countries.

  12. Stereopsis and positional acuity under dark adaptation.

    PubMed

    Livingstone, M S; Hubel, D H

    1994-03-01

    Though experience tells us we can perceive depth in dim light, it is not so obvious that one of the chief mechanisms for depth perception, stereopsis, is possible under scotopic conditions. The only studies on human stereopsis in the dark adapted state seem to be those of Nagel [(1902) Zeitschrift für Psychologie, 27, 264-266] and Mueller and Lloyd [(1948) Proceedings of the National Academy of Science, U.S.A., 34, 223-227], both of which used real objects or line stereograms. We tested stereopsis using both random-dot and line stereograms and, in agreement with these studies, found that stereopsis is indeed possible in dark adaptation. We also measured stereo acuity and positional acuity (both of which are examples of hyperacuity) and compared these with grating acuity at several levels of light and dark adaptation. At all illumination levels tested, acuities for stereopsis and relative line position were both higher than for grating acuity. As light levels decreased, positional and grating acuity declined in parallel fashion, whereas stereoacuity declined more steeply.

  13. Visual impairment due to retinopathy of prematurity (ROP) in New Zealand: a 22-year review.

    PubMed

    Tan, Zachary; Chong, CheeFoong; Darlow, Brian; Dai, Shuan

    2015-06-01

    To evaluate retinopathy of prematurity (ROP)-related visual impairment in New Zealand children. 22-year retrospective review of medical records of children with moderate to severe visual impairment registered with the Blind and Low Vision Education Network New Zealand. The cohort was divided into two periods (1991-2004; 2005-2012) for analysis. 232 children with ROP were treated in the study period (109 in period 1, 123 in period 2). 36 children, 63.9% of whom were of male sex, were identified with subsequent significant visual impairment (27 in period 1, 9 in period 2). The incidence of new cases of visual impairment from ROP declined from 271.6 infants/100 000 live very preterm births per annum (period 1) to 146.1 per annum (period 2). Mean gestational age and mean birth weight were comparable between the two study periods. 75% of children with visual impairment from ROP received treatment for their condition (period 1, 74.1%; period 2, 77.8%) and modalities used changed significantly over time. The modal visual outcome overall was Snellen visual acuity <6/18-6/60 (55.6%) (period 1, 51.9%; period 2, 66.7%). The proportion of children with no light perception bilaterally decreased over time (period 1, 3.7%; period 2, 0%). There has been a reduction in the incidence of infants with significant visual impairment from ROP over time in New Zealand, likely due to progress in clinical management of ROP. Our study suggests the current ROP screening criteria of <31 weeks' gestation or <1250 g are of sufficient breadth. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Visual outcome of cataract surgery; study from the European Registry of Quality Outcomes for Cataract and Refractive Surgery.

    PubMed

    Lundström, Mats; Barry, Peter; Henry, Ype; Rosen, Paul; Stenevi, Ulf

    2013-05-01

    To analyze the visual outcome after cataract surgery. Cataract surgery clinics in 15 European countries. Database study. Data were drawn from case series of cataract extractions reported to the European Registry of Quality Outcomes for Cataract and Refractive Surgery database. These data were entered into the database via the Web by surgeons or by transfer from existing national registries or electronic medical record systems. The database contains individual anonymous data on preoperative, intraoperative, and postoperative measurements. Data on 368,256 cataract extractions were available for analysis. The best visual outcome was achieved in age groups 40 to 74 years, and men showed a higher percentage of excellent vision (1.0 [20/20] or better) than women. A corrected distance visual acuity (CDVA) of 0.5 (20/40) or better and of 1.0 (20/20) or better was achieved in 94.3% and 61.3% of cases, respectively. Ocular comorbidity and postoperative complications were the strongest influences on the visual outcome; however, surgical complications and ocular changes requiring complex surgery also had a negative influence. Deterioration of visual acuity after the surgery (n= 6112 [1.7% of all cases]) was most common in patients with a good preoperative visual acuity. The visual outcomes of cataract surgery were excellent, with 61.3% of patients achieving a corrected distance visual acuity of 1.0 (20/20) or better. Age and sex influenced the visual outcomes, but the greatest influences were short-term postoperative complications, ocular comorbidity, surgical complications, and complex surgery. A weakness of the study could be that some of the data is self-reported to the registry. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  15. Visual Outcomes of Macular Hole Surgery.

    PubMed

    Khaqan, Hussain Ahmad; Lubna; Jameel, Farrukh; Muhammad

    2016-10-01

    To determine the mean visual improvement after internal limiting membrane (ILM) peeling assisted with brilliant blue staining of ILM in macular hole, and stratify the mean visual improvement in different stages of macular hole. Quasi-experimental study. Eye outpatient department (OPD), Lahore General Hospital, Lahore from October 2013 to December 2014. Patients with macular hole underwent measurement of best corrected visual acuity (BCVA) and fundus examination with indirect slit lamp biomicroscopy before surgery. The diagnosis of all patients was confirmed on optical coherence tomography. All patients had 23G trans-conjunctival three ports pars plana vitrectomy, ILM peeling, and endotamponade of SF6. The mean visual improvement of different stages of macular hole was noted. Paired t-test was applied. There were 30 patients, 15 males and 15 females (50%). The mean age was 62 ±10.95 years. They presented with low mean preoperative visual acuity (VA) of 0.96 ±0.11 logMar. The mean postoperative VAwas 0.63 ±0.24 logMar. The mean visual increase was 0.33 ±0.22 logMar (p < 0.001). In patients with stage 2 macular hole, mean visual increase was 0.35 ±0.20 logMar (p < 0.001). In patients with stage 3 macular hole, mean visual increase was 0.44 ±0.21 logMar (p < 0.001), and in patients with stage 4 macular hole it was 0.13 ± 0.1 logMar (p = 0.004). ILM peeling assisted with brilliant blue is a promising surgery for those patients who have decreased vision due to macular hole, in 2 - 4 stages of macular hole.

  16. Effect of microgravity on several visual functions during STS shuttle missions

    NASA Technical Reports Server (NTRS)

    Oneal, Melvin R.; Task, H. Lee; Genco, Louis V.

    1992-01-01

    Changes in the acuity of astronaut vision during flight are discussed. Parameters such as critical flicker vision, stereopsis to 10 seconds of arc, visual acuity in small steps to 20/7.7, cyclophoria, lateral and vertical phoria and retinal rivalry were tested using a visual function tester. Twenty-three Space Transportation System (STS) astronauts participated in the experiments. Their vision was assessed twice before launch and after landing, and three to four times while on-orbit and landing. No significant differences during space flight were observed for any of the visual parameters tested. In some cases, slight changes in acuity and stereopsis were observed with a subsequent return to normal vision after flight.

  17. Global motion perception is related to motor function in 4.5-year-old children born at risk of abnormal development

    PubMed Central

    Chakraborty, Arijit; Anstice, Nicola S.; Jacobs, Robert J.; Paudel, Nabin; LaGasse, Linda L.; Lester, Barry M.; McKinlay, Christopher J. D.; Harding, Jane E.; Wouldes, Trecia A.; Thompson, Benjamin

    2017-01-01

    Global motion perception is often used as an index of dorsal visual stream function in neurodevelopmental studies. However, the relationship between global motion perception and visuomotor control, a primary function of the dorsal stream, is unclear. We measured global motion perception (motion coherence threshold; MCT) and performance on standardized measures of motor function in 606 4.5-year-old children born at risk of abnormal neurodevelopment. Visual acuity, stereoacuity and verbal IQ were also assessed. After adjustment for verbal IQ or both visual acuity and stereoacuity, MCT was modestly, but significantly, associated with all components of motor function with the exception of gross motor scores. In a separate analysis, stereoacuity, but not visual acuity, was significantly associated with both gross and fine motor scores. These results indicate that the development of motion perception and stereoacuity are associated with motor function in pre-school children. PMID:28435122

  18. Combined hydrogel inlay and laser in situ keratomileusis to compensate for presbyopia in hyperopic patients: one-year safety and efficacy.

    PubMed

    Chayet, Arturo; Barragan Garza, Enrique

    2013-11-01

    To perform a feasibility study of the safety and efficacy of a corneal-contouring inlay with concurrent laser in situ keratomileusis (LASIK) to treat hyperopic presbyopia. Private clinic, Tijuana, Mexico. Prospective interventional case series. Hyperopic patients received LASIK in both eyes and a corneal inlay under the femtosecond laser flap in the nondominant eye. The inlay is designed to reshape the anterior corneal curvature, creating a near-center multifocal refractive effect. Main safety outcomes were retention of preoperative corrected distance and near visual acuities and reports of adverse events. Efficacy was determined through measurements of near, intermediate, and distance visual acuities and patient questionnaires on visual task ability and satisfaction. The study enrolled 16 patients. All eyes with an inlay achieved an uncorrected near visual acuity (UNVA) of 20/32 or better by the 1-week postoperative examination and at every visit thereafter. The mean monocular and binocular UNVA was 20/27 or better at all visits. The mean binocular uncorrected distance visual acuity improved significantly from 20/53 preoperatively to 20/19 postoperatively (P<10(-5)). One inlay was explanted during the study. At 1 year, all 14 patients analyzed were satisfied or very satisfied with their near, distance, and overall vision. The hydrogel corneal inlay with concurrent LASIK improved uncorrected near, intermediate, and distance visual acuity in hyperopic presbyopic patients with high patient satisfaction and visual task ability. This represents a new indication for this recently developed technology. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. Irregular Corneas: Improve Visual Function With Scleral Contact Lenses.

    PubMed

    de Luis Eguileor, Beatriz; Etxebarria Ecenarro, Jaime; Santamaria Carro, Alaitz; Feijoo Lera, Raquel

    2018-05-01

    To assess visual function in patients with irregular cornea who do not tolerate gas permeable (GP) corneal contact lenses and are fitted with GP scleral contact lenses (Rose K2 XL). In this prospective study, we analyzed 15 eyes of 15 patients who did not tolerate GP corneal contact lenses and were fitted with scleral contact lenses (Rose K2 XL). We assessed visual function using visual acuity and the visual function index (VF-14); we used the VF-14 as an indicator of patient satisfaction. The measurements were taken with the optical correction used before and 1 month after the fitting of the Rose K2 XL contact lenses. We also recorded the number of hours lenses had been worn over the first month. Using Rose K2 XL contact lenses, visual acuity was 0.06±0.07 logMAR. In all cases, visual acuity had improved compared with the measurement before fitting the lenses (0.31±0.18 logMAR; P=0.001). VF-14 scores were 72.74±12.38 before fitting of the scleral lenses, and 89.31±10.87 after 1 month of lens use (P=0.003). Patients used these scleral lenses for 9.33±2.99 comfortable hours of wear. Both visual acuity and VF-14 may improve after fitting Rose K2 XL contact lenses in patients with irregular corneas. In addition, in our patients, these lenses can be worn for a longer period than GP corneal contact lenses.

  20. Age-Related Eye Diseases and Visual Impairment Among U.S. Adults

    PubMed Central

    Chou, Chiu-Fang; Cotch, Mary Frances; Vitale, Susan; Zhang, Xinzhi; Klein, Ronald; Friedman, David S.; Klein, Barbara E.K.; Saaddine, Jinan B.

    2014-01-01

    Background Visual impairment is a common health-related disability in the U.S. The association between clinical measurements of age-related eye diseases and visual impairment in data from a national survey has not been reported. Purpose To examine common eye conditions and other correlates associated with visual impairment in the U.S. Methods Data from the 2005–2008 National Health and Nutrition Examination Survey of 5222 Americans aged ≥40 years were analyzed in 2012 for visual impairment (presenting distance visual acuity worse than 20/40 in the better-seeing eye), and visual impairment not due to refractive error (distance visual acuity worse than 20/40 after refraction). Diabetic retinopathy (DR) and age-related macular degeneration (AMD) were assessed from retinal fundus images; glaucoma was assessed from two successive frequency-doubling tests and a cup-to-disc ratio measurement. Results Prevalence of visual impairment and of visual impairment not due to refractive error was 7.5% (95% CI=6.9%, 8.1%) and 2.0% (1.7%, 2.3%), respectively. The prevalence of visual impairment not due to refractive error was significantly higher among people with AMD (2.2%) compared to those without AMD (0.8%), or with DR (3.5%) compared to those without DR (1.2%). Independent predictive factors of visual impairment not due to refractive error were AMD (OR=4.52, 95% CI=2.50, 8.17); increasing age (OR=1.09 per year, 95% CI=1.06, 1.13); and less than a high school education (OR=2.99, 95% CI=1.18, 7.55). Conclusions Visual impairment is a public health problem in the U.S. Visual impairment in two thirds of adults could be eliminated with refractive correction. Screening of the older population may identify adults at increased risk of visual impairment due to eye diseases. PMID:23790986

  1. The Impact of Change in Visual Field on Health-Related Quality of Life: The Los Angeles Latino Eye Study

    PubMed Central

    Patino, Cecilia M.; Varma, Rohit; Azen, Stanley P.; Conti, David V.; Nichol, Michael B.; McKean-Cowdin, Roberta

    2010-01-01

    Purpose To assess the impact of change in visual field (VF) on change in health related quality of life (HRQoL) at the population level. Design Prospective cohort study Participants 3,175 Los Angles Latino Eye Study (LALES) participants Methods Objective measures of VF and visual acuity and self-reported HRQoL were collected at baseline and 4-year follow-up. Analysis of covariance was used to evaluate mean differences in change of HRQoL across severity levels of change in VF and to test for effect modification by covariates. Main outcome measures General and vision-specific HRQoL. Results Of 3,175 participants, 1430 (46%) showed a change in VF (≥1 decibel [dB]) and 1651, 1715 (54%) reported a clinically important change (≥5 points) in vision-specific HRQoL. Progressive worsening and improvement in the VF were associated with increasing losses and gains in vision-specific HRQoL for the composite score and 10 of its 11 subscales (all Ptrends<0.05). Losses in VF > 5 dB and gains > 3 dB were associated with clinically meaningful losses and gains in vision-specific HRQoL, respectively. Areas of vision-specific HRQoL most affected by greater losses in VF were driving, dependency, role-functioning, and mental health. The effect of change in VF (loss or gain) on mean change in vision-specific HRQoL varied by level of baseline vision loss (in visual field and/or visual acuity) and by change in visual acuity (all P-interactions<0.05). Those with moderate/severe VF loss at baseline and with a > 5 dB loss in visual field during the study period had a mean loss of vision-specific HRQoL of 11.3 points, while those with no VF loss at baseline had a mean loss of 0.97 points Similarly, with a > 5 dB loss in VF and baseline visual acuity impairment (mild/severe) there was a loss in vision-specific HRQoL of 10.5 points, whereas with no visual acuity impairment at baseline there was a loss of vision-specific HRQoL of 3.7 points. Conclusion Both losses and gains in VF produce

  2. Five-year follow-up of low-level laser therapy (LLLT) in patients with age-related macular degeneration (AMD)

    NASA Astrophysics Data System (ADS)

    Koev, K.; Avramov, L.; Borissova, E.

    2018-03-01

    The objective of this study was to examine long-term effects of low-level laser therapy (LLLT) in patients with age-related macular degeneration (AMD). The research was implemented for a period of five years. For LLLT, a He-Ne Laser with continuous emission at 633 nm (0.1 mW/cm2) was used in patients with AMD of all stages (dry to wet exudative forms were included). In total, 33 patients (16 men and 17 women – 66 eyes) with AMD of various stages and a mean age of 68.7 ± 4.2 years were included in the study. Progressive, exudative AMD was diagnosed in 8 eyes. 58 eyes had drusen or were depigmented. Laser radiation was applied transpupillary to the macula for six times for three minutes once in two days; 22 patients with AMD (44 eyes) were randomly selected to receive mock treatment (control group 10 men and 12 women with a mean age of 69.3 ± 4.8 years). The visual acuity was followed for a five-year period. The perimetry and Amsler test were used to screen central scotomas. The fluorescein angiography of AMD and the control groups was examined. The visual acuity remained unchanged in all patients in the control group. There was a statistically significant increase in the visual acuity (p<0.001, end of study versus baseline) for AMD patients for the period of five years after the treatment. The edema and hemorrhage in the patients with progressive, exudative AMD significantly decreased. No side effects were observed during the therapy. The prevalence of metamorphopsia, scotoma in AMD group was reduced. In conclusion, this study shows that LLLT may be a novel long-lasting therapeutic option for both forms of AMD. It is a highly-effective treatment that results in a long-term improvement of the visual acuity.

  3. The Tribal Odisha Eye Disease Study (TOES) 1: prevalence and causes of visual impairment among tribal children in an urban school in Eastern India.

    PubMed

    Warkad, Vivekanand U; Panda, Lapam; Behera, Pradeep; Das, Taraprasad; Mohanta, Bikash C; Khanna, Rohit

    2018-04-01

    To estimate the prevalence and causes of visual impairment and other ocular comorbidities among tribal children in an urban school population in eastern India. In this cross-sectional study, vision screening tests were administered to tribal school children. Demographic data, including name, age, sex, home district, height, and weight of each child, and examination data, including unaided and pinhole visual acuity, external eye examination with a flashlight, slit-lamp examination, intraocular pressure (IOP) measurement, and undilated fundus photography, were collected. Children with visual acuity of less than 20/20, abnormal anterior or posterior segment findings, and IOP of >21 mm Hg were referred for further evaluation. Of 10,038 children (5,840 males [58.2%]) screened, 335 (median age, 9 years; range, 6-17 years) were referred. Refractive error was the most common cause of visual impairment (59.52%; 95% CI, 51.97-66.65) followed by amblyopia (17.2%; 95% CI, 12.3-23.6) and posterior segment anomaly (14.88%; 95% CI, 10.2-21.0). The prevalence of best-corrected visual acuity of 20/40 was 0.13%. The prevalence of blindness was 0.03%. Visual impairment among tribal children in this residential school is an uncommon but important disability. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  4. Comparison of the visual and intraocular optical performance of a refractive multifocal IOL with rotational asymmetry and an apodized diffractive multifocal IOL.

    PubMed

    Alió, Jorge L; Plaza-Puche, Ana B; Javaloy, Jaime; Ayala, María José

    2012-02-01

    To compare the visual outcomes and intraocular optical quality observed postoperatively in patients implanted with a rotationally asymmetric multifocal intraocular lens (IOL) and an apodized diffractive multifocal IOL. Seventy-four consecutive eyes of 40 cataract patients (age range: 36 to 79 years) were divided into two groups: zonal refractive group, 39 eyes implanted with a rotationally asymmetric multifocal IOL (Lentis Mplus LS-312 IOL, Oculentis GmbH); and diffractive group, 35 eyes implanted with an apodized diffractive multifocal IOL (ReSTOR SN6AD3, Alcon Laboratories Inc). Distance and near visual acuity outcomes, contrast sensitivity, intraocular optical quality, and defocus curves were evaluated during 3-month follow-up. Calculation of the intraocular aberrations was performed by subtracting corneal aberrations from total ocular aberrations. Uncorrected near visual acuity and distance-corrected near visual acuity were better in the diffractive group than in the zonal refractive group (P=.01), whereas intermediate visual acuity (defocus +1.00 and +1.50 diopters) was better in the zonal refractive group. Photopic contrast sensitivity was significantly better in the zonal refractive group (P=.04). Wavefront aberrations (total, higher order, tilt, primary coma) were significantly higher in the zonal refractive group than in the diffractive group (P=.02). Both multifocal IOLs are able to successfully restore visual function after cataract surgery. The zonal refractive multifocal IOL provides better results in contrast sensitivity and intermediate vision, whereas the diffractive multifocal IOL provides better near vision at a closer distance. Copyright 2012, SLACK Incorporated.

  5. Patterned light flash evoked short latency activity in the visual system of visually normal and in amblyopic subjects.

    PubMed

    Sjöström, A; Abrahamsson, M

    1994-04-01

    In a previous experimental study on anaesthetized cat it was shown that a short latency (35-40 ms) cortical potential changed polarity due to the presence or absence of a pattern in the flash stimulus. The results suggested one pathway of neuronal activation in the cortex to a pattern that was within the level of resolution and another to patterns that were not. It was implied that a similar difference in impulse transmission to pattern and non-pattern stimuli may be recorded in humans. The present paper describes recordings of the short-latency visual evoked response to varying light flash checkerboard pattern stimuli of high intensity in visually normal and amblyopic children and adults. When stimulating the normal eye a visual evoked response potential with a peak latency between 35 to 40 ms showed a polarity change to patterned compared to non-patterned stimulation. The visual evoked response resolution limit could be correlated to a visual acuity of 0.5 and below. In amblyopic eyes the shift in polarity was recorded at the acuity limit level. The latency of the pattern depending potential was increased in patients with amblyopia compared to normal, but not directly related to amblyopic degree. It is concluded that the short latency, visual evoked response that mainly represents the retino-geniculo-cortical activation may be used to estimate visual resolution below 0.5 in acuity level.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Temporal Evolution and Dose-Volume Histogram Predictors of Visual Acuity After Proton Beam Radiation Therapy of Uveal Melanoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Polishchuk, Alexei L.; Mishra, Kavita K., E-mail: Kavita.Mishra@ucsf.edu; Weinberg, Vivian

    2017-01-01

    Purpose: To perform an in-depth temporal analysis of visual acuity (VA) outcomes after proton beam radiation therapy (PBRT) in a large, uniformly treated cohort of uveal melanoma (UM) patients, to determine trends in VA evolution depending on pretreatment and temporally defined posttreatment VA measurements; and to investigate the relevance of specific patient, tumor and dose-volume parameters to posttreatment vision loss. Methods and Materials: Uveal melanoma patients receiving PBRT were identified from a prospectively maintained database. Included patients (n=645) received 56 GyE in 4 fractions, had pretreatment best corrected VA (BCVA) in the affected eye of count fingers (CF) or better, withmore » posttreatment VA assessment at specified post-PBRT time point(s). Patients were grouped according to the pretreatment BCVA into favorable (≥20/40) or unfavorable (20/50-20/400) and poor (CF) strata. Temporal analysis of BCVA changes was described, and univariate and forward stepwise multivariate logistic regression analyses were performed to identify predictors for VA loss. Results: Median VA follow-up was 53 months (range, 3-213 months). At 60-month follow up, among evaluable treated eyes with favorable pretreatment BCVA, 45% retained BCVA ≥20/40, whereas among evaluable treated eyes with initially unfavorable/poor BCVA, 21% had vision ≥20/100. Among those with a favorable initial BCVA, attaining BCVA of ≥20/40 at any posttreatment time point was associated with subsequent maintenance of excellent BCVA. Multivariate analysis identified volume of the macula receiving 28GyE (P<.0001) and optic nerve (P=.0004) as independent dose-volume histogram predictors of 48-month post-PBRT vision loss among initially favorable treated eyes. Conclusions: Approximately half of PBRT-treated UM eyes with excellent pretreatment BCVA assessed at 5 years after treatment will retain excellent long-term vision. 28GyE macula and optic nerve dose-volume histogram parameters

  7. Improvement of uncorrected visual acuity and contrast sensitivity with perceptual learning and transcranial random noise stimulation in individuals with mild myopia

    PubMed Central

    Camilleri, Rebecca; Pavan, Andrea; Ghin, Filippo; Battaglini, Luca; Campana, Gianluca

    2014-01-01

    Perceptual learning has been shown to produce an improvement of visual acuity (VA) and contrast sensitivity (CS) both in subjects with amblyopia and refractive defects such as myopia or presbyopia. Transcranial random noise stimulation (tRNS) has proven to be efficacious in accelerating neural plasticity and boosting perceptual learning in healthy participants. In this study, we investigated whether a short behavioral training regime using a contrast detection task combined with online tRNS was as effective in improving visual functions in participants with mild myopia compared to a 2-month behavioral training regime without tRNS (Camilleri et al., 2014). After 2 weeks of perceptual training in combination with tRNS, participants showed an improvement of 0.15 LogMAR in uncorrected VA (UCVA) that was comparable with that obtained after 8 weeks of training with no tRNS, and an improvement in uncorrected CS (UCCS) at various spatial frequencies (whereas no UCCS improvement was seen after 8 weeks of training with no tRNS). On the other hand, a control group that trained for 2 weeks without stimulation did not show any significant UCVA or UCCS improvement. These results suggest that the combination of behavioral and neuromodulatory techniques can be fast and efficacious in improving sight in individuals with mild myopia. PMID:25400610

  8. A 14-year-old girl who regained normal vision after bilateral visual impairment following hot water injury to the eyes.

    PubMed

    Monsudi, Kehinde F; Ayanniyi, Abdulkabir A

    2011-04-01

    A 14-year-old girl presented with bilateral visual impairment following hot water injury to the eyes. The patient was admitted for a week and managed with guttae tropicamide 0.5% 8 h, diclofenac sodium 0.1% 4 h, and fluoroquinolone 0.3% 6 h and ointment chloramphenicol 8 h. Also, the patient was managed with capsule doxycycline 100 mg 12 h for 10 days, tablet cataflam 50 mg 12 h for 7 days and intramuscular tetanus toxoid 0.5 mg stat and dermacine cream for facial scald. The visual acuities improved from 3/60 (right eye) and 6/24 (left eye) to 6/6 in both eyes. There were resolutions of facial/eye pain, tearing, photophobia, lid edema, blepharospasm, and conjunctival hyperemia. There was complete healing of facial wounds and corneal ulcers. She was discharged from hospital on the 7th day of admission. Prompt presentation, degree of scald sustained, and appropriate medical intervention enhanced visual recovery and wound healing in the patient.

  9. Contributions of Optical and Non-Optical Blur to Variation in Visual Acuity

    PubMed Central

    McAnany, J. Jason; Shahidi, Mahnaz; Applegate, Raymond A.; Zelkha, Ruth; Alexander, Kenneth R.

    2011-01-01

    Purpose To determine the relative contributions of optical and non-optical sources of intrinsic blur to variations in visual acuity (VA) among normally sighted subjects. Methods Best-corrected VA of sixteen normally sighted subjects was measured using briefly presented (59 ms) tumbling E optotypes that were either unblurred or blurred through convolution with Gaussian functions of different widths. A standard model of intrinsic blur was used to estimate each subject’s equivalent intrinsic blur (σint) and VA for the unblurred tumbling E (MAR0). For 14 subjects, a radially averaged optical point spread function due to higher-order aberrations was derived by Shack-Hartmann aberrometry and fit with a Gaussian function. The standard deviation of the best-fit Gaussian function defined optical blur (σopt). An index of non-optical blur (η) was defined as: 1-σopt/σint. A control experiment was conducted on 5 subjects to evaluate the effect of stimulus duration on MAR0 and σint. Results Log MAR0 for the briefly presented E was correlated significantly with log σint (r = 0.95, p < 0.01), consistent with previous work. However, log MAR0 was not correlated significantly with log σopt (r = 0.46, p = 0.11). For subjects with log MAR0 equivalent to approximately 20/20 or better, log MAR0 was independent of log η, whereas for subjects with larger log MAR0 values, log MAR0 was proportional to log η. The control experiment showed a statistically significant effect of stimulus duration on log MAR0 (p < 0.01) but a non-significant effect on σint (p = 0.13). Conclusions The relative contributions of optical and non-optical blur to VA varied among the subjects, and were related to the subject’s VA. Evaluating optical and non-optical blur may be useful for predicting changes in VA following procedures that improve the optics of the eye in patients with both optical and non-optical sources of VA loss. PMID:21460756

  10. Relationship between umami taste acuity with sweet or bitter taste acuity and food selection in Japanese women university students.

    PubMed

    Kubota, Masaru; Toda, Chikako; Nagai-Moriyama, Ayako

    2018-01-01

    Although there are many studies on the umami receptor and its signaling pathway, literature on the effect of umami taste acuity on dietary choices in healthy subjects is limited. The current study aims to clarify the relationship between umami taste acuity with sweet or bitter taste acuity, food preference and intake. Forty-two healthy Japanese female university students were enrolled. The acuity for umami, sweet, and bitter tastes was evaluated using the filter-paper disc method. The study population was divided into 32 umami normal tasters and 10 hypo-tasters based on the taste acuity at the posterior part of the tongue using monosodium glutamate. Umami hypo-tasters exhibited a significantly lower sensitivity to sweet tastes than normal tasters. However, the sensitivity to bitter taste was comparable between the two groups. Food preference was examined by the food preference checklist consisted of 81 food items. Among them, umami tasters preferred shellfish, tomato, carrot, milk, low fat milk, cheese, dried shiitake, and kombu significantly more than umami hypo-tasters did. A self-reported food frequency questionnaire revealed no significant differences in the intake of calories and three macronutrients between the two groups; however, umami tasters were found to eat more seaweeds and less sugar than umami hypo-tasters. These data together may indicate the possibility that umami taste acuity has an effect on a dietary life. Therefore, training umami taste acuity from early childhood is important for a healthy diet later in life.

  11. Sociodemographic, lifestyle, and medical risk factors for visual impairment in an urban asian population: the singapore malay eye study.

    PubMed

    Chong, Elaine W; Lamoureux, Ecosse L; Jenkins, Mark A; Aung, Tin; Saw, Seang-Mei; Wong, Tien Y

    2009-12-01

    To describe the associations between sociodemographic, lifestyle, and medical risk factors and visual impairment in a Southeast Asian population. Population-based cross-sectional study of 3280 (78.7% response rate) Malay Singaporeans aged 40 to 80 years. Participants underwent a standardized interview, in which detailed sociodemographic histories were obtained, and clinical assessments for presenting and best-corrected visual acuity. Visual impairment (logMAR > 0.30) was classified as unilateral (1 eye impaired) or bilateral (both eyes impaired). Analyses used multivariate-adjusted multinomial logistic regression. Older age and lack of formal education was associated with increased odds of both unilateral and bilateral visual impairment based on presenting and best-corrected visual acuity. The odds doubled for each decade older, and lower education increased the odds 1.59- to 2.83-fold. Bilateral visual impairment was associated with being unemployed (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.30-2.60), widowed status (OR, 1.51; 95% CI, 1.13-2.01), and higher systolic blood pressure (OR, 1.96; 95% CI, 1.44-2.66). Diabetes was associated with unilateral (OR, 1.47; 95% CI, 1.10-1.95) and bilateral (OR, 1.69; 95% CI, 1.23-2.32) visual impairment using best-corrected visual acuity. Older age, lower education, unemployment, being widowed, diabetes, and hypertension were independently associated with bilateral visual impairment. Public health interventions should be targeted to these at-risk populations.

  12. Global motion perception is related to motor function in 4.5-year-old children born at risk of abnormal development.

    PubMed

    Chakraborty, Arijit; Anstice, Nicola S; Jacobs, Robert J; Paudel, Nabin; LaGasse, Linda L; Lester, Barry M; McKinlay, Christopher J D; Harding, Jane E; Wouldes, Trecia A; Thompson, Benjamin

    2017-06-01

    Global motion perception is often used as an index of dorsal visual stream function in neurodevelopmental studies. However, the relationship between global motion perception and visuomotor control, a primary function of the dorsal stream, is unclear. We measured global motion perception (motion coherence threshold; MCT) and performance on standardized measures of motor function in 606 4.5-year-old children born at risk of abnormal neurodevelopment. Visual acuity, stereoacuity and verbal IQ were also assessed. After adjustment for verbal IQ or both visual acuity and stereoacuity, MCT was modestly, but significantly, associated with all components of motor function with the exception of fine motor scores. In a separate analysis, stereoacuity, but not visual acuity, was significantly associated with both gross and fine motor scores. These results indicate that the development of motion perception and stereoacuity are associated with motor function in pre-school children. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Baseline predictors for one-year visual outcomes with ranibizumab or bevacizumab for neovascular age-related macular degeneration.

    PubMed

    Ying, Gui-shuang; Huang, Jiayan; Maguire, Maureen G; Jaffe, Glenn J; Grunwald, Juan E; Toth, Cynthia; Daniel, Ebenezer; Klein, Michael; Pieramici, Dante; Wells, John; Martin, Daniel F

    2013-01-01

    To determine the baseline predictors of visual acuity (VA) outcomes 1 year after treatment with ranibizumab or bevacizumab for neovascular age-related macular degeneration (AMD). Cohort study within the Comparison of Age-related Macular Degeneration Treatments Trials (CATT). A total of 1105 participants with neovascular AMD, baseline VA 20/25 to 20/320, and VA measured at 1 year. Participants were randomly assigned to ranibizumab or bevacizumab on a monthly or as-needed schedule. Masked readers evaluated fundus morphology and features on optical coherence tomography (OCT). Visual acuity was measured using electronic VA testing. Independent predictors were identified using regression techniques. The VA score, VA score change from baseline, and ≥3-line gain at 1 year. At 1 year, the mean VA score was 68 letters, mean improvement from baseline was 7 letters, and 28% of participants gained ≥3 lines. Older age, larger area of choroidal neovascularization (CNV), and elevation of retinal pigment epithelium (RPE) were associated with worse VA (all P<0.005), less gain in VA (all P<0.02), and a lower proportion gaining ≥3 lines (all P<0.04). Better baseline VA was associated with better VA at 1 year, less gain in VA, and a lower proportion gaining ≥3 lines (all P<0.0001). Predominantly or minimally classic lesions were associated with worse VA than occult lesions (66 vs. 69 letters; P=0.0003). Retinal angiomatous proliferans (RAP) lesions were associated with more gain in VA (10 vs. 7 letters; P=0.03) and a higher proportion gaining ≥3 lines (odds ratio, 1.9; 95% confidence interval, 1.2-3.1). Geographic atrophy (GA) was associated with worse VA (64 vs. 68 letters; P=0.02). Eyes with total foveal thickness in the second quartile (325-425 μm) had the best VA (P=0.01) and were most likely to gain ≥3 lines (P=0.004). Predictors did not vary by treatment group. For all treatment groups, older age, better baseline VA, larger CNV area, predominantly or minimally

  14. Perceptual learning improves visual performance in juvenile amblyopia.

    PubMed

    Li, Roger W; Young, Karen G; Hoenig, Pia; Levi, Dennis M

    2005-09-01

    To determine whether practicing a position-discrimination task improves visual performance in children with amblyopia and to determine the mechanism(s) of improvement. Five children (age range, 7-10 years) with amblyopia practiced a positional acuity task in which they had to judge which of three pairs of lines was misaligned. Positional noise was produced by distributing the individual patches of each line segment according to a Gaussian probability function. Observers were trained at three noise levels (including 0), with each observer performing between 3000 and 4000 responses in 7 to 10 sessions. Trial-by-trial feedback was provided. Four of the five observers showed significant improvement in positional acuity. In those four observers, on average, positional acuity with no noise improved by approximately 32% and with high noise by approximately 26%. A position-averaging model was used to parse the improvement into an increase in efficiency or a decrease in equivalent input noise. Two observers showed increased efficiency (51% and 117% improvements) with no significant change in equivalent input noise across sessions. The other two observers showed both a decrease in equivalent input noise (18% and 29%) and an increase in efficiency (17% and 71%). All five observers showed substantial improvement in Snellen acuity (approximately 26%) after practice. Perceptual learning can improve visual performance in amblyopic children. The improvement can be parsed into two important factors: decreased equivalent input noise and increased efficiency. Perceptual learning techniques may add an effective new method to the armamentarium of amblyopia treatments.

  15. Uveal Melanoma Treated With Iodine-125 Episcleral Plaque: An Analysis of Dose on Disease Control and Visual Outcomes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Perez, Bradford A.; Mettu, Pradeep; Vajzovic, Lejla

    2014-05-01

    Purpose: To investigate, in the treatment of uveal melanomas, how tumor control, radiation toxicity, and visual outcomes are affected by the radiation dose at the tumor apex. Methods and Materials: A retrospective review was performed to evaluate patients treated for uveal melanoma with {sup 125}I plaques between 1988 and 2010. Radiation dose is reported as dose to tumor apex and dose to 5 mm. Primary endpoints included time to local failure, distant failure, and death. Secondary endpoints included eye preservation, visual acuity, and radiation-related complications. Univariate and multivariate analyses were performed to determine associations between radiation dose and the endpointmore » variables. Results: One hundred ninety patients with sufficient data to evaluate the endpoints were included. The 5-year local control rate was 91%. The 5-year distant metastases rate was 10%. The 5-year overall survival rate was 84%. There were no differences in outcome (local control, distant metastases, overall survival) when dose was stratified by apex dose quartile (<69 Gy, 69-81 Gy, 81-89 Gy, >89 Gy). However, increasing apex dose and dose to 5-mm depth were correlated with greater visual acuity loss (P=.02, P=.0006), worse final visual acuity (P=.02, P<.0001), and radiation complications (P<.0001, P=.0009). In addition, enucleation rates were worse with increasing quartiles of dose to 5 mm (P=.0001). Conclusions: Doses at least as low as 69 Gy prescribed to the tumor apex achieve rates of local control, distant metastasis–free survival, and overall survival that are similar to radiation doses of 85 Gy to the tumor apex, but with improved visual outcomes.« less

  16. Retrobulbar optic neuritis and rhegmatogenous retinal detachment in a fourteen-year-old girl with retinitis pigmentosa sine pigmento.

    PubMed

    Hatta, M; Hayasaka, S; Kato, T; Kadoi, C

    2000-01-01

    A 14-year-old girl complained of a sudden decrease in right visual acuity. The patient had night blindness, a mottled retina but no pigments, extinguished scotopic electroretinographic response, central scotoma in the right eye and rhegmatogenous retinal detachment. She had initially received laser photocoagulation around the retinal tear and then corticosteroid therapy, cryoretinopexy and segmental buckling. Her right visual acuity increased to 1.0. The association of retinitis pigmentosa sine pigmento, retrobulbar optic neuritis and rhegmatogenous retinal detachment, as demonstrated in our patient, may be uncommon. Copyright 2000 S. Karger AG, Basel

  17. Visual indices of motor vehicle drivers in relation to road safety in Nigeria.

    PubMed

    Emerole, C G; Nneli, R O

    2013-06-30

    This study assessed the visual profile of motor vehicle drivers in Owerri, Nigeria and to analyse the relationship between the various aspects of visual function in relation to road safety. A cross-sectional descriptive study of 150 commercial vehicles drivers and 130 private vehicles drivers was conducted between November 2005 and February 2006. Data were obtained using structured interviewer administered questionnaires and clinical examination was done. Standards procedures were used to determine visual indices. Data from the better eye (eye with a better visual acuity according to international and national standards) were reported, except in the analysis of near vision of the respondents. Twenty percent of the study group had normal visual acuity of ≥6/6 compared with 46.2% in the control group. The tonometric value in 88.0% and 93.1% of study and control groups respectively was less than 24mmHg. Both groups (96.8%) had normal confrontation visual field while 95.3% of study group and 97.7% of control group had normal colour vision. The most prevailing eye conditions that may reduce visual acuity were pterygium (51.3% in study group and 13.8% in the control group), retinopathy (16.7% of study group and 6.2% of control group) and glaucoma (12.0% and 6.9% of study and control groups respectively). Nineteen percent of the study group had regular eye examination compared with 38.5% in the control group. Alcohol consumption was 64.7% in the study group and 32.3% in the control group. Most of the commercial motor drivers in Owerri, Nigeria did not meet the Federal Road Safety Commission visual acuity standard for commercial motor drivers. Visual impairments and poor visibility are strongly associated with RTA among Nigerian motor vehicle drivers. Visual acuity and visual health care were poor among commercial motor drivers. There is need for renewed efforts to enforce a compulsory periodic visual examination for drivers, and to ensure that visual requirements for

  18. Optical coherence tomography patterns as predictors of visual outcome in dengue-related maculopathy.

    PubMed

    Teoh, Stephen C; Chee, Caroline K; Laude, Augustinus; Goh, Kong Y; Barkham, Timothy; Ang, Brenda S

    2010-03-01

    The purpose of this study was to characterize the presentations, long-term outcomes, and visual prognostic factors in dengue-related maculopathy of 41 patients with dengue fever and impaired vision from dengue-related maculopathy in a retrospective noninterventional and observational series. The medical records of patients with dengue-related maculopathy diagnosed over 18 months between July 2004 and December 2005 at The Eye Institute, Tan Tock Seng Hospital and Communicable Disease Center, Singapore, were reviewed and followed up for 24 months. Visual acuity and symptoms (presence of scotoma on automated visual fields and Amsler grid) were correlated with optical coherence tomography evaluation. Mean age was 28.7 years and there were more men (53.7%). The most common visual complaints were blurring of vision (51.2%) and central scotoma (34.1%). Most patients recovered best-corrected visual acuity >20/40. Optical coherence tomography showed 3 patterns of maculopathy: 1) diffuse retinal thickening; 2) cystoid macular edema; and 3) foveolitis. The visual outcome was independent of the extent of edema, but scotomata persisted longest in patients with foveolitis and shortest with those with diffuse retinal thickening. Dengue-associated ocular inflammation is an emerging ophthalmic condition and often involves the posterior segment. Prognosis is variable. Patients usually regain good vision but may retain persistent scotomata even at 2 years despite clinical resolution of the disease. Optical coherence tomography patterns in dengue maculopathy are useful for characterization, monitoring, and prognostication of the visual defect.

  19. Comparison of visual outcomes after bilateral implantation of extended range of vision and trifocal intraocular lenses.

    PubMed

    Ruiz-Mesa, Ramón; Abengózar-Vela, Antonio; Aramburu, Ana; Ruiz-Santos, María

    2017-06-26

    To compare visual outcomes after cataract surgery with bilateral implantation of 2 intraocular lenses (IOLs): extended range of vision and trifocal. Each group of this prospective study comprised 40 eyes (20 patients). Phacoemulsification followed by bilateral implantation of a FineVision IOL (group 1) or a Symfony IOL (group 2) was performed. The following outcomes were assessed up to 1 year postoperatively: binocular uncorrected distance visual acuity (UDVA), binocular uncorrected intermediate visual acuity (UIVA) at 60 cm, binocular uncorrected near visual acuity (UNVA) at 40 cm, spherical equivalent (SE) refraction, defocus curves, mesopic and photopic contrast sensitivity, halometry, posterior capsule opacification (PCO), and responses to a patient questionnaire. The mean binocular values in group 1 and group 2, respectively, were SE -0.15 ± 0.25 D and -0.19 ± 0.18 D; UDVA 0.01 ± 0.03 logMAR and 0.01 ± 0.02 logMAR; UIVA 0.11 ± 0.08 logMAR and 0.09 ± 0.08 logMAR; UNVA 0.06 ± 0.07 logMAR and 0.17 ± 0.06 logMAR. Difference in UNVA between IOLs (p<0.05) was statistically significant. There were no significant differences in contrast sensitivity, halometry, or PCO between groups. Defocus curves were similar between groups from 0 D to -2 D, but showed significant differences from -2.50 D to -4.00 D (p<0.05). Both IOLs provided excellent distance and intermediate visual outcomes. The FineVision IOL showed better near visual acuity. Predictability of the refractive results and optical performance were excellent; all patients achieved spectacle independence. The 2 IOLs gave similar and good contrast sensitivity in photopic and mesopic conditions and low perception of halos by patients.

  20. A Visual Profile of Queensland Indigenous Children.

    PubMed

    Hopkins, Shelley; Sampson, Geoff P; Hendicott, Peter L; Wood, Joanne M

    2016-03-01

    Little is known about the prevalence of refractive error, binocular vision, and other visual conditions in Australian Indigenous children. This is important given the association of these visual conditions with reduced reading performance in the wider population, which may also contribute to the suboptimal reading performance reported in this population. The aim of this study was to develop a visual profile of Queensland Indigenous children. Vision testing was performed on 595 primary schoolchildren in Queensland, Australia. Vision parameters measured included visual acuity, refractive error, color vision, nearpoint of convergence, horizontal heterophoria, fusional vergence range, accommodative facility, AC/A ratio, visual motor integration, and rapid automatized naming. Near heterophoria, nearpoint of convergence, and near fusional vergence range were used to classify convergence insufficiency (CI). Although refractive error (Indigenous, 10%; non-Indigenous, 16%; p = 0.04) and strabismus (Indigenous, 0%; non-Indigenous, 3%; p = 0.03) were significantly less common in Indigenous children, CI was twice as prevalent (Indigenous, 10%; non-Indigenous, 5%; p = 0.04). Reduced visual information processing skills were more common in Indigenous children (reduced visual motor integration [Indigenous, 28%; non-Indigenous, 16%; p < 0.01] and slower rapid automatized naming [Indigenous, 67%; non-Indigenous, 59%; p = 0.04]). The prevalence of visual impairment (reduced visual acuity) and color vision deficiency was similar between groups. Indigenous children have less refractive error and strabismus than their non-Indigenous peers. However, CI and reduced visual information processing skills were more common in this group. Given that vision screenings primarily target visual acuity assessment and strabismus detection, this is an important finding as many Indigenous children with CI and reduced visual information processing may be missed. Emphasis should be placed on identifying

  1. Improved retinal and visual function following panmacular subthreshold diode micropulse laser for retinitis pigmentosa.

    PubMed

    Luttrull, Jeffrey K

    2018-06-01

    To examine the effect of subthreshold diode micropulse laser (SDM) on pattern electroretinography (PERG) and visual function in retinitis pigmentosa (RP). The records of all patients (pts) undergoing SDM in a vitreoretinal subspecialty practice were reviewed. Inclusion criteria included the presence of RP evaluated before and after SDM by PERG. As a secondary outcome measure, the results of automated omnifield resolution perimetry (ORP) were also reviewed. All eyes undergoing SDM for RP were eligible study, including 26 eyes of 15 pts; seven male and eight female, aged 16-69 (avg. 47) years. Retinal function by PERG improved by all indices, with significant improvements in the 24° field signal latency measures; the MagD(µV)/ Mag(µV) ratio (P < 0.0001) and the MagD(µV) amplitude (P = 0.0003). ORP significantly improved by all indices (p = 0.02-0.002). Average best-corrected chart visual acuities improved from 0.6 to 0.4 logMAR units (p = 0.02). There were no adverse treatment effects. SDM significantly improved chart visual acuity, mesopic logMAR visual acuity perimetry, and retinal function by PERG in RP without adverse treatment effects. Treatment responses indicate a significant capacity for rescue of dysfunctional retina. These results suggest that early and periodic treatment with SDM might slow disease progression and reduce long-term vision loss.

  2. Reversal of myopic anisometropic amblyopia with occlusion therapy in a 25 year old.

    PubMed

    Megbelayin, E; Ekpenyong, S M; Azunobi, J; Ejiro, G

    2014-03-01

    To report a reversal of myopic anisometropic amblyopia with occlusion therapy in a 25 year old. Case report. Eye clinic of a University Teaching Hospital in a metropolitan city. an index patient. Occlusion therapy. Post occlusion visual acuity. Presenting unaided visual acuity of right eye: 6/6, left eye: 4/60. Refraction result was: right eye: -0.50DS (6/6), left eye: -3.50DS (6/18). Following day time occlusion therapy of at least 6 hours for about 4 weeks, subjective refraction was: right eye: -0.5DS (6/5), left eye: -3.50DS (6/6(+3)). The remarkable improvement in vision at age 25 years of a patient with myopic anisometropic amblyopia shows that occlusion therapy might still be useful long after amblyogenic period.

  3. Effect of Background Luminance Level on the Assessment of Color Visual Acuity Using Colored Landolt Rings in Young Healthy Subjects.

    PubMed

    Tanaka, Yoshiki; Yokoyama, Sho; Horai, Rie; Kojima, Takashi; Hiroyuki, Sato; Kato, Yukihito; Takagi, Mari; Nakamura, Hideki; Tanaka, Kiyoshi; Ichikawa, Kazuo; Tanabe, Shoko

    2018-03-01

    To evaluate the color visual acuity (CVA) of young healthy subjects using colored Landolt rings and the effect of background luminance level on the CVA. We measured the CVA of 20 young healthy subjects (age: 23.8 ± 3.8 years) with different colors using a computer and a liquid crystal display, with 15 Landolt ring colors (30 cd/m 2 ) with a background luminance of 30 cd/m 2 , and then 100 cd/m 2 . We then used different background luminance levels (15-50 cd/m 2 ) using four Landolt ring colors (red, green-yellow, green, and blue-green) to evaluate the effect of the background luminance level on CVA. The CVA significantly differed among the colors with a background luminance of 30 cd/m 2 (p < 0.0001). Green-yellow and blue-purple had poor CVA (high LogMAR value; 0.808 ± 0.107 and 0.633 ± 0.150, respectively) with a background luminance of 30 cd/m 2 (same luminance as the Landolt rings). There were no significant differences in the CVAs among the colors with a background luminance of 100 cd/m 2 (p = 0.5999). There were no significant difference in the CVA between background luminance 30 cd/m 2 and other luminance level ranging from 28 to 32 cd/m 2 for colors of red, green-yellow, green, and blue-green. The results reveal that the background luminance of Landolt rings affects the CVA. Distinctive CVAs for each color are measured by equalizing the luminance between the Landolt ring and the background. We consider that the poor CVAs of these colors reflect the visual function of S-cone, because GY and BP are included in the confusion locus of tritan axis on the chromaticity diagram. We believe that CVA assessment may be useful for individuals who have known or suspected ocular dysfunction or color vision deficiencies.

  4. Determination of myopes' visual acuity using stimuli with different contrast

    NASA Astrophysics Data System (ADS)

    Ikaunieks, G.; Caure, E.; Kassaliete, E.; Meskovska, Z.

    2012-10-01

    The influence of different contrast stimuli on the myopes’ visual acuity (VA) was studied using positive (35.7), negative (-0.97) and low contrast (-0.11) Landolt optotypes. Test subjects were 13 myopes with corrected eyesight and 8 emmetropes, all of them being 20-22 years old. For VA determination the FrACT computer program was employed. In the tests it was found that for emmetropes the positive and negative contrast VA values do not differ significantly, while for myopes the respective values are better with positive than with negative contrast stimuli. These differences were the same in the measurements taken with spectacles or contact lenses. Our results also show that the retinal straylight created by clean spectacles or soft contact lenses is similar in both cases. Dažu autoru pētījumi rāda, ka miopijas gadījumā redzes asums ir labāks ar pozitīva Vēbera kontrasta stimuliem (balts stimuls uz melna fona) nekā negatīva kontrasta stimuliem (melns stimuls uz balta fona). Šis fenomens tiek saistītas ar neirālām izmaiņām ON un OFF ceļos un miopiskās acīs. Citi pētījumi rāda, ka arī acī izkliedētās gaismas ietekmē labāks redzes asums ir ar pozitīviem kontrasta stimuliem nekā negatīva. Miopijas gadījumā papildus gaismas izkliedi rada briļļu lēcas vai kontaktlēcas. Mēs savā pētījumā vēlējāmies noskaidrot, cik lielā mērā labāks redzes asums ar pozitīva kontrasta stimuliem miopiskās acīs ir saistāms ar optiskās korekcijas radīto gaismas izkliedi. Pētījumā piedalījās 21 dalībnieks - 8 emetropi un 13 miopi ar sfērisko refrakcijas lielumu no -1.25 līdz -6,25 D. Dalībnieku vecums bija no 20 līdz 22 gadi. Izmantojot FrACT datorprogrammu, tika noteiks monokulārais redzes asums VA ar Landolta gredzeniem pie pozitīva, negatīva un zema kontrasta fotopiskos apstākļos. Vēbera kontrasti stimuliem attiecīgi bija 35.7, -0.97 un -0.11. Miopiem mērījumi tika veikti gan ar brillēm, gan

  5. Causes of severe visual impairment and blindness in children attending schools for the visually handicapped in the Czech Republic

    PubMed Central

    Kocur, I; Kuchynka, P; Rodny, S; Barakova, D; Schwartz, E

    2001-01-01

    AIMS—To describe the causes of severe visual impairment and blindness in children in schools for the visually handicapped in the Czech Republic in 1998.
METHODS—Pupils attending all 10 primary schools for the visually handicapped were examined. A modified WHO/PBL eye examination record for children with blindness and low vision was used.
RESULTS—229 children (146 males and 83 females) aged 6-15 years were included in the study: 47 children had severe visual impairment (20.5%) (visual acuity in their better eye less than 6/60), and 159 were blind (69.5%) (visual acuity in their better eye less than 3/60). Anatomically, the most affected parts of the eye were the retina (124, 54.2%), optic nerve (35, 15.3%), whole globe (25, 10.9%), lens (20, 8.7%), and uvea (12, 5.2%). Aetiologically (timing of insult leading to visual loss), the major cause of visual impairment was retinopathy of prematurity (ROP) (96, 41.9 %), followed by abnormalities of unknown timing of insult (97, 42.4%), and hereditary disease (21, 9.2%). In 90 children (40%), additional disabilities were present: mental disability (36, 16%), physical handicap (16, 7%), and/or a combination of both (19, 8%). It was estimated that 127 children (56%) suffer from visual impairment caused by potentially preventable and/or treatable conditions (for example, ROP, cataract, glaucoma).
CONCLUSIONS—Establishing a study group for comprehensive evaluation of causes of visual handicap in children in the Czech Republic, as well as for detailed analysis of present practice of screening for ROP was recommended.

 PMID:11567954

  6. The contribution of visual processing to academic achievement in adolescents born extremely preterm or extremely low birth weight.

    PubMed

    Molloy, Carly S; Di Battista, Ashley M; Anderson, Vicki A; Burnett, Alice; Lee, Katherine J; Roberts, Gehan; Cheong, Jeanie Ly; Anderson, Peter J; Doyle, Lex W

    2017-04-01

    Children born extremely preterm (EP, <28 weeks) and/or extremely low birth weight (ELBW, <1000 g) have more academic deficiencies than their term-born peers, which may be due to problems with visual processing. The aim of this study is to determine (1) if visual processing is related to poor academic outcomes in EP/ELBW adolescents, and (2) how much of the variance in academic achievement in EP/ELBW adolescents is explained by visual processing ability after controlling for perinatal risk factors and other known contributors to academic performance, particularly attention and working memory. A geographically determined cohort of 228 surviving EP/ELBW adolescents (mean age 17 years) was studied. The relationships between measures of visual processing (visual acuity, binocular stereopsis, eye convergence, and visual perception) and academic achievement were explored within the EP/ELBW group. Analyses were repeated controlling for perinatal and social risk, and measures of attention and working memory. It was found that visual acuity, convergence and visual perception are related to scores for academic achievement on univariable regression analyses. After controlling for potential confounds (perinatal and social risk, working memory and attention), visual acuity, convergence and visual perception remained associated with reading and math computation, but only convergence and visual perception are related to spelling. The additional variance explained by visual processing is up to 6.6% for reading, 2.7% for spelling, and 2.2% for math computation. None of the visual processing variables or visual motor integration are associated with handwriting on multivariable analysis. Working memory is generally a stronger predictor of reading, spelling, and math computation than visual processing. It was concluded that visual processing difficulties are significantly related to academic outcomes in EP/ELBW adolescents; therefore, specific attention should be paid to academic

  7. Does Assessing Eye Alignment along with Refractive Error or Visual Acuity Increase Sensitivity for Detection of Strabismus in Preschool Vision Screening?

    PubMed Central

    2007-01-01

    Purpose Preschool vision screenings often include refractive error or visual acuity (VA) testing to detect amblyopia, as well as alignment testing to detect strabismus. The purpose of this study was to determine the effect of combining screening for eye alignment with screening for refractive error or reduced VA on sensitivity for detection of strabismus, with specificity set at 90% and 94%. Methods Over 3 years, 4040 preschool children were screened in the Vision in Preschoolers (VIP) Study, with different screening tests administered each year. Examinations were performed to identify children with strabismus. The best screening tests for detecting children with any targeted condition were noncycloplegic retinoscopy (NCR), Retinomax autorefractor (Right Manufacturing, Virginia Beach, VA), SureSight Vision Screener (Welch-Allyn, Inc., Skaneateles, NY), and Lea Symbols (Precision Vision, LaSalle, IL and Good-Lite Co., Elgin, IL) and HOTV optotypes VA tests. Analyses were conducted with these tests of refractive error or VA paired with the best tests for detecting strabismus (unilateral cover testing, Random Dot “E” [RDE] and Stereo Smile Test II [Stereo Optical, Inc., Chicago, IL]; and MTI PhotoScreener [PhotoScreener, Inc., Palm Beach, FL]). The change in sensitivity that resulted from combining a test of eye alignment with a test of refractive error or VA was determined with specificity set at 90% and 94%. Results Among the 4040 children, 157 were identified as having strabismus. For screening tests conducted by eye care professionals, the addition of a unilateral cover test to a test of refraction generally resulted in a statistically significant increase (range, 15%–25%) in detection of strabismus. For screening tests administered by trained lay screeners, the addition of Stereo Smile II to SureSight resulted in a statistically significant increase (21%) in sensitivity for detection of strabismus. Conclusions The most efficient and low-cost ways to achieve

  8. Simulation of thalamic prosthetic vision: reading accuracy, speed, and acuity in sighted humans.

    PubMed

    Vurro, Milena; Crowell, Anne Marie; Pezaris, John S

    2014-01-01

    The psychophysics of reading with artificial sight has received increasing attention as visual prostheses are becoming a real possibility to restore useful function to the blind through the coarse, pseudo-pixelized vision they generate. Studies to date have focused on simulating retinal and cortical prostheses; here we extend that work to report on thalamic designs. This study examined the reading performance of normally sighted human subjects using a simulation of three thalamic visual prostheses that varied in phosphene count, to help understand the level of functional ability afforded by thalamic designs in a task of daily living. Reading accuracy, reading speed, and reading acuity of 20 subjects were measured as a function of letter size, using a task based on the MNREAD chart. Results showed that fluid reading was feasible with appropriate combinations of letter size and phosphene count, and performance degraded smoothly as font size was decreased, with an approximate doubling of phosphene count resulting in an increase of 0.2 logMAR in acuity. Results here were consistent with previous results from our laboratory. Results were also consistent with those from the literature, despite using naive subjects who were not trained on the simulator, in contrast to other reports.

  9. Comparison of the Handy Eye Chart and the Lea Symbols Chart in a population of deaf children aged 7–18 years

    PubMed Central

    Gorham, John Paul; Bruce, Beau B.; Hutchinson, Amy K.

    2016-01-01

    Purpose To compare the results of visual acuity testing in a population of deaf children using the Handy Eye Chart versus the Lea Symbols Chart and to compare testability and preference between charts. Methods A total of 24 participants were recruited at the Atlanta Area School for the Deaf. Visual Acuity was evaluated using the Handy Eye Chart and the Lea Symbols Chart. Patient preference and duration of testing were measured. Results The mean difference between the visual acuity as measured by each chart was –0.02 logMAR (95% CI, −0.06 to 0.03). Testing with the Handy Eye Chart was an average of 13.79 seconds faster than testing with the Lea Symbols Chart (95% CI, 1.1–26.47; P = 0.03). Of the 24 participants, 17 (71%) preferred the Handy Eye Chart (95% CI: 49%–87%; P = 0.07). Conclusions The Handy Eye Chart is a fast, valid, and preferred tool for measuring visual acuity in deaf children age 7–18 years. Additional research is needed to evaluate the utility of the Handy Eye Chart in younger children and deaf adults. PMID:27164427

  10. [Osteo-odonto-keratoprosthesis. A summary of 6 years surgical experience].

    PubMed

    Hille, K; Landau, H; Ruprecht, K W

    2002-02-01

    In patients with severe corneal scarring and vascularisation, corneal grafts have a high risk of failure. In those patients an osteo-odonto-keratoprosthesis (OOKP) can be performed. We performed OOKP in eight patients in all with ocular pemphigoid, severe alkali burns, or repulsion of a corneal graft. Each of the patients had finger-counting visual acuity or less. The OOKP consisted of a PMMA cylinder 8 mm long, with a diameter of 3-4 mm, and from a root of the patient's tooth. This was implanted in the cornea and covered with buccal mucosa. The medium follow-up was 3 years. The implants are now well incorporated. The best visual acuity was between 0.6 and 0.9 in four patients with intact retinas. In the remaining patients, visual acuity was dependent on the posterior segment findings. The visual field was centred. Five of the eight patients had vitreous bleeding after the operation that was spontaneously absorbed. Revision of the mucous coverage was necessary in four patients, and one of them had a severe inflammation with partial absorption of the bone and tooth implant. One patient developed a secondary angle-closure glaucoma and was treated successfully by implantation of an Ahmed valve. Two patients developed membranes behind the cylinder that were successfully removed. There was no loss of any prosthesis during follow-up. In impasse in severe corneal scars, the osteo-odonto-keratoprosthesis is still indicated and shows good results in visual rehabilitation of patients.

  11. Suicides in Visually Impaired Persons: A Nation-Wide Register-Linked Study from Finland Based on Thirty Years of Data

    PubMed Central

    Meyer-Rochow, Victor Benno; Hakko, Helinä; Ojamo, Matti; Uusitalo, Hannu; Timonen, Markku

    2015-01-01

    Focusing on seasonality, gender, age, and suicide methods a Finnish nation-wide cohort-based study was carried out to compare suicide data between sighted, visually-impaired (WHO impairment level I-II, i.e., visual acuity >0.05, but <0.3) and blind (WHO impairment level III-V, i.e., visual acuity <0.05) victims. Standardized mortality ratios (SMR) of age- and gender-matched populations from official 1982–2011 national registers were used. Group differences in categorical variables were assessed with Pearson's Chi-square or Fisher's Exact test and in continuous variables with Mann-Whitney U-test. Seasonality was assessed by Chi-square for multinomials; ratio of observed to expected number of suicides was calculated with 95% confidence level. Hanging, poisoning, drowning, but rarely shooting or jumping from high places, were preferred suicide methods of the blind. Mortality was significantly increased in the visually impaired (SMR = 1.3; 95% CI 1.07–1.61), but in gender-stratified analyses the increase only affected males (1.34; 95% CI = 1.06–1.70) and not females (1.24; 95% CI 0.82–1.88). Age-stratified analyses identified blind males of working age rather than older men (as in the general population) as a high risk group that requires particular attention. The statistically significant spring suicide peak in blind subjects mirrors that of sighted victims and its possible cause in the blind is discussed. PMID:26509899

  12. Suicides in Visually Impaired Persons: A Nation-Wide Register-Linked Study from Finland Based on Thirty Years of Data.

    PubMed

    Meyer-Rochow, Victor Benno; Hakko, Helinä; Ojamo, Matti; Uusitalo, Hannu; Timonen, Markku

    2015-01-01

    Focusing on seasonality, gender, age, and suicide methods a Finnish nation-wide cohort-based study was carried out to compare suicide data between sighted, visually-impaired (WHO impairment level I-II, i.e., visual acuity >0.05, but <0.3) and blind (WHO impairment level III-V, i.e., visual acuity <0.05) victims. Standardized mortality ratios (SMR) of age- and gender-matched populations from official 1982-2011 national registers were used. Group differences in categorical variables were assessed with Pearson's Chi-square or Fisher's Exact test and in continuous variables with Mann-Whitney U-test. Seasonality was assessed by Chi-square for multinomials; ratio of observed to expected number of suicides was calculated with 95% confidence level. Hanging, poisoning, drowning, but rarely shooting or jumping from high places, were preferred suicide methods of the blind. Mortality was significantly increased in the visually impaired (SMR = 1.3; 95% CI 1.07-1.61), but in gender-stratified analyses the increase only affected males (1.34; 95% CI = 1.06-1.70) and not females (1.24; 95% CI 0.82-1.88). Age-stratified analyses identified blind males of working age rather than older men (as in the general population) as a high risk group that requires particular attention. The statistically significant spring suicide peak in blind subjects mirrors that of sighted victims and its possible cause in the blind is discussed.

  13. Visual functions of commercial drivers in relation to road accidents in Nigeria

    PubMed Central

    Oladehinde, M. K.; Adeoye, A. O.; Adegbehingbe, B. O.; Onakoya, A. O.

    2007-01-01

    Objective: To determine the effects of the visual functions on the occurrence of road traffic accidents (RTA) amongst commercial drivers in Ife central local government area (LGA) of Osun state of Nigeria. Design: A cross-sectional study. Settings: Four major motor parks located at Ife Central LGA. Materials and Methods: Of the estimated 270 commercial drivers in the four major parks of the LGA, 215 consecutive drivers were interviewed and had their eyes examined. Structured questionnaires were administered by an ophthalmologist. Results: The prevalence of visual impairment (visual acuity < 6/18) in the better eye without correction was 3.3% ± 2.4 and there was a significant association between uncorrected visual acuity impairment in the better eye and RTA (P = 0.0152). Refractive error was seen in 8.4% of the drivers, but none of these wear corrective glasses. Visual field defect, abnormal stereopsis and color vision impairment did not have any significant association with RTA. Conclusion: Poor visual acuity is strongly associated with RTA amongst Nigerian commercial drivers as opposed to visual field defect, abnormal color vision and stereopsis. A significant proportion of visual impairment was due to uncorrected refractive errors. PMID:21938219

  14. [Visual diagnosis: Waardenburg syndrome].

    PubMed

    Hager, T; Walter, H-S; Seitz, B; Käsmann-Kellner, B

    2010-07-01

    Waardenburg syndrome (WS) is a rare disease characterized by a sensorineural hearing loss and pigment anomalies of the iris, skin and hair due to mutations in PAX3. WS can be subdivided into four groups according to major and minor clinical signs. We report the case of a 2 1/2-year-old coloured patient who presented in our department of paediatric ophthalmology for a syndrome search. The patient presented with hearing loss, brilliant blue iris colour and dystopia canthorum. The patient was slightly hypermetropic. Visual acuity was within normal limits according to the Cardiff acuity test. The ocular fundus examination revealed no abnormalities. According to the major and minor criteria defined by the Waardenburg consortium our patient showed the major criteria of WS1, i.e. hearing loss, hypopigmentation of the pigment epithelium of the iris and dystopic canthi. Diagnosis of WS is usually based on the clinical presentation. An additional molecular genetic analysis is possible.

  15. Patient-reported utilities in bilateral visual impairment from amblyopia and age-related macular degeneration.

    PubMed

    van de Graaf, Elizabeth S; Despriet, Dominiek D G; Klaver, Caroline C W; Simonsz, Huibert J

    2016-05-17

    Utility of visual impairment caused by amblyopia is important for the cost-effectiveness of screening for amblyopia (lazy eye, prevalence 3-3.5 %). We previously measured decrease of utility in 35-year-old persons with unilateral persistent amblyopia. The current observational case-control study aimed to measure loss of utility in patients with amblyopia with recent decrease of vision in their better eye. As these patients are rare, the sample was supplemented by patients with bilateral age-related macular degeneration with similar decrease of vision. From our out-patient department, two groups of patients with recent deterioration to bilateral visual acuity less than Snellen 0.5 (bilateral visual impairment, BVI) were recruited, with either persistent amblyopia and age-related macular degeneration (AMB + AMD), or with bilateral age-related macular degeneration (BAMD). To measure utility, the time trade-off method and the standard gamble method were applied through interviews. Correlations were sought between utility values and visual acuity, age and Visual Function Questionnaire-25 scores. Seventeen AMB + AMD patients (mean age 72.9 years), and 63 BAMD patients (mean age 79.6 years) were included in the study. Among AMB + AMD, 80 % were willing to trade lifetime in exchange for cure. The overall mean time trade-off utility was 0.925. Among BAMD, 75 % were willing to trade, utility was 0.917. Among AMB + AMD, 38 % accepted risk of death in exchange for cure, overall mean standard gamble utility was 0.999. Among BAMD, 49 % accepted risk of death, utility was 0.998. Utility was not related to visual acuity but it was to age (p = 0.02). Elderly patients with BVI, caused by persistent amblyopia and age-related macular degeneration (AMD) or by bilateral AMD, had an approximately 8 % loss of TTO utility. Notably, the 8 % loss in elderly with BVI differs little from the 3.7 % loss we found previously in 35-year-old persons with unilateral

  16. A population-based study of visual impairment among pre-school children in Beijing: the Beijing study of visual impairment in children.

    PubMed

    Lu, Qing; Zheng, Yuanyuan; Sun, Baochen; Cui, Tongtong; Congdon, Nathan; Hu, Ailian; Chen, Jianhua; Shi, Jiliang

    2009-06-01

    To evaluate the prevalence and causes of visual impairment among Chinese children aged 3 to 6 years in Beijing. Population-based prevalence survey. Presenting and pinhole visual acuity were tested using picture optotypes or, in children with pinhole vision < 6/18, a Snellen tumbling E chart. Comprehensive eye examinations and cycloplegic refraction were carried out for children with pinhole vision < 6/18 in the better-seeing eye. All examinations were completed on 17,699 children aged 3 to 6 years (95.3% of sample). Subjects with bilateral correctable low vision (presenting vision < 6/18 correctable to >or= 6/18) numbered 57 (0.322%; 95% confidence interval [CI], 0.237% to 0.403%), while 14 (0.079%; 95% CI, 0.038% to 0.120%) had bilateral uncorrectable low vision (best-corrected vision of < 6/18 and >or= 3/60), and 5 subjects (0.028%; 95% CI, 0.004% to 0.054%) were bilaterally blind (best-corrected acuity < 3/60). The etiology of 76 cases of visual impairment included: refractive error in 57 children (75%), hereditary factors (microphthalmos, congenital cataract, congenital motor nystagmus, albinism, and optic nerve disease) in 13 children (17.1 %), amblyopia in 3 children (3.95%), and cortical blindness in 1 child (1.3%). The cause of visual impairment could not be established in 2 (2.63%) children. The prevalence of visual impairment did not differ by gender, but correctable low vision was significantly (P < .0001) more common among urban as compared with rural children. The leading causes of visual impairment among Chinese preschool-aged children are refractive error and hereditary eye diseases. A higher prevalence of refractive error is already present among urban as compared with rural children in this preschool population.

  17. Macular morphology and visual acuity in the comparison of age-related macular degeneration treatments trials.

    PubMed

    Jaffe, Glenn J; Martin, Daniel F; Toth, Cynthia A; Daniel, Ebenezer; Maguire, Maureen G; Ying, Gui-Shuang; Grunwald, Juan E; Huang, Jiayan

    2013-09-01

    To describe the effects of treatment for 1 year with ranibizumab or bevacizumab on macular morphology and the association of macular morphology with visual acuity (VA) in eyes with neovascular age-related macular degeneration (AMD). Prospective cohort study within a randomized clinical trial. Participants in the Comparison of Age-related Macular Degeneration Treatments Trials. Participants were assigned randomly to treatment with ranibizumab or bevacizumab on a monthly or as-needed schedule. Optical coherence tomography (OCT), fluorescein angiography (FA), color fundus photography (FP), and VA testing were performed periodically throughout 52 weeks. Masked readers graded images. General linear models were applied to evaluate effects of time and treatment on outcomes. Fluid type and location and thickness by OCT, size, and lesion composition on FP, FA, and VA. Intraretinal fluid (IRF), subretinal fluid (SRF), subretinal pigment epithelium fluid, and retinal, subretinal, and subretinal tissue complex thickness decreased in all treatment groups. A higher proportion of eyes treated monthly with ranibizumab had fluid resolution at 4 weeks, and the difference persisted through 52 weeks. At 52 weeks, there was little association between the presence of fluid of any type (without regard to fluid location) and the mean VA. However, at all time points, eyes with residual IRF, especially foveal IRF, had worse mean VA (9 letters) than those without IRF. Eyes with abnormally thin (<120 μm) or thick (>212 μm) retinas had worse VA than those with normal thickness (120-212 μm). At week 52, eyes with larger neovascular lesions or with foveal scar had worse VA than eyes without these features. Anti-vascular endothelial growth factor (VEGF) therapy reduced lesion activity and improved VA in all treatment groups. At all time points, eyes with residual IRF had worse VA than those without. Eyes with abnormally thin or thick retinas, residual large lesions, and scar also had worse VA

  18. Defining lactation acuity to improve patient safety and outcomes.

    PubMed

    Mannel, Rebecca

    2011-05-01

    While substantial evidence exists identifying risks factors associated with premature weaning from breastfeeding, there are no previously published definitions of patient acuity in the lactation field. This article defines evidence-based levels of lactation acuity based on maternal and infant characteristics. Patient acuity, matching severity of illness to intensity of care required, is an important determinant of patient safety and outcomes. It is often used as part of a patient classification system to determine staffing needs and acceptable workloads in health care settings. As acuity increases, more resources, including more skilled clinicians, are needed to provide optimal care. Developing an evidence-based definition of lactation acuity can help to standardize terminology, more effectively distribute health care staff resources, encourage research to verify the validity and reliability of lactation acuity, and potentially improve breastfeeding initiation and duration rates.

  19. [Evaluation of visual functions in elderly patients with femoral neck fracture].

    PubMed

    Oner, Mithat; Oner, Ayşe; Güney, Ahmet; Halici, Mehmet; Arda, Hatice; Bilal, Okkeş

    2009-01-01

    We aimed at assessing the visual functions in elderly patients with femoral neck fracture and to compare the results with age-matched controls in this three-year prospective study. Seventy-one patients with a history of fall related hip fracture (39 females, 32 males; mean age 76.3+/-9.7 years; range 64 to 90 years) and who were diagnosed with femoral neck fracture after direct graphy were treated by means of bipolar partial prosthesis and they were contacted postoperatively or prior to discharge to participate in the study. Visual acuity, depth perception, the presence of cataract in the red reflex were evaluated. A dilated fundus and slit-lamp examination were performed if possible. On completion of the examination, the ophthalmologist documented the causes of any visual impairment found. Control group was comprised of age-matched 40 subjects (22 females, 18 males; mean age 73.2+/-7.6 years; range 62 to 90 years) who applied to ophtalmology clinic for routine examination. The visual acuity was significantly decreased in the patient group as was stereopsis (p<0.05). We found no difference between the study group and the controls when we evaluate the distribution of self reported eye disease and eye disease found on ocular examination. The rate of cases who reported not usually wearing glasses was 35% while it was 5% in the control group. When we evaluate the time since last examination, 38% of cases had not had an eye examination for over four years, as compared with 22.5% of controls. This study shows that elderly people should have their eyes tested at least once every two years, refractive errors should be corrected and eye diseases should be treated to decrease the risk of fall-related femoral neck fractures.

  20. Visual function of police officers who have undergone refractive surgery.

    PubMed

    Hovis, Jeffery K; Ramaswamy, Shankaran

    2006-11-01

    The visual acuity and contrast sensitivity of police recruits and officers was evaluated in both normal and dim illumination conditions to determine whether officers who have had refractive surgery have compromised night vision. The control group consisted of 76 officers and recruits who have not had refractive surgery and the refractive surgery group consisted of 22 officers and recruits who had refractive surgery. Visual acuity and contrast sensitivity were measured under both room illumination and dim illumination. The room illumination test series included high contrast acuity, low contrast acuity and Pelli-Robson contrast sensitivity. The dim illumination test series included high contrast acuity, low contrast acuity, Pelli-Robson contrast sensitivity, license plate number acuity (with and without glare) and the Mesotest. The general findings were that the refractive surgery group had lower acuity scores on low contrast targets in both room and dim light levels along with a reduction in the Mesotest scores with a glare source compared to the control group. Although refractive surgery police recruits and officers had reduced performance on some vision tests, these reductions were small and it is unlikely that their performance on vision related tasks would be compromised, on average. The major concern is the small number of refractive surgery candidates whose results were well outside the range of the non-surgical candidates. Their vision may be unacceptable for policing. Copyright (c) 2006 Wiley-Liss, Inc.