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.

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.

Vision-related fitness to drive mobility scooters: A practical driving test.

PubMed

Cordes, Christina; Heutink, Joost; Tucha, Oliver M; Brookhuis, Karel A; Brouwer, Wiebo H; Melis-Dankers, Bart J M

2017-03-06

To investigate practical fitness to drive mobility scooters, comparing visually impaired participants with healthy controls. Between-subjects design. Forty-six visually impaired (13 with very low visual acuity, 10 with low visual acuity, 11 with peripheral field defects, 12 with multiple visual impairment) and 35 normal-sighted controls. Participants completed a practical mobility scooter test-drive, which was recorded on video. Two independent occupational therapists specialized in orientation and mobility evaluated the videos systematically. Approximately 90% of the visually impaired participants passed the driving test. On average, participants with visual impairments performed worse than normal-sighted controls, but were judged sufficiently safe. In particular, difficulties were observed in participants with peripheral visual field defects and those with a combination of low visual acuity and visual field defects. People with visual impairment are, in practice, fit to drive mobility scooters; thus visual impairment on its own should not be viewed as a determinant of safety to drive mobility scooters. However, special attention should be paid to individuals with visual field defects with or without a combined low visual acuity. The use of an individual practical fitness-to-drive test is advised.

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/

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. Our findings can be used to predict the visual prognosis in LHON patients.

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...

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...

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.

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 term. Further studies are needed to verify the efficacy of the 2 treatments.

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.

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 procedures. Low-to-moderate correlations among vision test scores suggest that several different dimensions of visual function are being assessed.

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.

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

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.

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.

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.

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.

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.

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.

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.

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

[Effect of artificial media opacities on Frisén ring perimetry and conventional light sense perimetry. A comparative study].

PubMed

Meyer, J H; Funk, J

1994-04-01

In this study we compare the influence of blurring by diffusor foils (Bangerter) on visual acuity and on the thresholds of ring and light sense perimetry. Light sense perimetry was performed using the G1 program of the Octopus 1-2-3 perimeter [1], and ring perimetry with the "ring" test, version 2.20 (High-Tech-Vision) designed by Frisén [4]. Ten eyes of ten healthy persons with a visual acuity of 1.25 or better were examined at six different levels corresponding to visual acuities between 1.6 and hand movements. With both perimeters sensitivity decreased with decreasing visual acuity. At good visual acuities (1.2-1.6) no changes were found in either ring perimetry or light sense perimetry. At acuity levels of 0.8 and below a more pronounced decrease in sensitivity was found with the ring perimeter than with the light sense perimeter. At the level of hand movements there were only absolute scotomas in the ring perimeter, while the Octopus 1-2-3 still detected a baseline sensitivity. Sensitivity was correlated with the logarithm of the visual acuity with both perimeters (Octopus 1-2-3: r = 0.99, P < 0.001; ring perimeter: r = 0.98, P < 0.001). The decrease in sensitivity per log-unit of visual acuity was 9.43 dB (Octopus 1-2-3) or 5.19 dB (ring perimeter). The ring perimeter, at least in its currently available version giving an absolute scotoma at mean scores > 14 dB, is obviously more sensitive to media opacities than the Octopus 1-2-3. This may be of importance in the clinical evaluation of the test results.

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.

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.

Brightness discrimination and contrast sensitivity in chronic glaucoma--a clinical study.

PubMed

Teoh, S L; Allan, D; Dutton, G N; Foulds, W S

1990-04-01

The visual acuity, the difference in sensitivity of the two eyes to light (brightness ratio), and contrast sensitivity were assessed in 28 patients with chronic open angle glaucoma and compared with those of 41 normal controls of similar ages and visual acuity. The results obtained were related to the results of Tübingen visual field analysis in patients with glaucoma. Twenty-four of the 28 glaucoma patients (86%) had a significant disparity in brightness ratio between the two eyes. This was found to match the frequency of visual field loss. Moreover, there was a significant relationship between the interocular differences in brightness sense and the difference in the degree of visual field loss between the two eyes. Of the glaucoma patients 39% had sum contrast sensitivities outside the normal range for age-matched normal controls. No significant correlation was found between the interocular difference in brightness sense and the visual acuity or the interocular difference in sum contrast sensitivity. It is concluded that, in the presence of a normal visual acuity, the brightness ratio test warrants evaluation as a potential screening test for chronic open angle glaucoma.

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

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.

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.

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

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.

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.

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.

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.

Are Covert Saccade Functionally Relevant in Vestibular Hypofunction?

PubMed

Hermann, R; Pelisson, D; Dumas, O; Urquizar, Ch; Truy, E; Tilikete, C

2018-06-01

The vestibulo-ocular reflex maintains gaze stabilization during angular or linear head accelerations, allowing adequate dynamic visual acuity. In case of bilateral vestibular hypofunction, patients use saccades to compensate for the reduced vestibulo-ocular reflex function, with covert saccades occurring even during the head displacement. In this study, we questioned whether covert saccades help maintain dynamic visual acuity, and evaluated which characteristic of these saccades are the most relevant to improve visual function. We prospectively included 18 patients with chronic bilateral vestibular hypofunction. Subjects underwent evaluation of dynamic visual acuity in the horizontal plane as well as video recording of their head and eye positions during horizontal head impulse tests in both directions (36 ears tested). Frequency, latency, consistency of covert saccade initiation, and gain of covert saccades as well as residual vestibulo-ocular reflex gain were calculated. We found no correlation between residual vestibulo-ocular reflex gain and dynamic visual acuity. Dynamic visual acuity performance was however positively correlated with the frequency and gain of covert saccades and negatively correlated with covert saccade latency. There was no correlation between consistency of covert saccade initiation and dynamic visual acuity. Even though gaze stabilization in space during covert saccades might be of very short duration, these refixation saccades seem to improve vision in patients with bilateral vestibular hypofunction during angular head impulses. These findings emphasize the need for specific rehabilitation technics that favor the triggering of covert saccades. The physiological origin of covert saccades is discussed.

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 within the lesion, the subject got 48% correct, compared to 78% correct when the stimulus was outside the lesion. TSLO microperimetry revealed reduced, but detectible, sensitivity thresholds within the lesion. Fundus-referenced visual testing proved useful to identify functional cones despite apparent photoreceptor loss identified using AOSLO and SD-OCT. While AOSLO and SD-OCT appear to be sensitive for the detection of abnormal or absent photoreceptors, changes in photoreceptors that are identified with these imaging tools do not correlate completely with visual function in every patient. Fundus-referenced vision testing is a useful tool to indicate the presence of cones that may be amenable to recovery or response to experimental therapies despite not being visible on confocal AOSLO or SD-OCT images.

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.

Optimizing wavefront-guided corrections for highly aberrated eyes in the presence of registration uncertainty

PubMed Central

Shi, Yue; Queener, Hope M.; Marsack, Jason D.; Ravikumar, Ayeswarya; Bedell, Harold E.; Applegate, Raymond A.

2013-01-01

Dynamic registration uncertainty of a wavefront-guided correction with respect to underlying wavefront error (WFE) inevitably decreases retinal image quality. A partial correction may improve average retinal image quality and visual acuity in the presence of registration uncertainties. The purpose of this paper is to (a) develop an algorithm to optimize wavefront-guided correction that improves visual acuity given registration uncertainty and (b) test the hypothesis that these corrections provide improved visual performance in the presence of these uncertainties as compared to a full-magnitude correction or a correction by Guirao, Cox, and Williams (2002). A stochastic parallel gradient descent (SPGD) algorithm was used to optimize the partial-magnitude correction for three keratoconic eyes based on measured scleral contact lens movement. Given its high correlation with logMAR acuity, the retinal image quality metric log visual Strehl was used as a predictor of visual acuity. Predicted values of visual acuity with the optimized corrections were validated by regressing measured acuity loss against predicted loss. Measured loss was obtained from normal subjects viewing acuity charts that were degraded by the residual aberrations generated by the movement of the full-magnitude correction, the correction by Guirao, and optimized SPGD correction. Partial-magnitude corrections optimized with an SPGD algorithm provide at least one line improvement of average visual acuity over the full magnitude and the correction by Guirao given the registration uncertainty. This study demonstrates that it is possible to improve the average visual acuity by optimizing wavefront-guided correction in the presence of registration uncertainty. PMID:23757512

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.

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.

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

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.

Brightness discrimination and contrast sensitivity in chronic glaucoma--a clinical study.

PubMed Central

Teoh, S L; Allan, D; Dutton, G N; Foulds, W S

1990-01-01

The visual acuity, the difference in sensitivity of the two eyes to light (brightness ratio), and contrast sensitivity were assessed in 28 patients with chronic open angle glaucoma and compared with those of 41 normal controls of similar ages and visual acuity. The results obtained were related to the results of Tübingen visual field analysis in patients with glaucoma. Twenty-four of the 28 glaucoma patients (86%) had a significant disparity in brightness ratio between the two eyes. This was found to match the frequency of visual field loss. Moreover, there was a significant relationship between the interocular differences in brightness sense and the difference in the degree of visual field loss between the two eyes. Of the glaucoma patients 39% had sum contrast sensitivities outside the normal range for age-matched normal controls. No significant correlation was found between the interocular difference in brightness sense and the visual acuity or the interocular difference in sum contrast sensitivity. It is concluded that, in the presence of a normal visual acuity, the brightness ratio test warrants evaluation as a potential screening test for chronic open angle glaucoma. PMID:2186795

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.

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.

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

Fixation preference test: reliability for the detection of amblyopia in patients with strabismus and interexaminer agreement.

PubMed

Erkan Turan, Kadriye; Taylan Sekeroglu, Hande; Karahan, Sevilay; Sanac, Ali Sefik

2017-12-01

The purpose of this study was to analyze the reliability of the fixation preference test (FPT) in the detection of amblyopia, and to determine interexaminer agreement. Eighty patients whose visual acuity could be tested objectively and had a horizontal misalignment of more than 10 prism diopters were enrolled. The best corrected visual acuity (BCVA) and orthoptic findings were all recorded. Non-preferred eye in primary position and fixation preference grade were assessed independently by two masked experienced examiners. The primary outcome measures were reliability of FPT in terms of its correlation with BCVA and interexaminer agreement. There was no significant correlation between fixation preference grades and interocular visual acuity difference as well as the type and amount of deviation, the presence of fusion, stereopsis, anisometropia, and previous strabismus surgery for none of the examiners (p > 0.05 for all). Sensitivity was 52.0% for examiner 1 and 54.0% for examiner 2 while specificity was 50.0 and 46.7%, respectively. Interexaminer agreement was 76.7% (p < 0.001) for all patients. FPT is widely used in children particularly when the visual acuity cannot be determined in an objective manner. The test may not be accurate and reliable in the detection of amblyopia and also in predicting the visual acuity difference between both eyes, even though it was found to show a high degree of agreement between examiners. In conclusion, it should be kept in mind that the reliability of FPT may be limited and the results should be interpreted with caution and be supported by other tests.

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

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…

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

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-performed ETDRS charts in terms of photometric compliance with high contrast acuity standards.

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-performed ETDRS charts in terms of photometric compliance with high contrast acuity standards. PMID:27002333

Developing a Very Low Vision Orientation and Mobility Test Battery (O&M-VLV).

PubMed

Finger, Robert P; Ayton, Lauren N; Deverell, Lil; O'Hare, Fleur; McSweeney, Shane C; Luu, Chi D; Fenwick, Eva K; Keeffe, Jill E; Guymer, Robyn H; Bentley, Sharon A

2016-09-01

This study aimed to determine the feasibility of an assessment of vision-related orientation and mobility (O&M) tasks in persons with severe vision loss. These tasks may be used for future low vision rehabilitation clinical assessments or as outcome measures in vision restoration trials. Forty legally blind persons (mean visual acuity logMAR 2.3, or hand movements) with advanced retinitis pigmentosa participated in the Orientation & Mobility-Very Low Vision (O&M-VLV) subtests from the Low Vision Assessment of Daily Activities (LoVADA) protocol. Four categories of tasks were evaluated: route travel in three indoor hospital environments, a room orientation task (the "cafe"), a visual exploration task (the "gallery"), and a modified version of the Timed Up and Go (TUG) test, which assesses re-orientation and route travel. Spatial cognition was assessed using the Stuart Tactile Maps test. Visual acuity and visual fields were measured. A generalized linear regression model showed that a number of measures in the O&M-VLV tasks were related to residual visual function. The percentage of preferred walking speed without an aid on three travel routes was associated with visual field (p < 0.01 for all routes) whereas the number of contacts with obstacles during route travel was associated with acuity (p = 0.001). TUG-LV task time was associated with acuity (p = 0.003), as was the cafe time and distance traveled (p = 0.006 and p < 0.001, respectively). The gallery score was the only measure that was significantly associated with both residual acuity and fields (p < 0.001 and p = 0.001, respectively). The O&M-VLV was designed to capture key elements of O&M performance in persons with severe vision loss, which is a population not often studied previously. Performance on these tasks was associated with both binocular visual acuity and visual field. This new protocol includes assessments of orientation, which may be of benefit in vision restoration clinical trials.

[Solar retinopathy].

PubMed

Kawa, P; Mańkowska, A; Mackiewicz, J; Zagórski, Z

1998-01-01

The purpose of this study is the present clinical evaluation of 21 patients (number of affected eyes--33), who watched eclipse of the sun on 12 October 1996. All patients had general ophthalmic examination with emphasis on visual acuity, visual field, Amsler test, fluorescein angiography and fundus appearance. Eleven out of 21 patients had at least one follow up examination (number of affected eyes--17). None of the patient received any treatment. All patients revealed tiny, central scotomata--positive Amsler test and decreased visual acuity on the first visit; reading Snellen chart could be improved in all patients by adequate head tilt or eye movement (improvement up to 3 Snellen chart lines). No signs of retinopathy were observed in two eyes with uncorrected refractive error and one amblyopic eye. After 7-8 weeks the visual acuity was decreased to 5/30 in two eyes and to 5/10 in ten eyes. In all those eyes persisted a tiny, central scotoma. Looking at the eclipse of the sun in spite of using primitive eye protection may cause irreversible retinal damage. Return of visual acuity to 5/5 does not always imply complete recovery because of persistent central scotoma.

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 them. Statistically within the normal ageing and cataract populations, visual acuity and straylight vary quite independently from each other. Visual acuity losses with cataract and other media opacities are not due to straylight, but caused by aberrations and micro-aberrations. Straylight defines disability glare, and causes symptoms of glare, haloes, hazy vision etc. Overall, visual acuity and straylight are rather independent aspects of quality of vision. © 2017 The Author Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

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.

Vision problems

MedlinePlus

... shade or curtain hanging across part of your visual field. Optic neuritis : inflammation of the optic nerve ... to ask your doctor Images Crossed eyes Eye Visual acuity test Slit-lamp exam Visual field test ...

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.

Vestibular function assessment using the NIH Toolbox

PubMed Central

Schubert, Michael C.; Whitney, Susan L.; Roberts, Dale; Redfern, Mark S.; Musolino, Mark C.; Roche, Jennica L.; Steed, Daniel P.; Corbin, Bree; Lin, Chia-Cheng; Marchetti, Greg F.; Beaumont, Jennifer; Carey, John P.; Shepard, Neil P.; Jacobson, Gary P.; Wrisley, Diane M.; Hoffman, Howard J.; Furman, Gabriel; Slotkin, Jerry

2013-01-01

Objective: Development of an easy to administer, low-cost test of vestibular function. Methods: Members of the NIH Toolbox Sensory Domain Vestibular, Vision, and Motor subdomain teams collaborated to identify 2 tests: 1) Dynamic Visual Acuity (DVA), and 2) the Balance Accelerometry Measure (BAM). Extensive work was completed to identify and develop appropriate software and hardware. More than 300 subjects between the ages of 3 and 85 years, with and without vestibular dysfunction, were recruited and tested. Currently accepted gold standard measures of static visual acuity, vestibular function, dynamic visual acuity, and balance were performed to determine validity. Repeat testing was performed to examine reliability. Results: The DVA and BAM tests are affordable and appropriate for use for individuals 3 through 85 years of age. The DVA had fair to good reliability (0.41–0.94) and sensitivity and specificity (50%–73%), depending on age and optotype chosen. The BAM test was moderately correlated with center of pressure (r = 0.42–0.48) and dynamic posturography (r = −0.48), depending on age and test condition. Both tests differentiated those with and without vestibular impairment and the young from the old. Each test was reliable. Conclusion: The newly created DVA test provides a valid measure of visual acuity with the head still and moving quickly. The novel BAM is a valid measure of balance. Both tests are sensitive to age-related changes and are able to screen for impairment of the vestibular system. PMID:23479540

Panoramic Night Vision Goggle Testing For Diagnosis and Repair

DTIC Science & Technology

2000-01-01

Visual Acuity Visual Acuity [ Marasco & Task, 1999] measures how well a human observer can see high contrast targets at specified light levels through...grid through the PNVG in-board and out-board channels simultaneously and comparing the defects to the size of grid features ( Marasco & Task, 1999). The

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.

Psychophysical Vision Simulation of Diffractive Bifocal and Trifocal Intraocular Lenses

PubMed Central

Brezna, Wolfgang; Lux, Kirsten; Dragostinoff, Nikolaus; Krutzler, Christian; Plank, Nicole; Tobisch, Rainer; Boltz, Agnes; Garhöfer, Gerhard; Told, Reinhard; Witkowska, Katarzyna; Schmetterer, Leopold

2016-01-01

Purpose The visual performance of monofocal, bifocal, and trifocal intraocular lenses was evaluated by human individuals using a vision simulator device. This allowed investigation of the visual impression after cataract surgery, without the need actually to implant the lenses. Methods The randomized, double-masked, three-way cross-over study was conducted on 60 healthy male and female subjects aged between 18 and 35 years. Visual acuity (Early Treatment Diabetic Retinopathy Study; ETDRS) and contrast sensitivity tests (Pelli-Robson) under different lighting conditions (luminosities from 0.14–55 cd/m2, mesopic to photopic) were performed at different distances. Results Visual acuity tests showed no difference for corrected distance visual acuity data of bi- and trifocal lens prototypes (P = 0.851), but better results for the trifocal than for the bifocal lenses at distance corrected intermediate (P = 0.021) and distance corrected near visual acuity (P = 0.044). Contrast sensitivity showed no differences between bifocal and trifocal lenses at the distant (P = 0.984) and at the near position (P = 0.925), but better results for the trifocal lens at the intermediate position (P = 0.043). Visual acuity and contrast sensitivity showed a strong dependence on luminosity (P < 0.001). Conclusions At all investigated distances and all lighting conditions, the trifocal lens prototype often performed better, but never worse than the bifocal lens prototype. Translational Relevance The vision simulator can fill the gap between preclinical lens development and implantation studies by providing information of the perceived vision quality after cataract surgery without implantation. This can reduce implantation risks and promotes the development of new lens concepts due to the cost effective test procedure. PMID:27777828

Intravitreal triamcinolone acetonide injections in the treatment of retinal vein occlusions.

PubMed

Roth, Daniel B; Cukras, Catherine; Radhakrishnan, Ravi; Feuer, William J; Yarian, David L; Green, Stuart N; Wheatley, Harold M; Prenner, Jonathan

2008-01-01

To report the visual acuity response after intravitreal triamcinolone injection in patients with macular edema due to retinal vein occlusions. Retrospective nonrandomized interventional series of 172 consecutive patients with macular edema due to retinal vein occlusions who were treated with intravitreal triamcinolone acetonide injection. Patients underwent Snellen visual acuity testing and ophthalmoscopic examination at baseline and 1, 3, 6, and 12 months after intravitreal triamcinolone acetonide injection. All subtypes of retinal vein occlusions showed significant improvements in mean visual acuity 1 month after injection. This improvement in visual acuity was maintained over the 12-month period for all but the central retinal vein occlusion group. Seventy-one (41.3%) of the 172 patients received more than one intravitreal triamcinolone injection for unresolved or recurrent macular edema. This study demonstrates a benefit associated with intravitreal triamcinolone acetonide injection for retinal vein occlusions that was maintained by patients with branch retinal vein occlusions and hemiretinal vein occlusions over a 12-month period. Visual acuity improvement was not maintained in patients with central retinal vein occlusions with this course of treatment.

Vision loss among diabetics in a group model Health Maintenance Organization (HMO).

PubMed

Fong, Donald S; Sharza, Mohktar; Chen, Wansu; Paschal, John F; Ariyasu, Reginald G; Lee, Paul P

2002-02-01

To report the management of diabetic retinopathy in one group model health maintenance organization and assess the quality of care. Cross-sectional study. A chart review of 1200 randomly identified patients with diabetes mellitus, continuously enrolled for 3 years in Kaiser Permanente (KP) Southern California, the largest provider of managed care in Southern California, was performed. A total of 1047 patients were included in the analyses. Patient characteristics as well as information from the last eye examination were abstracted. Charts from patients with visual acuity less than 20/200 in their better eye (legal blindness) were selected for extensive chart review to determine the cause of visual loss and the antecedent process of care. T tests or the Wilcoxon rank sum test was used to compare continuous variables. The chi(2) test or the Fisher exact test was used to compare categorical variables. All analyses were performed on the Statistical Analyses System (SAS Institute, North Carolina). Our study population of 1047 diabetic patients was 51.7% male, had a mean age of 60.4 years, a mean duration of diabetes of 9.6 years, and a mean hemoglobin A1c of 8.3%. During the study period, 77.5% of patients received a screening eye examination with examination by an ophthalmologist, an optometrist, or review of a retinal photograph. Of those with a visual acuity assessment (n = 687, 65.6% of 1047), 1.5% had visual acuity of 20/200 or worse (legally blind) in the better eye, while 8.2% had this level of visual acuity in the worse eye. Of eyes with new onset clinically significant macular edema and visual acuity < 20/40, 40% had documentation of focal laser performed within 1 month of diagnosis. Of eyes with vitreous hemorrhage and visual acuity < 20/40, 50% had documentation of vitrectomy. Among eyes that had vitrectomy, over 80% had this procedure within 1 year of diagnosis of vitreous hemorrhage. The current report is the largest study of diabetic retinopathy outcomes among patients enrolled in a prepaid health plan. Further research is necessary to investigate the impact of managed care on health outcomes.

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

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

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.

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

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

Monocular oral reading after treatment of dense congenital unilateral cataract

PubMed Central

Birch, Eileen E.; Cheng, Christina; Christina, V; Stager, David R.

2010-01-01

Background Good long-term visual acuity outcomes for children with dense congenital unilateral cataracts have been reported following early surgery and good compliance with postoperative amblyopia therapy. However, treated eyes rarely achieve normal visual acuity and there has been no formal evaluation of the utility of the treated eye for reading. Methods Eighteen children previously treated for dense congenital unilateral cataract were tested monocularly with the Gray Oral Reading Test, 4th edition (GORT-4) at 7 to 13 years of age using two passages for each eye, one at grade level and one at +1 above grade level. In addition, right eyes of 55 normal children age 7 to 13 served as a control group. The GORT-4 assesses reading rate, accuracy, fluency, and comprehension. Results Visual acuity of treated eyes ranged from 0.1 to 2.0 logMAR and of fellow eyes from −0.1 to 0.2 logMAR. Treated eyes scored significantly lower than fellow and normal control eyes on all scales at grade level and at +1 above grade level. Monocular reading rate, accuracy, fluency, and comprehension were correlated with visual acuity of treated eyes (rs = −0.575 to −0.875, p < 0.005). Treated eyes with 0.1-0.3 logMAR visual acuity did not differ from fellow or normal control eyes in rate, accuracy, fluency, or comprehension when reading at grade level or at +1 above grade level. Fellow eyes did not differ from normal controls on any reading scale. Conclusions Excellent visual acuity outcomes following treatment of dense congenital unilateral cataracts are associated with normal reading ability of the treated eye in school-age children. PMID:20603057

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.

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 (P

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

Optic neuritis

MedlinePlus

... optic neuritis is unknown. The optic nerve carries visual information from your eye to the brain. The nerve can swell when it becomes suddenly ... may include: Color vision testing MRI of the brain , including special images of the optic nerve Visual acuity testing Visual field testing Examination of the ...

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.

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 (mean improvement, 0.20 log U [95% CI, 0.10-0.30 log U]; P < .001). Contrast sensitivity and visual acuity were significantly higher 2 hours after consumption of a dark chocolate bar compared with a milk chocolate bar, but the duration of these effects and their influence in real-world performance await further testing. clinicaltrials.gov Identifier: NCT03326934.

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.

Neuronal adaptation to simulated and optically-induced astigmatic defocus.

PubMed

Ohlendorf, Arne; Tabernero, Juan; Schaeffel, Frank

2011-03-25

It is well established that spatial adaptation can improve visual acuity over time in the presence of spherical defocus. It is less well known how far adaptation to astigmatic defocus can enhance visual acuity. We adapted subjects to "simulated" and optically-induced "real" astigmatic defocus, and studied how much they adapt and how selective adaptation was for the axis of astigmatism. Ten subjects with a mean age of 26.7±2.4years (range 23-30) were enrolled in the study, three of them myopic (average spherical equivalent (SE)±SD: -3.08±1.42D) and seven emmetropic (average SE±SD: -0.11±0.18D). All had a corrected minimum visual acuity (VA) of logVA 0.0. For adaptation, subjects watched a movie at 4m distance for 10min that was convolved frame-by-frame with an astigmatic point spread function, equivalent to +3D defocus, or they watched an unfiltered movie but with spectacle frames with a 0/+3D astigmatic trial lenses. Subsequently, visual acuity was determined at the same distance, using high contrast letter acuity charts. Four experiments were performed. In experiment (1), simulated astigmatic defocus was presented both for adaptation and testing, in experiment (2) optically-induced astigmatic defocus was presented both for adaptation and testing of visual acuity. In all these cases, the +3D power meridian was at 0°. In experiments (3) and (4), the +3D power meridian was at 0° during adaptation but rotated to 90° during testing. Astigmatic defocus was simulated in experiment (3) but optically-induced in experiment (4). Experiments 1 and 2: adaptation to either simulated or real astigmatic defocus increased visual acuity in both test paradigms, simulated (change in VA 0.086±0.069 log units; p<0.01) and lens-induced astigmatic defocus (change in VA 0.068±0.031 log units; p<0.001). Experiments 3 and 4: when the axis was rotated, the improvement in visual acuity failed to reach significance, both for simulated (change in VA 0.042±0.079 log units; p=0.13) and lens-induced astigmatic defocus (change in VA 0.038±0.086 log units; p=0.19). Adaptation to astigmatic defocus occurs for both simulated and real defocus, and the effects of adaptation seem to be selective for the axis of astigmatism. These observations suggest that adaptation involves a re-adjustment of the spatial filters selectively for astigmatic meridians, although the underlying mechanism must be more complicated than just changes in shapes of the receptive fields of retinal or cortical neurons. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

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 (P

Use of a Neural Net to Model the Impact of Optical Coherence Tomography Abnormalities on Vision in Age-related Macular Degeneration.

PubMed

Aslam, Tariq M; Zaki, Haider R; Mahmood, Sajjad; Ali, Zaria C; Ahmad, Nur A; Thorell, Mariana R; Balaskas, Konstantinos

2018-01-01

To develop a neural network for the estimation of visual acuity from optical coherence tomography (OCT) images of patients with neovascular age-related macular degeneration (AMD) and to demonstrate its use to model the impact of specific controlled OCT changes on vision. Artificial intelligence (neural network) study. We assessed 1400 OCT scans of patients with neovascular AMD. Fifteen physical features for each eligible OCT, as well as patient age, were used as input data and corresponding recorded visual acuity as the target data to train, validate, and test a supervised neural network. We then applied this network to model the impact on acuity of defined OCT changes in subretinal fluid, subretinal hyperreflective material, and loss of external limiting membrane (ELM) integrity. A total of 1210 eligible OCT scans were analyzed, resulting in 1210 data points, which were each 16-dimensional. A 10-layer feed-forward neural network with 1 hidden layer of 10 neurons was trained to predict acuity and demonstrated a root mean square error of 8.2 letters for predicted compared to actual visual acuity and a mean regression coefficient of 0.85. A virtual model using this network demonstrated the relationship of visual acuity to specific, programmed changes in OCT characteristics. When ELM is intact, there is a shallow decline in acuity with increasing subretinal fluid but a much steeper decline with equivalent increasing subretinal hyperreflective material. When ELM is not intact, all visual acuities are reduced. Increasing subretinal hyperreflective material or subretinal fluid in this circumstance reduces vision further still, but with a smaller gradient than when ELM is intact. The supervised machine learning neural network developed is able to generate an estimated visual acuity value from OCT images in a population of patients with AMD. These findings should be of clinical and research interest in macular degeneration, for example in estimating visual prognosis or highlighting the importance of developing treatments targeting more visually destructive pathologies. Copyright © 2017 Elsevier Inc. All rights reserved.

[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.

Your Child's Vision

MedlinePlus

... 3½, kids should have eye health screenings and visual acuity tests (tests that measure sharpness of vision) ... eye rubbing extreme light sensitivity poor focusing poor visual tracking (following an object) abnormal alignment or movement ...

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 increases in center point thickening with increases in visual acuity as well as paradoxical decreases in center point thickening with decreases in visual acuity were not uncommon. Thus, although OCT measurements of retinal thickness represent an important tool in clinical evaluation, they cannot reliably substitute as a surrogate for visual acuity at a given point in time. This study does not address whether short-term changes on OCT are predictive of long-term effects on visual acuity. PMID:17123615

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

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 disability in a range >5.77 μV. The results could be useful, especially in cases of no obvious pale disc with trauma. Visual acuity quantification using absolute value of amplitude in pattern visual evoked potentials was useful in confirming subjective visual acuity for cutoff values >5.77 μV in disability evaluation to discriminate the malingering from real disability.

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 acuity associated with malingering vs. real disability in a range >5.77 μV. The results could be useful, especially in cases of no obvious pale disc with trauma. Conclusions Visual acuity quantification using absolute value of amplitude in pattern visual evoked potentials was useful in confirming subjective visual acuity for cutoff values >5.77 μV in disability evaluation to discriminate the malingering from real disability. PMID:22866948

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 throughout the testing. Using the chair as a portable and reliable way to test DVA, we aim to test returning astronauts to assess the amount of retinal slip that they experience. By comparing these measurements to their motion sickness scores (using a scale of 1 to 20 where 20 is vomiting), we will correlate the amount of retinal slip to the level of motion sickness experienced. In addition to testing this in returning astronauts, we will perform ground-based studies to determine the effectiveness of stroboscopic goggles in reducing retinal slip and improving DVA. Finally, we will employ stroboscopic goggles in the field to astronauts experiencing high levels of motion sickness to minimize retinal slip and reduce their symptoms.

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

[Efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema].

PubMed

Razo Blanco-Hernández, Dulce Milagros; Lima-Gómez, Virgilio; Asbun-Bojalil, Juan

2014-01-01

Photocoagulation reduces the incidence of visual loss in diabetic patients with focal macular edema, but it can induce it for Efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema 6 weeks after treatment and produces visual improvement in some cases. Topical ketorolac may reduce the inflammation caused by photocoagulation and improve visual outcome. To determine the efficacy of topical ketorolac for improving visual function after photocoagulation in diabetic patients with focal macular edema. An experimental, comparative, prospective, longitudinal study in diabetic patients with focal macular edema was conducted. Eyes were randomized into two groups of topical treatment for 3 weeks after photocoagulation (A: ketorolac, B: placebo). Best corrected visual acuity before and after treatment was compared in each group (paired t test), and the proportion of eyes with visual improvement was compared between groups (χ(2)). The evaluation was repeated after stratifying for initial visual acuity (≥ 0.5, < 0.5). There were 105 eyes included. In group A (n= 46) mean visual acuity changed from 0.50 to 0.58 (p= 0.003), and from 0.55 to 0.55 in group B (n= 59, p= 0.83); mean percent change was 22.3% in group A and 3.5% in group B (p= 0.03). Visual improvement was identified in 25 eyes from group A (54.3%) and 19 from group B (32.2%, p= 0.019, RR 1.65); the difference only persisted when initial visual acuity was ≥ 0.5 (10 [40%], group A, 5 [14.7%], group B, p= 0.02, RR 2.72). Topical ketorolac was more effective than placebo to improve best corrected visual acuity in diabetic patients with focal macular edema.

[Vision-and health-related quality of life in patients with uveitis].

PubMed

Zhang, J; Yan, H G; Chi, Y; Guo, C Y; Yang, L

2016-06-11

To evaluate vision-and health-related quality of life in patients with uveitis, and to evaluate the relationship between quality of life and visual acuity. Cross-sectional study. One hundred and eleven patients with uveitis were enrolled in the study from January 1, 2013 to April 1, 2014 in Peking University First Hospital. Clinical data collected included medical history, complete ophthalmologic examination and best corrected visual acuity (LogMAR). Basic clinical data (gender, diagnosis, etc.) was also collected. The National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) and the 36-Item Short Form Health Survey (SF-36) were administered. The patients were divided into two groups, anterior uveitis group (ATU), and other types of uveitis in this study (OTU). T-test was used for analysis of the data which obey standard normal distribution, otherwise rank sum test was used for data analysis. Correlation and Linear regression were constructed between bilateral visual acuity and the scores of NEI VFQ-25 and SF-36 questionnaires. For all the 111 cases included in this study, 87 (78.4%) of them were anterior uveitis (ATU), 5 of them were intermediate uveitis, 7 of them were posterior uveitis and 12 of them were pan uveitis. Mean visual acuity of better and worse eye were 0.0 and 0.2 in ATU patients, respectively. Mean visual acuity of better and worse eye were 0.1 and 0.4 in OTU patients, respectively. Patients rated the general health subscale score of NEI VFQ-25 and SF-36 lower than other subscales, respectively (score of general health was 25.0 (25.0-50.0) in NEI VFQ-25 and 46.8 (19.8) in SF-36). ATU group scored higher that OTU group (Mean score of SF-36 was 77.5 (10.7) and 68.8 (16.9) in ATU and OTU group respectively, P value of SF-36< 0.01, t=9.54. Mean score of NEI VFQ-25 was 77.3 (12.8) and 59.1 (16.5) in ATU and OTU group respectively, P value of NEI VFQ-25<0.01, t=33.16). Mean score of NEI VFQ-25 of all patients was 73.4 (15.5). Mean visual acuity of better eye and worse eye of all patients were 0.0 (-0.2-1.0) and 0.3 (0.5), respectively. The correlation coefficient was -0.497 (P<0.01, t=-5.98) between NEI VFQ -25 score and visual acuity in better eye, and -0.32 (t=-3.48, P<0.01) between NEI VFQ-25 score and visual acuity in worse eye. The coefficient was -3.9 in linear regression of visual acuity in better eye against NEI VFQ-25 score (t=-5.98, P<0.01), and -1.1 of visual acuity in worse eye against NEI VFQ-25 score (t=-3.48,P<0.01). General health was more affected than other function subscales in uveitis. The quality of life in anterior uveitis was higher than other types of uveitis in this study. Vision-related quality of life correlated with both eyes.(Chin J Ophthalmol, 2016, 52: 429-436).

Clinical evaluation of a new pupil independent diffractive multifocal intraocular lens with a +2.75 D near addition: a European multicentre study.

PubMed

Kretz, Florian T A; Gerl, Matthias; Gerl, Ralf; Müller, Matthias; Auffarth, Gerd U

2015-12-01

To evaluate the clinical outcomes after cataract surgery with implantation of a new diffractive multifocal intraocular lens (IOL) with a lower near addition (+2.75 D.). 143 eyes of 85 patients aged between 40 years and 83 years that underwent cataract surgery with implantation of the multifocal IOL (MIOL) Tecnis ZKB00 (Abbott Medical Optics,Santa Ana, California, USA) were evaluated. Changes in uncorrected (uncorrected distance visual acuity, uncorrected intermediate visual acuity, uncorrected near visual acuity) and corrected (corrected distance visual acuity, corrected near visual acuity) logMAR distance, intermediate visual acuity and near visual acuity, as well as manifest refraction were evaluated during a 3-month follow-up. Additionally, patients were asked about photic phenomena and spectacle dependence. Postoperative spherical equivalent was within ±0.50 D and ±1.00 D of emmetropia in 78.1% and 98.4% of eyes, respectively. Postoperative mean monocular uncorrected distance visual acuity, uncorrected near visual acuity and uncorrected intermediate visual acuity was 0.20 LogMAR or better in 73.7%, 81.1% and 83.9% of eyes, respectively. All eyes achieved monocular corrected distance visual acuity of 0.30 LogMAR or better. A total of 100% of patients referred to be at least moderately happy with the outcomes of the surgery. Only 15.3% of patients required the use of spectacles for some daily activities postoperatively. The introduction of low add MIOLs follows a trend to increase intermediate visual acuity. In this study a near add of +2.75 D still reaches satisfying near results and leads to high patient satisfaction for intermediate visual acuity. 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/

[Vitrectomy and gas-fluid exchange for the treatment of serous macular detachment due to optic disc pit: long-term evaluation].

PubMed

Moreira Neto, Carlos Augusto; Moreira Junior, Carlos Augusto

2013-01-01

To evaluate 5 patients with serous macular detachment due to optic disc pit that were submitted to pars plana vitrectomy and were followed for at least 7 years. Patients were submitted to pars plana vitrectomy, posterior hyaloid removal, autologous serum injection and gas-fluid exchange, without laser photocoagulation, and were evaluated pre and post-operatively with visual acuity and Amsler grid testing, retinography, and recently, with autofluorescence imaging and high resolution OCT. All 5 eyes improved visual acuity significantly following the surgical procedure maintaining good vision throughout the follow-up period. Mean pre-operative visual acuity was 20/400 and final visual acuity was 20/27 with a mean follow-up time of 13.6 years. No recurrences of serous detachments were observed. OCT examinations demonstrated an attached retina up to the margin of the pit. Serous macular detachments due to optic disc pits were adequately treated with pars plana vitrectomy and gas fluid exchange, without the need for laser photocoagulation, maintaining excellent visual results for a long period of time.

Functional Defects in Color Vision in Patients With Choroideremia.

PubMed

Jolly, Jasleen K; Groppe, Markus; Birks, Jacqueline; Downes, Susan M; MacLaren, Robert E

2015-10-01

To characterize defects in color vision in patients with choroideremia. Prospective cohort study. Thirty patients with choroideremia (41 eyes) and 10 age-matched male controls (19 eyes) with visual acuity of ≥6/36 attending outpatient clinics in Oxford Eye Hospital underwent color vision testing with the Farnsworth-Munsell 100 hue test, visual acuity testing, and autofluorescence imaging. To exclude changes caused by degeneration of the fovea, a subgroup of 14 patients with a visual acuity ≥6/6 was analyzed. Calculated color vision total error scores were compared between the groups and related to a range of factors using a random-effects model. Mean color vision total error scores were 120 (95% confidence interval [CI] 92, 156) in the ≥6/6 choroideremia group, 206 (95% CI 161, 266) in the <6/6 visual acuity choroideremia group, and 47 (95% CI 32, 69) in the control group. Covariate analysis showed a significant difference in color vision total error score between the groups (P < .001 between each group). Patients with choroideremia have a functional defect in color vision compared with age-matched controls. The color vision defect deteriorates as the degeneration encroaches on the fovea. The presence of an early functional defect in color vision provides a useful biomarker against which to assess successful gene transfer in gene therapy trials. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Occlusion properties of prosthetic contact lenses for the treatment of amblyopia.

PubMed

Collins, Randall S; McChesney, Megan E; McCluer, Craig A; Schatz, Martha P

2008-12-01

The efficacy of opaque contact lenses as occlusion therapy for amblyopia has been established in the literature. Prosthetic contact lenses use similar tints to improve cosmesis in scarred or deformed eyes and may be an alternative in occlusion therapy. To test this idea, we determined the degree of vision penalization elicited by prosthetic contact lenses and their effect on peripheral fusion. We tested 19 CIBA Vision DuraSoft 3 Prosthetic soft contact lenses with varying iris prints, underprints, and opaque pupil sizes in 10 volunteers with best-corrected Snellen distance visual acuity of 20/20 or better in each eye. Snellen visual acuity and peripheral fusion using the Worth 4-Dot test at near were measured on each subject wearing each of the 19 lenses. Results were analyzed with 3-factor analysis of variance. Mean visual acuity through the various lenses ranged from 20/79 to 20/620. Eight lenses allowed preservation of peripheral fusion in 50% or more of the subjects tested. Iris print pattern and opaque pupil size were significant factors in determining visual acuity (p < 0.05). Sufficient vision penalization can be achieved to make occlusion with prosthetic contact lenses a viable therapy for amblyopia. The degree of penalization can be varied and different iris print patterns and pupil sizes, using peripheral fusion, can be preserved with some lenses. Prosthetic contact lenses can be more cosmetically appealing and more tolerable than other amblyopia treatment modalities. These factors may improve compliance in occlusion therapy.

The Effect of Dioptric Blur on Reading Performance

PubMed Central

Chung, Susana T.L.; Jarvis, Samuel H.; Cheung, Sing-Hang

2013-01-01

Little is known about the systematic impact of blur on reading performance. The purpose of this study was to quantify the effect of dioptric blur on reading performance in a group of normally sighted young adults. We measured monocular reading performance and visual acuity for 19 observers with normal vision, for five levels of optical blur (no blur, 0.5, 1, 2 and 3D). Dioptric blur was induced using convex trial lenses placed in front of the testing eye, with the pupil dilated and in the presence of a 3 mm artificial pupil. Reading performance was assessed using eight versions of the MNREAD Acuity Chart. For each level of dioptric blur, observers read aloud sentences on one of these charts, from large to small print. Reading time for each sentence and the number of errors made were recorded and converted to reading speed in words per minute. Visual acuity was measured using 4-orientation Landolt C stimuli. For all levels of dioptric blur, reading speed increased with print size up to a certain print size and then remained constant at the maximum reading speed. By fitting nonlinear mixed-effects models, we found that the maximum reading speed was minimally affected by blur up to 2D, but was ~23% slower for 3D of blur. When the amount of blur increased from 0 (no-blur) to 3D, the threshold print size (print size corresponded to 80% of the maximum reading speed) increased from 0.01 to 0.88 logMAR, reading acuity worsened from −0.16 to 0.58 logMAR, and visual acuity worsened from −0.19 to 0.64 logMAR. The similar rates of change with blur for threshold print size, reading acuity and visual acuity implicates that visual acuity is a good predictor of threshold print size and reading acuity. Like visual acuity, reading performance is susceptible to the degrading effect of optical blur. For increasing amount of blur, larger print sizes are required to attain the maximum reading speed. PMID:17442363

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.

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.

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

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.

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.

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.

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.

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.

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 available, and will be made available online at https://phekb.org. PMID:27146002

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.

[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) .

Is vision function related to physical functional ability in older adults?

PubMed

West, Catherine G; Gildengorin, Ginny; Haegerstrom-Portnoy, Gunilla; Schneck, Marilyn E; Lott, Lori; Brabyn, John A

2002-01-01

To assess the relationship between a broad range of vision functions and measures of physical performance in older adults. Cross-sectional study. Population-based cohort of community-dwelling older adults, subset of an on-going longitudinal study. Seven hundred eighty-two adults aged 55 and older (65% of living eligible subjects) had subjective health measures and objective physical performance evaluated in 1989/91 and again in 1993/95 and a battery of vision functions tested in 1993/95. Comprehensive battery of vision tests (visual acuity, contrast sensitivity, effects of illumination level, contrast and glare on acuity, visual fields with and without attentional load, color vision, temporal sensitivity, and the impact of dimming light on walking ability) and physical function measures (self-reported mobility limitations and observed measures of walking, rising from a chair and tandem balance). The failure rate for all vision functions and physical performance measures increased exponentially with age. Standard high-contrast visual acuity and standard visual fields showed the lowest failure rates. Nonstandard vision tests showed much higher failure rates. Poor performance on many individual vision functions was significantly associated with particular individual measures of physical performance. Using constructed combination vision variables, significant associations were found between spatial vision, field integrity, binocularity and/or adaptation, and each of the functional outcomes. Vision functions other than standard visual acuity may affect day-to-day functioning of older adults. Additional studies of these other aspects of vision and how they can be treated or rehabilitated are needed to determine whether these aspects play a role in strategies for reducing disability in older adults.

[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.

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

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.

Cataract Surgery Outcomes in Uveitis: The Multicenter Uveitis Steroid Treatment Trial.

PubMed

Sen, H Nida; Abreu, Francis M; Louis, Thomas A; Sugar, Elizabeth A; Altaweel, Michael M; Elner, Susan G; Holbrook, Janet T; Jabs, Douglas A; Kim, Rosa Y; Kempen, John H

2016-01-01

To assess the visual outcomes of cataract surgery in eyes that received fluocinolone acetonide implant or systemic therapy with oral corticosteroids and immunosuppression during the Multicenter Uveitis Steroid Treatment (MUST) Trial. Nested prospective cohort study of patients enrolled in a randomized clinical trial. Patients that underwent cataract surgery during the first 2 years of follow-up in the MUST Trial. Visual outcomes of cataract surgery were evaluated 3, 6, and 9 months after surgery using logarithmic visual acuity charts. Change in visual acuity over time was assessed using a mixed-effects model. Best-corrected visual acuity. After excluding eyes that underwent cataract surgery simultaneously with implant surgery, among the 479 eyes in the MUST Trial, 117 eyes (28 eyes in the systemic, 89 in the implant group) in 82 patients underwent cataract surgery during the first 2 years of follow-up. Overall, visual acuity increased by 23 letters from the preoperative visit to the 3-month visit (95% confidence interval [CI], 17-29 letters; P < 0.001) and was stable through 9 months of follow-up. Eyes presumed to have a more severe cataract, as measured by inability to grade vitreous haze, gained an additional 42 letters (95% CI, 34-56 letters; P < 0.001) beyond the 13-letter gain in eyes that had gradable vitreous haze before surgery (95% CI, 9-18 letters; P < 0.001) 3 months after surgery, making up for an initial difference of -45 letters at the preoperative visit (95% CI, -56 to -34 letters; P < 0.001). Black race, longer time from uveitis onset, and hypotony were associated with worse preoperative visual acuity (P < 0.05), but did not affect postsurgical recovery (P > 0.05, test of interaction). After adjusting for other risk factors, there was no significant difference in the improvement in visual acuity between the 2 treatment groups (implant vs. systemic therapy, 2 letters; 95% CI, -10 to 15 letters; P = 0.70). Cataract surgery resulted in substantial, sustained, and similar visual acuity improvement in the eyes of patients with uveitis treated with the fluocinolone acetonide implant or standard systemic therapy. Published by Elsevier Inc.

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-trabeculectomy-trabeculectomy sequence for black patients and of the trabeculectomy-ALT-trabeculectomy sequence for white patients without life-threatening health problems. The choice of treatment should take into account individual patient characteristics and needs.

Testing the generality of the zoom-lens model: Evidence for visual-pathway specific effects of attended-region size on perception.

PubMed

Goodhew, Stephanie C; Lawrence, Rebecca K; Edwards, Mark

2017-05-01

There are volumes of information available to process in visual scenes. Visual spatial attention is a critically important selection mechanism that prevents these volumes from overwhelming our visual system's limited-capacity processing resources. We were interested in understanding the effect of the size of the attended area on visual perception. The prevailing model of attended-region size across cognition, perception, and neuroscience is the zoom-lens model. This model stipulates that the magnitude of perceptual processing enhancement is inversely related to the size of the attended region, such that a narrow attended-region facilitates greater perceptual enhancement than a wider region. Yet visual processing is subserved by two major visual pathways (magnocellular and parvocellular) that operate with a degree of independence in early visual processing and encode contrasting visual information. Historically, testing of the zoom-lens has used measures of spatial acuity ideally suited to parvocellular processing. This, therefore, raises questions about the generality of the zoom-lens model to different aspects of visual perception. We found that while a narrow attended-region facilitated spatial acuity and the perception of high spatial frequency targets, it had no impact on either temporal acuity or the perception of low spatial frequency targets. This pattern also held up when targets were not presented centrally. This supports the notion that visual attended-region size has dissociable effects on magnocellular versus parvocellular mediated visual processing.

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.

Measuring colour rivalry suppression in amblyopia.

PubMed

Hofeldt, T S; Hofeldt, A J

1999-11-01

To determine if the colour rivalry suppression is an index of the visual impairment in amblyopia and if the stereopsis and fusion evaluator (SAFE) instrument is a reliable indicator of the difference in visual input from the two eyes. To test the accuracy of the SAFE instrument for measuring the visual input from the two eyes, colour rivalry suppression was measured in six normal subjects. A test neutral density filter (NDF) was placed before one eye to induce a temporary relative afferent defect and the subject selected the NDF before the fellow eye to neutralise the test NDF. In a non-paediatric private practice, 24 consecutive patients diagnosed with unilateral amblyopia were tested with the SAFE. Of the 24 amblyopes, 14 qualified for the study because they were able to fuse images and had no comorbid disease. The relation between depth of colour rivalry suppression, stereoacuity, and interocular difference in logMAR acuity was analysed. In normal subjects, the SAFE instrument reversed temporary defects of 0.3 to 1. 8 log units to within 0.6 log units. In amblyopes, the NDF to reverse colour rivalry suppression was positively related to interocular difference in logMAR acuity (beta=1.21, p<0.0001), and negatively related to stereoacuity (beta=-0.16, p=0.019). The interocular difference in logMAR acuity was negatively related to stereoacuity (beta=-0.13, p=0.009). Colour rivalry suppression as measured with the SAFE was found to agree closely with the degree of visual acuity impairment in non-paediatric patients with amblyopia.

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.

Temporal Ventriloquism Reveals Intact Audiovisual Temporal Integration in Amblyopia.

PubMed

Richards, Michael D; Goltz, Herbert C; Wong, Agnes M F

2018-02-01

We have shown previously that amblyopia involves impaired detection of asynchrony between auditory and visual events. To distinguish whether this impairment represents a defect in temporal integration or nonintegrative multisensory processing (e.g., cross-modal matching), we used the temporal ventriloquism effect in which visual temporal order judgment (TOJ) is normally enhanced by a lagging auditory click. Participants with amblyopia (n = 9) and normally sighted controls (n = 9) performed a visual TOJ task. Pairs of clicks accompanied the two lights such that the first click preceded the first light, or second click lagged the second light by 100, 200, or 450 ms. Baseline audiovisual synchrony and visual-only conditions also were tested. Within both groups, just noticeable differences for the visual TOJ task were significantly reduced compared with baseline in the 100- and 200-ms click lag conditions. Within the amblyopia group, poorer stereo acuity and poorer visual acuity in the amblyopic eye were significantly associated with greater enhancement in visual TOJ performance in the 200-ms click lag condition. Audiovisual temporal integration is intact in amblyopia, as indicated by perceptual enhancement in the temporal ventriloquism effect. Furthermore, poorer stereo acuity and poorer visual acuity in the amblyopic eye are associated with a widened temporal binding window for the effect. These findings suggest that previously reported abnormalities in audiovisual multisensory processing may result from impaired cross-modal matching rather than a diminished capacity for temporal audiovisual integration.

[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.

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.

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.).

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.

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.

Presumed latent ocular tuberculosis diagnosed with the positive quantiFERON-TB Gold In-Tube Test in a HLA-A29-positive patient.

PubMed

Rangel, Carlos Mario; Atencia, Cesar; Merayo-Lloves, Jesus; Fernandez-Vega Sanz, Alvaro

2015-06-04

A 59-year-old Hispanic woman presented with a 3-year history of floaters associated with bilateral reduced visual acuity. Her best-corrected visual acuity (BCVA) was 20/40. Both anterior segments were without inflammation, but fundoscopy showed mild vitreous inflammation and multiple inflammatory choroidal lesions. Tests for inflammatory and infectious diseases were negative except for human leucocyte antigen A29. The patient was diagnosed with birdshot choroidoretinopathy, and treatment was initiated with cyclosporine A 2.5 mg/kg/day. One year after treatment, the patient reported systemic symptoms with no improvement in visual acuity. Fundus findings remained with vitreal inflammation. QuantiFERON-TB Gold In-Tube Test was positive, and a diagnosis of presumed latent ocular tuberculosis (TB) was made. We initiated anti-TB treatment for 9 months. At 6 months of anti-TB therapy, there was no active inflammation. The patient was followed for 2 years with no medications and no active inflammation. Her final BCVA was 20/25. 2015 BMJ Publishing Group Ltd.

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 to accommodate this newly discovered independence of acuity and crowding. PMID:24799622

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.

Maternal and infant essential fatty acid status in Havana, Cuba.

PubMed

Krasevec, Julia M; Jones, Peter J; Cabrera-Hernandez, Alejandrina; Mayer, D Luisa; Connor, William E

2002-10-01

Adequate intake of essential fatty acids (EFAs) is required for optimal development of the central nervous system and visual acuity in infants. Little information exists regarding the EFA status of vulnerable populations living in Southern regions. We examined the adequacy of EFA status in Cuban breast-feeding mothers and their infants. Blood and breast-milk samples were obtained from a cross-sectional sample of mothers and term infants in Havana at 2 mo postpartum. We determined the fatty acid profiles of total lipids in breast milk, plasma, and erythrocytes and assessed infant visual acuity by using Teller acuity cards. Of the 56 mothers and infants examined, none showed biochemical signs of poor EFA status. Compared with values reported in the literature, mothers had an adequate EFA profile in their breast milk, plasma, and erythrocytes. The docosahexaenoic acid (DHA) concentration in breast milk was 0.43 +/- 0.26% of total fatty acids. It appeared that these breast-fed infants had an adequate dietary supply of DHA, as reflected by the mean plasma and erythrocyte DHA concentrations (2.82 +/- 0.84% and 7.41 +/- 1.16% of total fatty acids, respectively). Infant visual acuity testing showed a mean of 2.00 +/- 0.68 cycles/degree, which is within the normal range of mean binocular acuities for 2-mo-old term infants. The data did not show any relation between EFA concentrations and visual acuity. The results suggest that n-3 fatty acid deficiency and potential related deficits in early visual neural development are rare, if they exist at all, in breast-feeding women and their infants in Havana.

Visual abilities of students with severe developmental delay in special needs education - a vision screening project in Northern Jutland, Denmark.

PubMed

Welinder, Lotte G; Baggesen, Kirsten L

2012-12-01

To investigate the visual abilities of students with severe developmental delay (DD) age 6-8 starting in special needs education. Between 1 January 2000 and 31 December 2008, we screened all students with severe DD starting in special needs schools in Northern Jutland, Denmark for vision. All students with visual acuities ≤6/12 were refractioned and examined by an ophthalmologist. Of 502 students, 56 (11%) had visual impairment (VI) [visual acuity (VA) ≤ 6/18], of which 21 had been previously undiagnosed. Legal blindness was found in 15 students (3%), of whom three had previously been undiagnosed. Students tested with preferential looking systems (N = 78) had significantly lower visual acuities [VA (decimal) = 0.55] than students tested with ortho types [VA (decimal) = 0.91] and had problems participating in the colour and form tests, possibly due to cerebral VI. The number of students with decreased vision identified by screening decreased significantly during the study period (r = 0.724, p = 0.028). The number of students needed to be screened to find one student with VI was 24 and to identify legal blindness 181 needed to be screened. Visual impairment is a common condition in students with severe DD. Despite increased awareness of VI in the school and health care system, we continued to find a considerable number of students with hitherto undiagnosed decreased vision. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

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.

Spatial and Global Sensory Suppression Mapping Encompassing the Central 10° Field in Anisometropic Amblyopia.

PubMed

Li, Jingjing; Li, Jinrong; Chen, Zidong; Liu, Jing; Yuan, Junpeng; Cai, Xiaoxiao; Deng, Daming; Yu, Minbin

2017-01-01

We investigate the efficacy of a novel dichoptic mapping paradigm in evaluating visual function of anisometropic amblyopes. Using standard clinical measures of visual function (visual acuity, stereo acuity, Bagolini lenses, and neutral density filters) and a novel quantitative mapping technique, 26 patients with anisometropic amblyopia (mean age = 19.15 ± 4.42 years) were assessed. Two additional psychophysical interocular suppression measurements were tested with dichoptic global motion coherence and binocular phase combination tasks. Luminance reduction was achieved by placing neutral density filters in front of the normal eye. Our study revealed that suppression changes across the central 10° visual field by mean luminance modulation in amblyopes as well as normal controls. Using simulation and an elimination of interocular suppression, we identified a novel method to effectively reflect the distribution of suppression in anisometropic amblyopia. Additionally, the new quantitative mapping technique was in good agreement with conventional clinical measures, such as interocular acuity difference (P < 0.001) and stereo acuity (P = 0.005). There was a good consistency between the results of interocular suppression with dichoptic mapping paradigm and the results of the other two psychophysical methods (suppression mapping versus binocular phase combination, P < 0.001; suppression mapping versus global motion coherence, P = 0.005). The dichoptic suppression mapping technique is an effective method to represent impaired visual function in patients with anisometropic amblyopia. It offers a potential in "micro-"antisuppression mapping tests and therapies for amblyopia.

STS-44 Pilot Henricks uses Visual Function Tester (VFT) on OV-104's middeck

NASA Image and Video Library

1991-12-01

STS044-14-013 (24 Nov-1 Dec 1991) --- Terence T. (Tom) Henricks, STS-44 pilot, tests his visual acuity with the Visual Function Test (VFT) apparatus. This photograph was among the first released by NASA following the eight day mission, dedicated to the Department of Defense.

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.

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, respectively). At 15 years of age, most children treated for moderate amblyopia when younger than 7 years have good visual acuity, although mild residual amblyopia is common. The outcome is similar regardless of initial treatment with atropine or patching. The results indicate that improvement occurring with amblyopia treatment is maintained until at least 15 years of age. clinicaltrials.gov Identifier: NCT00000170.

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.

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.

Medical Surveillance Programs for Aircraft Maintenance Personnel Performing Nondestructive Inspection and Testing

DTIC Science & Technology

2005-11-01

visible and fl uorescent inspection techniques, while radiography relies on the individual’s ability to detect subtle differences in contrast either...binocular measurement of visual acuity may better predict a person’s functional capability in the workplace . However, measurement of monocular acuities

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 determinants of reduced performance on the Stroop color-word test in normal aging individuals.

PubMed

van Boxtel, M P; ten Tusscher, M P; Metsemakers, J F; Willems, B; Jolles, J

2001-10-01

It is unknown to what extent the performance on the Stroop color-word test is affected by reduced visual function in older individuals. We tested the impact of common deficiencies in visual function (reduced distant and close acuity, reduced contrast sensitivity, and color weakness) on Stroop performance among 821 normal individuals aged 53 and older. After adjustment for age, sex, and educational level, low contrast sensitivity was associated with more time needed on card I (word naming), red/green color weakness with slower card 2 performance (color naming), and reduced distant acuity with slower performance on card 3 (interference). Half of the age-related variance in speed performance was shared with visual function. The actual impact of reduced visual function may be underestimated in this study when some of this age-related variance in Stroop performance is mediated by visual function decrements. It is suggested that reduced visual function has differential effects on Stroop performance which need to be accounted for when the Stroop test is used both in research and in clinical settings. Stroop performance measured from older individuals with unknown visual status should be interpreted with caution.

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.

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

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.

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

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.

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.

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

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

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.

Combination therapy with diquafosol tetrasodium and sodium hyaluronate in patients with dry eye after laser in situ keratomileusis.

PubMed

Toda, Ikuko; Ide, Takeshi; Fukumoto, Teruki; Ichihashi, Yoshiyuki; Tsubota, Kazuo

2014-03-01

To evaluate the possible advantages of combination therapy with diquafosol tetrasodium and sodium hyaluronate for dry eye after laser in situ keratomileusis (LASIK). Prospective randomized comparative trial. A total of 206 eyes of 105 patients who underwent LASIK were enrolled in this study. Patients were randomly assigned to 1 of 4 treatment groups according to the postoperative treatment: artificial tears, sodium hyaluronate, diquafosol tetrasodium, and a combination of hyaluronate and diquafosol. Questionnaire responses reflecting subjective dry eye symptoms, uncorrected and corrected visual acuity, functional visual acuity, manifest refraction, tear break-up time, fluorescein corneal staining, Schirmer test, and corneal sensitivity were examined before and 1 week and 1 month after LASIK. Distance uncorrected visual acuity was significantly better in the combination group than in the hyaluronate group 1 week and 1 month after LASIK. Near uncorrected visual acuity was significantly better in the combination group than in the artificial tear and diquafosol groups 1 week and 1 month after LASIK. Distance functional visual acuity improved significantly only in the combination group 1 month after LASIK. The Schirmer value in the combination group was significantly higher than that in the hyaluronate group at 1 month after LASIK. Subjective dry eye symptoms in the combination group improved significantly compared with those in the other groups 1 week after surgery. Our results suggest that hyaluronate and diquafosol combination therapy is beneficial for early stabilization of visual performance and improvement of subjective dry eye symptoms in patients after LASIK. Copyright © 2014 Elsevier Inc. All rights reserved.

[Astigmatic keratotomy with the femtosecond laser: correction of high astigmatisms after keratoplasty].

PubMed

Kook, D; Bühren, J; Klaproth, O K; Bauch, A S; Derhartunian, V; Kohnen, T

2011-02-01

The purpose of this study was to evaluate a novel technique for the correction of postoperative astigmatism after penetrating keratoplasty with the use of the femtosecond laser creating astigmatic keratotomies (femto-AK) in the scope of a retrospective case series. Clinical data of ten eyes of nine patients with high residual astigmatism after penetrating keratoplasty undergoing paired femto-AK using a 60-kHz femtosecond laser (IntraLase™, AMO) were analyzed. A new software algorithm was used to create paired arcuate cuts deep into the donor corneal button with different cut angles. Target values were refraction, uncorrected visual acuity, best corrected visual acuity, topographic data (Orbscan®, Bausch & Lomb, Rochester, NY, USA), and corneal wavefront analysis using Visual Optics Lab (VOL)-Pro 7.14 Software (Sarver and Associates). Vector analysis was performed using the Holladay, Cravy and Koch formula. Statistical analysis was performed to detect significances between visits using Student's t test. All procedures were performed without any major complications. The mean follow-up was 13 months. The mean patient age was 48.7 years. The preoperative mean uncorrected visual acuity (logMAR) was 1.27, best corrected visual acuity 0.55, mean subjective cylinder -7.4 D, and mean topometric astigmatism 9.3 D. The postoperative mean uncorrected visual acuity (logMAR) was 1.12, best corrected visual acuity 0.47, mean subjective cylinder -4.1 D, and mean topometric astigmatism 6.5 D. Differences between corneal higher order aberrations showed a high standard deviation and were therefore not statistically significant. Astigmatic keratotomy using the femtosecond laser seems to be a safe and effective tool for the correction of higher corneal astigmatisms. Due to the biomechanical properties of the cornea and missing empirical data for the novel femto-AK technology, higher numbers of patients are necessary to develop optimal treatment nomograms.

The influence of visual ability on learning and memory performance in 13 strains of mice.

PubMed

Brown, Richard E; Wong, Aimée A

2007-03-01

We calculated visual ability in 13 strains of mice (129SI/Sv1mJ, A/J, AKR/J, BALB/cByJ, C3H/HeJ, C57BL/6J, CAST/EiJ, DBA/2J, FVB/NJ, MOLF/EiJ, SJL/J, SM/J, and SPRET/EiJ) on visual detection, pattern discrimination, and visual acuity and tested these and other mice of the same strains in a behavioral test battery that evaluated visuo-spatial learning and memory, conditioned odor preference, and motor learning. Strain differences in visual acuity accounted for a significant proportion of the variance between strains in measures of learning and memory in the Morris water maze. Strain differences in motor learning performance were not influenced by visual ability. Conditioned odor preference was enhanced in mice with visual defects. These results indicate that visual ability must be accounted for when testing for strain differences in learning and memory in mice because differences in performance in many tasks may be due to visual deficits rather than differences in higher order cognitive functions. These results have significant implications for the search for the neural and genetic basis of learning and memory in mice.

Clinical outcomes of combined versus separate carbachol and brimonidine drops in correcting presbyopia.

PubMed

Abdelkader, Almamoun; Kaufman, Herbert E

2016-01-01

To test and compare in a masked fashion the efficacy of using a parasympathomimetic drug (3% carbachol) and an alpha-2 agonist (0.2% brimonidine) in both combined and separate forms to create optically beneficial miosis to pharmacologically improve vision in presbyopia. A prospective, double-masked, randomized, controlled clinical trial was conducted. Ten naturally emmetropic and presbyopic subjects between 42 and 58 years old with uncorrected distance visual acuity of at least 20/20 in both eyes without additional ocular pathology were eligible for inclusion. All subjects received 3% carbachol and 0.2% brimonidine in both combined and separate forms, 3% carbachol alone and 0.2% brimonidine (control) alone in their non-dominant eye in a crossover manner with one week washout between tests. The subjects' pupil sizes and both near and distance visual acuities will be evaluated pre- and post-treatment at 1, 2, 4, and 8 h, by a masked examiner at the same room illumination. Statistically significant improvement in mean near visual acuity (NVA) was achieved in all subjects who received combined 3% carbachol and 0.2% brimonidine in the same formula compared with those who received separate forms or carbachol alone or brimonidine alone ( P  < 0.0001). Based on the data, the combined solution demonstrated greater efficacy than the other solutions that were tested. Improving the depth of focus by making the pupil small caused statistically significant improvement in near visual acuity, with no change in binocular distance vision. ACTRN12616001565437. Registered 11 November 2016.

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) in the type 2 patients (age-adjusted odds ratio, 3.9). Visual acuity and visual field area were more impaired in patients with type 1 than type 2 Usher syndrome. Of note, 27 of 53 type 1 (51%) and 87 of 120 type 2 (72%) patients had a visual acuity of 20/40 or better in at least 1 eye. These data are useful for overall counseling of patients with Usher syndrome.

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.

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

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.

The challenges of developing a contrast-based video game for treatment of amblyopia

PubMed Central

Hussain, Zahra; Astle, Andrew T.; Webb, Ben S.; McGraw, Paul V.

2014-01-01

Perceptual learning of visual tasks is emerging as a promising treatment for amblyopia, a developmental disorder of vision characterized by poor monocular visual acuity. The tasks tested thus far span the gamut from basic psychophysical discriminations to visually complex video games. One end of the spectrum offers precise control over stimulus parameters, whilst the other delivers the benefits of motivation and reward that sustain practice over long periods. Here, we combined the advantages of both approaches by developing a video game that trains contrast sensitivity, which in psychophysical experiments, is associated with significant improvements in visual acuity in amblyopia. Target contrast was varied adaptively in the game to derive a contrast threshold for each session. We tested the game on 20 amblyopic subjects (10 children and 10 adults), who played at home using their amblyopic eye for an average of 37 sessions (approximately 11 h). Contrast thresholds from the game improved reliably for adults but not for children. However, logMAR acuity improved for both groups (mean = 1.3 lines; range = 0–3.6 lines). We present the rationale leading to the development of the game and describe the challenges of incorporating psychophysical methods into game-like settings. PMID:25404922

The challenges of developing a contrast-based video game for treatment of amblyopia.

PubMed

Hussain, Zahra; Astle, Andrew T; Webb, Ben S; McGraw, Paul V

2014-01-01

Perceptual learning of visual tasks is emerging as a promising treatment for amblyopia, a developmental disorder of vision characterized by poor monocular visual acuity. The tasks tested thus far span the gamut from basic psychophysical discriminations to visually complex video games. One end of the spectrum offers precise control over stimulus parameters, whilst the other delivers the benefits of motivation and reward that sustain practice over long periods. Here, we combined the advantages of both approaches by developing a video game that trains contrast sensitivity, which in psychophysical experiments, is associated with significant improvements in visual acuity in amblyopia. Target contrast was varied adaptively in the game to derive a contrast threshold for each session. We tested the game on 20 amblyopic subjects (10 children and 10 adults), who played at home using their amblyopic eye for an average of 37 sessions (approximately 11 h). Contrast thresholds from the game improved reliably for adults but not for children. However, logMAR acuity improved for both groups (mean = 1.3 lines; range = 0-3.6 lines). We present the rationale leading to the development of the game and describe the challenges of incorporating psychophysical methods into game-like settings.

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.

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 visual performance.

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 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. We found that healthy subjects (n=20) have a significantly impaired DVA while wearing the minifying lenses, demonstrating that the VOR is in an adaptive state and retinal slip is occurring. When subjects' acuity was tested wearing the stroboscopic goggles with the minifying lenses, there was no significant difference in their DVA compared to their baseline DVA. This suggests that stroboscopic goggles are preventing retinal slip and would function as an efficient countermeasure for VOR adaptations and thus help mitigate landing sickness symptoms experienced by long-duration crewmembers. These goggles might also be used to counter blurred vision (caused by retinal slip) experienced by crewmembers during launch where the vehicle vibrations are greatest. The stroboscopic effect could be built into a section of their head mounted displays on the visor of their helmets to be used in these high vibration situation if a mission critical task is necessary.

Comparison of contrast sensitivity in β-thalassemia patients treated by deferoxamine or deferasirox.

PubMed

Ghazanfari, Azam; Jafarzadehpour, Ebrahim; Heydarian, Samira; Nowroozpoor Dailami, Kiumars; Karami, Hosein

2018-03-10

To compare contrast sensitivity (CS) in multi-transfused β-thalassemia patients who received deferoxamine with those who received Osveral. In this cross sectional study a total of 60 β-thalassemia patients (30 used deferoxamine and 30 used deferasirox) were regarded as case group and 30 age and sex matched healthy subjects were selected as control group. All subjects had a set of examinations including refraction, visual acuity, Biomicroscopy, ophthalmoscopy and CS. Contrast threshold was assessed with the use of Freiberg visual acuity and contrast test under the mesopic light condition for three frequencies; 1, 5, 15cpd. All data analysis was performed using SPSS, version 17. In visual acuity tests, thalassemic patients did not have any problem. Contrast threshold was higher in thalassemic patients who infuse deferoxamine (1.87±0.63, 1.46±0.81, and 2.96±1.68 in 1, 5, and 15cpd, respectively) than that of those who intake deferasirox (1.74±0.80 (P=0.743), 0.99±0.74 (P=0.047), and 2.42±1.36 (P=0.321) for 1, 5, and 15cpd, respectively), and also than healthy patients (1.33±0.58 (P=0.009), 0.95±0.68 (P=0.022), and 2.24±1.23 (P=0.135) for 1, 5, and 15cpd, respectively). Comparing those who used deferasirox with healthy subjects, contrast threshold was higher in deferasirox group at all special frequencies (P>0.05). No significant relationship was observed between CS values and duration of transfusion, serum ferritin concentration and dose of chelation therapy (P>0.05). CS tests can detect visual disturbance in thalassemic patients before the impairment of visual acuity. It is suggested that CS tests be included in their regular eye examination. Copyright © 2018 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

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-reported vision as both screening tool and outcome measure, but did not directly measure vision. One study used a combination of self-reported vision and visual acuity measurement: participants reporting vision problems at screening were treated by the attending doctor, referred to an eye care specialist or given information about resources that were available to assist with poor vision. There was a similar risk of "not seeing well" at follow-up in people screened compared with people not screened in meta-analysis of six studies (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.97 to 1.14, 4522 participants high-certainty evidence). One trial reported "improvement in vision" and this occurred slightly less frequently in the screened group (RR 0.85, 95% CI 0.52 to 1.40, 230 participants, moderate-certainty evidence).Two trials compared vision screening (visual acuity testing) alone with no vision screening. In one study, distance visual acuity was similar in the two groups at follow-up (mean difference (MD) 0.02 logMAR, 95% CI -0.02 to 0.05, 532 participants, high-certainty evidence). There was also little difference in near acuity (MD 0.02 logMAR, 95% CI -0.03 to 0.07, 532 participants, high-certainty evidence). There was no evidence of any important difference in quality of life (MD -0.06 National Eye Institute 25-item visual function questionnaire (VFQ-25) score adjusted for baseline VFQ-25 score, 95% CI -2.3 to 1.1, 532 participants, high-certainty evidence). The other study could not be included in the data analysis as the number of participants in each of the arms at follow-up could not be determined. However the authors stated that there was no significant difference in mean visual acuity in participants who had visual acuity assessed at baseline (39 letters) as compared to those who did not have their visual acuity assessed (35 letters, P = 0.25, 121 participants).One trial compared a detailed health assessment including measurement of visual acuity (intervention) with a brief health assessment including one question about vision (standard care). People given the detailed health assessment had a similar risk of visual impairment (visual acuity worse than 6/18 in either eye) at follow-up compared with people given the brief assessment (RR 1.07, 95% CI 0.84 to 1.36, 1807 participants, moderate-certainty evidence). The mean composite score of the VFQ-25 was 86.0 in the group that underwent visual acuity screening compared with 85.6 in the standard care group, a difference of 0.40 (95% CI -1.70 to 2.50, 1807 participants, high-certainty evidence). The evidence from RCTs undertaken to date does not support vision screening for older people living independently in a community setting, whether in isolation or as part of a multi-component screening package. This is true for screening programmes involving questions about visual problems, or direct measurements of visual acuity.The most likely reason for this negative review is that the populations within the trials often did not take up the offered intervention as a result of the vision screening and large proportions of those who did not have vision screening appeared to seek their own intervention. Also, trials that use questions about vision have a lower sensitivity and specificity than formal visual acuity testing. Given the importance of visual impairment among older people, further research into strategies to improve vision of older people is needed. The effectiveness of an optimised primary care-based screening intervention that overcomes possible factors contributing to the observed lack of benefit in trials to date warrants assessment; trials should consider including more dependent participants, rather than those living independently in the community.

[Grid laser photocoagulation in diffuse diabetic macular edema].

PubMed

Degenring, Robert F; Hugger, Philipp; Sauder, Gangolf; Jonas, Jost B

2004-01-01

To evaluate the clinical outcome of macular grid laser photocoagulation in the treatment of diffuse diabetic macular oedema. The retrospective study included 30 consecutive patients (41 eyes) who were treated by macular argon green grid laser photocoagulation for diffuse diabetic macular oedema. Follow-up time was 31.4 +/- 19.6 weeks. Visual acuity decreased from 0.25 +/- 0.18 (range, 0.03 - 0.8) to 0.20 +/- 0.18 (range, 0.02 - 0.8) (P = 0.045), representing a change of - 0.9 +/- 2,32 lines. 5 (12.2 %) eyes gained in visual acuity, visual acuity remained unchanged for 23 (56.1 %) eyes, and 13 (31.7 %) eyes showed a visual loss of more than one line. In eyes with a baseline visual acuity > or = 0.2 (N = 24) visual acuity dropped from 0.36 +/- 0.15 (0.2 - 0.8; median 0.3) to 0.29 +/- 0.19 (0.05 - 0.8; median 0.2) (p = 0.038). 3 eyes (12.5 %) gained > or = 2 lines, 11 eyes (45.8 %) lost > or = 2 lines, 10 eyes (41.7 %) remained stable. Mean loss was - 1.63 +/- 2.53 lines. Eyes with a baseline visual acuity < or = 0.2 did not change significantly. In the present study mean visual acuity decreased in the whole population and especially in the subgroup with a baseline visual acuity of > or = 0.2 after macular grid laser photocoagulation for diffuse diabetic macular oedema. Mean visual loss was just below the predefined 2 lines. In view of these results and upcoming new pharmacological and surgical treatment modalities, the significance of grid laser photocoagulation should be re-discussed.

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.

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.

Sequels, complications and management of a chemical burn associated with cement splash.

PubMed

Lim, Gerald C S; Yeh, Lung-Kun; Lin, Hsin-Chiung; Hwang, Chao-Ming

2006-01-01

We present a case of successful superficial keratectomy and amniotic membrane grafting to re-establish ocular surface from denuded stroma and significant limbal ischemia caused by a cement splash. We fully documented a case report about the sequels, complications and management strategies of a chemical burn to the eyes associated with a cement splash. Slit lamp examination, visual acuity test as well as all common cultures and stains were performed to measure the outcome. Visual acuity significantly improved from 0.2 to best-corrected visual acuity 0.7 at the 5-month postoperative visit. The cornea regained its clarity. Total re-epithelialization of the injured area was observed. It is of primary importance to remove all the debris from a cement splash at the first available opportunity. Superficial keratectomy and amniotic membrane grafting may be the best methods for the re-epithelialization and reconstruction of the ocular surface.

An ancient eye test--using the stars.

PubMed

Bohigian, George M

2008-01-01

Vision testing in ancient times was as important as it is today. The predominant vision testing in some cultures was the recognition and identification of constellations and celestial bodies of the night sky. A common ancient naked eye test used the double star of the Big Dipper in the constellation Ursa Major or the Big Bear. The second star from the end of the handle of the Big Dipper is an optical double star. The ability to perceive this separation of these two stars, Mizar and Alcor, was considered a test of good vision and was called the "test" or presently the Arab Eye Test. This article is the first report of the correlation of this ancient eye test to the 20/20 line in the current Snellen visual acuity test. This article describes the astronomy, origin, history, and the practicality of this test and how it correlates with the present day Snellen visual acuity test.

Does functional vision behave differently in low-vision patients with diabetic retinopathy?--A case-matched study.

PubMed

Ahmadian, Lohrasb; Massof, Robert

2008-09-01

A retrospective case-matched study designed to compare patients with diabetic retinopathy (DR) and other ocular diseases, managed in a low-vision clinic, in four different types of functional vision. Reading, mobility, visual motor, and visual information processing were measured in the patients (n = 114) and compared with those in patients with other ocular diseases (n = 114) matched in sex, visual acuity (VA), general health status, and age, using the Activity Inventory as a Rasch-scaled measurement tool. Binocular distance visual acuity was categorized as normal (20/12.5-20/25), near normal (20/32-20/63), moderate (20/80-20/160), severe (20/200-20/400), profound (20/500-20/1000), and total blindness (20/1250 to no light perception). Both Wilcoxon matched pairs signed rank test and the sign test of matched pairs were used to compare estimated functional vision measures between DR cases and controls. Cases ranged in age from 19 to 90 years (mean age, 67.5), and 59% were women. The mean visual acuity (logMar scale) was 0.7. Based on the Wilcoxon signed rank test analyses and after adjusting the probability for multiple comparisons, there was no statistically significant difference (P > 0.05) between patients with DR and control subjects in any of four functional visions. Furthermore, diabetic retinopathy patients did not differ (P > 0.05) from their matched counterparts in goal-level vision-related functional ability and total visual ability. Visual impairment in patients with DR appears to be a generic and non-disease-specific outcome that can be explained mainly by the end impact of the disease in the patients' daily lives and not by the unique disease process that results in the visual impairment.

Comparison of Aflibercept, Bevacizumab, and Ranibizumab for Treatment of Diabetic Macular Edema: Extrapolation of Data to Clinical Practice.

PubMed

Heier, Jeffrey S; Bressler, Neil M; Avery, Robert L; Bakri, Sophie J; Boyer, David S; Brown, David M; Dugel, Pravin U; Freund, K Bailey; Glassman, Adam R; Kim, Judy E; Martin, Daniel F; Pollack, John S; Regillo, Carl D; Rosenfeld, Philip J; Schachat, Andrew P; Wells, John A

2016-01-01

The Diabetic Retinopathy Clinical Research Network (DRCR Network), sponsored by the National Eye Institute, reported the results of a comparative effectiveness randomized clinical trial (RCT) evaluating the 3 anti-vascular endothelial growth factor (anti-VEGF) agents aflibercept (2.0 mg), bevacizumab (1.25 mg), and ranibizumab (0.3 mg) for treatment of diabetic macular edema (DME) involving the center of the retina and associated with visual acuity loss. The many important findings of the RCT prompted the American Society of Retina Specialists to convene a group of experts to provide their perspective regarding clinically relevant findings of the study. To describe specific outcomes of the RCT judged worthy of highlighting, to discuss how these and other clinically relevant results should be considered by specialists treating DME, and to identify unanswered questions that merit consideration before treatment. The DRCR Network-authored publication on primary outcomes of the comparative effectiveness RCT at 89 sites in the United States. The study period of the RCT was August 22, 2012, to August 28, 2013. On average, all 3 anti-VEGF agents led to improved visual acuity in eyes with DME involving the center of the retina and with visual acuity impairment, including mean (SD) improvements by +13.3 (11.1) letters with aflibercept vs +9.7 (10.1) letters with bevacizumab (P < .001) and +11.2 (9.4) letters with ranibizumab (P = .03). Worse visual acuity when initiating therapy was associated with greater visual acuity benefit of aflibercept (+18.9 [11.5]) over bevacizumab (+11.8 [12.0]) or ranibizumab (14.2 [10.6]) 1 year later (P < .001 for interaction with visual acuity as a continuous variable, and P = .002 for interaction with visual acuity as a categorical variable). It is unknown whether different visual acuity outcomes associated with the use of the 3 anti-VEGF agents would be noted with other treatment regimens or with adequately repackaged bevacizumab, as well as in patients with criteria that excluded them from the RCT, such as persistent DME despite recent anti-VEGF treatment. On average, all 3 anti-VEGF agents led to improved visual acuity in eyes with DME involving the center of the retina and visual acuity impairment. Worse visual acuity when initiating therapy was associated with greater visual acuity benefit of aflibercept over bevacizumab or ranibizumab 1 year later. Care needs to be taken when attempting to extrapolate outcomes of this RCT to differing treatment regimens. With access to adequately repackaged bevacizumab, many specialists might initiate therapy with bevacizumab when visual acuity is good (ie, 20/32 to 20/40 as measured in the DRCR Network), recognizing that the cost-effectiveness of bevacizumab outweighs that of aflibercept or ranibizumab.

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.

Agnosic vision is like peripheral vision, which is limited by crowding.

PubMed

Strappini, Francesca; Pelli, Denis G; Di Pace, Enrico; Martelli, Marialuisa

2017-04-01

Visual agnosia is a neuropsychological impairment of visual object recognition despite near-normal acuity and visual fields. A century of research has provided only a rudimentary account of the functional damage underlying this deficit. We find that the object-recognition ability of agnosic patients viewing an object directly is like that of normally-sighted observers viewing it indirectly, with peripheral vision. Thus, agnosic vision is like peripheral vision. We obtained 14 visual-object-recognition tests that are commonly used for diagnosis of visual agnosia. Our "standard" normal observer took these tests at various eccentricities in his periphery. Analyzing the published data of 32 apperceptive agnosia patients and a group of 14 posterior cortical atrophy (PCA) patients on these tests, we find that each patient's pattern of object recognition deficits is well characterized by one number, the equivalent eccentricity at which our standard observer's peripheral vision is like the central vision of the agnosic patient. In other words, each agnosic patient's equivalent eccentricity is conserved across tests. Across patients, equivalent eccentricity ranges from 4 to 40 deg, which rates severity of the visual deficit. In normal peripheral vision, the required size to perceive a simple image (e.g., an isolated letter) is limited by acuity, and that for a complex image (e.g., a face or a word) is limited by crowding. In crowding, adjacent simple objects appear unrecognizably jumbled unless their spacing exceeds the crowding distance, which grows linearly with eccentricity. Besides conservation of equivalent eccentricity across object-recognition tests, we also find conservation, from eccentricity to agnosia, of the relative susceptibility of recognition of ten visual tests. These findings show that agnosic vision is like eccentric vision. Whence crowding? Peripheral vision, strabismic amblyopia, and possibly apperceptive agnosia are all limited by crowding, making it urgent to know what drives crowding. Acuity does not (Song et al., 2014), but neural density might: neurons per deg 2 in the crowding-relevant cortical area. Copyright © 2017 Elsevier Ltd. All rights reserved.

Special tinted contact lens on colour-defects.

PubMed

Mutilab, H A; Sharanjeet-Kaur; Keu, L K; Choo, P F

2012-01-01

The objective of this study was to determine the visual function of colour-deficient subjects when wearing special red tint contact lenses. A total of 17 subjects with congenital colour vision deficiency (14 deutans and 3 protans), voluntarily participated in this study. The average age for the subjects was 23.00 ± 4.06 years old. Visual functions tested were visual acuity (LogMAR), contrast sensitivity (FACT Chart) and stereopsis (TNO and Howard Dolman tests). Two types of special red tint lenses were used in this study; Type I (light red) and Type II (dark red). The protans and deutans showed no significant changes in visual acuity and contrast sensitivity when wearing either type of contact lens. Stereopsis testing using the Horward-Dolman test gave no significant changes but significant differences were seen using the TNO test. Stereopsis using the TNO test was significantly poorer with the red tinted contact lenses compared to without for both protons and deutans. Testing binocularly with Ishihara plates showed that 88% (n=15) of patients passed the test with Type I and Type II contact lenses. When D15 test was done, 3 patients (17.6%) were 'normal' when using the Type I contact lenses and 2 patients (11.8%) were 'normal' when using the Type II contact lenses. However, with FM100Hue test, most patients showed deutan responses. Total error scores (TES) were found to be higher with Type I and Type II contact lenses compared to without. The Type I and II special tinted contact lens used in this study did not cause a reduction of visual acuity and contrast sensitivity for the colour defects. Stereopsis was also not reduced with the Type I and Type II contact lenses for the colour defects except when tested with the TNO test. Colour vision defects became difficult to detect using the Ishihara plates but FM100Hue test did not show any improvement with the Type I and Type II contact lenses.

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.

Eye Dominance Predicts fMRI Signals in Human Retinotopic Cortex

PubMed Central

Mendola, Janine D.; Conner, Ian P.

2009-01-01

There have been many attempts to define eye dominance in normal subjects, but limited consensus exists, and relevant physiological data is scarce. In this study, we consider two different behavioral methods for assignment of eye dominance, and how well they predict fMRI signals evoked by monocular stimulation. Sighting eye dominance was assessed with two standard tests, the Porta Test, and a ‘hole in hand’ variation of the Miles Test. Acuity dominance was tested with a standard eye chart and with a computerized test of grating acuity. We found limited agreement between the sighting and acuity methods for assigning dominance in our individual subjects. We then compared the fMRI response generated by dominant eye stimulation to that generated by non-dominant eye, according to both methods, in 7 normal subjects. The stimulus consisted of a high contrast hemifield stimulus alternating with no stimulus in a blocked paradigm. In separate scans, we used standard techniques to label the borders of visual areas V1, V2, V3, VP, V4, V3A, and MT. These regions of interest (ROIs) were used to analyze each visual area separately. We found that percent change in fMRI BOLD signal was stronger for the dominant eye as defined by the acuity method, and this effect was significant for areas located in the ventral occipital territory (V1v, V2v, VP, V4). In contrast, assigning dominance based on sighting produced no significant interocular BOLD differences. We conclude that interocular BOLD differences in normal subjects exist, and may be predicted by acuity measures. PMID:17194544

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, cognition and their interaction with diseases in this community. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

Visual impairment evaluation in 119 children with congenital Zika syndrome.

PubMed

Ventura, Liana O; Ventura, Camila V; Dias, Natália de C; Vilar, Isabelle G; Gois, Adriana L; Arantes, Tiago E; Fernandes, Luciene C; Chiang, Michael F; Miller, Marilyn T; Lawrence, Linda

2018-06-01

To assess visual impairment in a large sample of infants with congenital Zika syndrome (CZS) and to compare with a control group using the same assessment protocol. The study group was composed of infants with confirmed diagnosis of CZS. Controls were healthy infants matched for age, sex, and socioeconomic status. All infants underwent comprehensive ophthalmologic evaluation including visual acuity, visual function assessment, and visual developmental milestones. The CZS group included 119 infants; the control group, 85 infants. At examination, the mean age of the CZS group was 8.5 ± 1.2 months (range, 6-13 months); of the controls, 8.4 ± 1.8 months (range, 5-12 months; P = 0.598). Binocular Teller Acuity Card (TAC) testing was abnormal in 107 CZS infants and in 4 controls (89.9% versus 5% [P < 0.001]). In the study group, abnormal monocular TAC results were more frequent in eyes with funduscopic alterations (P = 0.008); however, 104 of 123 structurally normal eyes (84.6%) also presented abnormal TAC results. Binocular contrast sensitivity was reduced in 87 of 107 CZS infants and in 8 of 80 controls (81.3% versus 10% [P < 0.001]). The visual development milestones were less achieved by infants with CZS compared to controls (P < 0.001). Infants with CZS present with severe visual impairment. A protocol for assessment of the ocular findings, visual acuity, and visual developmental milestones tested against age-matched controls is suggested. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

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...

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.

Corneal ulcers and infections

MedlinePlus

... eye Scratches (abrasions) on the eye surface Severely dry eyes Severe allergic eye disease Various inflammatory disorders Wearing ... response Refraction test Slit-lamp examination Tests for dry eye Visual acuity Blood tests to check for inflammatory ...

Comparison of the visual results after SMILE and femtosecond laser-assisted LASIK for myopia.

PubMed

Lin, Fangyu; Xu, Yesheng; Yang, Yabo

2014-04-01

To perform a comparative clinical analysis of the safety, efficacy, and predictability of two surgical procedures (ie, small incision lenticule extraction [SMILE] and femtosecond laser-assisted LASIK [FS-LASIK]) to correct myopia. Sixty eyes of 31 patients with a mean spherical equivalent of -5.13 ± 1.75 diopters underwent myopia correction with the SMILE procedure. Fifty-one eyes of 27 patients with a mean spherical equivalent of -5.58 ± 2.41 diopters were treated with the FS-LASIK procedure. Postoperative uncorrected and corrected distance visual acuity, manifest refraction, and higher-order aberrations were analyzed statistically at 1 and 3 months postoperatively. No statistically significant differences were found at 1 and 3 months in parameters that included the percentage of eyes with an uncorrected distance visual acuity of 20/20 or better (P = .556, .920) and mean spherical equivalent refraction (P = .055, .335). At 1 month, 4 SMILE-treated eyes and 1 FS-LASIK-treated eye lost one or more line of visual acuity (P = .214, chi-square test). At 3 months, 2 SMILE-treated eyes lost one or more line of visual acuity, whereas all FS-LASIK-treated eyes had an unchanged or corrected distance visual acuity. Higher-order aberrations and spherical aberration were significantly lower in the SMILE group than the FS-LASIK group at 1 (P = .007, .000) and 3 (P = .006, .000) months of follow-up. SMILE and FS-LASIK are safe, effective, and predictable surgical procedures to treat myopia. SMILE has a lower induction rate of higher-order aberrations and spherical aberration than the FS-LASIK procedure. Copyright 2014, SLACK Incorporated.

Stereoacuity in children with anisometropic amblyopia.

PubMed

Wallace, David K; Lazar, Elizabeth L; Melia, Michele; Birch, Eileen E; Holmes, Jonathan M; Hopkins, Kristine B; Kraker, Raymond T; Kulp, Marjean T; Pang, Yi; Repka, Michael X; Tamkins, Susanna M; Weise, Katherine K

2011-10-01

To determine factors associated with pretreatment and posttreatment stereoacuity in subjects with moderate anisometropic amblyopia. Data for subjects enrolled in seven studies conducted by the Pediatric Eye Disease Investigator Group were pooled. The sample included 633 subjects aged 3 to <18 years with anisometropic amblyopia, no heterotropia observed by cover test, and baseline amblyopic eye acuity of 20/100 or better. A subset included 248 subjects who were treated with patching or Bangerter filters and had stereoacuity testing at both the baseline and outcome examinations. Multivariate regression models identified factors associated with baseline stereoacuity and with outcome stereoacuity as measured by the Randot Preschool Stereoacuity test. Better baseline stereoacuity was associated with better baseline amblyopic eye acuity (P < 0.001), less anisometropia (P = 0.03), and anisometropia due to astigmatism alone (P < 0.001). Better outcome stereoacuity was associated with better baseline stereoacuity (P < 0.001) and better amblyopic eye acuity at outcome (P < 0.001). Among 48 subjects whose amblyopic eye visual acuity at outcome was 20/25 or better and within one line of the fellow eye, stereoacuity was worse than that of children with normal vision of the same age. In children with anisometropic amblyopia of 20/40 to 20/100 inclusive, better posttreatment stereoacuity is associated with better baseline stereoacuity and better posttreatment amblyopic eye acuity. Even if their visual acuity deficit resolves, many children with anisometropic amblyopia have stereoacuity worse than that of nonamblyopic children of the same age. Copyright © 2011 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

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

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.

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

[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 = -1.295, t1-3 = -1.435). The reading position was 48.55 ± 6.69, 48.99 ± 7.49 and 49.00 ± 6.76, respectively(t1-2 = -1.019, t2-3 = -0.019, t1-3 = -0.816). The total number of character strokes was 185.54 ± 7.55, 187.69 ± 13.76 and 182.62 ± 8.17, respectively(t1-2 = 0.191, t2-3 = 1.385, t1-3 = 1.686). A practical design of the Chinese reading visual chart should consider size, increment, legibility in selection of reading sentences. Reading visual acuity, critical threshold and effective reading speed could be used to express the reading visual function.

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.

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 Ophthalmology. Published by Elsevier Inc. All rights reserved.

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 eyes within the first year after surgery.

Multi-country real-life experience of anti-vascular endothelial growth factor therapy for wet age-related macular degeneration

PubMed Central

Holz, Frank G; Tadayoni, Ramin; Beatty, Stephen; Berger, Alan; Cereda, Matteo G; Cortez, Rafael; Hoyng, Carel B; Hykin, Philip; Staurenghi, Giovanni; Heldner, Stephanie; Bogumil, Timon; Heah, Theresa; Sivaprasad, Sobha

2015-01-01

Background/aims Real-life anti-vascular endothelial growth factor (VEGF) therapy use in patients with wet age-related macular degeneration (wAMD) was assessed in a retrospective, observational study in Canada, France, Germany, Ireland, Italy, the Netherlands, UK and Venezuela. Methods Medical records of patients with wAMD, who started ranibizumab treatment between 1 January 2009 and 31 August 2009, were evaluated. Data were collected until the end of treatment and/or monitoring or until 31 August 2011. Results 2227 patients who received ≥1 anti-VEGF injection with a baseline visual acuity assessment and ≥1 postbaseline visual acuity assessment for the treated eye were evaluated. Visual acuity improved until about day 120; thereafter, visual acuity gains were not maintained. Mean change in visual acuity score from baseline to years 1 and 2 was +2.4 and +0.6 letters, respectively. Patients received a mean of 5.0 and 2.2 injections in the first and second year, respectively. There were substantial differences in visual outcomes and injection frequency between countries. More frequent visits and injections were associated with greater improvements in visual acuity. Conclusions In clinical practice, fewer injections are administered than in clinical trials. Anti-VEGF treatment resulted in an initial improvement in visual acuity; however, this was not maintained over time. Trial registration number NCT01447043. PMID:25193672

Randomized trial of a home monitoring system for early detection of choroidal neovascularization home monitoring of the Eye (HOME) study.

PubMed

Chew, Emily Y; Clemons, Traci E; Bressler, Susan B; Elman, Michael J; Danis, Ronald P; Domalpally, Amitha; Heier, Jeffrey S; Kim, Judy E; Garfinkel, Richard

2014-02-01

To determine whether home monitoring with the ForeseeHome device (Notal Vision Ltd, Tel Aviv, Israel), using macular visual field testing with hyperacuity techniques and telemonitoring, results in earlier detection of age-related macular degeneration-associated choroidal neovascularization (CNV), reflected in better visual acuity, when compared with standard care. The main predictor of treatment outcome from anti-vascular endothelial growth factor (VEGF) agents is the visual acuity at the time of CNV treatment. Unmasked, controlled, randomized clinical trial. One thousand nine hundred and seventy participants 53 to 90 years of age at high risk of CNV developing were screened. Of these, 1520 participants with a mean age of 72.5 years were enrolled in the Home Monitoring of the Eye study at 44 Age-Related Eye Disease Study 2 clinical centers. In the standard care and device arms arm, investigator-specific instructions were provided for self-monitoring vision at home followed by report of new symptoms to the clinic. In the device arm, the device was provided with recommendations for daily testing. The device monitoring center received test results and reported changes to the clinical centers, which contacted participants for examination. The main outcome measure was the difference in best-corrected visual acuity scores between baseline and detection of CNV. The event was determined by investigators based on clinical examination, color fundus photography, fluorescein angiography, and optical coherence tomography findings. Masked graders at a central reading center evaluated the images using standardized protocols. Seven hundred sixty-three participants were randomized to device monitoring and 757 participants were randomized to standard care and were followed up for a mean of 1.4 years between July 2010 and April 2013. At the prespecified interim analysis, 82 participants progressed to CNV, 51 in the device arm and 31 in the standard care arm. The primary analysis achieved statistical significance, with the participants in the device arm demonstrating a smaller decline in visual acuity with fewer letters lost from baseline to CNV detection (median, -4 letters; interquartile range [IQR], -11.0 to -1.0 letters) compared with standard care (median, -9 letters; IQR, -14.0 to -4.0 letters; P = 0.021), resulting in better visual acuity at CNV detection in the device arm. The Data and Safety Monitoring Committee recommended early study termination for efficacy. Persons at high risk for CNV developing benefit from the home monitoring strategy for earlier detection of CNV development, which increases the likelihood of better visual acuity results after intravitreal anti-VEGF therapy. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

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

Functional vision loss: a diagnosis of exclusion.

PubMed

Villegas, Rex B; Ilsen, Pauline F

2007-10-01

Most cases of visual acuity or visual field loss can be attributed to ocular pathology or ocular manifestations of systemic pathology. They can also occasionally be attributed to nonpathologic processes or malingering. Functional vision loss is any decrease in vision the origin of which cannot be attributed to a pathologic or structural abnormality. Two cases of functional vision loss are described. In the first, a 58-year-old man presented for a baseline eye examination for enrollment in a vision rehabilitation program. He reported bilateral blindness since a motor vehicle accident with head trauma 4 years prior. Entering visual acuity was "no light perception" in each eye. Ocular health examination was normal and the patient made frequent eye contact with the examiners. He was referred for neuroimaging and electrophysiologic testing. The second case was a 49-year-old man who presented with a long history of intermittent monocular diplopia. His medical history was significant for psycho-medical evaluations and a diagnosis of factitious disorder. Entering uncorrected visual acuities were 20/20 in each eye, but visual field testing found constriction. No abnormalities were found that could account for the monocular diplopia or visual field deficit. A diagnosis of functional vision loss secondary to factitious disorder was made. Functional vision loss is a diagnosis of exclusion. In the event of reduced vision in the context of a normal ocular health examination, all other pathology must be ruled out before making the diagnosis of functional vision loss. Evaluation must include auxiliary ophthalmologic testing, neuroimaging of the visual pathway, review of the medical history and lifestyle, and psychiatric evaluation. Comanagement with a psychiatrist is essential for patients with functional vision loss.

[Binocular status of dyslexics--are there differences to a healthy comparison group?].

PubMed

Riebeling, P; Brunner, E; Grossjohann, R; Clemens, S

2009-10-01

Despite numerous studies dealing with the question of a possible relation of visual problems and dyslexia, which is negated by most ophthalmologists, some opticians still favour the treatment of dyslexia by correction of the "Winkelfehlsichtigkeit" following MCH. Our aim was by also including the Pola test to check the usefulness of this treatment. In a 2-year prospective study we examined the 4th grade elementary school students in our city who had dyslexia as an assured diagnosis (n = 21). The results were compared to those of an age-matched group without pathological findings regarding their reading and spelling ability (n = 21). Examinations included visual acuity, eye position by cover test, Maddox cylinder and Pola test for near distance, binocular vision (Bagolini and Worth test, Lang test I and II, Titmus test, amplitude of fusion), amplitude of accommodation, refraction in cycloplegia and organic status. A significant difference was found between the two groups regarding the amplitude of divergence in near (p = 0.009) and far distance (p = 0.019) which were both smaller for the dyslexia group, as well as the binocular near visual acuity (p = 0.04). Using the SAS procedure STEPDISC we discriminated the normal and dyslexia group by amplitude of divergence, near visual acuity and alternating near prism cover test with a sensitivity of 81 % and a specifity of 75 %. The results of the Pola test did not show any significant difference between the groups. No differences were found between the groups regarding the eye position. Therefore a treatment of dyslexia using prisms does not appear reasonable. However because of the group sizes the significance of the results is limited. Georg Thieme Verlag KG Stuttgart.New York.

Early vitrectomy effective for Norrie disease.

PubMed

Walsh, Mark K; Drenser, Kimberly A; Capone, Antonio; Trese, Michael T

2010-04-01

To review our experience with Norrie disease to determine if early vitrectomy abrogates the natural history of this rare disease; namely, bilateral no light perception visual acuity and phthisis bulbi. We retrospectively reviewed the medical records of all patients seen in our tertiary care pediatric retinal clinical practice from 1988 through 2008 with a potential diagnosis of Norrie disease. Inclusion required not only clinical findings consistent with Norrie disease but also genetics and/or a family history consistent with Norrie disease. Medical record review revealed 14 boys with clinically diagnosed Norrie disease and either Norrie disease gene (NDP) mutations noted on genetic testing (13 patients) and/or a clear family history consistent with Norrie disease (4 patients). All 14 boys with definite Norrie disease had vitrectomy with or without lensectomy in at least 1 eye prior to 12 months of age. Of the 14 boys with definite Norrie disease, 7 maintained at least light perception visual acuity in 1 eye and 3 had no light perception visual acuity bilaterally; visual acuity data were not available for 4 patients. Only 2 of 24 (8%) eyes became phthisical. Historically, no treatment has been offered to mitigate the dismal natural history of Norrie disease. We recommend consideration of early vitrectomy in Norrie disease.

Clinical results from low-level laser therapy in patients with autosomal dominant cone-rod dystrophy

NASA Astrophysics Data System (ADS)

Koev, K.; Avramov, L.; Borissova, E.

2018-03-01

The objective of this study is to examine long-term effects of low-level laser therapy (LLLT) in patients with autosomal dominant cone-rod dystrophy (CRDs). A He-Ne Laser with continuous emission at 633 nm (01 mW/cm2) was used on five patients with autosomal dominant pedigree of Romani origin with non-syndromic CRDs. The laser radiation was applied transpupillary to the macula six times for three minutes every other day. The experiment was conducted for a period of three years. The clinical evaluation included best corrected visual acuity determination, funduscopy, Humphrey perimetry, Farnsworth Hue-28 color testing, fluorescein angiography, and full-field electroretinogram (ERG). All affected individuals presented reduced visual acuity (0.01 – 0.4) and photophobia. The funduscopic examination and fluorescein angiography revealed advanced changes including bone spicule-like pigment deposits in the midperiphery and the macular area, along with retinal atrophy, narrowing of the vessels, and waxy optic discs. The visual fields demonstrated central scotoma. The electrophysiologic examination of the patients detected an abnormal cone-rod ERG (20 – 30 μV) with photopic amplitudes more markedly reduced than the scotopic. Flicker responses were missing and Farnsworth Hue-28 test found protanopia. There was a statistically significant increase in the visual acuity (p<0.001, end of study versus baseline) for CRDs patients for the period of three years after the treatment with LLLT. Following the LLLT, the central absolute scotoma in CRDs was reduced, as was the prevalence of metamorphopsia in CRDs. This study shows that LLLT may prove be a novel long-lasting therapeutic option for both forms of CRDs. It is a highly effective treatment resulting in a long-term improvement of the visual acuity.

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.

Piggyback intraocular lens implantation to correct pseudophakic refractive error after segmental multifocal intraocular lens implantation.

PubMed

Venter, Jan A; Oberholster, Andre; Schallhorn, Steven C; Pelouskova, Martina

2014-04-01

To evaluate refractive and visual outcomes of secondary piggyback intraocular lens implantation in patients diagnosed as having residual ametropia following segmental multifocal lens implantation. Data of 80 pseudophakic eyes with ametropia that underwent Sulcoflex aspheric 653L intraocular lens implantation (Rayner Intraocular Lenses Ltd., East Sussex, United Kingdom) to correct residual refractive error were analyzed. All eyes previously had in-the-bag zonal refractive multifocal intraocular lens implantation (Lentis Mplus MF30, models LS-312 and LS-313; Oculentis GmbH, Berlin, Germany) and required residual refractive error correction. Outcome measurements included uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, distance-corrected near visual acuity, manifest refraction, and complications. One-year data are presented in this study. The mean spherical equivalent ranged from -1.75 to +3.25 diopters (D) preoperatively (mean: +0.58 ± 1.15 D) and reduced to -1.25 to +0.50 D (mean: -0.14 ± 0.28 D; P < .01). Postoperatively, 93.8% of eyes were within ±0.50 D and 98.8% were within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity improved significantly from 0.28 ± 0.16 to 0.01 ± 0.10 logMAR and 78.8% of eyes achieved 6/6 (Snellen 20/20) or better postoperatively. The mean uncorrected near visual acuity changed from 0.43 ± 0.28 to 0.19 ± 0.15 logMAR. There was no significant change in corrected distance visual acuity or distance-corrected near visual acuity. No serious intraoperative or postoperative complications requiring secondary intraocular lens removal occurred. Sulcoflex lenses proved to be a predictable and safe option for correcting residual refractive error in patients diagnosed as having pseudophakia. Copyright 2014, SLACK Incorporated.

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"…

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.

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 become the better-seeing eye after refraction, so that the eye behind a balance lens should be refracted as well. Proprietary or commercial disclosure may be found after the references. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Topical brinzolamide (Azopt) versus placebo in the treatment of infantile nystagmus syndrome (INS).

PubMed

Hertle, Richard W; Yang, Dongsheng; Adkinson, Tonia; Reed, Michael

2015-04-01

To test the hypothesis that the topical carbonic anhydrase inhibitor brinzolamide (Azopt) has beneficial effects versus placebo on measures of nystagmus and visual acuity in adult subjects with infantile nystagmus syndrome (INS). Prospective, cross-over, double masked clinical trial. Single centre. Five subjects ≥18 years old with typical INS and best-binocular visual acuity in their primary position null zone ETDRS 55 letters to 85 letters (20/200 to 20/50) and had no previous treatment for nystagmus. In a randomised order, each subject received one drop of Azopt or placebo in both eyes three times a day separated by a washout period of at least a week followed by Azopt or placebo in both eyes three times a day; thus each subject got the drug and placebo, each acting as his or her own control. The nystagmus acuity function and INS waveforms obtained from eye movement recordings, binocular optotype visual acuity, using the ETDRS protocol analysed individually and as a group before and after Azopt and placebo. Versus placebo and baseline measures, topical Azopt significantly improved; INS waveform characteristics in the primary position null zone, group mean values of the nystagmus acuity function across gaze (p<0.01) and group mean ETDRS binocular letter visual acuity (p<0.05). There was a predictable decrease in intraocular pressure (IOP) without any systemic or ocular adverse events. Although a prospective large-scale clinical trial is needed to prove effectiveness, an eye-drop-based therapy for INS may emerge as a viable addition to optical, surgical, behavioural and systemic drug therapies for INS. NCT01312402. 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.

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).

Pituitary apoplexy in a teenager--case report.

PubMed

Chao, Chen-Cheng; Lin, Chun-Ju

2014-06-01

Pituitary apoplexy is a rare clinical emergency which results from hemorrhage or infarction in the pituitary gland. We present a 14-year-old girl with pituitary apoplexy and review the literature. Our patient experienced blurred vision, nausea, and headache. Her best-corrected visual acuity was 20/200 and 20/20. Confrontation test visual field testing revealed bitemporal hemianopsia. Brain imaging demonstrated a suprasellar mass. The microscopic endonasal transsphenoidal approach only found 5-10 mL brownish fluid-like material. Pathology confirmed no malignancy. Pituitary apoplexy was diagnosed. Her nausea and headache gradually improved. Six months after operation, her best-corrected visual acuity had improved to 20/30 and 20/20. Although pituitary apoplexy is rare in pediatric patients, prompt evaluation including detailed ophthalmic examination, biochemical evaluation, endocrine workup, and image study are very important. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Vision and night driving abilities of elderly drivers.

PubMed

Gruber, Nicole; Mosimann, Urs P; Müri, René M; Nef, Tobias

2013-01-01

In this article, we review the impact of vision on older people's night driving abilities. Driving is the preferred and primary mode of transport for older people. It is a complex activity where intact vision is seminal for road safety. Night driving requires mesopic rather than scotopic vision, because there is always some light available when driving at night. Scotopic refers to night vision, photopic refers to vision under well-lit conditions, and mesopic vision is a combination of photopic and scotopic vision in low but not quite dark lighting situations. With increasing age, mesopic vision decreases and glare sensitivity increases, even in the absence of ocular diseases. Because of the increasing number of elderly drivers, more drivers are affected by night vision difficulties. Vision tests, which accurately predict night driving ability, are therefore of great interest. We reviewed existing literature on age-related influences on vision and vision tests that correlate or predict night driving ability. We identified several studies that investigated the relationship between vision tests and night driving. These studies found correlations between impaired mesopic vision or increased glare sensitivity and impaired night driving, but no correlation was found among other tests; for example, useful field of view or visual field. The correlation between photopic visual acuity, the most commonly used test when assessing elderly drivers, and night driving ability has not yet been fully clarified. Photopic visual acuity alone is not a good predictor of night driving ability. Mesopic visual acuity and glare sensitivity seem relevant for night driving. Due to the small number of studies evaluating predictors for night driving ability, further research is needed.

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. Increased age was a significant risk factor for blindness and visual impairment. Conclusions There is a high prevalence of blindness and visual impairment among those aged ≥40 years in Tema, Ghana, West Africa. Refractive error is a major cause of blindness and visual impairment in this population, followed by cataract, glaucoma, and corneal disease. PMID:22677425

Amblyopia in Astigmatic Children: Patterns of Deficits

PubMed Central

Harvey, Erin M.; Dobson, Velma; Miller, Joseph M.; Clifford-Donaldson, Candice E.

2007-01-01

Neural changes that result from disruption of normal visual experience during development are termed amblyopia. To characterize visual deficits specific to astigmatism-related amblyopia, we compared best-corrected visual performance in 330 astigmatic and 475 non-astigmatic kindergarten through 6th grade children. Astigmatism was associated with deficits in letter, grating and vernier acuity, high and middle spatial frequency contrast sensitivity, and stereoacuity. Although grating acuity, vernier acuity, and contrast sensitivity were reduced across stimulus orientation, astigmats demonstrated orientation-dependent deficits (meridional amblyopia) only for grating acuity. Astigmatic children are at risk for deficits across a range of visual functions. PMID:17184807

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.

[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.

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.

77 FR 20879 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-06

... loss of vision in his right due to a traumatic injury sustained at age 9. The visual acuity in his left... due to a traumatic injury sustained in 1989. The best corrected visual acuity in his right eye is 20... traumatic injury sustained 10 years ago. The visual acuity in his left eye is 20/20. Following an...

76 FR 64169 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-17

... detachment in his left eye due to a traumatic injury that occurred in 1982. The best corrected visual acuity... traumatic injury sustained in 2000. The best corrected visual acuity in his right eye is 20/30. Following an... to an injury sustained in 1976. The best corrected visual acuity in his left eye is 20/15. Following...

[Investigation of color vision in acute unilateral optic neuritis using a web-based color vision test].

PubMed

Kuchenbecker, J; Blum, M; Paul, F

2016-03-01

In acute unilateral optic neuritis (ON) color vision defects combined with a decrease in visual acuity and contrast sensitivity frequently occur. This study investigated whether a web-based color vision test is a reliable detector of acquired color vision defects in ON and, if so, which charts are particularly suitable. In 12 patients with acute unilateral ON, a web-based color vision test ( www.farbsehtest.de ) with 25 color plates (16 Velhagen/Broschmann and 9 Ishihara color plates) was performed. For each patient the affected eye was tested first and then the unaffected eye. The mean best-corrected distance visual acuity (BCDVA) in the ON eye was 0.36 ± 0.20 and 1.0 ± 0.1 in the contralateral eye. The number of incorrectly read plates correlated with the visual acuity. For the ON eye a total of 134 plates were correctly identified and 166 plates were incorrectly identified, while for the disease-free fellow eye, 276 plates were correctly identified and 24 plates were incorrectly identified. Both of the blue/yellow plates were identified correctly 14 times and incorrectly 10 times using the ON eye and exclusively correctly (24 times) using the fellow eye. The Velhagen/Broschmann plates were incorrectly identified significantly more frequently in comparison with the Ishihara plates. In 4 out of 16 Velhagen/Broschmann plates and 5 out of 9 Ishihara plates, no statistically significant differences between the ON eye and the fellow eye could be detected. The number of incorrectly identified plates correlated with a decrease in visual acuity. Red/green and blue/yellow plates were incorrectly identified significantly more frequently with the ON eye, while the Velhagen/Broschmann color plates were incorrectly identified significantly more frequently than the Ishihara color plates. Thus, under defined test conditions the web-based color vision test can also be used to detect acquired color vision defects, such as those caused by ON. Optimization of the test by altering the combination of plates may be a useful next step.

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.

[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.

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.

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

Safety and Effectiveness of Cataract Surgery with Simultaneous Intravitreal Anti-VEGF in Patients with Previously Treated Exudative Age-Related Macular Degeneration.

PubMed

Falcão, Manuel Sousa; Freitas-Costa, Paulo; Beato, João Nuno; Pinheiro-Costa, João; Rocha-Sousa, Amândio; Carneiro, Ângela; Brandão, Elisete Maria; Falcão-Reis, Fernando

2017-02-27

To evaluate the safety and impact on visual acuity, retinal and choroidal morphology of simultaneous cataract surgery and intravitreal anti-vascular endothelial growth factor on patients with visually significant cataracts and previously treated exudative age-related macular degeneration. Prospective study, which included 21 eyes of 20 patients with exudative age-related macular degeneration submitted to simultaneous phacoemulsification and intravitreal ranibizumab or bevacizumab. The patients were followed for 12 months after surgery using a pro re nata strategy. Visual acuity, foveal and choroidal thickness changes were evaluated 1, 6 and 12 months post-operatively. There was a statistically significant increase in mean visual acuity at one (13.4 letters, p < 0.05), six (11.5 letters, p < 0.05) and twelve months (11.3 letters, p < 0.05) without significant changes in retinal or choroidal morphology. At 12 months, 86% of eyes were able to maintain visual acuity improvement. There were no significant differences between the two anti-vascular endothelial growth factor drugs and no complications developed during follow-up. Simultaneous phacoemulsification and intravitreal anti- vascular endothelial growth factor is safe and allows improvement in visual acuity in patients with visually significant cataracts and exudative age-related macular degeneration. Visual acuity gains were maintained with a pro re nata strategy showing that in this subset of patients, phacoemulsification may be beneficial. Cataract surgery and simultaneous anti-vascular endothelial growth factor therapy improves visual acuity in patients with exudative age-related macular degeneration.

Effect of stimulus configuration on crowding in strabismic amblyopia.

PubMed

Norgett, Yvonne; Siderov, John

2017-11-01

Foveal vision in strabismic amblyopia can show increased levels of crowding, akin to typical peripheral vision. Target-flanker similarity and visual-acuity test configuration may cause the magnitude of crowding to vary in strabismic amblyopia. We used custom-designed visual acuity tests to investigate crowding in observers with strabismic amblyopia. LogMAR was measured monocularly in both eyes of 11 adults with strabismic or mixed strabismic/anisometropic amblyopia using custom-designed letter tests. The tests used single-letter and linear formats with either bar or letter flankers to introduce crowding. Tests were presented monocularly on a high-resolution display at a test distance of 4 m, using standardized instructions. For each condition, five letters of each size were shown; testing continued until three letters of a given size were named incorrectly. Uncrowded logMAR was subtracted from logMAR in each of the crowded tests to highlight the crowding effect. Repeated-measures ANOVA showed that letter flankers and linear presentation individually resulted in poorer performance in the amblyopic eyes (respectively, mean normalized logMAR = 0.29, SE = 0.07, mean normalized logMAR = 0.27, SE = 0.07; p < 0.05) and together had an additive effect (mean = 0.42, SE = 0.09, p < 0.001). There was no difference across the tests in the fellow eyes (p > 0.05). Both linear presentation and letter rather than bar flankers increase crowding in the amblyopic eyes of people with strabismic amblyopia. These results suggest the influence of more than one mechanism contributing to crowding in linear visual-acuity charts with letter flankers.

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

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.

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 measurements was less than that of macular thickness measurements, the stronger correlation of PROS length with visual acuity suggests that the PROS measures may be more directly related to visual function. Photoreceptor outer segment length may be a useful physiologic outcome measure, both clinically and as a direct assessment of treatment effects.

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 clinically meaningful changes in vision-specific HRQoL. In the presence of pre-existing vision loss (VF and visual acuity), similar levels of visual field change produce greater losses in quality of life. PMID:21458074

Clinical and microperimetric predictors of reading speed in low vision patients: a structural equation modeling approach.

PubMed

Giacomelli, Giovanni; Virgili, Gianni; Giansanti, Fabrizio; Sato, Giovanni; Cappello, Ezio; Cruciani, Filippo; Varano, Monica; Menchini, Ugo

2013-06-27

To investigate the simultaneous association of several psychophysical measures with reading ability in patients with mild and moderate low vision attending rehabilitation services. Standard measurements of reading ability (Minnesota Reading [MNREAD] charts), visual acuity (Early Treatment of Diabetic Retinopathy Study [ETDRS] charts), contrast sensitivity (Pelli-Robson charts), reading contrast threshold (Reading Explorer [REX] charts), retinal sensitivity, and fixation stability and localization (Micro Perimeter 1 [MP1] fundus perimetry) were obtained in 160 low vision patients with better eye visual acuity ranging from 0.3 to 1.0 logarithm of the minimum angle of resolution and affected by either age-related macular degeneration or diabetic retinopathy. All variables were moderately associated with reading performance measures (MNREAD reading speed and reading acuity and REX reading contrast threshold), as well as among each other. In a structural equation model, REX reading contrast threshold was highly associated with MNREAD reading speed (standardized coefficient, 0.63) and moderately associated with reading acuity (standardized coefficient, -0.30). REX test also mediated the effects of Pelli-Robson contrast sensitivity (standardized coefficient, 0.44), MP1 fixation eccentricity (standardized coefficient, -0.19), and the mean retinal sensitivity (standardized coefficient, 0.23) on reading performance. The MP1 fixation stability was associated with both MNREAD reading acuity (standardized coefficient, -0.24) and MNREAD reading speed (standardized coefficient, 0.23), while ETDRS visual acuity only affected reading acuity (standardized coefficient, 0.44). Fixation instability and contrast sensitivity loss are key factors limiting reading performance of patients with mild or moderate low vision. REX charts directly assess the impact of text contrast on letter recognition and text navigation and may be a useful aid in reading rehabilitation.

Factors influencing self-reported vision-related activity limitation in the visually impaired.

PubMed

Tabrett, Daryl R; Latham, Keziah

2011-07-15

The use of patient-reported outcome (PRO) measures to assess self-reported difficulty in visual activities is common in patients with impaired vision. This study determines the visual and psychosocial factors influencing patients' responses to self-report measures, to aid in understanding what is being measured. One hundred visually impaired participants completed the Activity Inventory (AI), which assesses self-reported, vision-related activity limitation (VRAL) in the task domains of reading, mobility, visual information, and visual motor tasks. Participants also completed clinical tests of visual function (distance visual acuity and near reading performance both with and without low vision aids [LVAs], contrast sensitivity, visual fields, and depth discrimination), and questionnaires assessing depressive symptoms, social support, adjustment to visual loss, and personality. Multiple regression analyses identified that an acuity measure (distance or near), and, to a lesser extent, near reading performance without LVAs, visual fields, and contrast sensitivity best explained self-reported VRAL (28%-50% variance explained). Significant psychosocial correlates were depression and adjustment, explaining an additional 6% to 19% unique variance. Dependent on task domain, the parameters assessed explained 59% to 71% of the variance in self-reported VRAL. Visual function, most notably acuity without LVAs, is the best predictor of self-reported VRAL assessed by the AI. Depression and adjustment to visual loss also significantly influence self-reported VRAL, largely independent of the severity of visual loss and most notably in the less vision-specific tasks. The results suggest that rehabilitation strategies addressing depression and adjustment could improve perceived visual disability.

77 FR 27852 - Qualification of Drivers; Exemption Applications; Vision

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-11

... amblyopia in his right eye since childhood. The best corrected visual acuity in his right eye is 20/400, and..., has had amblyopia in his right eye since birth. The best corrected visual acuity in his right eye is... amblyopia in his right eye since childhood. The best corrected visual acuity in his right eye is 20/80, and...

Intravitreal bevacizumab injections for treatment of central retinal vein occlusion: six-month results of a prospective trial.

PubMed

Priglinger, Siegfried G; Wolf, Armin H; Kreutzer, Thomas C; Kook, Daniel; Hofer, Anja; Strauss, Rupert W; Alge, Claudia S; Kunze, Christian; Haritoglou, Christos; Kampik, Anselm

2007-10-01

To evaluate the effect of intravitreal bevacizumab (Avastin; Genentech, Inc., South San Francisco, CA) injections on visual acuity and foveal retinal thickness in patients with central retinal vein occlusion (CRVO). In this prospective, noncomparative, consecutive, interventional case series, 46 patients received repeated intravitreal injections (1.25 mg) of bevacizumab. Main outcome measures were visual acuity (Snellen and ETDRS charts) and optical coherence tomography measurements in a 6-month follow-up period. Mean visual acuity improved from 20/250 at baseline to 20/80 at the 6-month follow-up (P < 0.001). ETDRS chart findings revealed a mean letter gain +/-SD from baseline to 6 months of 13.9 +/- 14.4 letters. Mean central retinal thickness +/-SD decreased from 535 +/- 148 microm at baseline to 323 +/- 116 microm at the 6-month follow-up. Ischemic CRVO was associated with significantly lower visual acuity than nonischemic CRVO (P < 0.001). However, visual acuity gain was similar in both groups. Independent of duration of symptoms, CRVO was associated with a similar gain in visual acuity. Intravitreal injection of bevacizumab appears to be a new treatment option for patients with macular edema secondary to CRVO.

Comparison of visual outcomes after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of an extended depth of focus intraocular lens with a diffractive bifocal intraocular lens

PubMed Central

de Medeiros, André Lins; de Araújo Rolim, André Gustavo; Motta, Antonio Francisco Pimenta; Ventura, Bruna Vieira; Vilar, César; Chaves, Mário Augusto Pereira Dias; Carricondo, Pedro Carlos; Hida, Wilson Takashi

2017-01-01

Purpose The purpose of this study was to compare the visual outcomes and subjective visual quality between bilateral implantation of a diffractive trifocal intraocular lens, Alcon Acrysof IQ® PanOptix® TNFT00 (group A), and blended implantation of an extended depth of focus lens, J&J Tecnis Symfony® ZXR00 with a diffractive bifocal intraocular lens, J&J Vision Tecnis® ZMB00 (group B). Methods This prospective, nonrandomized, consecutive, comparative study included the assessment of 40 eyes in 20 patients implanted with multifocal intraocular lens. Exclusion criteria were existence of any corneal, retina, or optic nerve disease, previous eye surgery, illiteracy, previous refractive surgery, high axial myopia, expected postoperative corneal astigmatism of >1.00 cylindrical diopter (D), and intraoperative or postoperative complications. Binocular visual acuity was tested in all cases. Ophthalmological evaluation included the measurement of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), and uncorrected intermediate visual acuity (UIVA), with the analysis of contrast sensitivity (CS), and visual defocus curve. Results Postoperative UDVA was 0.01 and −0.096 logMAR (p<0.01) in groups A and B, respectively; postoperative CDVA was −0.07 and −0.16 logMAR (p<0.01) in groups A and B, respectively; UIVA was 0.14 and 0.20 logMAR (p<0.01) in groups A and B, respectively; UNVA was −0.03 and 0.11 logMAR (p<0.01) in groups A and B, respectively. Under photopic conditions group B had better CS at low frequencies with and without glare. Conclusion Both groups promoted good quality of vision for long, intermediate, and short distances. Group B exhibited a better performance for very short distances and for intermediate and long distances ≥−1.50 D of vergence. Group A exhibited a better performance for UIVA at 60 cm and for UNVA at 40 cm. PMID:29138533

An Analysis of the Effects of Phenytoin in Treating Motion Sickness and the Effects of Motion Sickness on the Human Electroencephalogram

DTIC Science & Technology

1990-12-01

ears ( tinnitus ) and/or a reduced auditory acuity resulted from the dosing. These side effects have been shown to 29 occur in some subjects as a result of...examinations. 5. Complete blood count (CBC). 6. Blood biochemistry screen (Chem 18 including liver function tests). 7. Blood cholesterol and lipids . 8. Chest X...blood lipids and cholesterol, chest X-ray, urinalysis, visual acuity test, vestibular evaluation and liver function studies. Subjects will then take

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

The Influence of Visual Ability on Learning and Memory Performance in 13 Strains of Mice

ERIC Educational Resources Information Center

Brown, Richard E.; Wong, Aimee A.

2007-01-01

We calculated visual ability in 13 strains of mice (129SI/Sv1mJ, A/J, AKR/J, BALB/cByJ, C3H/HeJ, C57BL/6J, CAST/EiJ, DBA/2J, FVB/NJ, MOLF/EiJ, SJL/J, SM/J, and SPRET/EiJ) on visual detection, pattern discrimination, and visual acuity and tested these and other mice of the same strains in a behavioral test battery that evaluated visuo-spatial…

The King-Devick (K-D) test of rapid eye movements: a bedside correlate of disability and quality of life in MS.

PubMed

Moster, Stephen; Wilson, James A; Galetta, Steven L; Balcer, Laura J

2014-08-15

We investigated the King-Devick (K-D) test of rapid number naming as a visual performance measure in a cohort of patients with multiple sclerosis (MS). In this cross-sectional study, 81 patients with MS and 20 disease-free controls from an ongoing study of visual outcomes underwent K-D testing. A test of rapid number naming, K-D requires saccadic eye movements as well as intact vision, attention and concentration. To perform the K-D test, participants are asked to read numbers aloud as quickly as possible from three test cards; the sum of the three test card times in seconds constitutes the summary score. High-contrast visual acuity (VA), low-contrast letter acuity (1.25% and 2.5% levels), retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), MS Functional Composite (MSFC) and vision-specific quality of life (QOL) measures (25-Item NEI Visual Functioning Questionnaire [NEI-VFQ-25] and 10-Item Neuro-Ophthalmic Supplement) were also assessed. K-D time scores in the MS cohort (total time to read the three test cards) were significantly higher (worse) compared to those for disease-free controls (P=0.003, linear regression, accounting for age). Within the MS cohort, higher K-D scores were associated with worse scores for the NEI-VFQ-25 composite (P<0.001), 10-Item Neuro-Ophthalmic Supplement (P<0.001), binocular low-contrast acuity (2.5%, 1.25%, P<0.001, and high-contrast VA (P=0.003). Monocular low-contrast vision scores (P=0.001-0.009) and RNFL thickness (P=0.001) were also reduced in eyes of patients with worse K-D scores (GEE models accounting for age and within-patient, inter-eye correlations). Patients with a history of optic neuritis (ON) had increased (worse) K-D scores. Patients who classified their work disability status as disabled (receiving disability pension) did worse on K-D testing compared to those working full-time (P=0.001, accounting for age). The K-D test, a <2 minute bedside test of rapid number naming, is associated with visual dysfunction, neurologic impairment, and reduced vision-specific QOL in patients with MS. Scores reflect work disability as well as structural changes as measured by OCT imaging. History of ON and abnormal binocular acuities were associated with worse K-D scores, suggesting that abnormalities detected by K-D may go along with afferent dysfunction in MS patients. A brief test that requires saccadic eye movements, K-D should be considered for future MS trials as a rapid visual performance measure. Copyright © 2014 Elsevier B.V. All rights reserved.

Visual Screening: A Procedure.

ERIC Educational Resources Information Center

Williams, Robert T.

Vision is a complex process involving three phases: physical (acuity), physiological (integrative), and psychological (perceptual). Although these phases cannot be considered discrete, they provide the basis for the visual screening procedure used by the Reading Services of Colorado State University and described in this document. Ten tests are…

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.

A binocular iPad treatment for amblyopic children.

PubMed

Li, S L; Jost, R M; Morale, S E; Stager, D R; Dao, L; Stager, D; Birch, E E

2014-10-01

Monocular amblyopia treatment (patching or penalization) does not always result in 6/6 vision and amblyopia often recurs. As amblyopia arises from abnormal binocular visual experience, we evaluated the effectiveness of a novel home-based binocular amblyopia treatment. Children (4-12 y) wore anaglyphic glasses to play binocular games on an iPad platform for 4 h/w for 4 weeks. The first 25 children were assigned to sham games and then 50 children to binocular games. Children in the binocular group had the option of participating for an additional 4 weeks. Compliance was monitored with calendars and tracking fellow eye contrast settings. About half of the children in each group were also treated with patching at a different time of day. Best-corrected visual acuity, suppression, and stereoacuity were measured at baseline, at the 4- and 8-week outcome visits, and 3 months after cessation of treatment. Mean (±SE) visual acuity improved in the binocular group from 0.47±0.03 logMAR at baseline to 0.39±0.03 logMAR at 4 weeks (P<0.001); there was no significant change for the sham group. The effect of binocular games on visual acuity did not differ for children who were patched vs those who were not. The median stereoacuity remained unchanged in both groups. An additional 4 weeks of treatment did not yield additional visual acuity improvement. Visual acuity improvements were maintained for 3 months after the cessation of treatment. Binocular iPad treatment rapidly improved visual acuity, and visual acuity was stable for at least 3 months following the cessation of treatment.

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

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.

The Specificity of Colored Lenses as Visual Aids in Retinal Disease.

ERIC Educational Resources Information Center

Gawande, A.; And Others

1992-01-01

This study of the effects of lenses of different colors on the visual abilities and comfort of 20 patients with retinal disease found that, in home trials, the critical issue was density more than color. Office tests of visual acuity and contrast sensitivity with colored lenses did not predict subjective benefit. (Author/JDD)

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

Fine lattice lines on the corneal surface after laser in situ keratomileusis (LASIK).

PubMed

Carpel, E F; Carlson, K H; Shannon, S

2000-03-01

To present an example of a pattern of lines resembling fine lattice on the corneal surface subsequent to laser in situ keratomileusis (LASIK). This subtle phenomenon may be relatively common and may affect visual outcome. Case report. A 41-year-old year old man with high myopia and best-corrected visual acuity of 20/20 +2 in each eye underwent laser in situ keratomileusis (LASIK). No operative or postoperative complications occurred. No striae were evident on slit-lamp examination with direct illumination and retroillumination at the time of surgery or in the postoperative period. Postoperative uncorrected visual acuity was 20/25 with a best-corrected spectacle correction of 20/25 in both eyes. Fine lines in a lattice pattern were seen only with fluorescein dye in the precorneal tear film as areas of "negative stain" within the LASIK flap. With tear film supplementation, the lines were less evident and visual acuity improved. One year postoperatively, his uncorrected visual acuity was 20/25 in both eyes. The best-corrected spectacle visual acuity was RE: 20/20 -2, LE: 20/25. The fine lines were still present within the flap. A soft contact lens improved visual acuity to 20/20 in both eyes. Although all four puncta were occluded, he had no epiphora. Fine lines in a lattice pattern that may represent folds in the epithelium or Bowman layer may be present within the flap after LASIK and may adversely affect visual acuity. They may be visible as areas of negative stain with fluorescein dye in the precorneal tear film in the absence of any striae visible in the flap. These superficial lines have been seen more in patients with high degrees of correction and in patients with dry eye. If visual acuity is affected, it may be improved with punctal occlusion, tear supplements, or a contact lens.

Vision related quality of life in patients with type 2 diabetes in the EUROCONDOR trial.

PubMed

Trento, Marina; Durando, Olga; Lavecchia, Sonia; Charrier, Lorena; Cavallo, Franco; Costa, Miguel Angelo; Hernández, Cristina; Simó, Rafael; Porta, Massimo

2017-07-01

To evaluate vision related quality of life in the patients enrolled in The European Consortium for the Early Treatment of Diabetic Retinopathy, a clinical trial on prevention of diabetic retinopathy. Four-hundred-forty-nine patients, 153 women, with type 2 Diabetes and no or mild diabetic retinopathy were enrolled in a 2-year multicenter randomized controlled trial. The 25-item National Eye Institute Visual Functioning Questionnaire was used to explore 12 subscales of vision related quality of life. The patients were 62.8 ± 6.7 years old and had 11.1 ± 5.6 years known disease duration. Diabetic retinopathy was absent in 193 (43.0 %) and mild in 256 (57.0 %). Patients without diabetic retinopathy were older, had shorter diabetes duration and used less insulin and glucose-lowering agents but did not differ by gender, best corrected visual acuity or any subscale, except vision specific mental health and vision specific role difficulties. Patients with reduced retinal thickness at the ganglion cell layer (n = 36) did not differ for diabetic retinopathy but were older, had lower best corrected visual acuity and worse scores for ocular pain, color vision and peripheral vision. On multivariable analysis, worse scores for general vision remained associated with reduced retinal thickness, diabetes duration and best corrected visual acuity, and scores for visual specific mental health with diabetic retinopathy and lower best corrected visual acuity. Visual specific role difficulties were only associated with reduced best corrected visual acuity. Scores for driving decreased among females, with worsening of Hemoglobin A1c and best corrected visual acuity. Color vision depended only on reduced retinal thickness, and peripheral vision on both reduced thickness and best corrected visual acuity. The National Eye Institute Visual Functioning Questionnaire could detect subtle changes in patients' perception of visual function, despite absent/minimal diabetic retinopathy.

Perceptual Learning in Children With Infantile Nystagmus: Effects on Reading Performance.

PubMed

Huurneman, Bianca; Boonstra, F Nienke; Goossens, Jeroen

2016-08-01

Perceptual learning improves visual acuity and reduces crowding in children with infantile nystagmus (IN). Here, we compare reading performance of 6- to 11-year-old children with IN with normal controls, and evaluate whether perceptual learning improves their reading. Children with IN were divided in two training groups: a crowded training group (n = 18; albinism: n = 8; idiopathic IN: n = 10) and an uncrowded training group (n = 17; albinism: n = 9; idiopathic IN: n = 8). Also 11 children with normal vision participated. Outcome measures were: reading acuity (the smallest readable font size), maximum reading speed, critical print size (font size below which reading is suboptimal), and acuity reserve (difference between reading acuity and critical print size). We used multiple regression analyses to test if these reading parameters were related to the children's uncrowded distance acuity and/or crowding scores. Reading acuity and critical print size were 0.65 ± 0.04 and 0.69 ± 0.08 log units larger for children with IN than for children with normal vision. Maximum reading speed and acuity reserve did not differ between these groups. After training, reading acuity improved by 0.12 ± 0.02 logMAR and critical print size improved by 0.11 ± 0.04 logMAR in both IN training groups. The changes in reading acuity, critical print size, and acuity reserve of children with IN were tightly related to changes in their uncrowded distance acuity and the changes in magnitude and extent of crowding. Our findings are the first to show that visual acuity is not the only factor that restricts reading in children with IN, but that crowding also limits their reading performance. By targeting both of these spatial bottlenecks in children with IN, our perceptual learning paradigms significantly improved their reading acuity and critical print size. This shows that perceptual learning can effectively transfer to reading.

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. © 2014 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Nocardia keratitis: clinical course and effect of corticosteroids.

PubMed

Lalitha, Prajna; Srinivasan, Muthiah; Rajaraman, Revathi; Ravindran, Meenakshi; Mascarenhas, Jeena; Priya, Jeganathan Lakshmi; Sy, Aileen; Oldenburg, Catherine E; Ray, Kathryn J; Zegans, Michael E; McLeod, Stephen D; Lietman, Thomas M; Acharya, Nisha R

2012-12-01

To compare the clinical course of Nocardia species keratitis with keratitis resulting from other bacterial organisms and to assess the effect of corticosteroids as adjunctive therapy using data collected from the Steroids for Corneal Ulcers Trial. Subgroup analysis of a randomized controlled trial. setting: Multicenter randomized controlled trial. study population: Five hundred patients with bacterial keratitis randomized 1:1 to topical corticosteroid or placebo who had received at least 48 hours of topical moxifloxacin. intervention/observation procedure: Topical prednisolone phosphate 1% or placebo and clinical course of Nocardia keratitis. main outcome measures: Best spectacle-corrected visual acuity and infiltrate or scar size at 3 months from enrollment. Of 500 patients enrolled in the trial, 55 (11%) had a Nocardia corneal ulcer. Patients with Nocardia ulcers had better presentation visual acuity compared with non-Nocardia ulcers (median Snellen visual acuity, 20/45, compared with 20/145; P < .001) and comparable 3-month visual acuity (median, 20/25, vs 20/40; P = .25). Nocardia ulcers had approximately 2 lines less of improvement in visual acuity compared with non-Nocardia ulcers (0.21 logarithm of the minimal angle of resolution; 95% confidence interval, 0.09 to 0.33 logarithm of the minimal angle of resolution; P = .001). This difference may reflect the better starting visual acuity in patients with Nocardia ulcers. In Nocardia ulcers, corticosteroids were associated with an average 0.4-mm increase in 3-month infiltrate or scar size (95% confidence interval, 0.03 to 0.77 mm; P = .03). Nocardia ulcers responded well to treatment. They showed less overall improvement in visual acuity than non-Nocardia ulcers, but had better presentation acuity. Corticosteroids may be associated with worse outcomes. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

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

Towards an assistive peripheral visual prosthesis for long-term treatment of retinitis pigmentosa: evaluating mobility performance in immersive simulations

NASA Astrophysics Data System (ADS)

Zapf, Marc Patrick H.; Boon, Mei-Ying; Matteucci, Paul B.; Lovell, Nigel H.; Suaning, Gregg J.

2015-06-01

Objective. The prospective efficacy of a future peripheral retinal prosthesis complementing residual vision to raise mobility performance in non-end stage retinitis pigmentosa (RP) was evaluated using simulated prosthetic vision (SPV). Approach. Normally sighted volunteers were fitted with a wide-angle head-mounted display and carried out mobility tasks in photorealistic virtual pedestrian scenarios. Circumvention of low-lying obstacles, path following, and navigating around static and moving pedestrians were performed either with central simulated residual vision of 10° alone or enhanced by assistive SPV in the lower and lateral peripheral visual field (VF). Three layouts of assistive vision corresponding to hypothetical electrode array layouts were compared, emphasizing higher visual acuity, a wider visual angle, or eccentricity-dependent acuity across an intermediate angle. Movement speed, task time, distance walked and collisions with the environment were analysed as performance measures. Main results. Circumvention of low-lying obstacles was improved with all tested configurations of assistive SPV. Higher-acuity assistive vision allowed for greatest improvement in walking speeds—14% above that of plain residual vision, while only wide-angle and eccentricity-dependent vision significantly reduced the number of collisions—both by 21%. Navigating around pedestrians, there were significant reductions in collisions with static pedestrians by 33% and task time by 7.7% with the higher-acuity layout. Following a path, higher-acuity assistive vision increased walking speed by 9%, and decreased collisions with stationary cars by 18%. Significance. The ability of assistive peripheral prosthetic vision to improve mobility performance in persons with constricted VFs has been demonstrated. In a prospective peripheral visual prosthesis, electrode array designs need to be carefully tailored to the scope of tasks in which a device aims to assist. We posit that maximum benefit might come from application alongside existing visual aids, to further raise life quality of persons living through the prolonged early stages of RP.

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 performance of some subjects nicely parallels the stereotypical recovery curve observed in the group mean data. Others show dramatic changes in DVA from one test day to another. These changes may be indicative of a re-adaptation process that is not characterized by a steady improvement with the passage of time, but is instead a dynamic search for appropriate coordinative strategy to achieve the desired gaze stabilization goal. Ground-based data have been collected in our lab using DVA with one of the goals being to improve the DVA test itself. In one of these studies, the DVA test was repeated using a visual target viewing distance of 0.5 meters. While walking, the relative contributions of the otoliths and semi-circular canals that are required to stabilize gaze are affected by visual target viewing distance. It may be possible to exploit this using the current treadmill DVA test to differentially assess changes in these vestibular subsystems. The postflight DVA evaluations currently used have been augmented to include the near target version of the test. Preliminary results from these assessments, as well as the results from the ground-based tests will also be reported. DVA provides a direct measure of a subject's ability to see clearly in the presence of self-motion. The use of the current tests for providing a functionally relevant metric is evident. However, it is possible to expand the scope of DVA testing to include scenarios other than walking. A facility for measuring DVA in the presence of passive movements is being created. Using a mechanized platform to provide the perturbation, it should be possible to simulate aircraft and automobile vibration profiles. Used in conjunction with the far and near visual displays this facility should be able to assess a subject s ability to clearly see distant objects as well as those that appear on the dashboard or instrument control panel during functionally relevant situations.

The effect of amblyopia treatment on stereoacuity.

PubMed

Stewart, Catherine E; Wallace, Michael P; Stephens, David A; Fielder, Alistair R; Moseley, Merrick J

2013-04-01

To explore how stereoacuity changes in patients while they are being treated for amblyopia. The Monitored Occlusion Treatment for Amblyopia Study (MOTAS) comprised 3 distinct phases. In the first phase, baseline, assessments of visual function were made to confirm the initial visual and binocular visual deficit. The second phase, refractive adaptation, now commonly termed "optical treatment," was an 18-week period of spectacle wear with measurements of logMAR visual acuity and stereoacuity with the Frisby test at weeks 0, 6, 12, and 18. In the third phase, occlusion, participants were prescribed 6 hours of patching per day. A total of 85 children were enrolled (mean age, 5.1 ± 1.5 years). In 21 children amblyopia was associated with anisometropia; in 29, with strabismus; and in 35, with both. At study entry, poor stereoacuity was associated with poor visual acuity (P < 0.001) in the amblyopic eye and greater angle of strabismus (P < 0.001). Of 66 participants, 25 (38%) who received refractive adaptation and 19 (29%) who received occlusion improved by at least one octave in stereoacuity, exceeding test-retest variability. Overall, 38 (45%) improved one or more octaves across both treatment phases. Unmeasureable stereoacuity was observed in 56 participants (66%) at study entry and in 37 (43%) at study exit. Stereoacuity improved for almost one half of the study participants. Improvement was observed in both treatment phases. Factors associated with poor or nil stereoacuity at study entry and exit were poor visual acuity of the amblyopic eye and large-angle strabismus. Copyright © 2013 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

[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.

Grating test of contrast sensitivity in patients with Minamata disease.

PubMed Central

Mukuno, K; Ishikawa, S; Okamura, R

1981-01-01

Thirty cases of Minamata disease caused by methyl mercury poisoning with the lesion mainly at the occipital cortex were selected and their spatial contrast sensitivity of vision was examined by the Arden grating chart. At the same time their visual acuity, visual field, and visual evoked cortical potential (VECP) were also investigated. In all cases the results of the Arden test indicated abnormality. Poor results were obtained at higher frequencies of the gratings. VECP elicited by grating pattern reversal stimulus was undertaken in 12 cases out of the 30. The results revealed abnormality almost equal to that shown by the Arden test. Seven out of the 12 cases showed no VECP response. The other 5, giving a response, showed abnormality: when the size of the grating became smaller at higher frequencies, the VECP paused or was not recorded, whereas at low frequencies it was recorded. This finding was in good agreement or was not recorded, whereas at low frequencies it was recorded. This finding was in good agreement with the results of the Arden test. Visual acuity and visual field tests were less sensitive in detecting abnormality. The Arden chart is a sensitive clinical tool for patients with lesions at the cerebral cortex. Furthermore, the test can be used for screening patients who may have come in contrast with organic mercury. PMID:7236573

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

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.

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.

[Application of Ocular Trauma Score in Mechanical Ocular Injury in Forensic Medicine].

PubMed

Xiang, Jian; Guo, Zhao-ming; Wang, Xu; Yu, Li-li; Liu, Hui

2015-10-01

To evaluate the application value for the prognosis of mechanical ocular injury cases using ocular trauma score (OTS). Four hundred and eleven cases of mechanical ocular trauma were retrospectively reviewed. Of the 449 eyes, there were 317 closed globe injury and 132 open globe injury. OTS variables included numerical values as initial visual acuity, rupture, endophthalmitis, perforat- ing or penetrating injury, retinal detachment and relative afferent pupillary block. The differences be- tween the distribution of the final visual acuity and the probability of standard final visual acuity were compared to analyze the correlation between OTS category and final visual acuity. The different types of ocular trauma were compared. Compared with the distribution of final visual acuity in standard OTS score, the ratio in OTS-3 category was statistically different in present study, and no differences were found in other categories. Final visual acuity showed a great linear correlation with OTS category (r = 0.71) and total score (r = 0.73). Compared with closed globe injury, open globe injury was generally associated with lower total score and poorer prognosis. Rupture injury had poorer prognosis compared with penetrating injury. The use of OTS for the patients with ocular trauma can provide re- liable information for the evaluation of prognosis in forensic medicine.

Clinical study on evaluation of anti-cataract effect of Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in Timira (immature cataract).

PubMed

Bhati, Hitesh; Manjusha, R

2015-01-01

Senile cataract is the leading cause of blindness according to the World Health Report, 1998. Till date no accepted medical treatment is available for cataract. In Ayurveda visual disturbances are described in the context of Timira, Kacha and Linganasha. Timira is an early stage characterized by blurring of vision and Linganasha is end stage where complete loss of vision occurs. Ancient scholars have advocated different Anjana application and oral medications in the Timira and Kacha stage. To study the efficacy of test drugs Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in immature cataract. In this trial patients having Senile Immature Cataract were randomized with equal probability to one of the two treatment Groups A and B (n = 20 each). In Group A Triphaladi Ghana Vati 500 mg internally for 3 months and in Group B Triphaladi Ghana Vati 500 mg internally and Elaneer Kuzhambu Anjana for local application were given. Assessment was done on the basis of blurring of vision, visualization of nonexisting things, difficulty in bright light and dim light or night vision, distant visual acuity, pinhole vision, best corrected visual acuity and cataract grading on slit lamp. Both groups showed statistically significant changes in blurring of vision, difficulty in glare, daytime and bright light, distant visual activity, pinhole vision, and best-corrected visual acuity. Group B also showed significant changes in difficulty in night time, visualization of nonexisting things and in nuclear cataract. The study establishes that test drugs can reduce and control the progress of immature cataract, and combined therapy was found more effective. Chakshushya Rasayana, early diagnosis and proper management on Doshic lines can prevent arrest or delay senile cataract.

Clinical study on evaluation of anti-cataract effect of Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in Timira (immature cataract)

PubMed Central

Bhati, Hitesh; Manjusha, R.

2015-01-01

Introduction: Senile cataract is the leading cause of blindness according to the World Health Report, 1998. Till date no accepted medical treatment is available for cataract. In Ayurveda visual disturbances are described in the context of Timira, Kacha and Linganasha. Timira is an early stage characterized by blurring of vision and Linganasha is end stage where complete loss of vision occurs. Ancient scholars have advocated different Anjana application and oral medications in the Timira and Kacha stage. Aim: To study the efficacy of test drugs Triphaladi Ghana Vati and Elaneer Kuzhambu Anjana in immature cataract. Materials and Methods: In this trial patients having Senile Immature Cataract were randomized with equal probability to one of the two treatment Groups A and B (n = 20 each). In Group A Triphaladi Ghana Vati 500 mg internally for 3 months and in Group B Triphaladi Ghana Vati 500 mg internally and Elaneer Kuzhambu Anjana for local application were given. Assessment was done on the basis of blurring of vision, visualization of nonexisting things, difficulty in bright light and dim light or night vision, distant visual acuity, pinhole vision, best corrected visual acuity and cataract grading on slit lamp. Results: Both groups showed statistically significant changes in blurring of vision, difficulty in glare, daytime and bright light, distant visual activity, pinhole vision, and best-corrected visual acuity. Group B also showed significant changes in difficulty in night time, visualization of nonexisting things and in nuclear cataract. Conclusion: The study establishes that test drugs can reduce and control the progress of immature cataract, and combined therapy was found more effective. Chakshushya Rasayana, early diagnosis and proper management on Doshic lines can prevent arrest or delay senile cataract. PMID:27313415

Chorioretinal Lesions Presumed Secondary to Zika Virus Infection in an Immunocompromised Adult.

PubMed

Henry, Christopher R; Al-Attar, Luma; Cruz-Chacón, Alexis M; Davis, Janet L

2017-04-01

Zika virus has spread rapidly throughout the Americas since 2015. The public health implications of Zika virus infection lend special importance to identifying the virus in unsuspected hosts. To describe relevant imaging studies and clinical features of chorioretinal lesions that are presumably associated with Zika virus and that share analogous features with chorioretinal lesions reported in cases of Dengue fever and West Nile virus. This is a case report from an academic referral center in Miami, Florida, of a woman in her 60s from Guaynabo, Puerto Rico, who presented with reduced visual acuity and bilateral diffuse, subretinal, confluent, placoid, and multifocal chorioretinal lesions. The patient was observed over a 5-month period. Visual acuity, clinical course, and multimodal imaging study results. Fluorescein angiography revealed early hypofluorescence and late staining of the chorioretinal lesions. Optical coherence tomography demonstrated outer retinal disruption in the placoid macular lesions. Zika RNA was detected in a plasma sample by real-time reverse transcription polymerase chain reaction testing and was suspected to be the cause of chorioretinal lesions after other viral and infectious causes were ruled out. Three weeks after the onset of symptoms, the patient's visual acuity had improved to 20/60 OD and 20/25 OS, with intraocular pressures of 18 mm Hg OD and 19 mm Hg OS. In 6 weeks, the chorioretinal lesions had healed and visual acuity had improved to 20/25 OD and 20/20 OS. Follow-up optical coherence tomography demonstrated interval recovery of the outer retina and photoreceptors. Acute-onset, self-resolving, placoid, or multifocal nonnecrotizing chorioretinal lesions may be a feature of active Zika virus chorioretinitis, as reported in other Flavivirus infections in adults. Similar findings in potentially exposed adults suggest that clinicians should consider IgM antibody or polymerase chain reaction testing for Zika virus as well as diagnostic testing for Dengue fever and West Nile virus.

Very Similar Spacing-Effect Patterns in Very Different Learning/Practice Domains

PubMed Central

Kornmeier, Jürgen; Spitzer, Manfred; Sosic-Vasic, Zrinka

2014-01-01

Temporally distributed (“spaced”) learning can be twice as efficient as massed learning. This “spacing effect” occurs with a broad spectrum of learning materials, with humans of different ages, with non-human vertebrates and also invertebrates. This indicates, that very basic learning mechanisms are at work (“generality”). Although most studies so far focused on very narrow spacing interval ranges, there is some evidence for a non-monotonic behavior of this “spacing effect” (“nonlinearity”) with optimal spacing intervals at different time scales. In the current study we focused both the nonlinearity aspect by using a broad range of spacing intervals and the generality aspect by using very different learning/practice domains: Participants learned German-Japanese word pairs and performed visual acuity tests. For each of six groups we used a different spacing interval between learning/practice units from 7 min to 24 h in logarithmic steps. Memory retention was studied in three consecutive final tests, one, seven and 28 days after the final learning unit. For both the vocabulary learning and visual acuity performance we found a highly significant effect of the factor spacing interval on the final test performance. In the 12 h-spacing-group about 85% of the learned words stayed in memory and nearly all of the visual acuity gain was preserved. In the 24 h-spacing-group, in contrast, only about 33% of the learned words were retained and the visual acuity gain dropped to zero. The very similar patterns of results from the two very different learning/practice domains point to similar underlying mechanisms. Further, our results indicate spacing in the range of 12 hours as optimal. A second peak may be around a spacing interval of 20 min but here the data are less clear. We discuss relations between our results and basic learning at the neuronal level. PMID:24609081

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.

Small refractive errors--their correction and practical importance.

PubMed

Skrbek, Matej; Petrová, Sylvie

2013-04-01

Small refractive errors present a group of specifc far-sighted refractive dispositions that are compensated by enhanced accommodative exertion and aren't exhibited by loss of the visual acuity. This paper should answer a few questions about their correction, flowing from theoretical presumptions and expectations of this dilemma. The main goal of this research was to (dis)confirm the hypothesis about convenience, efficiency and frequency of the correction that do not raise the visual acuity (or if the improvement isn't noticeable). The next goal was to examine the connection between this correction and other factors (age, size of the refractive error, etc.). The last aim was to describe the subjective personal rating of the correction of these small refractive errors, and to determine the minimal improvement of the visual acuity, that is attractive enough for the client to purchase the correction (glasses, contact lenses). It was confirmed, that there's an indispensable group of subjects with good visual acuity, where the correction is applicable, although it doesn't improve the visual acuity much. The main importance is to eliminate the asthenopia. The prime reason for acceptance of the correction is typically changing during the life, so as the accommodation is declining. Young people prefer the correction on the ground of the asthenopia, caused by small refractive error or latent strabismus; elderly people acquire the correction because of improvement of the visual acuity. Generally the correction was found useful in more than 30%, if the gain of the visual acuity was at least 0,3 of the decimal row.

A binocular iPad treatment for amblyopic children

PubMed Central

Li, S L; Jost, R M; Morale, S E; Stager, D R; Dao, L; Stager, D; Birch, E E

2014-01-01

Purpose Monocular amblyopia treatment (patching or penalization) does not always result in 6/6 vision and amblyopia often recurs. As amblyopia arises from abnormal binocular visual experience, we evaluated the effectiveness of a novel home-based binocular amblyopia treatment. Methods Children (4–12 y) wore anaglyphic glasses to play binocular games on an iPad platform for 4 h/w for 4 weeks. The first 25 children were assigned to sham games and then 50 children to binocular games. Children in the binocular group had the option of participating for an additional 4 weeks. Compliance was monitored with calendars and tracking fellow eye contrast settings. About half of the children in each group were also treated with patching at a different time of day. Best-corrected visual acuity, suppression, and stereoacuity were measured at baseline, at the 4- and 8-week outcome visits, and 3 months after cessation of treatment. Results Mean (±SE) visual acuity improved in the binocular group from 0.47±0.03 logMAR at baseline to 0.39±0.03 logMAR at 4 weeks (P<0.001); there was no significant change for the sham group. The effect of binocular games on visual acuity did not differ for children who were patched vs those who were not. The median stereoacuity remained unchanged in both groups. An additional 4 weeks of treatment did not yield additional visual acuity improvement. Visual acuity improvements were maintained for 3 months after the cessation of treatment. Conclusions Binocular iPad treatment rapidly improved visual acuity, and visual acuity was stable for at least 3 months following the cessation of treatment. PMID:25060850

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.

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.

Nearsightedness

MedlinePlus

... The most common surgery to correct myopia is LASIK . An excimer laser is used to reshape (flatten) ... Images Visual acuity test Normal, nearsightedness, and farsightedness Lasik eye surgery - series References Chia A, Chua WH, ...

Prevalence and risk factors of undercorrected refractive errors among Singaporean Malay adults: the Singapore Malay Eye Study.

PubMed

Rosman, Mohamad; Wong, Tien Y; Tay, Wan-Ting; Tong, Louis; Saw, Seang-Mei

2009-08-01

To describe the prevalence and the risk factors of undercorrected refractive error in an adult urban Malay population. This population-based, cross-sectional study was conducted in Singapore in 3280 Malay adults, aged 40 to 80 years. All individuals were examined at a centralized clinic and underwent standardized interviews and assessment of refractive errors and presenting and best corrected visual acuities. Distance presenting visual acuity was monocularly measured by using a logarithm of the minimum angle of resolution (logMAR) number chart at a distance of 4 m, with the participants wearing their "walk-in" optical corrections (spectacles or contact lenses), if any. Refraction was determined by subjective refraction by trained, certified study optometrists. Best corrected visual acuity was monocularly assessed and recorded in logMAR scores using the same test protocol as was used for presenting visual acuity. Undercorrected refractive error was defined as an improvement of at least 0.2 logMAR (2 lines equivalent) in the best corrected visual acuity compared with the presenting visual acuity in the better eye. The mean age of the subjects included in our study was 58 +/- 11 years, and 52% of the subjects were women. The prevalence rate of undercorrected refractive error among Singaporean Malay adults in our study (n = 3115) was 20.4% (age-standardized prevalence rate, 18.3%). More of the women had undercorrected refractive error than the men (21.8% vs. 18.8%, P = 0.04). Undercorrected refractive error was also more common in subjects older than 50 years than in subjects aged 40 to 49 years (22.6% vs. 14.3%, P < 0.001). Non-spectacle wearers were more likely to have undercorrected refractive errors than were spectacle wearers (24.4% vs. 14.4%, P < 0.001). Persons with primary school education or less were 1.89 times (P = 0.03) more likely to have undercorrected refractive errors than those with post-secondary school education or higher. In contrast, persons with a history of eye disease were 0.74 times (P = 0.003) less likely to have undercorrected refractive errors. The proportion of undercorrected refractive error among the Singaporean Malay adults with refractive errors was higher than that of the Singaporean Chinese adults with refractive errors. Undercorrected refractive error is a significant cause of correctable visual impairment among Singaporean Malay adults, affecting one in five persons.

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/.

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 children with CI and reduced visual information processing given the potential effect of these conditions on school performance.

Disease course in patients with autosomal recessive retinitis pigmentosa due to the USH2A gene.

PubMed

Sandberg, Michael A; Rosner, Bernard; Weigel-DiFranco, Carol; McGee, Terri L; Dryja, Thaddeus P; Berson, Eliot L

2008-12-01

To estimate the mean rates of ocular function loss in patients with autosomal recessive retinitis pigmentosa due to USH2A mutations. In 125 patients with USH2A mutations, longitudinal regression was used to estimate mean rates of change in Snellen visual acuity, Goldmann visual field area (V4e white test light), and 30-Hz (cone) full-field electroretinogram amplitude. These rates were compared with those of previously studied cohorts with dominant retinitis pigmentosa due to RHO mutations and with X-linked retinitis pigmentosa due to RPGR mutations. Rates of change in patients with the Cys759Phe mutation, the USH2A mutation associated with nonsyndromic disease, were compared with rates of change in patients with the Glu767fs mutation, the most common USH2A mutation associated with Usher syndrome type II (i.e., retinitis pigmentosa and hearing loss). Mean annual exponential rates of decline for the USH2A patients were 2.6% for visual acuity, 7.0% for visual field area, and 13.2% for electroretinogram amplitude. The rate of acuity loss fell between the corresponding rates for the RHO and RPGR patients, whereas the rates for field and ERG amplitude loss were faster than those for the RHO and RPGR patients. No significant differences were found for patients with the Cys759Phe mutation versus patients with the Glu767fs mutation. On average, USH2A patients lose visual acuity faster than RHO patients and slower than RPGR patients. USH2A patients lose visual field and cone electroretinogram amplitude faster than patients with RHO or RPGR mutations. Patients with a nonsyndromic USH2A mutation have the same retinal disease course as patients with syndromic USH2A disease.

Prevalence of blindness and cataract surgical outcomes in Takeo Province, Cambodia.

PubMed

Mörchen, Manfred; Langdon, Toby; Ormsby, Gail M; Meng, Ngy; Seiha, Do; Piseth, Kong; Keeffe, Jill E

2015-01-01

To estimate the prevalence of blindness and cataract surgical outcomes in persons 50 years or older above in Takeo Province, Cambodia. A population based survey. A total of 93 villages were selected through probability proportionate to size using the Rapid Assessment of Avoidable Blindness methodology. Households from 93 villages were selected using compact segment sampling. Visual acuity (VA) of 4650 people 50 years or older was tested and lens status and cause of visual impairment were assessed. The response rate was 96.2%. The age- and sex-adjusted prevalence of bilateral blindness [presenting visual acuity (PVA) <3/60 in the better eye] was 3.4% (95% confidence interval, 2.8%-4.0%), resulting in an estimated 4187 people blind in Takeo Province. The age- and sex-adjusted prevalence of low vision (PVA <6/18 to 3/60) was 21.1%, an estimated 25,900 people. Cataract surgical coverage in the bilaterally blind was 64.7% (female 59.5%, male 78.1%). Cataract surgical outcome was poor (best-corrected visual acuity <6/60) in only 7.7% and good in 88.7% (best-corrected visual acuity ≥6/18) of eyes operated in the last 5 years before the survey. The cataract surgical coverage for women is less than that for men. The increased life expectancy in Cambodia and the fact that women constitute 60.6% of the population (aged ≥50 years) at Takeo Province could have had an impact on cataract workload and high prevalence of blindness. A repeated survey using the same methodology after 8-12 years might be helpful in proving genuine change over time.

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

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.

[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.

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

Spontaneous resolution of macular edema after panretinal photocoagulation in florid proliferative diabetic retinopathy.

PubMed

Gaucher, David; Fortunato, Pina; LeCleire-Collet, Amélie; Bourcier, Tristan; Speeg-Schatz, Claude; Tadayoni, Ramin; Massin, Pascale

2009-10-01

To report the evolution of diabetic macular edema (DME) after extensive panretinal photocoagulation in patients with Type 1 diabetes exhibiting florid proliferative diabetic retinopathy (FPDR). This retrospective observational case series comprised 17 eyes of 10 consecutive patients (8 women and 2 men). All patients exhibited FPDR combined with severe DME, and all underwent panretinal photocoagulation. The evolution of visual acuity and progression of FPDR were evaluated. The evolution of DME during follow-up was assessed by fluorescein angiography and repeated optical coherence tomography examinations. At baseline, all eyes had diffuse DME. Mean logMAR visual acuity was 0.402 +/- 0.46. Mean central macular thickness was 468.23 +/- 113.63 microm. After panretinal photocoagulation, DME regressed spontaneously in all eyes after a mean follow-up of 7.1 +/- 2.68 months. Mean central macular thickness decreased to 268.12 +/-54.67 microm (t-test, P < 0.0001). Mean visual acuity improved significantly to 0.184 +/- 0.12 (t-test, P = 0.048). Diabetic macular edema only recurred in two eyes. In DME combined with FPDR, extensive panretinal photocoagulation and glycemic control seem effective in reducing DME and improving vision. In FPDR, DME may be caused by excessive production of vascular endothelial growth factor by the unperfused retina.

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…

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.

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.

[Meta-analysis of clinical randomized controlled trials comparing refractive with diffractive multifocal intraocular lenses in cataract surgery].

PubMed

Shao, Dewang; He, Shouzhi

2014-02-01

To systematic review the effectiveness of refractive multifocal intraocular lens (MIOL) versus diffractive MIOL in the treatment of cataract. Randomized controlled trials comparing refractive MIOL with diffractive MIOL were identified by searching PubMed (1966 to May, 2013), EMbase (1980 to May, 2013), Medline (1966 to May, 2013), and The Cochrane Library (Issue 1, 2013). We also hand-searched related journals. All the searches were restricted in English or Chinese. Methodological quality of randomized controlled trials (RCT) was evaluated by simple evaluate method that recommended by the Cochrane Collaboration. Data extracted by two reviewers with designed extraction form. RevMan software (release 5.2) was used for data management and analysis. A total of 11 trials (1460 eyes) were included for systematic review. Subgroup analyses were used according to different model comparison of MIOL. The results showed a significant difference in the mean of the uncorrected distance visual acuity (UCDVA) and the uncorrected intermediate visual acuity (UCIVA) in the refractive MIOL group with WMD -0.04, 95%CI -0.06 to -0.03 (P < 0.01) and WMD -0.05, 95%CI -0.09 to -0.02 (P = 0.001). It showed a significantly difference in the mean of the uncorrected near visual acuity (UCNVA), complete spectacle independent rate, halo rate and glare rate in the diffractive MIOL group with WMD 0.11, 95%CI 0.08 to 0.15 (P < 0.01), WMD 2.98, 95%CI 2.17 to 4.09 (P < 0.01), WMD 1.52, 95%CI 1.14 to 2.04 (P = 0.004) and WMD 1.27, 95%CI 1.07 to 1.50 (P = 0.005). There was no significant difference between the two groups in the mean of the best corrected distance visual acuity (BCDVA), the best distance corrected intermediate visual acuity (BDCIVA), the best distance corrected near visual acuity (BDCNVA) and the best corrected near visual acuity (BCNVA) with WMD -0.01, 95%CI -0.03 to 0.01 (P = 0.45), WMD -0.06, 95%CI -0.15 to 0.03 (P = 0.18), WMD 0.08, 95%CI -0.01 to 0.17 (P = 0.09) and WMD -0.02, 95%CI -0.26 to 0.23 (P = 0.88). Patients implanted with refractive MIOL show better uncorrected distance and intermediate visual acuity; patients implanted with diffractive MIOL show better uncorrected near visual acuity with less likely to appear light halo, glare and other visual adverse reactions. As for spectacles correction cases, patients implanted with diffractive or refractive MIOL have considerable performances in the far, middle, near visual acuity.

[Use of liquid crystal eyeglasses for examination and recovery of binocular vision].

PubMed

Grigorian, A Iu; Avetisov, E S; Kashchenko, T P; Iachmeneva, E I

1999-01-01

A new method for diploptic treatment of strabismus is proposed, based on phase division of visual fields using liquid crystal eyeglasses --computer complex. The method is based on stereovision training (allowing stereothreshold measurements up to 150 ang. sec.). The method was tried in examinations of two groups of children: 10 controls and 74 patients with strabismus. Examinations of normal controls gave new criteria for measuring fusion reserves and stereovisual acuity by the proposed method. The therapeutic method was tried in 2 groups of patients. Time course of visual function improvement was followed up by several criteria: changes in binocular status by the color test and improvement of in-depth and stereoscopic visual acuity. The method is recommended for practice. The authors discuss the problem of small angle strabismus.

[Retrospective investigation of anti-VEGF treatment reality and effectiveness in patients with neovascular age-related macular degeneration (AMD) in Germany: treatment reality of ranibizumab for neovascular AMD in Germany].

PubMed

Ziemssen, F; Eter, N; Fauser, S; Bopp, S; Radermacher, M; Hasanbasic, Z; Holz, F G

2015-03-01

Neovascular (wet) age-related macular degeneration (wAMD) is a progressive and degenerative retinal disease. This study reports the real-life use in Germany of the standard anti-vascular endothelial growth factor (VEGF) therapy for wAMD as an intravitreal operative drug application. Within the framework of an international retrospective study the medical records of patients with wAMD who were first treated with ranibizumab between 1 January and 31 August 2009 were evaluated. Data were collected until the end of treatment and/or monitoring or until 31 August 2011. The primary objective was to evaluate changes in visual acuity after the start of anti-VEGF therapy. Secondary outcomes included determining real-life anti-VEGF treatment regimens and disease-monitoring practices. Out of 2227 patients who received ≥ 1 anti-VEGF injection with a baseline visual acuity assessment and ≥ 1 post-baseline visual acuity assessment for the treated eye, 420 were included in the German cohort. Visual acuity improved until about day 90 but these gains in visual acuity were not maintained. The mean changes in visual acuity scores from baseline to years 1 and 2 were 1.1 ± 15.7 and - 0.8 ± 17.2 letters, respectively. Patients received a mean of 4.3 ± 1.9 and 1.3 ± 2.2 injections in years 1 and 2, respectively. The majority of visits ( 98.6 %) were conducted irregularly and outside the time frame recommended at the time of the study, with an average of 47.7 ± 36.7 days between visits. More frequent visits and injections were associated with greater improvements in visual acuity. Treatment intensity was not sufficient to maintain the initial improvement in visual acuity by ranibizumab treatment. Real-life results for visual acuity and injection frequency in the German cohort were worse at that time than in other countries. Regular follow-up visits as well as timely retreatment in the presence of signs of disease activity are required to achieve optimal results in wAMD when applying a pro re nata-based strategy.

Photodynamic therapy for treatment subretinal neovascularization

NASA Astrophysics Data System (ADS)

Avetisov, Sergey E.; Budzinskaja, Maria V.; Kiseleva, Tatyana N.; Balatskaya, Natalia V.; Gurova, Irina V.; Loschenov, Viktor B.; Shevchik, Sergey A.; Kuzmin, Sergey G.; Vorozhtsov, Georgy N.

2007-07-01

This work are devoted our experience with photodynamic therapy (PDT) with <> for patients with choroidal neovascularization (CNV). 18 patients with subfoveal CNV in age-related macular degeneration (AMD), 24 patients with subfoveal CNV in pathological myopia (PM) and 4 patients with subfoveal CNV associated with toxoplasmic retinochoroiditis were observed. CNV was 100% classic in all study patients. Standardized protocol refraction, visual acuity testing, ophthalmologic examinations, biomicroscopy, fluorescein angiography, and ultrasonography were performed before treatment and 1 month, 3 months, 6 months, and 1 year after treatment; were used to evaluate the results of photodynamic therapy with <> (0.02% solution of mixture sulfonated aluminium phtalocyanine 0.05 mg/kg, intravenously). A diode laser (<>, Inc, Moscow) was used operating in the range of 675 nm. Need for retreatment was based on fluorescein angiographic evidence of leakage at 3-month follow-up intervals. At 3, 6, 9 month 26 (56.5%) patients had significant improvement in the mean visual acuity. At the end of the 12-month minimal fluorescein leakage from choroidal neovascularization was seen in 12 (26.1%) patients and the mean visual acuity was slightly worse than 0.2 which was not statistically significant as compared with the baseline visual acuity. Patients with fluorescein leakage from CNV underwent repeated PDT with <>. 3D-mode ultrasound shown the decreasing thickness of chorioretinal complex in CNV area. Photodynamic therapy with <> can safely reduce the risk of severe vision loss in patients with predominantly classic subfoveal choroidal neovascularization secondary to AMD, PM and toxoplasmic retinochoroiditis.

Long-term results of pars plana vitrectomy as an anti-inflammatory therapy of pediatric intermediate uveitis resistant to standard medical treatment.

PubMed

Darsová, Denisa; Pochop, Pavel; Štěpánková, Jana; Dotřelová, Dagmar

2018-01-01

To evaluate the efficacy of pars plana vitrectomy (PPV) as an anti-inflammatory therapy in pediatric recurrent intermediate uveitis. A retrospective study evaluated the long-term results of PPV indicated for intermediate uveitis with a mean observation period of 10.3 years (range 7-15.6 years) in 6 children (mean age 8 years, range 6-12 years). Pars plana vitrectomy was performed on 10 eyes in the standard manner and was initiated by vitreous sampling for laboratory examination. Data recorded were perioperative or postoperative vitrectomy complications, anatomic and functional results of PPV, and preoperative and postoperative best-corrected Snellen visual acuity. No perioperative or postoperative complications were observed. Bacteriologic, virologic, mycotic, and cytologic analysis of the vitreous was negative in all tested children. Five eyes were subsequently operated on for posterior subcapsular cataracts. An average preoperative visual acuity of 0.32 improved to an average postoperative visual acuity of 0.8. In the case of systemic immunosuppressive treatment failure in pediatric uveitis, particularly in eyes with cystoid macular edema, we recommend PPV relatively early.

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

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.

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.

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.

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.

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

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.

Quality of vision in refractive and cataract surgery, indirect measurers: review article.

PubMed

Parede, Taís Renata Ribeira; Torricelli, André Augusto Miranda; Mukai, Adriana; Vieira Netto, Marcelo; Bechara, Samir Jacob

2013-01-01

Visual acuity is the measurement of an individual's ability to recognize details of an object in a space. Visual function measurements in clinical ophthalmology are limited by factors such as maximum contrast and so it might not adequately reflect the real vision conditions at that moment as well as the subjective aspects of the world perception by the patient. The objective of a successful vision-restoring surgery lies not only in gaining visual acuity lines, but also in vision quality. Therefore, refractive and cataract surgeries have the responsibility of achieving quality results. It is difficult to define quality of vision by a single parameter, and the main functional-vision tests are: contrast sensitivity, disability glare, intraocular stray light and aberrometry. In the current review the different components of the visual function are explained and the several available methods to assess the vision quality are described.

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.

Visual Function Metrics in Early and Intermediate Dry Age-related Macular Degeneration for Use as Clinical Trial Endpoints.

PubMed

Cocce, Kimberly J; Stinnett, Sandra S; Luhmann, Ulrich F O; Vajzovic, Lejla; Horne, Anupama; Schuman, Stefanie G; Toth, Cynthia A; Cousins, Scott W; Lad, Eleonora M

2018-05-01

To evaluate and quantify visual function metrics to be used as endpoints of age-related macular degeneration (AMD) stages and visual acuity (VA) loss in patients with early and intermediate AMD. Cross-sectional analysis of baseline data from a prospective study. One hundred and one patients were enrolled at Duke Eye Center: 80 patients with early AMD (Age-Related Eye Disease Study [AREDS] stage 2 [n = 33] and intermediate stage 3 [n = 47]) and 21 age-matched, normal controls. A dilated retinal examination, macular pigment optical density measurements, and several functional assessments (best-corrected visual acuity, macular integrity assessment mesopic microperimety, dark adaptometry, low-luminance visual acuity [LLVA] [standard using a log 2.0 neutral density filter and computerized method], and cone contrast test [CCT]) were performed. Low-luminance deficit (LLD) was defined as the difference in numbers of letters read at standard vs low luminance. Group comparisons were performed to evaluate differences between the control and the early and intermediate AMD groups using 2-sided significance tests. Functional measures that significantly distinguished between normal and intermediate AMD were standard and computerized (0.5 cd/m 2 ) LLVA, percent reduced threshold and average threshold on microperimetry, CCTs, and rod intercept on dark adaptation (P < .05). The intermediate group demonstrated deficits in microperimetry reduced threshhold, computerized LLD2, and dark adaptation (P < .05) relative to early AMD. Our study suggests that LLVA, microperimetry, CCT, and dark adaptation may serve as functional measures differentiating early-to-intermediate stages of dry AMD. Copyright © 2018 Elsevier Inc. All rights reserved.

Clinical characteristics and outcomes of fall-related open globe injuries in Japan.

PubMed

Morikawa, Shohei; Okamoto, Yoshifumi; Okamoto, Fumiki; Inomoto, Naoki; Ishikawa, Hiroto; Harimoto, Kozo; Ueda, Tetsuo; Sakamoto, Taiji; Oshika, Tetsuro

2018-07-01

To investigate the clinical characteristics and visual outcomes in patients with fall-related open globe injuries and to evaluate differences between fall-related and non-fall-related open globe injuries in Japan. A retrospective review of patients with open globe injury who presented to Japan-Clinical Research of Study (J-CREST) hospitals between 2005 and 2015 was enrolled. Clinical information including age, sex, initial visual acuity, final visual acuity, type of injury, status of the crystalline lens, zone of injury, wound length, presence of retinal detachment, proliferative vitreoretinopathy, expulsive hemorrhage, and endophthalmitis was recorded. A total of 374 eyes were enrolled, of which 120 (32.1%) suffered from fall-related injury with average age of 73.7 ± 15.9 years (range, 11-101 years). A majority of patients were female (55.8%). Of 120 patients with fall-related injury, 109 (90.8%) presented with rupture and 11 (9.2%) with laceration. A multiple regression analysis revealed that final visual acuity was significantly associated with initial visual acuity (r = 0.99, P < 0.001). Compared to non-fall-related open globe injuries, fall-related open globe injuries were associated with elderly age, female sex, poorer initial and final visual acuity, rupture, absence of the lens, larger wound size, retinal detachment, expulsive hemorrhage, and absence of endophthalmitis (P < 0.01). Fall-related open globe injuries were more frequent in elderly female and accompanied by larger wound lengths and severer ocular complications. Visual outcomes in patients with fall-related open globe injuries were related to initial visual acuity.

Long-term results of repeated anti-vascular endothelial growth factor therapy in eyes with retinal pigment epithelial tears.

PubMed

Moreira, Carlos A; Arana, Luis A; Zago, Rommel J

2013-02-01

To evaluate the long-term results of retinal pigment epithelium tears in eyes treated with repeated anti-vascular endothelial growth factor (VEGF) therapy. Five patients with retinal pigment epithelial tears (without foveal center involvement) after anti-VEGF injection were studied retrospectively. Mean follow-up time was 52 months, with measurements of visual acuity and evaluation of macular findings by angiography and optical coherence tomography during this period. All eyes had a persistent submacular neovascular membrane 30 days after the tear. An anti-VEGF drug was reinjected until the membranes stopped leaking. The mean initial visual acuity immediately after the tear was 20/160, and the mean final visual acuity was 20/60. The number of anti-VEGF reinjections varied from two to eight during the follow-up period. Long-term optical coherence tomography analysis showed reduced fluid and remodeling of the torn retinal pigment epithelium. Long-term visual results with repeated anti-VEGF therapy are not as devastating as suggested previously. Visual acuity and metamorphopsia improve with time as long as the neovascular membrane is inactive. Optical coherence tomography changes in the macular area reflect the visual acuity improvement.

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.

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.

Training-induced recovery of low-level vision followed by mid-level perceptual improvements in developmental object and face agnosia

PubMed Central

Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri

2015-01-01

Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental stage of the adult visual system, can overcome such developmental impairments. Here, we visually trained LG, a developmental object and face agnosic individual. Prior to training, at the age of 20, LG's basic and mid-level visual functions such as visual acuity, crowding effects, and contour integration were underdeveloped relative to normal adult vision, corresponding to or poorer than those of 5–6 year olds (Gilaie-Dotan, Perry, Bonneh, Malach & Bentin, 2009). Intensive visual training, based on lateral interactions, was applied for a period of 9 months. LG's directly trained but also untrained visual functions such as visual acuity, crowding, binocular stereopsis and also mid-level contour integration improved significantly and reached near-age-level performance, with long-term (over 4 years) persistence. Moreover, mid-level functions that were tested post-training were found to be normal in LG. Some possible subtle improvement was observed in LG's higher-order visual functions such as object recognition and part integration, while LG's face perception skills have not improved thus far. These results suggest that corrective training at a post-developmental stage, even in the adult visual system, can prove effective, and its enduring effects are the basis for a revival of a developmental cascade that can lead to reduced perceptual impairments. PMID:24698161

Training-induced recovery of low-level vision followed by mid-level perceptual improvements in developmental object and face agnosia.

PubMed

Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri

2015-01-01

Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental stage of the adult visual system, can overcome such developmental impairments. Here, we visually trained LG, a developmental object and face agnosic individual. Prior to training, at the age of 20, LG's basic and mid-level visual functions such as visual acuity, crowding effects, and contour integration were underdeveloped relative to normal adult vision, corresponding to or poorer than those of 5-6 year olds (Gilaie-Dotan, Perry, Bonneh, Malach & Bentin, 2009). Intensive visual training, based on lateral interactions, was applied for a period of 9 months. LG's directly trained but also untrained visual functions such as visual acuity, crowding, binocular stereopsis and also mid-level contour integration improved significantly and reached near-age-level performance, with long-term (over 4 years) persistence. Moreover, mid-level functions that were tested post-training were found to be normal in LG. Some possible subtle improvement was observed in LG's higher-order visual functions such as object recognition and part integration, while LG's face perception skills have not improved thus far. These results suggest that corrective training at a post-developmental stage, even in the adult visual system, can prove effective, and its enduring effects are the basis for a revival of a developmental cascade that can lead to reduced perceptual impairments. © 2014 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

Mobility scooter driving ability in visually impaired individuals.

PubMed

Cordes, Christina; Heutink, Joost; Brookhuis, Karel A; Brouwer, Wiebo H; Melis-Dankers, Bart J M

2018-06-01

To investigate how well visually impaired individuals can learn to use mobility scooters and which parts of the driving task deserve special attention. A mobility scooter driving skill test was developed to compare driving skills (e.g. reverse driving, turning) between 48 visually impaired (very low visual acuity = 14, low visual acuity = 10, peripheral field defects = 11, multiple visual impairments = 13) and 37 normal-sighted controls without any prior experience with mobility scooters. Performance on this test was rated on a three-point scale. Furthermore, the number of extra repetitions on the different elements were noted. Results showed that visually impaired participants were able to gain sufficient driving skills to be able to use mobility scooters. Participants with visual field defects combined with low visual acuity showed most problems learning different skills and needed more training. Reverse driving and stopping seemed to be most difficult. The present findings suggest that visually impaired individuals are able to learn to drive mobility scooters. Mobility scooter allocators should be aware that these individuals might need more training on certain elements of the driving task. Implications for rehabilitation Visual impairments do not necessarily lead to an inability to acquire mobility scooter driving skills. Individuals with peripheral field defects (especially in combination with reduced visual acuity) need more driving ability training compared to normal-sighted people - especially to accomplish reversing. Individual assessment of visually impaired people is recommended, since participants in this study showed a wide variation in ability to learn driving a mobility scooter.

Visual defects in a mouse model of fetal alcohol spectrum disorder.

PubMed

Lantz, Crystal L; Pulimood, Nisha S; Rodrigues-Junior, Wandilson S; Chen, Ching-Kang; Manhaes, Alex C; Kalatsky, Valery A; Medina, Alexandre Esteves

2014-01-01

Alcohol consumption during pregnancy can lead to a multitude of neurological problems in offspring, varying from subtle behavioral changes to severe mental retardation. These alterations are collectively referred to as Fetal Alcohol Spectrum Disorders (FASD). Early alcohol exposure can strongly affect the visual system and children with FASD can exhibit an amblyopia-like pattern of visual acuity deficits even in the absence of optical and oculomotor disruption. Here, we test whether early alcohol exposure can lead to a disruption in visual acuity, using a model of FASD to mimic alcohol consumption in the last months of human gestation. To accomplish this, mice were exposed to ethanol (5 g/kg i.p.) or saline on postnatal days (P) 5, 7, and 9. Two to three weeks later we recorded visually evoked potentials to assess spatial frequency detection and contrast sensitivity, conducted electroretinography (ERG) to further assess visual function and imaged retinotopy using optical imaging of intrinsic signals. We observed that animals exposed to ethanol displayed spatial frequency acuity curves similar to controls. However, ethanol-treated animals showed a significant deficit in contrast sensitivity. Moreover, ERGs revealed a market decrease in both a- and b-waves amplitudes, and optical imaging suggest that both elevation and azimuth maps in ethanol-treated animals have a 10-20° greater map tilt compared to saline-treated controls. Overall, our findings suggest that binge alcohol drinking restricted to the last months of gestation in humans can lead to marked deficits in visual function.

Oxygenation state and twilight vision at 2438 m.

PubMed

Connolly, Desmond M

2011-01-01

Under twilight viewing conditions, hypoxia, equivalent to breathing air at 3048 m (10,000 ft), compromises low contrast acuity, dynamic contrast sensitivity, and chromatic sensitivity. Selected past experiments have been repeated under milder hypoxia, equivalent to altitude exposure below 2438 m (8000 ft), to further define the influence of oxygenation state on mesopic vision. To assess photopic and mesopic visual function, 12 subjects each undertook three experiments using the Contrast Acuity Assessment test, the Frequency Doubling Perimeter, and the Color Assessment and Diagnosis (CAD) test. Experiments were conducted near sea level breathing 15.2% oxygen (balance nitrogen) and 100% oxygen, representing mild hypobaric hypoxia at 2438 m (8000 ft) and the benefit of supplementary oxygen, respectively. Oxygenation state was a statistically significant determinant of visual performance on all three visual parameters at mesopic, but not photopic, luminance. Mesopic sensitivity was greater with supplementary oxygen, but the magnitude of each hypoxic decrement was slight. Hypoxia elevated mesopic contrast acuity thresholds by approximately 4%; decreased mesopic dynamic contrast sensitivity by approximately 2 dB; and extended mean color ellipse axis length by approximately one CAD unit at mesopic luminance (that is, hypoxia decreased chromatic sensitivity). The results indicate that twilight vision may be susceptible to conditions of altered oxygenation at upper-to-mid mesopic luminance with relevance to contemporary night flying, including using night vision devices. Supplementary oxygen should be considered when optimal visual performance is mission-critical during flight above 2438 m (8000 ft) in dim light.

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.

[Impairment of safety in navigation caused by alcohol: impact on visual function].

PubMed

Grütters, G; Reichelt, J A; Ritz-Timme, S; Thome, M; Kaatsch, H J

2003-05-01

So far in Germany, no legally binding standards for blood alcohol concentration exist that prove an impairment of navigability. The aim of our interdisciplinary project was to obtain data in order to identify critical blood alcohol limits. In this context the visual system seems to be of decisive importance. 21 professional skippers underwent realistic navigational demands soberly and alcoholized in a sea traffic simulator. The following parameters were considered: visual acuity, stereopsis, color vision, and accommodation. Under the influence of alcohol (average blood alcohol concentration: 1.08 per thousand ) each skipper considered himself to be completely capable of navigating. While simulations were running, all of the skippers made nautical mistakes or underestimated dangerous situations. Severe impairment in visual acuity or binocular function were not observed. Accommodation decreased by an average of 18% ( p=0.0001). In the test of color vision skippers made more mistakes ( p=0.017) and the time needed for this test was prolonged ( p=0.004). Changes in visual function as well as vegetative and psychological reactions could be the cause of mistakes and alcohol should therefore be regarded as a severe risk factor for security in sea navigation.

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.

Anomalous coagulation factors in non-arteritic anterior ischemic optic neuropathy with central retinal vein occlusion: A case report.

PubMed

Kim, Ji Hong; Kang, Min Ho; Seong, Mincheol; Cho, Heeyoon; Shin, Yong Un

2018-04-01

Non-arteritic anterior ischemic optic neuropathy (NAION) is characterized by sudden, painless visual loss and optic disc edema. NAION occurs mainly in the presence of cardiovascular disease and hypercoagulability, mainly in patients over 50 years of age. We experienced a case of NAION associated with central retinal vein occlusion (CRVO) in a young man with no underlying disease. A 46-year-old man was referred to our clinic following a sudden loss of vision in his right eye. The patient exhibited no underlying disease and reported no ongoing medication. Significant visual loss and visual disturbance of the right eye were observed. The pupil of the right eye was enlarged and an afferent pupillary defect was observed. On fundus examination, retinal hemorrhage was observed in the peripheral retina; macular edema was observed in optical coherence tomography analysis. However, optic disc edema was not evident. No abnormal findings were found in routine blood tests for hypercoagulability. After 3 days of steroid intravenous injection, macular edema disappeared and visual acuity was improved, but optic disc edema began to appear. One week later, optic disc edema was evident and visual acuity was significantly reduced; thus, the patient was diagnosed with NAION. In fluorescein angiography, peripheral retinal ischemia was observed, suggesting that CRVO was complicated. Blood tests, including analysis of coagulation factors, were performed again, showing that coagulation factors IX and XI were increased. Anomalous coagulation factors in non-arteritic anterior ischemic optic neuropathy with central retinal vein occlusion. Systemic steroids were administered. One month later, optic disc edema and retinal hemorrhage gradually diminished and eventually disappeared; however, visual acuity did not recover. In young patients without underlying disease, cases of NAION require careful screening for coagulation disorders. Even if there is no abnormality in the test for routine coagulation status, it may be necessary to confirm a coagulation defect through an additional coagulation factor assay.

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.

Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

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

Khan, Niloufer; Khan, Mohammad K.; Bena, James

Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200more » at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.« less

Biochemical, histological and behavioural aspects of visual function during early development of rainbow trout

USGS Publications Warehouse

Carvalho, Paulo S. M.; Noltie, Douglas B.; Tillitt, D.E.

2004-01-01

Retinal structure and concentration of retinoids involved in phototransduction changed during early development of rainbow trout Oncorhynchus mykiss, correlating with improvements in visual function. A test chamber was used to evaluate the presence of optokinetic or optomotor responses and to assess the functionality of the integrated cellular, physiological and biochemical components of the visual system. The results indicated that in rainbow trout optomotor responses start at 10 days post-hatch, and demonstrated for the first time that increases in acuity, sensitivity to low light as well as in motion detection abilities occur from this stage until exogenous feeding starts. The structure of retinal cells such as cone ellipsoids increased in length as photopic visual acuity improved, and rod densities increased concurrently with improvements in scotopic thresholds (2.2 log10 units). An increase in the concentrations of the chromophore all-trans-retinal correlated with improvements of all behavioural measures of visual function during the same developmental phase. ?? 2004 The Fisheries Society of the British Isles.

Construction and validation of a Tamil logMAR chart.

PubMed

Varadharajan, Srinivasa; Srinivasan, Krithica; Kumaresan, Brindha

2009-09-01

To design, construct and validate a new Tamil logMAR visual acuity chart based on current recommendations. Ten Tamil letters of equal legibility were identified experimentally and were used in the chart. Two charts, one internally illuminated and one externally illuminated, were constructed for testing at 4 m distance. The repeatability of the two charts was tested. For validation, the two charts were compared with a standard English logMAR chart (ETDRS). When compared to the ETDRS chart, a difference of 0.06 +/- 0.07 and 0.07 +/- 0.07 logMAR was found for the internally and externally illuminated charts respectively. Limits of agreement between the internally illuminated Tamil logMAR chart and ETDRS chart were found to be (-0.08, 0.19), and (-0.07, 0.20) for the externally illuminated chart. The test - retest results showed a difference of 0.02 +/- 0.04 and 0.02 +/- 0.06 logMAR for the internally and externally illuminated charts respectively. Limits of agreement for repeated measurements for the internally illuminated Tamil logMAR chart were found to be (-0.06, 0.10), and (-0.10, 0.14) for the externally illuminated chart. The newly constructed Tamil logMAR charts have good repeatability. The difference in visual acuity scores between the newly constructed Tamil logMAR chart and the standard English logMAR chart was within acceptable limits. This new chart can be used for measuring visual acuity in the literate Tamil population.

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

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.

Amblyopia: neural basis and therapeutic approaches.

PubMed

Bretas, Caio César Peixoto; Soriano, Renato Nery

2016-01-01

Abnormalities in visual processing caused by visual deprivation or abnormal binocular interaction may induce amblyopia, which is characterized by reduced visual acuity. Occlusion therapy, the conventional treatment, requires special attention as occlusion of the fellow normal eye may reduce its visual acuity and impair binocular vision. Besides recovering visual acuity, some researchers have recommended restoration of stereoacuity and motor fusion and reverse suppression in order to prevent diplopia. Recent studies have documented that the amblyopic visual cortex has a normal complement of cells but reduced spatial resolution and a disordered topographical map. Changes occurring in the late sensitive period selectively impact the parvocellular pathway. Distinct morphophysiologic and psychophysical deficits may demand individualization of therapy, which might provide greater and longer-lasting residual plasticity in some children.

An automated miniaturized Haploscope for testing binocular visual function

NASA Technical Reports Server (NTRS)

Decker, T. A.; Williams, R. E.; Kuether, C. L.; Wyman-Cornsweet, D.

1976-01-01

A computer-controlled binocular vision testing device has been developed as one part of a system designed for NASA to test the vision of astronauts during spaceflight. The device, called the Mark III Haploscope, utilizes semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phorias, fixation disparity and accommodation/convergence relationships. All tests are self-administered, yield quantitative data and may be used repeatedly without subject memorization. Future applications of this programmable, compact device include its use as a clinical instrument to perform routine eye examinations or vision screening, and as a research tool to examine the effects of environment or work-cycle upon visual function.

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

[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 impairment. Un-corrected refractive error(13.38%) also was the main cause of visual impairment. The prevalence of blindness and moderate and severe visual impairment in Shuangcheng City is relatively higher in China Nine Province Survey. Cataract, retinal diseases and un-corrected refractive error are the main causes of the blindness and moderate and severe visual impairment.

Randomized trial of the ForeseeHome monitoring device for early detection of neovascular age-related macular degeneration. The HOme Monitoring of the Eye (HOME) study design - HOME Study report number 1.

PubMed

Chew, Emily Y; Clemons, Traci E; Bressler, Susan B; Elman, Michael J; Danis, Ronald P; Domalpally, Amitha; Heier, Jeffrey S; Kim, Judy E; Garfinkel, Richard A

2014-03-01

To evaluate the effects of a home-monitoring device with tele-monitoring compared with standard care in detection of progression to choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD), the leading cause of blindness in the US. Participants, aged 55 to 90 years, at high risk of developing CNV associated with AMD were recruited to the HOme Monitoring of Eye (HOME) Study, an unmasked, multi-center, randomized trial of the ForeseeHome (FH) device plus standard care vs. standard care alone. The FH device utilizes preferential hyperacuity perimetry and tele-monitoring to detect changes in vision function associated with development of CNV, potentially prior to symptom and visual acuity loss. After establishing baseline measurements, subsequent changes on follow-up are detected by the device, causing the monitoring center to alert the clinical center to recall participants for an exam. Standard care consists of instructions for self-monitoring visual changes with subsequent self-report to the clinical center. The primary objective of this study is to determine whether home monitoring plus standard care in comparison with standard care alone, results in earlier detection of incident CNV with better present visual acuity. The primary outcome is the decline in visual acuity at CNV diagnosis from baseline. Detection of CNV prior to substantial vision loss is critical as vision outcome following anti-angiogenic therapy is dependent on the visual acuity at initiation of treatment. HOME Study is the first large scale study to test the use of home tele-monitoring system in the management of AMD patients. Published by Elsevier Inc.

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.

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 emmetropes. Moderately hyperopic children were found to have deficits in measures of attention. Hyperopic children with reduced near visual function also had lower scores on VMI and VP than emmetropic children.

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.

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).

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.

Nocardia keratitis: Clinical course and effect of corticosteroids

PubMed Central

Lalitha, Prajna; Srinivasan, Muthiah; Rajaraman, Revathi; Ravindran, Meenakshi; Mascarenhas, Jeena; Priya, Jeganathan Lakshmi; Sy, Aileen; Oldenburg, Catherine E.; Ray, Kathryn J.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

2012-01-01

Purpose To compare the clinical course of Nocardia spp keratitis with keratitis due to other bacterial organisms, and to assess the effect of corticosteroids as adjunctive therapy using data collected from the Steroids for Corneal Ulcers Trial (SCUT). Design Sub-group analysis of a randomized controlled trial Methods Setting Multicenter randomized controlled trial Study Population 500 patients with bacterial keratitis, randomized 1:1 to topical corticosteroid or placebo who had received at least 48 hours of topical moxifloxacin Intervention/Observation Procedure Topical prednisolone phosphate 1% or placebo; clinical course of Nocardia keratitis Main outcome measures Best spectacle-corrected visual acuity and infiltrate/scar size at 3 months from enrollment Results Of 500 patients enrolled in the trial, 55 (11%) had a Nocardia corneal ulcer. Patients with Nocardia ulcers had better presentation visual acuity compared to non-Nocardia ulcers (median Snellen 20/45 compared to 20/145, P<0.001), and comparable 3-month visual acuity (median 20/25 versus 20/40, P=0.25). Nocardia ulcers had approximately 2 lines less improvement in visual acuity compared to non-Nocardia ulcers (0.21 logMAR, 95% CI 0.09 to 0.33 logMAR, P=0.001). This difference may reflect the better starting visual acuity in patients with Nocardia ulcers. In Nocardia ulcers, corticosteroids were associated with an average 0.4 mm increase in 3-month infiltrate/scar size (95% CI 0.03 to 0.77mm, P=0.03). Conclusion Nocardia ulcers responded well to treatment. They showed less overall improvement in visual acuity than non-Nocardia ulcers, but had better presentation acuity. Corticosteroids may be associated with worse outcomes. PMID:22959881

Laterality of proprioception in the orofacial muscles and temporomandibular joint.

PubMed

Frayne, Ellie; Coulson, Susan; Adams, Roger; Croxson, Glen; Waddington, Gordon

2016-12-02

Laterality of function in the orofacial musculature suggests there may be side-to-side asymmetry of proprioceptive acuity in lip movement compared to the temporomandibular joint (TMJ). In the present work, 14 young adults were tested for acuity of lip and TMJ closure movements onto plugs varying from 5 to 8mm without visual feedback. Testing was conducted on both left and right sides, using the same psychophysical task and stimuli. Results showed superior proprioceptive acuity at the lips, with no significant side effect. However, there was side-to-side asymmetry in the correlations between proprioceptive performance for the two anatomical structures, with performance on the right side strongly correlated but not on the left. This is consistent with the need for coordination between structures during chewing. When acuity at different points in the stimulus range was examined, the right side lips were better with small stimuli. Overall, results support enhanced use-specific proprioception. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Clinical characteristics in 53 patients with cat scratch optic neuropathy.

PubMed

Chi, Sulene L; Stinnett, Sandra; Eggenberger, Eric; Foroozan, Rod; Golnik, Karl; Lee, Michael S; Bhatti, M Tariq

2012-01-01

To describe the clinical manifestations and to identify risk factors associated with visual outcome in a large cohort of patients with cat scratch optic neuropathy (CSON). Multicenter, retrospective chart review. Fifty-three patients (62 eyes) with serologically positive CSON from 5 academic neuro-ophthalmology services evaluated over an 11-year period. Institutional review board/ethics committee approval was obtained. Data from medical record charts were collected to detail the clinical manifestations and to analyze visual outcome metrics. Generalized estimating equations and logistic regression analysis were used in the statistical analysis. Six patients (9 eyes) were excluded from visual outcome statistical analysis because of a lack of follow-up. Demographic information, symptoms at presentation, clinical characteristics, length of follow-up, treatment used, and visual acuity (at presentation and final follow-up). Mean patient age was 27.8 years (range, 8-65 years). Mean follow-up time was 170.8 days (range, 1-1482 days). Simultaneous bilateral involvement occurred in 9 (17%) of 53 patients. Visual acuity on presentation ranged from 20/20 to counting fingers (mean, 20/160). Sixty-eight percent of eyes retained a visual acuity of 20/40 or better at final follow-up (defined as favorable visual outcome). Sixty-seven percent of patients endorsed a history of cat or kitten scratch. Neuroretinitis (macular star) developed in 28 eyes (45%). Only 5 patients had significant visual complications (branch retinal artery occlusion, macular hole, and corneal decompensation). Neither patient age nor any other factor except good initial visual acuity and absence of systemic symptoms was associated with a favorable visual outcome. There was no association between visual acuity at final follow-up and systemic antibiotic or steroid use. Patients with CSON have a good overall visual prognosis. Good visual acuity at presentation was associated with a favorable visual outcome. The absence of a macular star does not exclude the possibility of CSON. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

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…

The Effects of a Novel Head-Mounted Symbology on Spatial Disorientation and Flight Performance in U.S. Air Force Pilots

DTIC Science & Technology

2012-10-24

has been tested in a clinical environment and has proven capable of improving vestibular symptoms (e.g., dizziness, spinning, vertigo ) and...vestibular problems (e.g., dizziness, vertigo ). They also had no history of visual deficits and all possessed a Snellen visual acuity of 20/20 or

Predicting Visual Disability in Glaucoma With Combinations of Vision Measures.

PubMed

Lin, Stephanie; Mihailovic, Aleksandra; West, Sheila K; Johnson, Chris A; Friedman, David S; Kong, Xiangrong; Ramulu, Pradeep Y

2018-04-01

We characterized vision in glaucoma using seven visual measures, with the goals of determining the dimensionality of vision, and how many and which visual measures best model activity limitation. We analyzed cross-sectional data from 150 older adults with glaucoma, collecting seven visual measures: integrated visual field (VF) sensitivity, visual acuity, contrast sensitivity (CS), area under the log CS function, color vision, stereoacuity, and visual acuity with noise. Principal component analysis was used to examine the dimensionality of vision. Multivariable regression models using one, two, or three vision tests (and nonvisual predictors) were compared to determine which was best associated with Rasch-analyzed Glaucoma Quality of Life-15 (GQL-15) person measure scores. The participants had a mean age of 70.2 and IVF sensitivity of 26.6 dB, suggesting mild-to-moderate glaucoma. All seven vision measures loaded similarly onto the first principal component (eigenvectors, 0.220-0.442), which explained 56.9% of the variance in vision scores. In models for GQL scores, the maximum adjusted- R 2 values obtained were 0.263, 0.296, and 0.301 when using one, two, and three vision tests in the models, respectively, though several models in each category had similar adjusted- R 2 values. All three of the best-performing models contained CS. Vision in glaucoma is a multidimensional construct that can be described by several variably-correlated vision measures. Measuring more than two vision tests does not substantially improve models for activity limitation. A sufficient description of disability in glaucoma can be obtained using one to two vision tests, especially VF and CS.

Basic quantitative assessment of visual performance in patients with very low vision.

PubMed

Bach, Michael; Wilke, Michaela; Wilhelm, Barbara; Zrenner, Eberhart; Wilke, Robert

2010-02-01

A variety of approaches to developing visual prostheses are being pursued: subretinal, epiretinal, via the optic nerve, or via the visual cortex. This report presents a method of comparing their efficacy at genuinely improving visual function, starting at no light perception (NLP). A test battery (a computer program, Basic Assessment of Light and Motion [BaLM]) was developed in four basic visual dimensions: (1) light perception (light/no light), with an unstructured large-field stimulus; (2) temporal resolution, with single versus double flash discrimination; (3) localization of light, where a wedge extends from the center into four possible directions; and (4) motion, with a coarse pattern moving in one of four directions. Two- or four-alternative, forced-choice paradigms were used. The participants' responses were self-paced and delivered with a keypad. The feasibility of the BaLM was tested in 73 eyes of 51 patients with low vision. The light and time test modules discriminated between NLP and light perception (LP). The localization and motion modules showed no significant response for NLP but discriminated between LP and hand movement (HM). All four modules reached their ceilings in the acuity categories higher than HM. BaLM results systematically differed between the very-low-acuity categories NLP, LP, and HM. Light and time yielded similar results, as did localization and motion; still, for assessing the visual prostheses with differing temporal characteristics, they are not redundant. The results suggest that this simple test battery provides a quantitative assessment of visual function in the very-low-vision range from NLP to HM.

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.

Optical defocus: differential effects on size and contrast letter recognition thresholds.

PubMed

Rabin, J

1994-02-01

To determine if optical defocus produces a greater reduction in visual acuity or small-letter contrast sensitivity. Letter charts were used to measure visual acuity and small-letter contrast sensitivity (20/25 Snellen equivalent) as a function of optical defocus. Letter size (acuity) and contrast (contrast sensitivity) were varied in equal logarithmic steps to make the task the same for the two types of measurement. Both visual acuity and contrast sensitivity declined with optical defocus, but the effect was far greater in the contrast domain. However, measurement variability also was greater for contrast sensitivity. After correction for this variability, measurement in the contrast domain still proved to be a more sensitive (1.75x) index of optical defocus. Small-letter contrast sensitivity is a powerful technique for detecting subtle amounts of optical defocus. This adjunctive approach may be useful when there are small changes in resolution that are not detected by standard measures of visual acuity. Potential applications include evaluating the course of vision in refractive surgery, classification of cataracts, detection of corneal or macular edema, and detection of visual loss in the aging eye. Evaluation of candidates for occupations requiring unique visual abilities also may be enhanced by measuring resolution in the contrast domain.

Comparison of peripapillary retinal nerve fiber layer loss and visual outcome in fellow eyes following sequential bilateral non-arteritic anterior ischemic optic neuropathy.

PubMed

Dotan, Gad; Kesler, Anat; Naftaliev, Elvira; Skarf, Barry

2015-05-01

To report on the correlation of structural damage to the axons of the optic nerve and visual outcome following bilateral non-arteritic anterior ischemic optic neuropathy. A retrospective review of the medical records of 25 patients with bilateral sequential non-arteritic anterior ischemic optic neuropathy was performed. Outcome measures were peripapillary retinal nerve fiber layer thickness measured with the Stratus optical coherence tomography scanner, visual acuity and visual field loss. Median peripapillary retinal nerve fiber layer (RNFL) thickness, mean deviation (MD) of visual field, and visual acuity of initially involved NAION eyes (54.00 µm, -17.77 decibels (dB), 0.4, respectively) were comparable to the same parameters measured following development of second NAION event in the other eye (53.70 µm, p = 0.740; -16.83 dB, p = 0.692; 0.4, p = 0.942, respectively). In patients with bilateral NAION, there was a significant correlation of peripapillary RNFL thickness (r = 0.583, p = 0.002) and MD of the visual field (r = 0.457, p = 0.042) for the pairs of affected eyes, whereas a poor correlation was found in visual acuity of these eyes (r = 0.279, p = 0.176). Peripapillary RNFL thickness following NAION was positively correlated with MD of visual field (r = 0.312, p = 0.043) and negatively correlated with logMAR visual acuity (r = -0.365, p = 0.009). In patients who experience bilateral NAION, the magnitude of RNFL loss is similar in each eye. There is a greater similarity in visual field loss than in visual acuity between the two affected eyes with NAION of the same individual.

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.

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

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.

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.

[Radial optic neurotomy for severe central retinal vein occlusion: preliminary results].

PubMed

Le Rouic, J-F; Becquet, F; Zanlonghi, X; Péronnet, P; Pousset-Decré, C; Hermouet-Leclair, E; Ducournau, D

2003-06-01

To describe the results of radial optic neurotomy for the treatment of severe central retinal vein occlusion. Prospective noncomparative single-center study. Analysis of ten eyes of ten consecutive patients whose visual acuity was 0.1 or less. They underwent fluorescein angiography, visual field testing by automated perimetry, and macular thickness analysis by optical coherence tomography preoperatively at 3 months and at 6 months postoperatively. Mean visual acuity on an ETDRS chart increased from 30+/-12 points preoperatively to 42+/-15 points at the 3-month visit, (p=0.03), and mean macular thickness decreased from 580+/-150 micro m to 361+/-52 micro m (p=0.04). All patients had clinical improvement as determined by fundus examination and fluorescein angiography. An improvement in the central visual field was observed in all eyes. Mean visual acuity of the five patients followed-up for 6 months was 52.8+/-20 points. No visual loss was observed. None of the patients underwent laser photocoagulation or has presented with neovascularization so far. Optociliary veins developed in three eyes and a retinochoroidal anastomosis within the disk incision was observed in two eyes. These preliminary results are encouraging when compared to the reported natural progression of severe central retinal vein occlusion. A bypass of the site of occlusion is a possible mechanism for radial optic neurotomy. A randomized study should be conducted to assess the efficacy of radial optic neurotomy and determine the best candidates for surgery.

Evaluation of Different Power of Near Addition in Two Different Multifocal Intraocular Lenses

PubMed Central

Unsal, Ugur; Baser, Gonen

2016-01-01

Purpose. To compare near, intermediate, and distance vision and quality of vision, when refractive rotational multifocal intraocular lenses with 3.0 diopters or diffractive multifocal intraocular lenses with 2.5 diopters near addition are implanted. Methods. 41 eyes of 41 patients in whom rotational +3.0 diopters near addition IOLs were implanted and 30 eyes of 30 patients in whom diffractive +2.5 diopters near addition IOLs were implanted after cataract surgery were reviewed. Uncorrected and corrected distance visual acuity, intermediate visual acuity, near visual acuity, and patient satisfaction were evaluated 6 months later. Results. The corrected and uncorrected distance visual acuity were the same between both groups (p = 0.50 and p = 0.509, resp.). The uncorrected intermediate and corrected intermediate and near vision acuities were better in the +2.5 near vision added intraocular lens implanted group (p = 0.049, p = 0.005, and p = 0.001, resp.) and the uncorrected near vision acuity was better in the +3.0 near vision added intraocular lens implanted group (p = 0.001). The patient satisfactions of both groups were similar. Conclusion. The +2.5 diopters near addition could be a better choice in younger patients with more distance and intermediate visual requirements (driving, outdoor activities), whereas the + 3.0 diopters should be considered for patients with more near vision correction (reading). PMID:27340560

Genetic and Environmental Basis in Phenotype Correlation Between Physical Function and Cognition in Aging Chinese Twins.

PubMed

Xu, Chunsheng; Zhang, Dongfeng; Tian, Xiaocao; Wu, Yili; Pang, Zengchang; Li, Shuxia; Tan, Qihua

2017-02-01

Although the correlation between cognition and physical function has been well studied in the general population, the genetic and environmental nature of the correlation has been rarely investigated. We conducted a classical twin analysis on cognitive and physical function, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), handgrip strength, five-times-sit-to-stand test (FTSST), near visual acuity, and number of teeth lost in 379 complete twin pairs. Bivariate twin models were fitted to estimate the genetic and environmental correlation between physical and cognitive function. Bivariate analysis showed mildly positively genetic correlations between cognition and FEV1, r G = 0.23 [95% CI: 0.03, 0.62], as well as FVC, r G = 0.35 [95% CI: 0.06, 1.00]. We found that FTSST and cognition presented very high common environmental correlation, r C = -1.00 [95% CI: -1.00, -0.57], and low but significant unique environmental correlation, r E = -0.11 [95% CI: -0.22, -0.01], all in the negative direction. Meanwhile, near visual acuity and cognition also showed unique environmental correlation, r E = 0.16 [95% CI: 0.03, 0.27]. We found no significantly genetic correlation for cognition with handgrip strength, FTSST, near visual acuity, and number of teeth lost. Cognitive function was genetically related to pulmonary function. The FTSST and cognition shared almost the same common environmental factors but only part of the unique environmental factors, both with negative correlation. In contrast, near visual acuity and cognition may positively share part of the unique environmental factors.

Perceptual Learning Improves Stereoacuity in Amblyopia

PubMed Central

Xi, Jie; Jia, Wu-Li; Feng, Li-Xia; Lu, Zhong-Lin; Huang, Chang-Bing

2014-01-01

Purpose. Amblyopia is a developmental disorder that results in both monocular and binocular deficits. Although traditional treatment in clinical practice (i.e., refractive correction, or occlusion by patching and penalization of the fellow eye) is effective in restoring monocular visual acuity, there is little information on how binocular function, especially stereopsis, responds to traditional amblyopia treatment. We aim to evaluate the effects of perceptual learning on stereopsis in observers with amblyopia in the current study. Methods. Eleven observers (21.1 ± 5.1 years, six females) with anisometropic or ametropic amblyopia were trained to judge depth in 10 to 13 sessions. Red–green glasses were used to present three different texture anaglyphs with different disparities but a fixed exposure duration. Stereoacuity was assessed with the Fly Stereo Acuity Test and visual acuity was assessed with the Chinese Tumbling E Chart before and after training. Results. Averaged across observers, training significantly reduced disparity threshold from 776.7″ to 490.4″ (P < 0.01) and improved stereoacuity from 200.3″ to 81.6″ (P < 0.01). Interestingly, visual acuity also significantly improved from 0.44 to 0.35 logMAR (approximately 0.9 lines, P < 0.05) in the amblyopic eye after training. Moreover, the learning effects in two of the three retested observers were largely retained over a 5-month period. Conclusions. Perceptual learning is effective in improving stereo vision in observers with amblyopia. These results, together with previous evidence, suggest that structured monocular and binocular training might be necessary to fully recover degraded visual functions in amblyopia. Chinese Abstract PMID:24508791

Scharioth Macula Lens: A new intraocular implant for low-vision patients with stabilized maculopathy- first experience.

PubMed

Nekolova, Jana; Rozsival, Pavel; Sin, Martin; Jiraskova, Nada

2017-06-01

To present the initial results of Scharioth Macula Lens (SML) implantation. The SML is a new add-on intraocular lens designed to increase uncorrected near visual acuity (UCVA) in patients with stabilized maculopathy. Eight patients were included in the study. All met the indication criteria before SML implantation. An SML was implanted in the better seeing eye. Near and distance visual acuity were tested. Possible complications and patient complaints were recorded and patients were asked about their quality of vision after SML implantation. The examination was carried out on day 1, 1 week, 1, 3 and 6 months after surgery. Six-month-results are presented. Apart from one, all patients with the SML had good near visual acuity at a recommended reading distance of 15 cm. Preoperatively, the mean (min-max) near UCVA was J13 (J8-J16), mean distance BCVA was 0.27. Postoperatively, the best results were after 1 month - near UCVA was J2.5 (J1-J7), distance BCVA was 0.26. Three months after surgery, this decreased to J4.5 (J1-J8); distance VA remained 0.25. Six months postoperatively - near vision was J4 (J1-J8) and distance VA was unchanged. Patients reported problems with reading speed and reading distance. Daily exercise improved their reading ability. One patient converted to wet AMD 3 months post-implantation. The SML is a new hope for low-vision patients. It acts as a magnifier in the eye. It is a suitable method for increasing near visual acuity in patients with inactive maculopathy.

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.

Perceptual learning improves stereoacuity in amblyopia.

PubMed

Xi, Jie; Jia, Wu-Li; Feng, Li-Xia; Lu, Zhong-Lin; Huang, Chang-Bing

2014-04-15

Amblyopia is a developmental disorder that results in both monocular and binocular deficits. Although traditional treatment in clinical practice (i.e., refractive correction, or occlusion by patching and penalization of the fellow eye) is effective in restoring monocular visual acuity, there is little information on how binocular function, especially stereopsis, responds to traditional amblyopia treatment. We aim to evaluate the effects of perceptual learning on stereopsis in observers with amblyopia in the current study. Eleven observers (21.1 ± 5.1 years, six females) with anisometropic or ametropic amblyopia were trained to judge depth in 10 to 13 sessions. Red-green glasses were used to present three different texture anaglyphs with different disparities but a fixed exposure duration. Stereoacuity was assessed with the Fly Stereo Acuity Test and visual acuity was assessed with the Chinese Tumbling E Chart before and after training. Averaged across observers, training significantly reduced disparity threshold from 776.7″ to 490.4″ (P < 0.01) and improved stereoacuity from 200.3″ to 81.6″ (P < 0.01). Interestingly, visual acuity also significantly improved from 0.44 to 0.35 logMAR (approximately 0.9 lines, P < 0.05) in the amblyopic eye after training. Moreover, the learning effects in two of the three retested observers were largely retained over a 5-month period. Perceptual learning is effective in improving stereo vision in observers with amblyopia. These results, together with previous evidence, suggest that structured monocular and binocular training might be necessary to fully recover degraded visual functions in amblyopia. Chinese Abstract.

Vitreous hemorrhage and Rhegmatogenous retinal detachment that developed after botulinum toxin injection to the extraocular muscle: case report.

PubMed

Lee, Dong Hyun; Han, Jinu; Han, Sueng-Han; Lee, Sung Chul; Kim, Min

2017-12-13

The authors report a case of a rare complication that occurred after botulinum toxin injection to the extraocular muscle, which was easily overlooked and successfully corrected by surgery. A 34-year-old female patient visited our clinic for diplopia and ocular motility disorder after removal of an epidermoid tumor of the brain. At her initial visit, her best-corrected visual acuity (BCVA) was 20/20 for both eyes. An alternate cover test showed 45 prism-diopter esotropia and 3 prism-diopter hypertropia in the right eye. Following 6 months of observation, the deviation of the strabismus did not improve, and botulinum toxin was injected into the right medial rectus (RMR). After 6 days, she visited our clinic with decreased visual acuity of her right eye. The BCVA was found to be 20/50 for her right eye. Funduscopic examination presented a retinal tear inferonasal to the optic disc with preretinal hemorrhage. Subretinal fluid nasal to the fovea was seen on optical coherence tomography (OCT). Barrier laser photocoagulation was done around the retinal tear; however, her visual acuity continued to decrease, and vitreous hemorrhage and subretinal fluid at the lesion did not improve. In addition, a newly developed epiretinal membrane was seen on OCT. An alternate cover test presented 30 prism-diopter right esotropia. 19 weeks after RMR botulinum toxin injection, she received pars plana vitrectomy, membranectomy, endolaser barrier photocoagulation, and intravitreal bevacizumab (Avastin®) injection. After 4 months, her visual acuity improved to 20/20, and only 4 prism-diopter of right hypertropia and 3 prism-diopter of exotropia were noted. Vitreous opacity and the epiretinal membrane were completely removed, as confirmed by funduscopic and examination. Sudden loss of vision after injection of botulinum toxin into the extraocular muscle may suggest a serious complication, and a prompt, thorough ophthalmic examination should be performed. If improvements are not observed, rapid surgical intervention is recommended to prevent additional complications.

Epidemiology and clinical outcome of intraocular foreign bodies in Hong Kong: a 13-year review.

PubMed

Liu, Candice C H; Tong, Justin M K; Li, Patrick S H; Li, Kenneth K W

2017-02-01

The purpose of this study was to describe the epidemiology, visual outcome and prognostic factors of intraocular foreign body (IOFB) injuries in a tertiary centre in Hong Kong. A retrospective review of 21 eyes in 21 patients with IOFB that presented to United Christian Hospital from January 2001 to July 2014 was performed. IOFB represented 16 % of all open-globe traumas. There was a high male predominance (90 %). The mean age was 42. Work-related injuries (86 %) were the main cause, where only 10.5 % had eye protection. Hammering was the commonest mechanism of injury (43 %). Most IOFBs were metallic (67 %). The IOFB was found in the anterior segment in 31 % and posterior segment in 69 %. 57 % presented with an initial visual acuity of ≥0.1, and up to 24 % of patients had an initial visual acuity of better than or equal to 0.5. Most cases (76 %) received prompt surgical intervention within 24 h, and there was a low (0 %) endophthalmitis rate. Forty-eight percent had an improvement in visual acuity, defined as final visual acuity more than or equal to 2 lines of improvement from initial visual acuity, and 48 % attained a final visual acuity of better than or equal to 0.5. One case underwent evisceration. A smaller IOFB size (<5 mm) was associated with a good final visual acuity of better than or equal to 0.5 (p = 0.048). It was also found that a posterior segment IOFB was more likely to give a final VA of less than 0.5 (p = 0.035). IOFB remains a significant complication of work-related injuries in Hong Kong. This is the first local study that explores the epidemiology of IOFB injuries in Hong Kong. The favourable visual outcome and low endophthalmitis rate may be related to early removal of IOFB. Despite legal ordinances for mandatory eye protection, the uptake of eye protection was low.

Comparison of a new refractive multifocal intraocular lens with an inferior segmental near add and a diffractive multifocal intraocular lens.

PubMed

Alio, Jorge L; Plaza-Puche, Ana B; Javaloy, Jaime; Ayala, María José; Moreno, Luis J; Piñero, David P

2012-03-01

To compare the visual acuity outcomes and ocular optical performance of eyes implanted with a multifocal refractive intraocular lens (IOL) with an inferior segmental near add or a diffractive multifocal IOL. Prospective, comparative, nonrandomized, consecutive case series. Eighty-three consecutive eyes of 45 patients (age range, 36-82 years) with cataract were divided into 2 groups: group A, 45 eyes implanted with Lentis Mplus LS-312 (Oculentis GmbH, Berlin, Germany); group B, 38 eyes implanted with diffractive IOL Acri.Lisa 366D (Zeiss, Oberkochen, Germany). All patients underwent phacoemulsification followed by IOL implantation in the capsular bag. Distance corrected, intermediate, and near with the distance correction visual acuity outcomes and contrast sensitivity, intraocular aberrations, and defocus curve were evaluated postoperatively during a 3-month follow-up. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), corrected distance near and intermediate visual acuity (CDNVA), contrast sensitivity, intraocular aberrations, and defocus curve. A significant improvement in UDVA, CDVA, and UNVA was observed in both groups after surgery (P ≤ 0.04). Significantly better values of UNVA (P<0.01) and CDNVA (P<0.04) were found in group B. In the defocus curve, significantly better visual acuities were present in eyes in group A for intermediate vision levels of defocus (P ≤ 0.04). Significantly higher amounts of postoperative intraocular primary coma and spherical aberrations were found in group A (P<0.01). In addition, significantly better values were observed in photopic contrast sensitivity for high spatial frequencies in group A (P ≤ 0.04). The Lentis Mplus LS-312 and Acri.Lisa 366D IOLs are able to successfully restore visual function after cataract surgery. The Lentis Mplus LS-312 provided better intermediate vision and contrast sensitivity outcomes than the Acri.Lisa 366D. However, the Acri.Lisa design provided better distance and near visual outcomes and intraocular optical performance parameters. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Diagnostic Utility of Ocular Symptoms and Vision for Cytomegalovirus Retinitis.

PubMed

Liu, Yingna; Chen, Alexander S; Kamphaengkham, Siripim; Leenasirimakul, Prattana; Jirawison, Choeng; Ausayakhun, Somsanguan; Margolis, Todd P; Keenan, Jeremy D

2016-01-01

Cytomegalovirus (CMV) retinitis remains a leading cause of blindness in countries with a high burden of AIDS. Although dilated fundus examinations are recommended for those with CD4 counts below 100 cells/μL, in practice only those with poor vision and/or symptoms are routinely referred for screening. Therefore, the predictive value of this common practice should be assessed. This is a prospective cross-sectional study. Patients with known HIV and a CD4 count of less than 100 cells/μL attending an HIV clinic in Chiang Mai, Thailand completed a standardized questionnaire about visual symptoms and underwent visual acuity testing and dilated fundus examination. Participants without CMV retinitis were invited for repeated examinations every 3 months until their CD4 count exceeded 100 cells/μL. Patient-level statistical analyses were conducted to calculate diagnostic test characteristics, with bootstrapping to account for correlated data. Of 103 study participants, 16 had CMV retinitis diagnosed at some point during the study. Participants with CMV retinitis were more likely to complain of visual symptoms compared to those without CMV retinitis (p = 0.01), including scotoma (p = 0.0002), itchy or watery eyes (p < 0.0001), and eye pain (p = 0.003); they were also more likely to have visual acuity worse than Counting Fingers (p = 0.0003). However, the absence of eye symptoms and the absence of poor vision did not strongly affect the probability that a patient did not have disease (negative likelihood ratio 0.56 and 0.76, respectively). Ocular symptoms and poor visual acuity were poor diagnostic indicators for the presence of CMV retinitis. Systematic screening of HIV patients with CD4 counts below 100 cells/μl should be carried out to detect disease at an early stage, when blindness can still be prevented.

Visual outcomes of bilateral congenital and developmental cataracts in young children in south India and causes of poor outcome.

PubMed

Khanna, Rohit C; Foster, Allen; Krishnaiah, Sannapaneni; Mehta, Manohar K; Gogate, Parikshit M

2013-02-01

Bilateral pediatric cataracts are important cause of visual impairment in children. To study the outcome of bilateral pediatric cataract surgery in young children. Retrospective case series in a tertiary center. Records of pediatric cataracts operated between January 2001 and December 2003, with a minimum follow-up of 3 months, were reviewed retrospectively. Independent sample t-test, Fisher's exact test, and logistic regression using SPSS (Statistical Package for Social Science, Chicago, USA) version 12. 215/257 (83.7%) patients had a minimum follow-up of 3 months. The mean age of presentation to the hospital was 53 months (range: 0-168 months). Congenital cataract was present in 107 patients (58.2%) and developmental cataract in 77 patients (41.8%). The mean age at surgery was 55.2 months (range: 1-168 months). Out of 430 eyes, 269 (62.6%) had an intraocular lens implanted. The mean duration of follow-up was 13.1 months (range: 3-38 months). Pre-operatively, 102 patients (47.3%) had visual acuity <6/60, in the better eye, compared to 37 patients (17.2%) post-operatively ( P < 0.001). Eighty-five patients (39.5%) had visual acuity >6/18. The most common early post-operative complication was fibrinous uveitis in 57 eyes (13.3%) and the most common delayed post-operative complication was posterior capsular opacification in 118 eyes (27.4%). The most important prognostic factor for poor outcome was congenital cataract (odds ratio [OR]: 26.3; 95% confidence interval [CI], 4.4-158.5) and total cataract (OR: 4.8; 95% CI, 1.3-17). Nearly half of the eyes had visual acuity >6/18. The outcome was poorer in congenital cataracts, especially those operated after >1 year of age.

Impact of correcting visual impairment and low vision in deaf-mute students in Pune, India.

PubMed

Gogate, Parikshit; Bhusan, Shashi; Ray, Shantanu; Shinde, Amit

2016-12-01

The aim of this study was to evaluate visual acuity and vision function before and after providing spectacles and low vision devices (LVDs) in deaf-mute students. Schools for deaf-mute in West Maharashtra. Hearing-impaired children in all special schools in Pune district underwent detailed visual acuity testing (with teachers' help), refraction, external ocular examination, and fundoscopy. Students with refractive errors and low vision were provided with spectacles and LVD. The LV Prasad-Functional Vision Questionnaire consisting of twenty items was administered to each subject before and after providing spectacles, LVDs. Wilcoxon matched-pairs signed-ranks test. 252/929 (27.1%) students had a refractive error. 794 (85.5%) were profound deaf. Two-hundred and fifty students were dispensed spectacles and LVDs. Mean LogMAR visual acuity before introduction of spectacles and LVDs were 0.33 ± 0.36 which improved to 0.058 (P < 0.0001) after intervention. It was found that difference in functional vision pre- and post-intervention was statistically significant (P < 0.0001) for questions 1-19. The most commonly reported difficulties were for performing distance task like reading the bus destination (58.7%), making out the bus number (51.1%), copying from blackboard (47.7%), and seeing whether somebody is waving hand from across the road (45.5%). In response to question number 20, 57.4% of students felt that their vision was much worse than their friend's vision, which was reduced to 17.6% after dispensing spectacles and LVDs. Spectacle and LVD reduced visual impairment and improved vision function in deaf-mute students, augmenting their ability to negotiate in and out of school.

Perceptual Learning in Children With Infantile Nystagmus: Effects on Visual Performance.

PubMed

Huurneman, Bianca; Boonstra, F Nienke; Goossens, Jeroen

2016-08-01

To evaluate whether computerized training with a crowded or uncrowded letter-discrimination task reduces visual impairment (VI) in 6- to 11-year-old children with infantile nystagmus (IN) who suffer from increased foveal crowding, reduced visual acuity, and reduced stereopsis. Thirty-six children with IN were included. Eighteen had idiopathic IN and 18 had oculocutaneous albinism. These children were divided in two training groups matched on age and diagnosis: a crowded training group (n = 18) and an uncrowded training group (n = 18). Training occurred two times per week during 5 weeks (3500 trials per training). Eleven age-matched children with normal vision were included to assess baseline differences in task performance and test-retest learning. Main outcome measures were task-specific performance, distance and near visual acuity (DVA and NVA), intensity and extent of (foveal) crowding at 5 m and 40 cm, and stereopsis. Training resulted in task-specific improvements. Both training groups also showed uncrowded and crowded DVA improvements (0.10 ± 0.02 and 0.11 ± 0.02 logMAR) and improved stereopsis (670 ± 249″). Crowded NVA improved only in the crowded training group (0.15 ± 0.02 logMAR), which was also the only group showing a reduction in near crowding intensity (0.08 ± 0.03 logMAR). Effects were not due to test-retest learning. Perceptual learning with or without distractors reduces the extent of crowding and improves visual acuity in children with IN. Training with distractors improves near vision more than training with single optotypes. Perceptual learning also transfers to DVA and NVA under uncrowded and crowded conditions and even stereopsis. Learning curves indicated that improvements may be larger after longer training.

Purtscher's retinopathy associated with acute pancreatitis.

PubMed

Hamp, Ania M; Chu, Edward; Slagle, William S; Hamp, Robert C; Joy, Jeffrey T; Morris, Robert W

2014-02-01

Purtscher's retinopathy is a rare condition that is associated with complement-activating systemic diseases such as acute pancreatitis. After pancreatic injury or inflammation, proteases such as trypsin activate the complement system and can potentially cause coagulation and leukoembolization of retinal precapillary arterioles. Specifically, intermediate-sized emboli are sufficiently small enough to pass through larger arteries yet large enough to remain lodged in precapillary arterioles and cause the clinical appearance of Purtscher's retinopathy. This pathology may present with optic nerve edema, impaired visual acuity, visual field loss, as well as retinal findings such as cotton-wool spots, retinal hemorrhage, artery attenuation, venous dilation, and Purtscher flecken. A 57-year-old white man presented with an acute onset of visual field scotomas and decreased visual acuity 1 week after being hospitalized for acute pancreatitis. The retinal examination revealed multiple regions of discrete retinal whitening surrounding the disk, extending through the macula bilaterally, as well as bilateral optic nerve hemorrhages. The patient identified paracentral bilateral visual field defects on Amsler Grid testing, which was confirmed with subsequent Humphrey visual field analysis. Although the patient presented with an atypical underlying etiology, he exhibited classic retinal findings for Purtscher's retinopathy. After 2 months, best corrected visual acuity improved and the retinal whitening was nearly resolved; however, bilateral paracentral visual field defects remained. Purtscher's retinopathy has a distinctive clinical presentation and is typically associated with thoracic trauma but may be a sequela of nontraumatic systemic disease such as acute pancreatitis. Patients diagnosed with acute pancreatitis should have an eye examination to rule out Purtscher's retinopathy. Although visual improvement is possible, patients should be educated that there may be permanent ocular sequelae.

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

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.

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…

New pinhole sulcus implant for the correction of irregular corneal astigmatism.

PubMed

Trindade, Claudio C; Trindade, Bruno C; Trindade, Fernando C; Werner, Liliana; Osher, Robert; Santhiago, Marcony R

2017-10-01

To evaluate the effect on visual acuity of the implantation of a new intraocular pinhole device (Xtrafocus) in cases of irregular corneal astigmatism with significant visual impairment. University of São Paulo, São Paulo, Brazil. Prospective case series. Pseudophakic eyes of patients with irregular corneal astigmatism were treated with the pinhole device. The causes of irregular corneal astigmatism were keratoconus, post radial keratotomy (RK), post-penetrating keratoplasty (PKP), and traumatic corneal laceration. The device was implanted in the ciliary sulcus in a piggyback configuration to minimize the effect of corneal aberrations. Preoperative and postoperative visual parameters were compared. The main outcome variables were manifest refraction, uncorrected and corrected distance and near visual acuities, subjective patient satisfaction, and intraoperative and postoperative adverse events and complications. Twenty-one patients (ages 35 to 85 years) were included. There was statistically significant improvement in uncorrected and corrected (CDVA) distance visual acuities. The median CDVA improved from 20/200 (range 20/800 to 20/60) preoperatively to 20/50 (range 20/200 to 20/20) in the first month postoperatively and remained stable over the following months. Manifest refraction remained unchanged, while a subjective visual performance questionnaire revealed perception of improvement in all the tested working distances. No major complication was observed. One case presented with decentration of the device, which required an additional surgical intervention. The intraocular pinhole device performed well in patients with irregular astigmatism caused by keratoconus, RK, PKP, and traumatic corneal laceration. There was marked improvement in visual function, with high patient satisfaction. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Pars Plana Vitrectomy with Internal Limiting Membrane Peeling for Nontractional Diabetic Macular Edema.

PubMed

Ulrich, Jan Niklas

2017-01-01

Diabetes mellitus remains the leading cause of blindness among working age Americans with diabetic macular edema being the most common cause for moderate and severe vision loss. To investigate the anatomical and visual benefits of pars plana vitrectomy with inner limiting membrane peeling in patients with nontractional diabetic macular edema as well as correlation of integrity of outer retinal layers on spectral domain optical coherence tomography to visual outcomes. We retrospectively reviewed the charts of 42 diabetic patients that underwent vitrectomy with internal limiting membrane peeling for nontractional diabetic macula edema. The integrity of outer retinal layers was evaluated and preoperative central macular thickness and visual acuity were compared with data at 1 month, 3 months and 6 months postoperatively. The student t-test was used to compare the groups. 31 eyes were included. While no differences were seen at 1 and 3 months, there was significant improvement of both central macular thickness and visual acuity at the 6 months follow up visit compared to preoperatively (357, 427 microns; p=0.03. 20/49, 20/82; p=0.03) . Patients with intact external limiting membrane and ellipsoid zone had better preoperative vision than patients with outer retinal layer irregularities (20/54, 20/100; p=0.03) and greater visual gains postoperatively (20/33, p<0.001 versus 20/81; p=non-significant). Pars plana vitrectomy with internal limiting membrane peeling can improve retinal anatomy and visual acuity in patients with nontractional diabetic macular edema. Spectral domain optical coherence tomography may help identify patients with potential for visual improvement.

[Therapeutic schedule in ambliopia--experience of Eye Clinic Cluj].

PubMed

Vladuţiu, Cristina; Sevan, Simona; Popoviciu, Sarmisa

2009-01-01

To establlsh a protocol for the treatment of amblyopia and the methods used to maintain the results (visual acuity). Fifty children with amblyopia were treated in the Pediatric Ophthalmology Department of the Ophthalmological Cllnic in Cluj. Full time occlusion was used in all children. Pleoptic methods (Haidinger procedure, anti crowding fenomenon exercices and visual attention exercices) were done in the amblyopic children. The study analyzed the correlation of the visual acuity and the type of amblyopia (strabismic, anysometropic), the age of the patients and the age at the initiation of the treatment, the compliance. The visual acuity was followed up by check outs every 4-6 months. The study concluded that the treatment of choice in amblyopia is the full time occlusion. The partial occlusion and the optical penalization is reserved for the maintenance of the result (visual acuity) until the children reach the age of 7-8, when the sensitive period of visual development ends. The compliance of the children and parents is important. The hospitalization and the pleoptics used in a amlyopic children collectivity improve the children cooperation and the therapeutical results.

Colored floaters as a manifestation of digoxin toxicity.

PubMed

Shi, Lynn; Sun, Linus D; Odel, Jeffrey G

2018-06-01

Since its report in one patient more than 70 years ago, digitalis-induced colored muscae volitantes have not surfaced again in the literature. We report here a case of digoxin induced colored floaters. An 89-year-old man on 0.25 mg digoxin daily developed visual hallucinations and colored floaters. He had floaters in the past but now they were in various colors including yellow, green, blue and red, though predominantly in yellow. These "weirdly" shaped little particles wiggled around as if in a viscous solution and casted shadows in his vision. He also saw geometric shapes, spirals, and cross hatch patterns of various colors that moved and undulated, especially on wallpaper. Ophthalmic examination revealed reduced visual acuity, poor color vision especially in his left eye, along with central depression on Amsler grid and Humphrey visual field in his left eye. Discontinuation of digoxin resulted in complete resolution of his visual symptoms. On subsequent ophthalmic examination, the patient's visual acuity, field testing and color vision improved and he had normal Amsler grid test results. Colored floaters may occur in patients taking cardiac glycosides but this association has not been explored. Unlike optical illusions and visual hallucinations, floaters are entoptic phenomena casting a physical shadow upon the retina and their coloring likely arise from retinal dysfunction. Colored floaters may be a more common visual phenomenon than realized.

Ocular findings in MELAS syndrome – a case report.

PubMed

Modrzejewska, Monika; Chrzanowska, Martyna; Modrzejewska, Anna; Romanowska, Hanna; Ostrowska, Iwona; Giżewska, Maria

We present a case of a child with MELAS syndrome (mitochondrial encephalo-myopathy with lactic acidosis and stroke-like episodes), discussing clinical manifestation, ocular findings and diagnostic challenges. Predominant ocular symptom was a transient complete visual loss, while the predominant ocular sign was a visual field defect. The diagnosia was based on clinical manifestation, laboratory tests, brain scans and genetic testing which confirmed the pathognomonic mutation in the MTTL1 gene encoding the mitochondrial tRNA for leucine 3243> G. Ocular examination demonstrated decreased visual acuity (with bilateral best corrected visual acuity of .1). Periodical, transient visual loss and visual field defects were clinically predominant. Specialist investigations were carried out, which demonstrated homonymous hemianopia (kinetic perimetry), bilateral partial optic nerve atrophy (RetCam). Funduscopy and electrophysiology mfERG study did not confirm features of retinitis pigmentosa. The brain scans revealed numerous small cortical ischemic lesions within the frontal, parietal and temporal lobes, post-stroke focal areas within the occipital lobes and diffuse calcifications of the basal ganglia. During several years of follow-up, visual field defects showed progressive concentric narrowing. The patient received a long-term treatment with arginine, coenzyme Q and vitamin D, both oral and intravenous, but no beneficial effect for the improvement of ophthalmic condition was observed. As it is the case in severe MELAS syndrome, the course of disease was fatal and the patientdied at the age of 14.

Effect of povidone 2% preservative-free eyedrops on contact lens wearers with computer visual syndrome: pilot study.

PubMed

Guillon, Michel; Maissa, Cecile; Pouliquen, Pascale; Delval, Laurent

2004-01-01

To show that the use of povidone 2% preservative-free lubricating eyedrops reduces computer visual syndrome in contact lens wearers and to identify the best eyedrop instillation protocols. The test product was FILMABAK a CE-marked nonpreserved lubricant, povidone 2% delivered by the ABAK system. Three dispensing modalities were evaluated during contact lens wear and computer use: hourly instillation, symptom-related instillation, and patient's own instillation. During sustained computer use, a decrease in symptoms associated with the use of povidone 2% was statistically and clinically significant. However, the symptoms were not fully eliminated by the use of the test eyedrop. The three instillation routines achieved similar beneficial effects. No significant changes in ocular tissue response were observed, and the staining recorded after sustained computer use remained low. The use of povidone 2% preservative-free lubricating eyedrops under any of the three instillation modalities tested was also associated with a slight improvement in dynamic visual acuity. The use of povidone 2% preservative-free eyedrops was associated with an improvement in symptoms during sustained computer use. Any of the three instillation modalities decreased symptoms of ocular tiredness, dryness, and difficulty of focus; maintained an unchanged corneal surface; and improved dynamic visual acuity. Therefore, the most patient-friendly modality (patient's own instillation modality from symptom onset) could be recommended to contact lens wearers with computer visual syndrome.

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.

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

Clinical Evaluation of Functional Vision of +1.5 Diopters near Addition, Aspheric, Rotational Asymmetric Multifocal Intraocular Lens

PubMed Central

Khoramnia, Rahmin; Attia, Mary Safwat; Koss, Michael Janusz; Linz, Katharina; Auffarth, Gerd Uwe

2016-01-01

Purpose To evaluate postoperative outcomes and visual performance in intermediate distance after implantation of a +1.5 diopters (D) addition, aspheric, rotational asymmetric multifocal intraocular lens (MIOL). Methods Patients underwent bilateral cataract surgery with implantation of an aspheric, asymmetric MIOL with +1.5 D near addition. A complete ophthalmological examination was performed preoperatively and 3 months postoperatively. The main outcome measures were monocular and binocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), distance corrected intermediate visual acuity (DCIVA), uncorrected near visual acuity (UNVA) and distance corrected keratometry, and manifest refraction. The Salzburg Reading Desk was used to analyze unilateral and bilateral functional vision with uncorrected and corrected reading acuity, reading distance, reading speed, and the smallest log-scaled print size that could be read effectively at near and intermediate distances. Results The study comprised 60 eyes of 30 patients (mean age, 68.30 ± 9.26 years; range, 34 to 80 years). There was significant improvement in UDVA and CDVA. Mean UIVA was 0.01 ± 0.09 logarithm of the minimum angle of resolution (logMAR) and mean DCIVA was -0.02 ± 0.11 logMAR. In Salzburg Reading Desk analysis for UIVA, the mean subjective intermediate distance was 67.58 ± 8.59 cm with mean UIVA of -0.02 ± 0.09 logMAR and mean word count of 96.38 ± 28.32 words/min. Conclusions The new aspheric, asymmetric, +1.5 D near addition MIOL offers good results for distance visual function in combination with good performance for intermediate distances and functional results for near distance. PMID:27729759

Clinical Evaluation of Functional Vision of +1.5 Diopters near Addition, Aspheric, Rotational Asymmetric Multifocal Intraocular Lens.

PubMed

Kretz, Florian Tobias Alwin; Khoramnia, Rahmin; Attia, Mary Safwat; Koss, Michael Janusz; Linz, Katharina; Auffarth, Gerd Uwe

2016-10-01

To evaluate postoperative outcomes and visual performance in intermediate distance after implantation of a +1.5 diopters (D) addition, aspheric, rotational asymmetric multifocal intraocular lens (MIOL). Patients underwent bilateral cataract surgery with implantation of an aspheric, asymmetric MIOL with +1.5 D near addition. A complete ophthalmological examination was performed preoperatively and 3 months postoperatively. The main outcome measures were monocular and binocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), distance corrected intermediate visual acuity (DCIVA), uncorrected near visual acuity (UNVA) and distance corrected keratometry, and manifest refraction. The Salzburg Reading Desk was used to analyze unilateral and bilateral functional vision with uncorrected and corrected reading acuity, reading distance, reading speed, and the smallest log-scaled print size that could be read effectively at near and intermediate distances. The study comprised 60 eyes of 30 patients (mean age, 68.30 ± 9.26 years; range, 34 to 80 years). There was significant improvement in UDVA and CDVA. Mean UIVA was 0.01 ± 0.09 logarithm of the minimum angle of resolution (logMAR) and mean DCIVA was -0.02 ± 0.11 logMAR. In Salzburg Reading Desk analysis for UIVA, the mean subjective intermediate distance was 67.58 ± 8.59 cm with mean UIVA of -0.02 ± 0.09 logMAR and mean word count of 96.38 ± 28.32 words/min. The new aspheric, asymmetric, +1.5 D near addition MIOL offers good results for distance visual function in combination with good performance for intermediate distances and functional results for near distance.

[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-test, p < 0.005). No significant changes were observed in the pupillary reaction. The training device was useful for improving the accommodative functions and accommodative excess, suggesting that it may be able to suppress the progression of low myopia, development of which is known to be strongly influenced by environmental factors.

Optical functional performance of the osteo-odonto-keratoprosthesis.

PubMed

Lee, Richard M H; Ong, Gek L; Lam, Fook Chang; White, Joy; Crook, David; Liu, Christopher S C; Hull, Chris C

2014-10-01

The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP). Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities. The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.

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.

Face recognition in age related macular degeneration: perceived disability, measured disability, and performance with a bioptic device.

PubMed

Tejeria, L; Harper, R A; Artes, P H; Dickinson, C M

2002-09-01

(1) To explore the relation between performance on tasks of familiar face recognition (FFR) and face expression difference discrimination (FED) with both perceived disability in face recognition and clinical measures of visual function in subjects with age related macular degeneration (AMD). (2) To quantify the gain in performance for face recognition tasks when subjects use a bioptic telescopic low vision device. 30 subjects with AMD (age range 66-90 years; visual acuity 0.4-1.4 logMAR) were recruited for the study. Perceived (self rated) disability in face recognition was assessed by an eight item questionnaire covering a range of issues relating to face recognition. Visual functions measured were distance visual acuity (ETDRS logMAR charts), continuous text reading acuity (MNRead charts), contrast sensitivity (Pelli-Robson chart), and colour vision (large panel D-15). In the FFR task, images of famous people had to be identified. FED was assessed by a forced choice test where subjects had to decide which one of four images showed a different facial expression. These tasks were repeated with subjects using a bioptic device. Overall perceived disability in face recognition did not correlate with performance on either task, although a specific item on difficulty recognising familiar faces did correlate with FFR (r = 0.49, p<0.05). FFR performance was most closely related to distance acuity (r = -0.69, p<0.001), while FED performance was most closely related to continuous text reading acuity (r = -0.79, p<0.001). In multiple regression, neither contrast sensitivity nor colour vision significantly increased the explained variance. When using a bioptic telescope, FFR performance improved in 86% of subjects (median gain = 49%; p<0.001), while FED performance increased in 79% of subjects (median gain = 50%; p<0.01). Distance and reading visual acuity are closely associated with measured task performance in FFR and FED. A bioptic low vision device can offer a significant improvement in performance for face recognition tasks, and may be useful in reducing the handicap associated with this disability. There is, however, little evidence for a correlation between self rated difficulty in face recognition and measured performance for either task. Further work is needed to explore the complex relation between the perception of disability and measured performance.

Face recognition in age related macular degeneration: perceived disability, measured disability, and performance with a bioptic device

PubMed Central

Tejeria, L; Harper, R A; Artes, P H; Dickinson, C M

2002-01-01

Aims: (1) To explore the relation between performance on tasks of familiar face recognition (FFR) and face expression difference discrimination (FED) with both perceived disability in face recognition and clinical measures of visual function in subjects with age related macular degeneration (AMD). (2) To quantify the gain in performance for face recognition tasks when subjects use a bioptic telescopic low vision device. Methods: 30 subjects with AMD (age range 66–90 years; visual acuity 0.4–1.4 logMAR) were recruited for the study. Perceived (self rated) disability in face recognition was assessed by an eight item questionnaire covering a range of issues relating to face recognition. Visual functions measured were distance visual acuity (ETDRS logMAR charts), continuous text reading acuity (MNRead charts), contrast sensitivity (Pelli-Robson chart), and colour vision (large panel D-15). In the FFR task, images of famous people had to be identified. FED was assessed by a forced choice test where subjects had to decide which one of four images showed a different facial expression. These tasks were repeated with subjects using a bioptic device. Results: Overall perceived disability in face recognition did not correlate with performance on either task, although a specific item on difficulty recognising familiar faces did correlate with FFR (r = 0.49, p<0.05). FFR performance was most closely related to distance acuity (r = −0.69, p<0.001), while FED performance was most closely related to continuous text reading acuity (r = −0.79, p<0.001). In multiple regression, neither contrast sensitivity nor colour vision significantly increased the explained variance. When using a bioptic telescope, FFR performance improved in 86% of subjects (median gain = 49%; p<0.001), while FED performance increased in 79% of subjects (median gain = 50%; p<0.01). Conclusion: Distance and reading visual acuity are closely associated with measured task performance in FFR and FED. A bioptic low vision device can offer a significant improvement in performance for face recognition tasks, and may be useful in reducing the handicap associated with this disability. There is, however, little evidence for a correlation between self rated difficulty in face recognition and measured performance for either task. Further work is needed to explore the complex relation between the perception of disability and measured performance. PMID:12185131

A population based eye survey of older adults in Tirunelveli district of south India: blindness, cataract surgery, and visual outcomes

PubMed Central

Nirmalan, P K; Thulasiraj, R D; Maneksha, V; Rahmathullah, R; Ramakrishnan, R; Padmavathi, A; Munoz, S R; Ellwein, L B

2002-01-01

Aims: To assess the prevalence of vision impairment, blindness, and cataract surgery and to evaluate visual acuity outcomes after cataract surgery in a south Indian population. Methods: Cluster sampling was used to randomly select a cross sectional sample of people ≥50 years of age living in the Tirunelveli district of south India. Eligible subjects in 28 clusters were enumerated through a door to door household survey. Visual acuity measurements and ocular examinations were performed at a selected site within each of the clusters in early 2000. The principal cause of visual impairment was identified for eyes with presenting visual acuity <6/18. Independent replicate testing for quality assurance monitoring was performed in subjects with reduced vision and in a sample of those with normal vision for six of the study clusters. Results: A total of 5795 people in 3986 households were enumerated and 5411 (93.37%) were examined. The prevalence of presenting and best corrected visual acuity ≥6/18 in both eyes was 59.4% and 75.7%, respectively. Presenting vision <6/60 in both eyes (the definition of blindness in India) was found in 11.0%, and in 4.6% with best correction. Presenting blindness was associated with older age, female sex, and illiteracy. Cataract was the principal cause of blindness in at least one eye in 70.6% of blind people. The prevalence of cataract surgery was 11.8%—with an estimated 56.5% of the cataract blind already operated on. Surgical coverage was inversely associated with illiteracy and with female sex in rural areas. Within the cataract operated sample, 31.7% had presenting visual acuity ≥6/18 in both eyes and 11.8% were <6/60; 40% were bilaterally operated on, with 63% pseudophakic. Presenting vision was <6/60 in 40.7% of aphakic eyes and in 5.1% of pseudophakic eyes; with best correction the percentages were 17.6% and 3.7%, respectively. Refractive error, including uncorrected aphakia, was the main cause of visual impairment in cataract operated eyes. Vision <6/18 was associated with cataract surgery in government, as opposed to that in non-governmental/private facilities. Age, sex, literacy, and area of residence were not predictors of visual outcomes. Conclusion: Treatable blindness, particularly that associated with cataract and refractive error, remains a significant problem among older adults in south Indian populations, especially in females, the illiterate, and those living in rural areas. Further study is needed to better understand why a significant proportion of the cataract blind are not taking advantage of free of charge eye care services offered by the Aravind Eye Hospital and others in the district. While continuing to increase cataract surgical volume to reduce blindness, emphasis must also be placed on improving postoperative visual acuity outcomes. PMID:11973242

A Brief Guide to Color Vision Testing for Ophthalmology Residents.

DTIC Science & Technology

1988-02-01

degeneration (ARMD), diabetic retinopathy, central serous retinopathy, cystoid macular edema (CME), and chloroquine toxicity. Uptic nerve problems may be due to...blue caps if the macula is normal. Pseudo-Isochromtic Plates Test If the visual acuity is 20/200 or better, the patient should have no trouble

Reading ability and retinal sensitivity after surgery for macular hole and macular pucker.

PubMed

Cappello, Ezio; Virgili, Gianni; Tollot, Luigina; Del Borrello, Michele; Menchini, Ugo; Zemella, Marco

2009-09-01

To assess whether reading ability and microperimetry improve as demonstrated for visual acuity after surgery for macular hole and macular pucker. Fifty-nine consecutive patients underwent pars plana vitrectomy for macular pucker (n = 41) or full-thickness macular holes (n = 18). Functional assessment was made at 3, 6, and 12 months after surgery and included far visual acuity (Early Treatment Diabetic Retinopathy Study charts), retinal sensitivity using the microperimeter (MP1, Nidek Technologies, Padova, Italy), and reading ability (MNRead charts). An improvement was recorded both for macular holes and puckers not only for visual acuity, but also for reading acuity and mean central retinal sensitivity (P < 0.01 for the overall comparisons between baseline and follow-up values). Maximum reading speed was already good at baseline both for puckers and holes overall, and a significant mean improvement was recorded only in patients with macular hole at 6 and 12 months (P < 0.01). Although eyes with macular holes had worse baseline visual function compared with puckers (P < 0.01 for all measures of visual function except for reading speed), they recovered to similar levels thanks to greater improvement (P < 0.05 for the difference in improvement during follow-up between puckers and holes for all measures of visual function). No differences were found among indocyanine green or trypan blue staining compared with no staining for internal limiting membrane removal based on all outcome measures (P > 0.05 for the overall difference of visual function improvement during follow-up). The improvement found for visual acuity after vitrectomy for macular hole and pucker also regards retinal sensitivity and reading ability for up to 12 months. This is reassuring concerning the benefits for the patients, and this shows that visual acuity is a valid functional measure for investigating the efficacy of macular surgery.

Identifying a Clinically Meaningful Threshold for Change in Uveitic Macular Edema Evaluated by Optical Coherence Tomography

PubMed Central

Sugar, Elizabeth A.; Jabs, Douglas A.; Altaweel, Michael M.; Lightman, Sue; Acharya, Nisha; Vitale, Albert T.; Thorne, Jennifer E.

2011-01-01

Purpose To identify a clinically meaningful threshold for change in retinal thickness measured by optical coherence tomography (OCT) for patients with uveitic macular edema, using correlation with change in visual acuity. Design Cross-sectional and longitudinal study. Methods 128 eyes (101 individuals) with macular edema enrolled in the Multicenter Uveitis Steroid Treatment (MUST) trial. At enrollment and after six months of follow-up, retinal thickness was measured at the central subfield with time domain OCT and visual acuity was measured with logarithmic (ETDRS) visual acuity charts. Participants were classified as having macular edema if the retinal thickness was ≥260μm. Results A threshold for change in retinal center subfield thickness of 20% balanced the percentage of false positives and negatives for predicting greater than 10-letter change in visual acuity with sensitivity of 77% and a specificity of 75%. The results were similar for greater than 5 or 15 or greater letter changes. Those with a 20% or greater reduction in retinal thickness had a mean 11.0 letter improvement (95% CI: 7.7 to 14.3) as compared to a -0.4 letter change (95% CI: -4.1 to 3.3) in visual acuity for those without a 20% reduction (p < 0.01). Conclusions In addition to being above the level of measurement uncertainty, a 20% change in retinal thickness in patients with macular edema appears to be optimal for clinically important changes in visual acuity and may be considered as an outcome for clinical trials of treatments for uveitic macular edema. PMID:21861971

Fixation Patterns and Reading Rates in Eyes with Central Scotomas from Advanced Atrophic Age-related Macular Degeneration and Stargardt Disease

PubMed Central

Sunness, Janet S.; Applegate, Carol A.; Haselwood, David; Rubin, Gary S.

2009-01-01

Purpose To study fixation patterns and reading rates in eyes with central scotomas from geographic atrophy (GA) of age-related macular degeneration and to compare fixation patterns with those of patients with Stargardt disease. Methods Scanning laser ophthalmoscope analysis of fixation patterns in eyes with 20/80 to 20/200 visual acuity. Included were 41 eyes of 35 patients with GA and 10 eyes of 5 patients with Stargardt disease. The patients with GA also were tested for maximum reading rate, and the size of the areas of atrophy were measured by fundus photograph analysis. Results Sixty-three percent of GA eyes fixating outside the atrophy placed the scotoma to the right of fixation in visual field space, 22% placed the scotoma above fixation, and 15% placed it to the left, regardless of the laterality of the GA eye. Fixation was stable in subsequent years of testing for scotoma placement to the right of or above fixation. All GA eyes fixated immediately adjacent to the atrophy. In contrast, seven of ten eyes with Stargardt disease fixated at a considerable distance from the scotoma border, with the dense scotoma far above the fixation site in visual field space. For the patients with GA, the maximum reading rate was highly correlated with size of the atrophic area, but not with age or visual acuity within the limited visual acuity range tested. There was a trend to more rapid reading with the scotoma above fixation and slower reading with the scotoma to the left. Conclusion There is a preference for fixation with the scotoma to the right in eyes with GA. Patients with Stargardt disease use different strategies for fixation, perhaps due to subclinical pathology adjacent to the atrophic regions. The size of the atrophic area in GA plays the predominant role in reading rate for eyes that have already lost foveal vision. PMID:8841306

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.

Eye Disorders in Old People

PubMed Central

M., Khalaj; A., Barikani; H., Ghasemi

2013-01-01

Background: Visual impairment is one of a major public health problem among elderly people. Object: Aim of this study was determining the prevalence of visual impairment in median and old peoples in Qazvin (Iran). Method: In this cross sectional study, with a simple random sampling, 446 patients older than 5o years who were referred to outpatient ophthalmology clinics at Avecina hospital of Qazvin (a province of Iran) in 2010 were enrolled. Participants first complete a questionnaire with 25 questions toward demographic and past medical history and then were examined by ophthalmologist. These examinations includes direct and indirect ophthalmoscopy, slit lamp examination, measurement of uncorrected visual acuity and visual acuity with current glasses, lensometery of the previous glasses, refraction with and without the use of cycloplegic and determining the best corrected visual acuity. All slit lamp examinations were performed by the same ophthalmologist. Data were analyzed with SPSS16 with use of Chi – Square test with Pvalue <0.05. Results: In this study 446 patients were examined that 54.7% were male. Mean age of study population was 62+-9.3 years old. 96.4% of participants had refractory disorder. Prevalence of myopia, hyperopia and astigmatism were 33.6%, 45.9% and 16.8% respectively. Of patients 17.4% had diabetes. Of participants 28.9% had temporal headache, 37% red eye, 41.2% flashing, 27.3% and 28% had dryness and discharge of eye respectively. 31.1% of participants had eyelide problem, 4.7% Color Vision Deficiency (CVD) and 3.8% had family history of CVD. Of total 4.5% had glaucoma, 3.3% macular degeneration and 21.7% had hypertension. 0.6% of population had macular degeneration, 0.4% of population had glaucoma Of 892 eyes (446 individuals), 36.2% had visual acuity less than 7/10, 1.7% light perception (LP) and 0.22% no light perception (NLP) and 2.7% finger count. Conclusion: Refractory errors, cataract and amblyopia were most important eye disorders in older people in Qazvin. PMID:23283039

[Reduced vision in Wernicke's syndrome with symptoms of nystagmus].

PubMed

Lindholt, Michael E

2006-04-03

A 42-year-old man presented in the Department of Ophthalmology of Holstebro Central Hospital with a history of alcohol abuse, vomiting and weight loss. The initial symptoms of beriberi were stiffness of the legs and a picture of Wernicke's syndrome. He had bilateral loss of horizontal eccentric gaze holding and upbeat nystagmus, and visual acuity was reduced to counting fingers. Visual acuity was tested in the down-gaze position and increased to 0.3 because of reduced nystagmus. The patient's oculomotor function improved dramatically after treatment with thiamine. Wernicke's encephalopathy and beriberi are discussed, highlighting that nystagmus may be the single ocular symptom. It should be considered in the differential diagnosis of bilateral ophthalmoplegia even in the absence of altered mental status.

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, general health status, eyesight worry, and major chronic conditions, self-reported visual function loss remained significantly associated with depression (overall odds ratio, 1.9 [95% CI, 1.6–2.3]), whereas the association between presenting visual acuity impairment and depression was no longer statistically significant. Conclusions and Relevance Self-reported visual function loss, rather than loss of visual acuity, is significantly associated with depression. Health professionals should be aware of the risk of depression among persons reporting visual function loss. PMID:23471505

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 driving are met.

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).

Contact lens rehabilitation following repaired corneal perforations

PubMed Central

Titiyal, Jeewan S; Sinha, Rajesh; Sharma, Namrata; Sreenivas, V; Vajpayee, Rasik B

2006-01-01

Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 ± 0.13 while the same with contact lens was 0.58 ± 0.26. All the patients showed an improvement of ≥ 2 lines over spectacles in the snellen's acuity chart with contact lens. Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries. PMID:16536877

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

The prevalence of amblyopia in Germany: data from the prospective, population-based Gutenberg Health Study.

PubMed

Elflein, Heike M; Fresenius, Susanne; Lamparter, Julia; Pitz, Susanne; Pfeiffer, Norbert; Binder, Harald; Wild, Philipp; Mirshahi, Alireza

2015-05-08

Amblyopia is due to insufficient development of the visual system in early childhood and is a major source of lifelong impairment of visual acuity. Too little is known about the prevalence of amblyopia in Germany and the frequency of its various causes. The Gutenberg Health Study of the University of Mainz Faculty of Medicine is an ongoing population-based, prospective, monocentric cohort study with 15 010 participants aged 35 to 74. All participants are examined for the presence of ocular, cardiovascular, neoplastic, metabolic, immunologic, and mental diseases. 3227 participants aged 35 to 44 underwent ophthalmological examination from 2007 to 2012. Amblyopia was defined as impaired visual acuity in the absence of any organic pathology capable of explaining the condition, and in the presence of a known risk factor for amblyopia. Amblyopia, when defined as a visual acuity less than or equal to 0.63, was present in 182 participants (5.6%, 95% confidence interval [CI] 4.9-6.5%), 120 of whom had a visual acuity less than or equal to 0.5 (3.7%, 95% CI 3.3-5.2%). A narrower definition of amblyopia requiring, in addition, an interocular difference in acuity of at least two lines yielded slightly lower prevalence figures: 5.0% (95% CI 4.2-5.8%) and 3.7% (95% CI 3.1-4.4%), respectively. The causes of amblyopia (visual acuity ≤ 0.63) were anisometropia (different refractive strengths of the two eyes) in 49% of participants, strabismus (a squint) in 23%, both of these factors in 17%, and visual deprivation in 2%. 3 patients (2%) had relative amblyopia due to a traumatic cataract sustained in early childhood. 7% of the participants with amblyopia had binocular amblyopia. This study yielded a prevalence figure of 5.6% for amblyopia in Germany-a higher figure than in other, comparable population-based studies, which have generally yielded figures of ca. 3% for visual acuity ≤ 0.63. The distribution of the causes of amblyopia is similar across studies.

Long-term Outcomes of Cytomegalovirus Retinitis in the Era of Modern Antiretroviral Therapy; Results from a United States Cohort

PubMed Central

Jabs, Douglas A.; Ahuja, Alka; Van Natta, Mark L.; Lyon, Alice T.; Yeh, Steven; Danis, Ronald

2015-01-01

Objectives To describe the long-term outcomes of patients with cytomegalovirus (CMV) retinitis and the acquired immunodeficiency syndrome (AIDS)in the modern era of combination antiretroviral therapy. Design Prospective, observational, cohort study Participants Patients with AIDS and CMV retinitis Testing Immune recovery, defined as a CD4+ T cell count>100 cells/μL for ≥ 3 months. Main outcome measures Mortality, visual impairment (visual acuity worse than 20/40) and blindness (visual acuity 20/200 or worse) on logarithmic visual acuity charts, loss of visual field on quantitative Goldmann perimetry. Results Patients without immune recovery had a mortality of 44.4/100 person years (PY), and a median survival of 13.5 months after the diagnosis of CMV retinitis, whereas those with immune recovery had a mortality of 2.7/100 PY (P<0.001), and an estimated median survival of 27.0 years after the diagnosis of CMV retinitis. The rates of bilateral visual impairment and blindness were 0.9/100 PY and 0.4/100 PY, respectively, and were similar between those with and without immune recovery. Among those with immune recovery, the rate of visual field loss was ~1% of the normal field/year, whereas among those without immune recovery it was ~7% of the normal field/year. Conclusions Among persons with CMV retinitis and AIDS, if there is immune recovery, long-term survival is likely, whereas if there is no immune recovery, the mortality rate is substantial. Although higher than the rates seen in the non-HIV-infected population, the rates of bilateral visual impairment and blindness are low, especially when compared to rates seen in the era before modern antiretroviral therapy. PMID:25892019

Comparison of automatic and visual methods used for image segmentation in Endodontics: a microCT study.

PubMed

Queiroz, Polyane Mazucatto; Rovaris, Karla; Santaella, Gustavo Machado; Haiter-Neto, Francisco; Freitas, Deborah Queiroz

2017-01-01

To calculate root canal volume and surface area in microCT images, an image segmentation by selecting threshold values is required, which can be determined by visual or automatic methods. Visual determination is influenced by the operator's visual acuity, while the automatic method is done entirely by computer algorithms. To compare between visual and automatic segmentation, and to determine the influence of the operator's visual acuity on the reproducibility of root canal volume and area measurements. Images from 31 extracted human anterior teeth were scanned with a μCT scanner. Three experienced examiners performed visual image segmentation, and threshold values were recorded. Automatic segmentation was done using the "Automatic Threshold Tool" available in the dedicated software provided by the scanner's manufacturer. Volume and area measurements were performed using the threshold values determined both visually and automatically. The paired Student's t-test showed no significant difference between visual and automatic segmentation methods regarding root canal volume measurements (p=0.93) and root canal surface (p=0.79). Although visual and automatic segmentation methods can be used to determine the threshold and calculate root canal volume and surface, the automatic method may be the most suitable for ensuring the reproducibility of threshold determination.

Distant stereoacuity in children with anisometropic amblyopia.

PubMed

Chung, Yeon Woong; Park, Shin Hae; Shin, Sun Young

2017-09-01

To characterize changes in distant stereoacuity using Frisby-Davis Distance test (FD2) and Distant Randot test (DR) during treatment for anisometropic amblyopia, to determine factors that influence posttreatment stereoacuity and to compare the two distant stereotests. Fifty-eight anisometropic amblyopic patients with an interocular difference of ≥1.00 diopter who achieved the visual acuity 20/20 following amblyopia treatment were retrospectively included. Stereoacuity using FD2 and DR for distant and Titmus test for near measurement were assessed and compared at the initial, intermediate, and final visit. Multivariate regression models were used to identify factors associated with initial and final stereoacuity. The two distant stereotests revealed a significant improvement in distant stereoacuity after successful amblyopia treatment. Distant stereoacuity using FD2 showed the greatest improvement during the follow up period. The number of nil scores was higher in DR than FD2 at each period. In multivariate analysis, better final stereoacuity was associated with better initial amblyopic eye acuity in both distant stereotests, but not in the Titmus test. Comparing the two distant stereotests, final stereoacuity using FD2 was associated with initial stereoacuity and was moderately related with the Titmus test at each period, but final stereoacuity using DR was not. Distant stereoacuity measured with both FD2 and DR showed significant improvement when the visual acuity of the amblyopic eye achieved 20/20. Changes in distant stereoacuity by FD2 and DR during the amblyopia treatment were somewhat different.

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...

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.

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.

Ocular haemodynamic changes after single treatment with photodynamic therapy assessed with non-invasive techniques.

PubMed

Maar, Noemi; Pemp, Berthold; Kircher, Karl; Luksch, Alexandra; Weigert, Günther; Polska, Elzbieta; Tittl, Michael; Stur, Michael; Schmetterer, Leopold

2009-09-01

To investigate in patients with neovascular age-related macular degeneration (ARMD) the changes in ocular perfusion caused by single treatment with photodynamic therapy (PDT) by different non-invasive methods; to evaluate correlations between relative changes of ocular haemodynamic parameters after PDT among each other and compared to morphological parameters; and to assess this in relation to early changes of visual acuity. 17 consecutive patients with subfoveal choroidal neovascularization (CNV) caused by ARMD scheduled for PDT without previous PDT treatment (four patients with predominantly classic CNV and 13 patients with occult CNV). best-corrected visual acuity (before PDT, 6 and 8 weeks after PDT), fundus photography, fluorescein angiography, haemodynamic measurements with laser Doppler flowmetry (LDF), laser interferometry and ocular blood flow (OBF) tonometry (baseline and 1, 2, 6 and 8 weeks after treatment). choroidal blood flow (CHBF), fundus pulsation amplitude (FPA), pulsatile ocular blood flow (POBF), visual acuity. Changes smaller than 20% were considered clinically irrelevant. Ocular haemodynamic parameters did not change significantly in the follow-up period. Changes of haemodynamic parameters showed no correlation to treatment spot, morphological changes or visual acuity. Changes of visual acuity were comparable to results of earlier studies. Single treatment with PDT did not modify ocular blood flow parameters above 20% as assessed with different non-invasive methods.

A Randomized Trial Comparing Bangerter Filters and Patching for the Treatment of Moderate Amblyopia in Children

PubMed Central

2009-01-01

Objective To determine whether visual acuity improvement with Bangerter filters is similar to improvement with patching as initial therapy for children with moderate amblyopia. Design Randomized clinical trial. Participants 186 children, 3 to <10 years old, with moderate amblyopia (20/40 to 20/80). Methods Children were randomly assigned to receive either daily patching or to use a Bangerter filter on the spectacle lens in front of the fellow eye. Study visits were scheduled at 6, 12, 18 and 24 weeks. Main outcome measure Visual acuity in amblyopic eye at 24 weeks. Results At 24 weeks, amblyopic eye improvement averaged 1.9 lines in the Bangerter group and 2.3 lines in the patching group (difference in mean visual acuities between groups adjusted for baseline acuity = 0.38 line). The upper limit of a 1-sided 95% confidence interval was 0.76 line, which slightly exceeded a pre-specified non-inferiority limit of < 0.75 line. Similar percentages of subjects in each group improved ≥3 lines (Bangerter group 38% versus patching group 35%, P=0.61) or had 20/25 or better amblyopic eye acuity (36% versus 31%, respectively, P=0.86). There was a lower treatment burden in the Bangerter group as measured with the Amblyopia Treatment Index. With Bangerter filters, neither a fixation switch to the amblyopic eye nor induced blurring in the fellow eye to worse than that of the amblyopic eye was required for visual acuity improvement. Conclusion Because the average difference in visual acuity improvement between Bangerter filters and patching was less than half a line, and there was lower burden of treatment on the child and family, Bangerter filter treatment is a reasonable option to consider for initial treatment of moderate amblyopia. PMID:20163869

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 prism is currently available only for use as a trial set. Since the cosmetic appearance of the Fresnel "hard" prism is similar to that of the Fresnel membrane prism and it is easier to maintain, it would be the prism of choice (over all other types) for bilateral prescriptions in the young patient with emmetropia. The manufacturer is urged to make these prisms available to fit a special round adjustable frame, such as that developed in Europe for use with the wafer prism. Images FIGURE 14 A FIGURE 14 B FIGURE 2 A FIGURE 2 B FIGURE 12 PMID:754384

Streptococcus endophthalmitis outbreak after intravitreal injection of bevacizumab: one-year outcomes and investigative results.

PubMed

Goldberg, Roger A; Flynn, Harry W; Miller, Darlene; Gonzalez, Serafin; Isom, Ryan F

2013-07-01

To report the 1-year clinical outcomes of an outbreak of Streptococcus endophthalmitis after intravitreal injection of bevacizumab, including visual acuity outcomes, microbiological testing, and compound pharmacy investigations by the Food and Drug Administration (FDA). Retrospective consecutive case series. Twelve eyes of 12 patients who developed endophthalmitis after receiving intravitreal bevacizumab prepared by a single compounding pharmacy. Medical records of patients were reviewed; phenotypic and DNA analyses were performed on microbes cultured from patients and from unused syringes. An inspection report by the FDA based on site visits to the pharmacy that prepared the bevacizumab syringes was summarized. Visual acuity, interventions received, time to intervention, microbiological consistency, and FDA inspection findings. Between July 5 and 8, 2011, 12 patients developed endophthalmitis after intravitreal bevacizumab from syringes prepared by a single compounding pharmacy. All patients received initial vitreous tap and injection, and 8 patients (67%) subsequently underwent pars plana vitrectomy (PPV). After 12 months follow-up, outcomes have been poor. Seven patients (58%) required evisceration or enucleation, and only 1 patient regained pre-injection visual acuity. Molecular testing using real-time polymerase chain reaction, partial sequencing of the groEL gene, and multilocus sequencing of 7 housekeeping genes confirmed the presence of a common strain of Streptococcus mitis/oralis in vitreous specimens and 7 unused syringes prepared by the compounding pharmacy at the same time. An FDA investigation of the compounding pharmacy noted deviations from standard sterile technique, inconsistent documentation, and inadequate testing of equipment required for safe preparation of medications. In this outbreak of endophthalmitis, outcomes have been generally poor, and PPV did not improve visual results at 1-year follow-up. Molecular testing confirmed a common strain of S. mitis/oralis. Contamination seems to have occurred at the compounding pharmacy, where numerous problems in sterile technique were noted by public health investigators. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Streptococcus Endophthalmitis Outbreak after Intravitreal Injection of Bevacizumab: One-year Outcomes and Investigative Results

PubMed Central

Goldberg, Roger A.; Flynn, Harry W.; Miller, Darlene; Gonzalez, Serafin; Isom, Ryan F.

2013-01-01

Purpose To report the one-year clinical outcomes of an outbreak of Streptococcus endophthalmitis after intravitreal injection of bevacizumab, including visual acuity outcomes, microbiological testing and compound pharmacy investigations by the Food and Drug Administration (FDA). Design Retrospective consecutive case series. Participants 12 eyes of 12 patients who developed endophthalmitis after receiving intravitreal bevacizumab prepared by a single compounding pharmacy. Methods Medical records of patients were reviewed; phenotypic and DNA analyses were performed on microbes cultured from patients and from unused syringes. An inspection report by the FDA based on site-visits to the pharmacy that prepared the bevacizumab syringes was summarized. Main Outcome Measures Visual acuity, interventions received, time-to-intervention; microbiological consistency; FDA inspection findings. Results Between July 5 and July 8, 2011, 12 patients developed endophthalmitis after intravitreal bevacizumab from syringes prepared by a single compounding pharmacy. All patients received initial vitreous tap and injection, and eight (67%) subsequently underwent pars plana vitrectomy (PPV). After twelve months follow-up, outcomes have been poor: 7 patients (58%) required evisceration or enucleation, and only one patient regained pre-injection visual acuity. Molecular testing using real time polymerase chain reaction, partial sequencing of the groEL gene, and multilocus sequencing of 7 housekeeping genes confirmed the presence of a common strain of Streptococcus mitis/oralis in vitreous specimens and seven unused syringes prepared by the compounding pharmacy at the same time. An FDA investigation of the compounding pharmacy noted deviations from standard sterile technique, inconsistent documentation, and inadequate testing of equipment required for safe preparation of medications. Conclusions In this outbreak of endophthalmitis, outcomes have been generally poor and PPV did not improve visual results at one year follow-up. Molecular testing confirmed a common strain of Streptococcus mitis/oralis. Contamination appears to have occurred at the compounding pharmacy, where numerous problems in sterile technique were noted by public health investigators. PMID:23453511

Visual acuity test

MedlinePlus

... contact lenses and stand or sit 20 feet (6 meters) from the eye chart. You will keep both eyes open. You will be asked to cover one eye with the palm of your hand, a piece of paper, or a small paddle while you ...

Test-Retest Intervisit Variability of Functional and Structural Parameters in X-Linked Retinoschisis.

PubMed

Jeffrey, Brett G; Cukras, Catherine A; Vitale, Susan; Turriff, Amy; Bowles, Kristin; Sieving, Paul A

2014-09-01

To examine the variability of four outcome measures that could be used to address safety and efficacy in therapeutic trials with X-linked juvenile retinoschisis. Seven men with confirmed mutations in the RS1 gene were evaluated over four visits spanning 6 months. Assessments included visual acuity, full-field electroretinograms (ERG), microperimetric macular sensitivity, and retinal thickness measured by optical coherence tomography (OCT). Eyes were separated into Better or Worse Eye groups based on acuity at baseline. Repeatability coefficients were calculated for each parameter and jackknife resampling used to derive 95% confidence intervals (CIs). The threshold for statistically significant change in visual acuity ranged from three to eight letters. For ERG a-wave, an amplitude reduction greater than 56% would be considered significant. For other parameters, variabilities were lower in the Worse Eye group, likely a result of floor effects due to collapse of the schisis pockets and/or retinal atrophy. The criteria for significant change (Better/Worse Eye) for three important parameters were: ERG b/a-wave ratio (0.44/0.23), point wise sensitivity (10.4/7.0 dB), and central retinal thickness (31%/18%). The 95% CI range for visual acuity, ERG, retinal sensitivity, and central retinal thickness relative to baseline are described for this cohort of participants with X-linked juvenile retinoschisis (XLRS). A quantitative understanding of the variability of outcome measures is vital to establishing the safety and efficacy limits for therapeutic trials of XLRS patients.

Amblyopia and Binocular Vision

PubMed Central

Birch, Eileen E.

2012-01-01

Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3% to 3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia. PMID:23201436

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 consistent with the Lyon hypothesis of random X-inactivation. PMID:26143542

The impact of cataract surgery on visual functioning, vision-related disability and psychological distress: a randomized controlled trial.

PubMed

Walker, Janine G; Anstey, Kaarin J; Hennessy, Michael P; Lord, Stephen R; von Sanden, Chwee

2006-11-01

Determine whether there are changes in visual functioning, vision-related disability, health status and mood after cataract surgery. 45 adults (mean age = 73.7 years) with bilateral cataract needing surgery for the first eye were recruited from public ophthalmology clinics. The Visual Functioning-14 survey assessed visual disability. Minimal angle of resolution tested visual acuity, and the Melbourne Edge Test examined contrast sensitivity. Demographic, psychological, health and medication use variables were examined. Participants were randomized to either an intervention or control arm. Controls were assessed on two occasions at a 3-month interval before having surgery. The intervention group was assessed 1-2 weeks before surgery and then reassessed 3 months after surgery. Visual functioning improved for those who had cataract surgery with better visual acuity in the better (P = 0.010) and worse (P = 0.028) eye compared with controls. The intervention group reported fewer difficulties with overall vision-related disability (P = 0.0001), reading (P = 0.004) and instrumental activities of daily living (P = 0.010) post-surgery compared with controls. People with improved depression scores (P = 0.048) after surgery had less difficulty with reading compared with those with unchanged or worsened depression scores. Cataract surgery did not improve health status. First eye cataract surgery is effective in improving outcomes in visual functioning and disability. Improved mood after surgery was related to less vision-related disability compared with unchanged or worse depression.

The Ohio Contrast Cards: Visual Performance in a Pediatric Low-vision Site

PubMed Central

Hopkins, Gregory R.; Dougherty, Bradley E.; Brown, Angela M.

2017-01-01

SIGNIFICANCE This report describes the first clinical use of the Ohio Contrast Cards, a new test that measures the maximum spatial contrast sensitivity of low-vision patients who cannot recognize and identify optotypes and for whom the spatial frequency of maximum contrast sensitivity is unknown. PURPOSE To compare measurements of the Ohio Contrast Cards to measurements of three other vision tests and a vision-related quality-of-life questionnaire obtained on partially sighted students at Ohio State School for the Blind. METHODS The Ohio Contrast Cards show printed square-wave gratings at very low spatial frequency (0.15 cycle/degree). The patient looks to the left/right side of the card containing the grating. Twenty-five students (13 to 20 years old) provided four measures of visual performance: two grating card tests (the Ohio Contrast Cards and the Teller Acuity Cards) and two letter charts (the Pelli-Robson contrast chart and the Bailey-Lovie acuity chart). Spatial contrast sensitivity functions were modeled using constraints from the grating data. The Impact of Vision Impairment on Children questionnaire measured vision-related quality of life. RESULTS Ohio Contrast Card contrast sensitivity was always less than 0.19 log10 units below the maximum possible contrast sensitivity predicted by the model; average Pelli-Robson letter contrast sensitivity was near the model prediction, but 0.516 log10 units below the maximum. Letter acuity was 0.336 logMAR below the grating acuity results. The model estimated the best testing distance in meters for optimum Pelli-Robson contrast sensitivity from the Bailey-Lovie acuity as distance = 1.5 − logMAR for low-vision patients. Of the four vision tests, only Ohio Contrast Card contrast sensitivity was independently and statistically significantly correlated with students' quality of life. CONCLUSIONS The Ohio Contrast Cards combine a grating stimulus, a looking indicator behavior, and contrast sensitivity measurement. They show promise for the clinical objective of advising the patient and his/her caregivers about the success the patient is likely to enjoy in tasks of everyday life. PMID:28972542

Temporal visual field defects are associated with monocular inattention in chiasmal pathology.

PubMed

Fledelius, Hans C

2009-11-01

Chiasmal lesions have been shown to give rise occasionally to uni-ocular temporal inattention, which cannot be compensated for by volitional eye movement. This article describes the assessments of 46 such patients with chiasmal pathology. It aims to determine the clinical spectrum of this disorder, including interference with reading. Retrospective consecutive observational clinical case study over a 7-year period comprising 46 patients with chiasmal field loss of varying degrees. Observation of reading behaviour during monocular visual acuity testing ascertained from consecutive patients who appeared unable to read optotypes on the temporal side of the chart. Visual fields were evaluated by kinetic (Goldmann) and static (Octopus) techniques. Five patients who clearly manifested this condition are presented in more detail. The results of visual field testing were related to absence or presence of uni-ocular visual inattentive behaviour for distance visual acuity testing and/or reading printed text. Despite normal eye movements, the 46 patients making up the clinical series perceived only optotypes in the nasal part of the chart, in one eye or in both, when tested for each eye in turn. The temporal optotypes were ignored, and this behaviour persisted despite instruction to search for any additional letters temporal to those, which had been seen. This phenomenon of unilateral visual inattention held for both eyes in 18 and was unilateral in the remaining 28 patients. Partial or full reversibility after treatment was recorded in 21 of the 39 for whom reliable follow-up data were available. Reading a text was affected in 24 individuals, and permanently so in six. A neglect-like spatial unawareness and a lack of cognitive compensation for varying degrees of temporal visual field loss were present in all the patients observed. Not only is visual field loss a feature of chiasmal pathology, but the higher visual function of affording attention within the temporal visual field by means of using conscious thought to invoke appropriate compensatory eye movement was also absent. This suggests the possibility of 'trans-synaptic dysfunction' caused by loss of visual input to higher visual centres. When inattention to the temporal side is manifest on monocular visual testing it should raise the suspicion of chiasmal pathology.

Rapid Onset of Retinal Toxicity From High-Dose Hydroxychloroquine Given for Cancer Therapy.

PubMed

Leung, Loh-Shan B; Neal, Joel W; Wakelee, Heather A; Sequist, Lecia V; Marmor, Michael F

2015-10-01

To report rapid onset of retinal toxicity in a series of patients followed on high-dose (1000 mg daily) hydroxychloroquine during an oncologic clinical trial studying hydroxychloroquine with erlotinib for non-small cell lung cancer. Retrospective observational case series. Ophthalmic surveillance was performed on patients in a multicenter clinical trial testing high-dose (1000 mg daily) hydroxychloroquine for advanced non-small cell lung cancer. The US Food & Drug Administration-recommended screening protocol included only visual acuity testing, dilated fundus examination, Amsler grid testing, and color vision testing. In patients seen at Stanford, additional sensitive screening procedures were added at the discretion of the retinal physician: high-resolution spectral-domain optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, Humphrey visual field (HVF) testing, and multifocal electroretinography (mfERG). Out of the 7 patients having exposure of at least 6 months, 2 developed retinal toxicity (at 11 and 17 months of exposure). Damage was identified by OCT imaging, mfERG testing, and, in 1 case, visual field testing. Fundus autofluorescence imaging remained normal. Neither patient had symptomatic visual acuity loss. These cases show that high doses of hydroxychloroquine can initiate the development of retinal toxicity within 1-2 years. Although synergy with erlotinib is theoretically possible, there are no prior reports of erlotinib-associated retinal toxicity despite over a decade of use in oncology. These results also suggest that sensitive retinal screening tests should be added to ongoing and future clinical trials involving high-dose hydroxychloroquine to improve safety monitoring and preservation of vision. Published by Elsevier Inc.

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.

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-effective strategies are needed to address these easily treatable causes of visual impairment. © 2017 Optometry Australia.

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.

Intravitreous injection of bevacizumab, tissue plasminogen activator, and gas in the treatment of submacular hemorrhage in age-related macular degeneration.

PubMed

Guthoff, Rainer; Guthoff, Tanja; Meigen, Thomas; Goebel, Winfried

2011-01-01

To investigate the benefit of adding bevacizumab to intravitreal recombinant tissue plasminogen activator (rTPA) and gas as initial therapy in subretinal hemorrhage and choroidal neovascularization because of age-related macular degeneration. Thirty-eight consecutive patients with recent (1-31 days) subretinal hemorrhage who were treated with intravitreal rTPA and gas (26 patients) or with intravitreal bevacizumab, rTPA, and gas (12 patients) were included in this retrospective analysis. In all patients, a standardized antivascular endothelial growth factor therapy was followed. Testing of best-corrected visual acuity, biomicroscopy, and fundus examination were performed at 4 weeks and 7 months. The mean pretreatment best-corrected visual acuity in the rTPA/gas group was 0.08 ± 0.09 and 0.12 ± 0.13 in the bevacizumab/rTPA/gas group. After 4 weeks, it was significantly higher in the bevacizumab/rTPA/gas group (0.25 ± 0.26) than in the rTPA/gas (0.08 ± 0.1) group (P < 0.05). Also, after 7 months, best-corrected visual acuity was significantly higher in the bevacizumab/rTPA/gas group (0.07 ± 0.07 vs. 0.24 ± 0.35; P < 0.05). Reading vision could be restored in 0% (rTPA/gas) versus 50% (bevacizumab/rTPA/gas). Stabilization (0 ± 2 lines) or improvement of best-corrected visual acuity was obtained in 62% (rTPA/gas) versus 84% (bevacizumab/rTPA/gas). From our retrospective pilot study, there is a strong indication that the addition of intravitreal bevacizumab is safe and superior to the displacement of submacular hemorrhages alone with rTPA and gas.

Assessment of hydroxychloroquine maculopathy after cessation of treatment: an optical coherence tomography and multifocal electroretinography study

PubMed Central

Moschos, Marilita M; Nitoda, Eirini; Chatziralli, Irini P; Gatzioufas, Zisis; Koutsandrea, Chryssanthi; Kitsos, George

2015-01-01

Objective This study was conducted to evaluate the macular status of patients treated with hydroxychloroquine before and after cessation of treatment. Methods Forty-two patients with systemic lupus erythematosus underwent ocular examination based on visual acuity evaluation, optical coherence tomography retinal thickness measurements, and multifocal electroretinography (mfERG) records at first visit. The tests were repeated 6 months after treatment withdrawal and compared to the findings at their first visit. Results Mean visual acuity (measured in log minimum angle of resolution) of both eyes was statistically increased after hydroxychloroquine discontinuation (difference in means: 0.06 [P<0.0001] and 0.01 [P=0.003] for the right and left eyes, respectively). Retinal response amplitudes of central and peripheral areas were significantly improved for both eyes. The following values were observed for central responses: the difference in means was −19.9 (P<0.0001) and −13.6 (P<0.0001) for the right eye and the left eye, respectively; for peripheral responses, difference in means was −10.3 (P<0.0001) and −9.5 (P<0.0001) for right eye and left eye, respectively, after the 6-month examination. There were no statistically significant differences in the retinal thickness of patients after cessation of treatment. The visual acuity of the patients was correlated to central and peripheral mfERG responses (r=−0.53 [P<0.0001] and r=−0.53 [P<0.0001], for the right eye and the left eye, respectively). Conclusion The visual acuity of patients receiving hydroxychloroquine improves along with the amplitudes of the mfERG responses 6 months after discontinuation of the drug, but no difference in retinal thickness is identified. PMID:26089648

Assessment of hydroxychloroquine maculopathy after cessation of treatment: an optical coherence tomography and multifocal electroretinography study.

PubMed

Moschos, Marilita M; Nitoda, Eirini; Chatziralli, Irini P; Gatzioufas, Zisis; Koutsandrea, Chryssanthi; Kitsos, George

2015-01-01

This study was conducted to evaluate the macular status of patients treated with hydroxychloroquine before and after cessation of treatment. Forty-two patients with systemic lupus erythematosus underwent ocular examination based on visual acuity evaluation, optical coherence tomography retinal thickness measurements, and multifocal electroretinography (mfERG) records at first visit. The tests were repeated 6 months after treatment withdrawal and compared to the findings at their first visit. Mean visual acuity (measured in log minimum angle of resolution) of both eyes was statistically increased after hydroxychloroquine discontinuation (difference in means: 0.06 [P<0.0001] and 0.01 [P=0.003] for the right and left eyes, respectively). Retinal response amplitudes of central and peripheral areas were significantly improved for both eyes. The following values were observed for central responses: the difference in means was -19.9 (P<0.0001) and -13.6 (P<0.0001) for the right eye and the left eye, respectively; for peripheral responses, difference in means was -10.3 (P<0.0001) and -9.5 (P<0.0001) for right eye and left eye, respectively, after the 6-month examination. There were no statistically significant differences in the retinal thickness of patients after cessation of treatment. The visual acuity of the patients was correlated to central and peripheral mfERG responses (r=-0.53 [P<0.0001] and r=-0.53 [P<0.0001], for the right eye and the left eye, respectively). The visual acuity of patients receiving hydroxychloroquine improves along with the amplitudes of the mfERG responses 6 months after discontinuation of the drug, but no difference in retinal thickness is identified.

Intrastromal femtosecond laser surgical compensation of presbyopia with six intrastromal ring cuts: 3-year results.

PubMed

Khoramnia, Ramin; Fitting, Anna; Rabsilber, Tanja M; Thomas, Bettina C; Auffarth, Gerd U; Holzer, Mike P

2015-02-01

To assess over a 36-month period functional results of the modified INTRACOR femtosecond laser-based intrastromal procedure to treat presbyopia. 20 eyes of 20 presbyopic patients with mild hyperopia were included. The INTRACOR procedure with a modified pattern (six concentric intrastromal ring cuts) was performed using the FEMTEC femtosecond laser (Bausch+Lomb/Technolas Perfect Vision, Munich, Germany). Patients were also randomly divided into three subgroups to compare the effect of three different small inner ring diameters (1.8/2.0/2.2 mm (Groups A/B/C)). Follow-up examinations were performed at 1, 3, 6, 12, 24 and 36 months, and included near and distance visual acuity tests, slit-lamp examinations and corneal topography. Median uncorrected near visual acuity (UNVA) increased from 0.7/0.7/0.7 logMAR (Groups A/B/C) to -0.1/0.1/0.1 logMAR 36 months after surgery. Uncorrected distance visual acuity changed slightly from 0.1/0.2/0.1 logMAR to 0.2/0.3/0.1 logMAR. Losses of two lines of binocular corrected distance visual acuity (CDVA) were noted in 0/25/0% of eyes. Median spherical equivalent changed from 0.75/0.75/0.75 dioptres to -0.19/0.13/-0.19 dioptres. Overall patient satisfaction with the procedure was 80%. INTRACOR with a modified pattern improved UNVA in all patients over a 36-month follow-up period. The possibility of reduced CDVA underlines the need for careful patient selection. NCT00928122. 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.

Presence of chronic diabetic foot ulcers is associated with more frequent and more advanced retinopathy.

PubMed

Sellman, A; Katzman, P; Andreasson, S; Löndahl, M

2018-05-23

To clarify the frequency and severity of diabetic retinopathy in a group of people with Type 2 diabetes and chronic diabetic foot ulcers, and to compare visual acuity, levels of retinopathy and clinical significant macular oedema with a matched control group of people with Type 2 diabetes without a history of chronic diabetic foot ulcers. Visual acuity and fundus imaging were evaluated in 90 white people with at least 3 months' duration of full-thickness diabetic foot ulcers below the ankle and the results compared with those in 180 white people with Type 2 diabetes without a history of chronic diabetic foot ulcers (control group). Controls were matched for age, sex and duration of diabetes. Despite similar age and diabetes duration, severe non-proliferative or proliferative diabetic retinopathy was present in 41% of the people in the diabetic foot ulcer group as compared to 15% in the control group (P<0.001). Only 6% in the diabetic foot ulcer group was without any diabetic retinopathy as compared to 34% among controls. Proliferative diabetic retinopathy was more common in the diabetic foot ulcer group (31% vs 8%; P<0.001), but time-to-proliferative diabetic retinopathy did not differ between groups. Clinically significant macular oedema was more frequently present, and the diabetic foot ulcer group exhibited significantly worse results in best and worst eye visual acuity testing. In this northern European setting almost all people with Type 2 diabetes and chronic diabetic foot ulcers had diabetic retinopathy. Almost one-third had proliferative diabetic retinopathy as compared to <10% in our matched control group. More advanced diabetic retinopathy was linked to worse visual acuity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Clinical predictors of the optimal spectacle correction for comfort performing desktop tasks.

PubMed

Leffler, Christopher T; Davenport, Byrd; Rentz, Jodi; Miller, Amy; Benson, William

2008-11-01

The best strategy for spectacle correction of presbyopia for near tasks has not been determined. Thirty volunteers over the age of 40 years were tested for subjective accommodative amplitude, pupillary size, fusional vergence, interpupillary distance, arm length, preferred working distance, near and far visual acuity and preferred reading correction in the phoropter and trial frames. Subjects performed near tasks (reading, writing and counting change) using various spectacle correction strengths. Predictors of the correction maximising near task comfort were determined by multivariable linear regression. The mean age was 54.9 years (range 43 to 71) and 40 per cent had diabetes. Significant predictors of the most comfortable addition in univariate analyses were age (p<0.001), interpupillary distance (p=0.02), fusional vergence amplitude (p=0.02), distance visual acuity in the worse eye (p=0.01), vision at 40 cm in the worse eye with distance correction (p=0.01), duration of diabetes (p=0.01), and the preferred correction to read at 40 cm with the phoropter (p=0.002) or trial frames (p<0.001). Target distance selected wearing trial frames (in dioptres), arm length, and accommodative amplitude were not significant predictors (p>0.15). The preferred addition wearing trial frames holding a reading target at a distance selected by the patient was the only independent predictor. Excluding this variable, distance visual acuity was predictive independent of age or near vision wearing distance correction. The distance selected for task performance was predicted by vision wearing distance correction at near and at distance. Multivariable linear regression can be used to generate tables based on distance visual acuity and age or near vision wearing distance correction to determine tentative near spectacle addition. Final spectacle correction for desktop tasks can be estimated by subjective refraction with trial frames.

Long term outcomes of bilateral congenital and developmental cataracts operated in Maharashtra, India. Miraj pediatric cataract study III.

PubMed

Gogate, Parikshit M; Sahasrabudhe, Mohini; Shah, Mitali; Patil, Shailbala; Kulkarni, Anil N; Trivedi, Rupal; Bhasa, Divya; Tamboli, Rahin; Mane, Rekha

2014-02-01

To study long term outcome of bilateral congenital and developmental cataract surgery. 258 pediatric cataract operated eyes of 129 children. Children who underwent pediatric cataract surgery in 2004-8 were traced and examined prospectively in 2010-11. Demographic and clinical factors were noted from retrospective chart readings. All children underwent visual acuity estimation and comprehensive ocular examination in a standardized manner. L. V. Prasad Child Vision Function scores (LVP-CVF) were noted for before and after surgery. Statistical analysis was done with SPSS version 16 including multi-variate analysis. Children aged 9.1 years (std dev 4.6, range 7 weeks-15 years) at the time of surgery. 74/129 (57.4%) were boys. The average duration of follow-up was 4.4 years (stddev 1.6, range 3-8 years). 177 (68.6%) eyes had vision <3/60 before surgery, while 109 (42.2%) had best corrected visual acuity (BCVA) >6/18 and 157 (60.9%) had BCVA >6/60 3-8 years after surgery. 48 (37.2%) had binocular stereoacuity <480 sec of arc by TNO test. Visual outcome depended on type of cataract (P = 0.004), type of cataract surgery (P < 0.001), type of intra-ocular lens (P = 0.05), age at surgery (P = 0.004), absence of post-operative uveitis (P = 0.01) and pre-operative vision (P < 0.001), but did not depend on delay (0.612) between diagnosis and surgery. There was a statistically significant improvement for all the 20 questions of the LVP-CVF scale (P < 0.001). Pediatric cataract surgery improved the children's visual acuity, stereo acuity and vision function. Developmental cataract, use of phacoemulsification, older children and those with better pre-operative vision had betterlong-termoutcomes.

[Vitrectomy for idiopathic and secondary preretinal macular membrane].

PubMed

Oficjalska-Młyńczak, Jolanta; Jamrozy-Witkowska, Agnieszka

2004-01-01

To evaluate the results of pars plana vitrectomy and membrane stripping for idiopathic and secondary preretinal macular membrane (PMM). Twenty one consecutive subjects (21 eyes) ranging in age from 40 to 78 (mean 66.9) with PMM underwent vitrectomy and membrane peeling. 17 cases had membranes that were considered idiopathic, and 4 cases were associated with other disorders: 3 occurred after successful retinal reattachment surgery, 1--after laserotherapy in the course of diabetic retinopathy. Visual acuity (VA), Amsler grid, and postoperative complications were assessed. The follow-up was 1 to 22 months, mean 5.7. Visual acuity improved postoperatively in 15 eyes (71.4%), at least two lines on the Snellen chart in 8 eyes (38.1%), entirely in patients with idiopathic PMM. It remained unchanged in 3 eyes (14.3%) and deteriorated in 3 eyes (14.3%). Eyes with transparent membrane showed greater visual improvement than opaque ones. The preoperative Amsler test was positive in 15 patients (71.4%), postoperatively--in 4 cases (19%). 2 idiopathic cases with VA of 0.7 showed postoperatively VA of 1.0. Complications included retinal detachment in 2 eyes (1 in idiopathic and 1 in secondary PMM), and development of nuclear sclerotic cataract in 2 eyes. At 6 months of follow-up, a residual membrane formation in 1 cases appeared. Macular pseudohole was observed in 1 eye with no impact on visual results. 1. Vitrectomy with membrane peeling for preretinal macular membrane provides improvement in visual acuity and reduces metamorphopsia 2. Thin, cellophane-like appearance of the membrane gives a better prognosis of visual function improvement.

Disease Course of Patients with Unilateral Pigmentary Retinopathy

PubMed Central

Potsidis, Emorfily; Berson, Eliot L.

2011-01-01

Purpose. To evaluate the change in ocular function by eye in patients with unilateral pigmentary retinopathy. Methods. Longitudinal regression was used to estimate mean exponential rates of change in Goldmann visual field area (V4e white test light) and in full-field electroretinogram (ERG) amplitudes to 0.5- and 30-Hz white flashes in 15 patients with unilateral pigmentary retinopathy. Snellen visual acuity was assessed case by case. Results. Mean annual rates of change for the affected eyes were −4.9% for visual field area, −4.7% for ERG amplitude to 0.5-Hz flashes, and −4.6% for ERG amplitude to 30-Hz flashes. All three rates were faster than the corresponding age-related rates of change for the fellow normal eyes (P = 0.0006, P = 0.003, P = 0.03, respectively). An initial cone ERG implicit time to 30-Hz flashes in affected eyes ≥40 ms predicted a faster mean rate of decline of visual field area and of ERG amplitude to 0.5- and 30-Hz flashes (P < 0.0001 for all three measures). The visual acuity of affected eyes was more likely to decrease in patients presenting at >35 years of age than in patients presenting at a younger age (P = 0.0004). Conclusions. The affected eye in unilateral pigmentary retinopathy shows a progressive loss of peripheral retinal function that cannot be attributed to aging alone and that is faster in eyes with a more prolonged initial cone ERG implicit time. Patients presenting at >35 years of age are at greater risk for losing visual acuity. PMID:21989720

Disease course of patients with unilateral pigmentary retinopathy.

PubMed

Potsidis, Emorfily; Berson, Eliot L; Sandberg, Michael A

2011-11-29

To evaluate the change in ocular function by eye in patients with unilateral pigmentary retinopathy. Longitudinal regression was used to estimate mean exponential rates of change in Goldmann visual field area (V4e white test light) and in full-field electroretinogram (ERG) amplitudes to 0.5- and 30-Hz white flashes in 15 patients with unilateral pigmentary retinopathy. Snellen visual acuity was assessed case by case. Mean annual rates of change for the affected eyes were -4.9% for visual field area, -4.7% for ERG amplitude to 0.5-Hz flashes, and -4.6% for ERG amplitude to 30-Hz flashes. All three rates were faster than the corresponding age-related rates of change for the fellow normal eyes (P = 0.0006, P = 0.003, P = 0.03, respectively). An initial cone ERG implicit time to 30-Hz flashes in affected eyes ≥ 40 ms predicted a faster mean rate of decline of visual field area and of ERG amplitude to 0.5- and 30-Hz flashes (P < 0.0001 for all three measures). The visual acuity of affected eyes was more likely to decrease in patients presenting at >35 years of age than in patients presenting at a younger age (P = 0.0004). The affected eye in unilateral pigmentary retinopathy shows a progressive loss of peripheral retinal function that cannot be attributed to aging alone and that is faster in eyes with a more prolonged initial cone ERG implicit time. Patients presenting at >35 years of age are at greater risk for losing visual acuity.

The child self-refraction study results from urban Chinese children in Guangzhou.

PubMed

He, Mingguang; Congdon, Nathan; MacKenzie, Graeme; Zeng, Yangfa; Silver, Joshua D; Ellwein, Leon

2011-06-01

To compare visual and refractive outcomes between self-refracting spectacles (Adaptive Eyecare, Ltd, Oxford, UK), noncycloplegic autorefraction, and cycloplegic subjective refraction. Cross-sectional study. Chinese school-children aged 12 to 17 years. Children with uncorrected visual acuity ≤ 6/12 in either eye underwent measurement of the logarithm of the minimum angle of resolution visual acuity, habitual correction, self-refraction without cycloplegia, autorefraction with and without cycloplegia, and subjective refraction with cycloplegia. Proportion of children achieving corrected visual acuity ≥ 6/7.5 with each modality; difference in spherical equivalent refractive error between each of the modalities and cycloplegic subjective refractive error. Among 556 eligible children of consenting parents, 554 (99.6%) completed self-refraction (mean age, 13.8 years; 59.7% girls; 54.0% currently wearing glasses). The proportion of children with visual acuity ≥ 6/7.5 in the better eye with habitual correction, self-refraction, noncycloplegic autorefraction, and cycloplegic subjective refraction were 34.8%, 92.4%, 99.5% and 99.8%, respectively (self-refraction versus cycloplegic subjective refraction, P<0.001). The mean difference between cycloplegic subjective refraction and noncycloplegic autorefraction (which was more myopic) was significant (-0.328 diopter [D]; Wilcoxon signed-rank test P<0.001), whereas cycloplegic subjective refraction and self-refraction did not differ significantly (-0.009 D; Wilcoxon signed-rank test P = 0.33). Spherical equivalent differed by ≥ 1.0 D in either direction from cycloplegic subjective refraction more frequently among right eyes for self-refraction (11.2%) than noncycloplegic autorefraction (6.0%; P = 0.002). Self-refraction power that differed by ≥ 1.0 D from cycloplegic subjective refractive error (11.2%) was significantly associated with presenting without spectacles (P = 0.011) and with greater absolute power of both spherical (P = 0.025) and cylindrical (P = 0.022) refractive error. Self-refraction seems to be less prone to accommodative inaccuracy than noncycloplegic autorefraction, another modality appropriate for use in areas where access to eye care providers is limited. Visual results seem to be comparable. Greater cylindrical power is associated with less accurate results; the adjustable glasses used in this study cannot correct astigmatism. Further studies of the practical applications of this modality are warranted. Proprietary or commercial disclosure may be found after the references. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Quality of Life and Mental State After Sight Restoration by Corneal Transplantation.

PubMed

Drzyzga, Karolina; Krupka-Matuszczyk, Irena; Drzyzga, Łukasz; Mrukwa-Kominek, Ewa; Kucia, Krzysztof

2016-01-01

Quality of life has frequently been reported to improve after corneal transplantation. However, mental status before and after surgery has until now been less well investigated. The aim of this study was to investigate quality of life and mental status before and after corneal transplantation including postoperative immunosuppression and visual acuity. A total of 45 patients were assessed before, and 3 weeks and 4 months after transplantation using the following questionnaires: Visual Function Questionnaire, Beck Depression Inventory, and Hamilton Anxiety Rating Scale. Assessment included a visual acuity test using the logMAR chart, and recognition of the role of postoperative immunosuppression. Finally, patients were asked if they would be willing to have the surgery again. In the candidates for surgery, quality of life was reduced, and symptoms of depression and anxiety were present. Corneal transplantation improved their quality of life and reduced symptoms of depression and anxiety. Changes in quality of life and in mental state were associated with a change in visual acuity in the grafted eye. Higher doses of prednisone were associated with a worse quality of life and with more severe symptoms of depression and anxiety after transplantation. Further, 82.5% of patients would have the surgery again. Assessment for psychiatric symptoms should be considered in individuals facing corneal surgery. Copyright © 2016 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

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.

The role of specific visual subfields in collisions with oncoming cars during simulated driving in patients with advanced glaucoma

PubMed Central

Kunimatsu-Sanuki, Shiho; Iwase, Aiko; Araie, Makoto; Aoki, Yuki; Hara, Takeshi; Fukuchi, Takeo; Udagawa, Sachiko; Ohkubo, Shinji; Sugiyama, Kazuhisa; Matsumoto, Chota; Nakazawa, Toru; Yamaguchi, Takuhiro; Ono, Hiroshi

2017-01-01

Background/aims To assess the role of specific visual subfields in collisions with oncoming cars during simulated driving in patients with advanced glaucoma. Methods Normal subjects and patients with glaucoma with mean deviation <–12 dB in both eyes (Humphrey Field Analyzer 24-2 SITA-S program) used a driving simulator (DS; Honda Motor, Tokyo). Two scenarios in which oncoming cars turned right crossing the driver's path were chosen. We compared the binocular integrated visual field (IVF) in the patients who were involved in collisions and those who were not. We performed a multivariate logistic regression analysis; the dependent parameter was collision involvement, and the independent parameters were age, visual acuity and mean sensitivity of the IVF subfields. Results The study included 43 normal subjects and 100 patients with advanced glaucoma. And, 5 of the 100 patients with advanced glaucoma experienced simulator sickness during the main test and were thus excluded. In total, 95 patients with advanced glaucoma and 43 normal subjects completed the main test of DS. Advanced glaucoma patients had significantly more collisions than normal patients in one or both DS scenarios (p<0.001). The patients with advanced glaucoma who were involved in collisions were older (p=0.050) and had worse visual acuity in the better eye (p<0.001) and had lower mean IVF sensitivity in the inferior hemifield, both 0°–12° and 13°–24° in comparison with who were not involved in collisions (p=0.012 and p=0.034). A logistic regression analysis revealed that collision involvement was significantly associated with decreased inferior IVF mean sensitivity from 13° to 24° (p=0.041), in addition to older age and lower visual acuity (p=0.018 and p<0.001). Conclusions Our data suggest that the inferior hemifield was associated with the incidence of motor vehicle collisions with oncoming cars in patients with advanced glaucoma. PMID:28400370

An intravenous microdose of bevacizumab for the treatment of pigment epithelial detachment associated to age-related macular degeneration refractory to intravitreal bevacizumab: a case report.

PubMed

Wu, Lihteh; Evans, Teodoro

2011-01-01

The purpose of this study was to report the visual and anatomical outcomes of an intravenous microdose of 10 mg of bevacizumab in a patient with a vascularized pigment epithelial detachment (PED) associated with exudative age-related macular degeneration refractory to several intravitreal bevacizumab injections. Interventional case report and literature review. A 62-year-old female patient with a PED secondary to age-related macular degeneration was treated with 9 consecutive intravitreal injections of 2.5 mg of bevacizumab. Despite an initial response where the PED decreased in size, the subretinal fluid reabsorbed and the visual acuity improved; after the seventh injection, the PED started to grow in size again causing a drop in visual acuity. After an intravenous injection of 10 mg of bevacizumab, the patient experienced an improvement in visual acuity and a flattening of her PED. An intravenous injection of a microdose of bevacizumab appears to have resolved the PED with a sustained improvement of visual acuity.

Identifying a clinically meaningful threshold for change in uveitic macular edema evaluated by optical coherence tomography.

PubMed

Sugar, Elizabeth A; Jabs, Douglas A; Altaweel, Michael M; Lightman, Sue; Acharya, Nisha; Vitale, Albert T; Thorne, Jennifer E

2011-12-01

To identify a clinically meaningful threshold for change in retinal thickness measured by optical coherence tomography for patients with uveitic macular edema using correlation with change in visual acuity. Cross-sectional and longitudinal study. One hundred twenty-eight eyes (101 individuals) with macular edema enrolled in the Multicenter Uveitis Steroid Treatment (MUST) trial. At enrollment and after 6 months of follow-up, retinal thickness was measured at the central subfield with time-domain optical coherence tomography and visual acuity was measured with logarithmic (Early Treatment Diabetic Retinopathy Study) visual acuity charts. Participants were classified as having macular edema if the retinal thickness was 260 μm or more. A threshold for change in retinal center subfield thickness of 20% balanced the percentage of false positives and false negatives for predicting more than a 10-letter change in visual acuity with a sensitivity of 77% and a specificity of 75%. The results were similar for more than 5-letter changes and for 15-letter or more changes. Those with a 20% or more reduction in retinal thickness had a mean 11.0-letter improvement (95% confidence interval, 7.7 to 14.3) as compared with a -0.4-letter change (95% confidence interval, -4.1 to 3.3) in visual acuity for those without a 20% reduction (P < .01). In addition to being above the level of measurement uncertainty, a 20% change in retinal thickness in patients with macular edema seems to be optimal for clinically important changes in visual acuity and may be considered as an outcome for clinical trials of treatments for uveitic macular edema. Copyright © 2011 Elsevier Inc. All rights reserved.

Home use of binocular dichoptic video content device for treatment of amblyopia: a pilot study.

PubMed

Mezad-Koursh, Daphna; Rosenblatt, Amir; Newman, Hadas; Stolovitch, Chaim

2018-04-01

To evaluate the efficacy of the BinoVision home system as measured by improvement of visual acuity in the patient's amblyopic eye. An open-label prospective pilot-trial of the system was conducted with amblyopic children aged 4-8 years at the pediatric ophthalmology unit, Tel-Aviv Medical Center, January 2014 to October 2015. Participants were assigned to the study or sham group for treatment with BinoVision for 8 or 12 weeks. Patients were instructed to watch animated television shows and videos at home using the BinoVision device for 60 minutes, 6 days a week. The BinoVision program incorporates elements at different contrast and brightness levels for both eyes, weak eye tracking training by superimposed screen images, and weak eye flicker stimuli with alerting sound manipulations. Patients were examined at 4, 8, 12, 24, and 36 weeks. A total of 27 children were recruited (14 boys), with 19 in the treatment group. Median age was 5 years (range, 4-8 years). Mean visual acuity improved by 0.26 logMAR lines in the treatment group from baseline to 12 weeks. Visual acuity was improved compared to baseline during all study and follow-up appointments (P < 0.01), with stabilization of visual acuity after cessation of treatment. The sham group completed 4 weeks of sham protocol with no change in visual acuity (P = 0.285). The average compliance rate was 88% ± 16% (50% to 100%) in treatment group. This pilot trial of 12 weeks of amblyopia treatment with the BinoVision home system demonstrated significant improvement in patients' visual acuity. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

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.

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

Use of Corrective Lenses among Adolescents: Findings from the National Health and Nutrition Examination Survey

PubMed Central

Kemper, Alex R.; Gurney, James G.; Eibschitz-Tsimhoni, Maya; DelMonte, Monte A.

2007-01-01

Purpose To evaluate demographic variations in the use of corrective lenses among adolescent children. Methods Cross-sectional analysis of 3,916 children 12-18 years who participated in the 1999-2002 National Health and Nutrition Examination Survey (NHANES) vision examination component, which included: questions regarding use of corrective lenses; distance visual acuity, with corrective lenses if available; and non-cycloplegic autorefraction. Results reflect population-level estimates. Results Overall, 32.2% (95% confidence interval [CI]: 29.5%-35.0%) reported wearing corrective lenses. Girls and those with any private insurance had greater adjusted odds of reporting wearing corrective lenses. In contrast, children aged 15 through 18 years versus those 12 through 14 years, and white children compared to Black or Hispanic children had greater adjusted odds of actually having them available at the time of NHANES participation. Although 12.6% (95% CI: 8.8%-16.3%) of those who did not have their previously prescribed corrective lenses available had 20/25 or better distance visual acuity in both eyes without correction, 26.9% (95% CI:21.6%-32.1%) with their corrective lenses had distance visual acuity of 20/40 or worse in at least one eye when using their corrective lenses. Limitations Near visual acuity was not measured and children with corrective lenses available only had their corrected distance visual acuity measured. No data regarding the accuracy of the NHANES assessment of distance visual acuity are available. Autorefraction was performed without cycloplegia. Conclusions Many adolescent children report wearing corrective lenses. Variations across demographic characteristics appear to be due to a combination of undertreatment, overtreatment, and compliance with previously recommended corrective lenses. PMID:18062494

Evaluation of the effect of erythropoietin + corticosteroid versus corticosteroid alone in methanol-induced optic nerve neuropathy.

PubMed

Zamani, Nasim; Hassanian-Moghaddam, Hossein; Shojaei, Maziar; Rahimian, Sara

2018-06-01

Following methanol intoxication, optic nerve neuropathy may occur, which is currently treated by different therapeutic regimens. Erythropoietin (EPO) has recently been introduced as a good therapeutic option in methanol-induced optic neuropathy. The aim of the current study was to evaluate the efficacy of EPO in improvement of the visual disturbances in methanol-intoxicated patients. In a case-control study, all patients who had referred to our toxicology centre with confirmed diagnosis of methanol toxicity were considered to be included. Of them, those who had referred with visual disturbances, survived, and their visual disturbances had not improved after haemodialysis were entered. Cases received EPO and corticosteroids while controls only received corticosteroids. They were then compared regarding their visual outcome. All five patients in the control group mentioned that after discharge, their visual acuity had improved while in the cases, three mentioned visual improvement, two mentioned their visual acuity had deteriorated after discharge, two mentioned no change in their visual acuity and three mentioned that their visual acuity had first improved but then deteriorated with a mean two-month interval period. In fundoscopic evaluations, two controls had normal fundospcopy while eight cases had abnormal fundoscopy (p = 0.055). Protective effect of EPO on methanol-induced optic nerve may be strong at the beginning of the intervention but is probably transient.

Brief Report: Vision in Children with Autism Spectrum Disorder: What Should Clinicians Expect?

ERIC Educational Resources Information Center

Anketell, Pamela M.; Saunders, Kathryn J.; Gallagher, Stephen M.; Bailey, Clare; Little, Julie-Anne

2015-01-01

Anomalous visual processing has been described in individuals with autism spectrum disorder (ASD) but relatively few studies have profiled visual acuity (VA) in this population. The present study describes presenting VA in children with ASD (n = 113) compared to typically developing controls (n = 206) and best corrected visual acuity (BCVA) in a…

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.

VITRECTOMY FOR MACULAR DISORDERS ASSOCIATED WITH LAMELLAR MACULAR HOLE EPIRETINAL PROLIFERATION.

PubMed

Choi, Won Seok; Merlau, Daniel J; Chang, Stanley

2018-04-01

To compare the surgical outcome of a lamellar macular hole (LMH) depending on lamellar hole-associated epiretinal proliferation (LHEP) and full-thickness macular hole. This is a retrospective chart review. Thirty-three patients were enrolled for this study. The patients were divided into three groups depending on the type of macular hole and presence of LHEP. Group 1 had epiretinal membranes with LMH without LHEP, Group 2 had LMH with LHEP, and Group 3 had full-thickness macular hole with LHEP. The best-corrected visual acuity was recorded and optical coherence tomography scans were obtained. Preoperative best-corrected visual acuity showed no significant difference between groups (P = 0.968). Final visual acuity of Group 1 was better than that of Group 2 (P = 0.009). Group 1 showed less postoperative ellipsoid zone disruption compared with Group 2 (P = 0.010), and the duration of LHEP to surgery had no significant correlation with postoperative visual acuity (P = 0.629). Lamellar macular hole with LHEP showed poorer visual outcomes compared with those with highly reflective epiretinal membranes. Lamellar macular hole with LHEP showed a greater chance of ellipsoid zone disruption. These findings may explain the wide variability of visual outcomes previously reported after vitrectomy for LMH.

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.

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.

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.).

Study of Retinal Nerve Fibre Layer Thickness and Visual Contrast Sensitivity in HIV Positive Individuals.

PubMed

Paul, Rudrajit; Ghosh, Asim K; Nag, Adwaita; Biswas, Shyamapada; Naiya, Britisundar; Mondal, Jayati

2017-06-01

Measurement of Retinal Nerve Fibre Layer Thickness (RNFLT) by Optical Coherence Tomography (OCT) is a sensitive, non invasive and cheap method of detecting early retinal changes in a variety of diseases. In HIV infection, RNFLT is altered and this may have effect on other visual functions like Contrast Sensitivity (CS) and visual acuity. Such ocular pathology can affect the daily life and profession (especially driving) of HIV infected individuals. However, studies on this topic in HIV infected population are rare from India. To study RNFLT, CS and their correlation in a sample of HIV positive Indian population. The present cross-sectional study was done in a tertiary care medical college hospital of Eastern India between May 2016 and September 2016. We did this study on HIV positive subjects with no clinically apparent ocular infection or other pathology. In this study, we have measured the RNFLT using the HRA-OCT Spectralis machine. The CS was tested using a smartphone version of the Pellie-Robson chart. CD4 count, visual acuity and colour vision were also tested. The data was analysed using SPSS version 20.0 for any correlation between these parameters. Pearson coefficient was used for continuous data and Spearman rank correlation was used for categorical data. A p-value <0.05 was considered significant. We had 17 patients, that is 34 eyes. RNFLT loss was found in 21% of the eyes and borderline thinning was found in a further 26%. Predominantly, the temporal quadrant was involved. The mean of log CS was 1.33±0.38. Taking 1.5 as the cut-off value for normalcy, 47% of the eyes tested showed decreased CS. Log CS showed significant correlation with RNFLT of the temporal quadrant only (r=0.37; 95% C.I. 0.041 to 0.631; p=0.02). Temporal RNFLT also showed statistical correlation with the CD4 count. The low CS was also significantly correlated with low visual acuity (r=0.5). In HIV infected persons, subtle ocular changes may occur and this may affect visual functions quite early. Hence, a comprehensive eye check-up should include parameters like CS and OCT.

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.

Outbreak of multidrug-resistant acute postoperative endophthalmitis due to Enterobacter aerogenes.

PubMed

Bhat, Shailaja S; Undrakonda, Vivekanand; Mukhopadhyay, Chiranjay; Parmar, Prachi Vikramsinh

2014-04-01

To report the clinical features, management, and outcome of 7 cases of culture-proven multidrug-resistant Enterobacter postoperative endophthalmitis following cataract surgery. Medical records of 7 cases of acute postoperative endophthalmitis after uneventful cataract surgery were reviewed. Details regarding age, gender, visual acuity and clinical features at presentation, microbiological profile, treatment interventions, and visual acuity and clinical features at 1 week, 1 month, and 3 months follow-up were collected. All patients reported decreased visual acuity and pain as presenting symptoms. All patients were resistant to intravitreal antibiotics such as vancomycin (1 mg/0.1 mL) and ceftazidime (2.25 mg/0.1 mL). Culture of aqueous and vitreous sample was positive for Enterobacter aerogenes and sensitive to co-trimoxazole, cefoperazone-sulbactam, imipenem-meropenem, and piperacillin-tazobactem. Two patients with panophthalmitis and no perception of light underwent evisceration. Three patients had visual acuity of ≥6/24 at the final follow-up. Multidrug-resistant Enterobacter acute postoperative endophthalmitis has a poor prognosis if not intercepted early.

[Importance of family examination in juvenile X-linked retinoschisis].

PubMed

Kłosowska-Zawadka, A; Bernardczyk-Meller, J; Gotz-Wieckowska, A; Krawczyński, M

2005-12-01

Congenital (juvenile) retinoschisis belongs to the group of hereditary vitreoretinopathies. This disorder is inherited in an X-linked recessive pattern and its onset usually occurs in 5- to 10-year-old boys. Presenting clinical signs include decreased visual acuity due to maculopathy. The authors present a case of a 17-year-old boy with decreased visual acuity, hypermetropia, and bilateral retinoschisis with maculopathy upon fundus examination. In view of a 50% risk of the disorder occurring in the brothers of the affected male, they underwent full ophthalmological and electrophysiological examinations (until then asymptomatic). In one of them decreased visual acuity, mixed astigmatism, and maculopathy were present, without any changes of the peripheral retina. In the youngest brother decreased visual acuity, hypermetropia, and maculopathy were diagnosed. Genetic counseling and ophthalmological examination of family members at risk facilitated early recognition of the pathological changes in the siblings. Genetic counseling with pedigree analysis and genetic analysis, if possible, should be offered to all affected patients and family members.

Visual development of human milk-fed preterm infants provided with extra energy and nutrients after hospital discharge.

PubMed

O'Connor, Deborah L; Weishuhn, Karen; Rovet, Joanne; Mirabella, Giuseppe; Jefferies, Ann; Campbell, Douglas M; Asztalos, Elizabeth; Feldman, Mark; Whyte, Hilary; Westall, Carol

2012-05-01

Human milk (HM) is the optimal way to nourish preterm low birth weight (LBW) infants after hospital discharge. However, there are few data on which to assess whether HM alone is sufficient to address hospital-acquired nutrition deficits, and no adequately powered studies have examined this question using neurodevelopment as an outcome. The purpose of this work was to determine whether adding extra energy and nutrients to the feedings of predominantly HM-fed LBW infants early after discharge improves their visual development. Visual development was used in this study as a surrogate marker for neurodevelopment. At discharge, 39 predominantly HM-fed LBW infants (750-1800 g, 1288 ± 288 g) were randomized to receive human milk alone (control) or around half of the HM received daily mixed with a multinutrient fortifier (intervention) for 12 weeks. Grating acuity (ie, visual acuity) and contrast sensitivity were assessed using sweep visual-evoked potential tests at 4 and 6 months corrected age. At 4 and 6 months corrected age, intervention infants demonstrated higher grating acuity compared to those in the control group (intervention: 7.8 ± 1.3 and 9.7 ± 1.2 [cycles/degree] vs control 6.9 ± 1.2 and 8.2 ± 1.3, P = .02). Differences in contrast sensitivity did not reach statistical significance (P = .11). Adding a multinutrient fortifier to a portion of the expressed breast milk provided to predominantly HM-fed LBW infants early after discharge improves their early visual development. Whether these subtle differences in visual development apply to other aspects of development or longer term neurodevelopment are worthy of future investigation.

[Features associated with retinal thickness extension in diabetic macular oedema].

PubMed

Razo Blanco-Hernández, Dulce Milagros; Lima-Gómez, Virgilio; García-Rubio, Yatzul Zuhaila

2015-01-01

Clinically significant macular edema has features that are associated with a major risk of visual loss, with thickening that involves the centre of the macula, field 7 or visual deficiency, although it is unknown if these features are related to retinal thickness extension. An observational, analytical, prospective, cross-sectional and open study was conducted. The sample was divided into initial visual acuity ≥0.5, central field thickness, center point thickness, field 7 and macular volume more than the reported 2 standard deviation mean value in eyes without retinopathy. The extension was determined by the number of the central field area equivalent thickening and these features were compared with by Student's t test for independent samples. A total of 199 eyes were included. In eyes with visual acuity of ≥0.5, the mean extension was 2.88±1.68 and 3.2±1.63 in area equivalent in eyes with visual acuity <0.5 (p=0.12). The mean extension in eyes with less than 2 standard deviation of central field thickness, center point thickness, field 7 and macular volume was significantly lower than in eyes with more than 2 standard deviations (1.9±0.93 vs. 4.07±1.49, 2.44±1.47 vs. 3.94±1.52, 1.79±1.07 vs. 3.61±1.57 and 1.6±0.9 vs. 3.9±1.4, respectively, p<0.001). The extension of retinal thickness is related with the anatomical features reported with a greater risk of visual loss, but is not related to initial visual deficiency. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

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.

Photographic Assessment of Baseline Fundus Morphology in the Comparison of Age-related Macular Degeneration Treatments Trials

PubMed Central

Grunwald, Juan E.; Daniel, Ebenezer; Ying, Gui-shuang; Pistilli, Maxwell; Maguire, Maureen G.; Alexander, Judith; Whittock-Martin, Revell; Parker, Candace R.; Sepielli, Krista; Blodi, Barbara A.; Martin, Daniel F.

2012-01-01

Objective To describe the methods used for assessment of baseline fundus characteristics from color photography and fluorescein angiography (FA) in the Comparison of the Age-Related Macular Degeneration Treatments Trials (CATT), and the relationship between these characteristics and visual acuity. Design Randomized, masked, multicenter trial. Participants This investigation included 1185 participants of the CATT study. Methods Baseline stereoscopic color fundus photographs and FAs of participants in the CATT study were assessed at a central fundus photograph reading center by masked readers. Replicate assessments of random samples of photographs were performed to assess intra- and inter-grader agreements. The association of the lesion characteristics with baseline visual acuity was assessed using analyses of variance and correlation coefficients. Main Outcome Measures Intra- and inter-grader reproducibility, visual acuity and lesion characteristics. Results Intra- and inter-grader reproducibility showed agreements ranging from 75% to 100% and weighted kappas ranging from 0.48 to 1.0 for qualitative determinations. The intra-class correlation coefficients were 0.96-0.97 for quantitative measurements of choroidal neovascularization (CNV) area and total area of CNV lesion. The mean visual acuity (SE) varied by the type of pathology in the foveal center: 64.5 (0.7) letters for fluid only, 59.0 (0.5) for CNV, and 58.7 (1.3) for hemorrhage (p<0.001). Fibrotic or atrophic scar present in the lesion, but not under the center of the fovea, was also associated with a markedly reduced visual acuity 48.4 (2.2), p<0.0001. Although total area of CNV lesion was weakly correlated with visual acuity when all participants were assessed (Spearman correlation coefficient ρ= −0.16, p<0.001), the correlation was stronger within patients with predominantly classic lesions (ρ=−0.42, p<0.001). Conclusions Our results show that the methodology used for grading CATT fundus images has good reproducibility. As expected, larger total CNV lesion area, and pathologic findings such as hemorrhage, fibrosis and atrophy at baseline are associated with decreased visual acuity. Financial Disclosures The authors have no proprietary or commercial interests in any materials discussed in this article. PMID:22512984

Functional vision in children with perinatal brain damage.

PubMed

Alimović, Sonja; Jurić, Nikolina; Bošnjak, Vlatka Mejaški

2014-09-01

Many authors have discussed the effects of visual stimulations on visual functions, but there is no research about the effects on using vision in everyday activities (i.e. functional vision). Children with perinatal brain damage can develop cerebral visual impairment with preserved visual functions (e.g. visual acuity, contrast sensitivity) but poor functional vision. Our aim was to discuss the importance of assessing and stimulating functional vision in children with perinatal brain damage. We assessed visual functions (grating visual acuity, contrast sensitivity) and functional vision (the ability of maintaining visual attention and using vision in communication) in 99 children with perinatal brain damage and visual impairment. All children were assessed before and after the visual stimulation program. Our first assessment results showed that children with perinatal brain damage had significantly more problems in functional vision than in basic visual functions. During the visual stimulation program both variables of functional vision and contrast sensitivity improved significantly, while grating acuity improved only in 2.7% of children. We also found that improvement of visual attention significantly correlated to improvement on all other functions describing vision. Therefore, functional vision assessment, especially assessment of visual attention is indispensable in early monitoring of child with perinatal brain damage.

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.

Osteo-odonto-keratoprosthesis in Japan.

PubMed

Fukuda, Masahiko; Hamada, Suguru; Liu, Christopher; Shimomura, Yoshikazu

2008-09-01

Osteo-odonto-keratoprosthesis (OOKP) is a keratoprosthesis technique in which the patient's own tooth root is used to support an optical cylinder. It was invented by Strampelli in 1963 and modified and established by Falcinelli about 10 years later. This method is particularly useful for restoring sight in end-stage Stevens-Johnson syndrome (SJS) and ocular cicatricial pemphigoid (OCP). We started performing OOKP surgery in June 2003 supported by Dr Christopher Liu of Sussex Eye Hospital, Brighton, UK. Till now, we have performed 4 OOKP surgeries for end-stage SJS and OCP. We modified the original method by using artificial buccal mucous membranes to the bone and buccal mucous membrane defects for better wound healing. Case 1 was a 49-year-old woman (SJS), and the corrected visual acuity was 0.5 in 4 years 8 months. Case 2 was a 68-year-old woman (SJS), and the corrected visual acuity was 0.04 in 3 years 10 months. Case 3 was a 63-year-old man (SJS), and the corrected visual acuity was 0.1 in 3 years 2 months. Case 4 was a 71-year-old woman (OCP), and the corrected visual acuity was 0.04 in 1 year 3 months. Despite some minor optical cylinder troubles such as MRSA colonization, tilting, and buccal mucous coverage, their visual acuities were stable without any serious complications. It was demonstrated that OOKP is useful for visual rehabilitation and durable with minimum eye care for severe ocular surface diseases.

Amblyopia and binocular vision.

PubMed

Birch, Eileen E

2013-03-01

Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

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.

[Amblyopia and uveitis in childhood].

PubMed

Eckstein, A; Robering, A; Rudolph, G; Esser, J

2007-06-01

Manifestations of uveitis in the sensitive period of childhood can cause amblyopia. In most of the cases band keratopathy, dense cataracts and cyclitic membranes cause deprivation amblyopia. Asymmetrical damage can result in relative amblyopia. Secondary squint can lead to suppression amblyopia. For these reasons every visit during uveitis treatment should be accompanied by a search for amblyogenic factors and visual acuity measurements. In the case of a side difference in the visual acuity, occlusion therapy should be started. The follow-up should not only contain visual acuity measurements but also cycloplegic refraction. Especially when pupil-dilating drugs are necessary for a longer period, bifocals should be prescribed.

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.

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.

Aflibercept, bevacizumab, or ranibizumab for diabetic macular edema.

PubMed

Wells, John A; Glassman, Adam R; Ayala, Allison R; Jampol, Lee M; Aiello, Lloyd Paul; Antoszyk, Andrew N; Arnold-Bush, Bambi; Baker, Carl W; Bressler, Neil M; Browning, David J; Elman, Michael J; Ferris, Frederick L; Friedman, Scott M; Melia, Michele; Pieramici, Dante J; Sun, Jennifer K; Beck, Roy W

2015-03-26

The relative efficacy and safety of intravitreous aflibercept, bevacizumab, and ranibizumab in the treatment of diabetic macular edema are unknown. At 89 clinical sites, we randomly assigned 660 adults (mean age, 61±10 years) with diabetic macular edema involving the macular center to receive intravitreous aflibercept at a dose of 2.0 mg (224 participants), bevacizumab at a dose of 1.25 mg (218 participants), or ranibizumab at a dose of 0.3 mg (218 participants). The study drugs were administered as often as every 4 weeks, according to a protocol-specified algorithm. The primary outcome was the mean change in visual acuity at 1 year. From baseline to 1 year, the mean visual-acuity letter score (range, 0 to 100, with higher scores indicating better visual acuity; a score of 85 is approximately 20/20) improved by 13.3 with aflibercept, by 9.7 with bevacizumab, and by 11.2 with ranibizumab. Although the improvement was greater with aflibercept than with the other two drugs (P<0.001 for aflibercept vs. bevacizumab and P=0.03 for aflibercept vs. ranibizumab), it was not clinically meaningful, because the difference was driven by the eyes with worse visual acuity at baseline (P<0.001 for interaction). When the initial visual-acuity letter score was 78 to 69 (equivalent to approximately 20/32 to 20/40) (51% of participants), the mean improvement was 8.0 with aflibercept, 7.5 with bevacizumab, and 8.3 with ranibizumab (P>0.50 for each pairwise comparison). When the initial letter score was less than 69 (approximately 20/50 or worse), the mean improvement was 18.9 with aflibercept, 11.8 with bevacizumab, and 14.2 with ranibizumab (P<0.001 for aflibercept vs. bevacizumab, P=0.003 for aflibercept vs. ranibizumab, and P=0.21 for ranibizumab vs. bevacizumab). There were no significant differences among the study groups in the rates of serious adverse events (P=0.40), hospitalization (P=0.51), death (P=0.72), or major cardiovascular events (P=0.56). Intravitreous aflibercept, bevacizumab, or ranibizumab improved vision in eyes with center-involved diabetic macular edema, but the relative effect depended on baseline visual acuity. When the initial visual-acuity loss was mild, there were no apparent differences, on average, among study groups. At worse levels of initial visual acuity, aflibercept was more effective at improving vision. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01627249.).

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 tuned to higher spatial frequencies than the ipsilateral pathway. At the highest spatial frequencies, the contralateral pathway strongly prefers to respond to visual stimuli along the cardinal (horizontal and vertical) axes. These results suggest that monocular, and not binocular, mechanisms set the limit of spatial acuity in mice. Furthermore, they suggest that the development of visual acuity and binocularity in mice involves different circuits. PMID:28924011

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.

Cumulative sum analysis score and phacoemulsification competency learning curve.

PubMed

Vedana, Gustavo; Cardoso, Filipe G; Marcon, Alexandre S; Araújo, Licio E K; Zanon, Matheus; Birriel, Daniella C; Watte, Guilherme; Jun, Albert S

2017-01-01

To use the cumulative sum analysis score (CUSUM) to construct objectively the learning curve of phacoemulsification competency. Three second-year residents and an experienced consultant were monitored for a series of 70 phacoemulsification cases each and had their series analysed by CUSUM regarding posterior capsule rupture (PCR) and best-corrected visual acuity. The acceptable rate for PCR was <5% (lower limit h) and the unacceptable rate was >10% (upper limit h). The acceptable rate for best-corrected visual acuity worse than 20/40 was <10% (lower limit h) and the unacceptable rate was >20% (upper limit h). The area between lower limit h and upper limit h is called the decision interval. There was no statistically significant difference in the mean age, sex or cataract grades between groups. The first trainee achieved PCR CUSUM competency at his 22 nd case. His best-corrected visual acuity CUSUM was in the decision interval from his third case and stayed there until the end, never reaching competency. The second trainee achieved PCR CUSUM competency at his 39 th case. He could reach best-corrected visual acuity CUSUM competency at his 22 nd case. The third trainee achieved PCR CUSUM competency at his 41 st case. He reached best-corrected visual acuity CUSUM competency at his 14 th case. The learning curve of competency in phacoemulsification is constructed by CUSUM and in average took 38 cases for each trainee to achieve it.

EFFECT OF INTERNAL LIMITING MEMBRANE PEELING DURING VITRECTOMY FOR DIABETIC MACULAR EDEMA: Systematic Review and Meta-analysis.

PubMed

Nakajima, Takuya; Roggia, Murilo F; Noda, Yasuo; Ueta, Takashi

2015-09-01

To evaluate the effect of internal limiting membrane (ILM) peeling during vitrectomy for diabetic macular edema. MEDLINE, EMBASE, and CENTRAL were systematically reviewed. Eligible studies included randomized or nonrandomized studies that compared surgical outcomes of vitrectomy with or without ILM peeling for diabetic macular edema. The primary and secondary outcome measures were postoperative best-corrected visual acuity and central macular thickness. Meta-analysis on mean differences between vitrectomy with and without ILM peeling was performed using inverse variance method in random effects. Five studies (7 articles) with 741 patients were eligible for analysis. Superiority (95% confidence interval) in postoperative best-corrected visual acuity in ILM peeling group compared with nonpeeling group was 0.04 (-0.05 to 0.13) logMAR (equivalent to 2.0 ETDRS letters, P = 0.37), and superiority in best-corrected visual acuity change in ILM peeling group was 0.04 (-0.02 to 0.09) logMAR (equivalent to 2.0 ETDRS letters, P = 0.16). There was no significant difference in postoperative central macular thickness and central macular thickness reduction between the two groups. The visual acuity outcomes using pars plana vitrectomy with ILM peeling versus no ILM peeling were not significantly different. A larger randomized prospective study would be necessary to adequately address the effectiveness of ILM peeling on visual acuity outcomes.

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

Femtosecond-LASIK outcomes using the VisuMax®-MEL® 80 platform for mixed astigmatism refractive surgery.

PubMed

Stanca, Horia Tudor; Munteanu, Mihnea; Jianu, Dragoş Cătălin; Motoc, Andrei Gheorghe Marius; Jecan, Cristian Radu; Tăbăcaru, Bogdana; Stanca, Simona; Preda, Maria Alexandra

2018-01-01

To evaluate the predictability, efficacy and safety of Femtosecond-laser-assisted in situ keratomileusis (LASIK) procedure for mixed astigmatism. We prospectively evaluated for 12 months 74 eyes (52 patients) with mixed astigmatism that underwent Femtosecond-LASIK treatment. The preoperative mean refractive sphere value was +1.879±1.313 diopters (D) and the mean refractive cylinder value was -4.169±1.091 D. The anterior corneal flap was cut using the VisuMax® femtosecond laser and then the stromal ablation was done using the MEL® 80 excimer laser. Mean age was 30.22±6.421 years with 61.53% female patients. Postoperative spherical equivalent at 12 months was within ±0.5D of emmetropia in 75.8% of eyes and within ±1D in 97.3% of eyes. Postoperative uncorrected distance visual acuity was equivalent to or better than the preoperative corrected distance visual acuity in 91.9% of eyes. Compared to the preoperative corrected distance visual acuity (CDVA), 8.1% of eyes gained one line, 2.7% gained two lines and 2.7% gained three lines of visual acuity. Femtosecond-LASIK using the VisuMax®-MEL® 80 platform appears to have safe, effective and predictable results in mixed astigmatic eyes. The results are impressive for high refractive error treatment and for improvement of both uncorrected and corrected distance visual acuity.

20 CFR 404.1581 - Meaning of blindness as defined in the law.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Statutory blindness is defined in the law as central visual acuity of 20/200 or less in the better eye with... diameter of the visual field subtends an angle no greater than 20 degrees is considered to have a central visual acuity of 20/200 or less. Your blindness must meet the duration requirement in § 404.1509. We do...

Retinal Image Quality During Accommodation

PubMed Central

López-Gil, N.; Martin, J.; Liu, T.; Bradley, A.; Díaz-Muñoz, D.; Thibos, L.

2013-01-01

Purpose We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Methods Subjects viewed a monochromatic (552nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Results Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Conclusions Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye’s higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced visual function may be a useful sign for diagnosing functionally-significant accommodative errors indicating the need for therapeutic intervention. PMID:23786386

Retinal image quality during accommodation.

PubMed

López-Gil, Norberto; Martin, Jesson; Liu, Tao; Bradley, Arthur; Díaz-Muñoz, David; Thibos, Larry N

2013-07-01

We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Subjects viewed a monochromatic (552 nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye's higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced visual function may be a useful sign for diagnosing functionally-significant accommodative errors indicating the need for therapeutic intervention. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

Clinical outcomes and surgeon assessment after implantation of a new diffractive multifocal toric intraocular lens.

PubMed

Kretz, Florian T A; Bastelica, Antoine; Carreras, Humberto; Ferreira, Tiago; Müller, Matthias; Gerl, Matthias; Gerl, Ralf; Saeed, Manzar; Schmickler, Stefanie; Auffarth, Gerd U

2015-03-01

To evaluate the clinical outcome in eyes with significant corneal astigmatism after cataract surgery with implantation of a new diffractive multifocal toric intraocular lens (IOL). Prospective, non-randomised multicentre clinical study including 57 eyes of 38 consecutive patients with an age between 37 and 84 years that underwent cataract surgery with implantation of the toric multifocal IOL Tecnis ZMT (Abbott Medical Optics, Santa Ana, California, USA). Changes in uncorrected and corrected logMAR distance, intermediate and near visual acuity ((uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA) uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), corrected near visual acuity) and manifest refraction were evaluated during a 2-4 month follow-up. Additionally, patients were asked about photic phenomena and spectacle dependence. The surgeons subjectively assessed various aspects of the surgery. A significant improvement in CDVA was observed postoperatively (p<0.01), with a significant reduction in manifest cylinder (p<0.01). Mean postoperative binocular UDVA and UNVA were 0.04±0.10 and 0.06±0.12, respectively. Monocular UDVA and UNVA was 0.20 or better in 85.4% and 87.0% of eyes, respectively. Mean binocular logMAR UIVA was 0.21±0.20. Only 10.5% of patients required postoperative correction for near or intermediate distance. The incidence of moderate to severe photic phenomena was limited. Surgeons defined the IOL implantation in most cases as easy or very easy, with a satisfaction rate with the procedure of 84%. The implantation of the multifocal toric IOL is a safe procedure that provides a very good visual rehabilitation in eyes with corneal astigmatism. 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.

Vitrectomy for the diagnosis and management of uveitis of unknown cause.

PubMed

Margolis, Ron; Brasil, Oswaldo F M; Lowder, Careen Y; Singh, Rishi P; Kaiser, Peter K; Smith, Scott D; Perez, Victor L; Sonnie, Christine; Sears, Jonathan E

2007-10-01

To determine the diagnostic yield of tests commonly used for vitreous fluid analysis in eyes with suspected intraocular infection or malignancy. Noncomparative interventional case series. Forty-four consecutive patients (45 eyes) treated from 1998 through 2006 with posterior segment inflammation who underwent pars plana vitrectomy for diagnostic purposes. Vitreous specimens obtained via pars plana vitrectomy were analyzed by microbiologic culture, cytologic analysis, and flow cytometry. Diagnostic yield and sensitivity of each test performed on vitreous specimens and visual outcomes of eyes that underwent diagnostic vitrectomy (DVx). Preoperative diagnoses were infection in 15 eyes and malignancy in 30 eyes. Overall, vitreous analysis identified a specific cause in 9 (20%) of 45 eyes. The overall sensitivity of DVx was 63.6%. The sensitivities of individual tests were: culture, 50%; cytologic analysis, 66.7%; and flow cytometry, 83.3%. The yields of diagnostic tests were: culture, 5.7%; cytologic analysis, 14.3%; and flow cytometry, 20.6%. Final diagnoses were infection in 6 eyes, malignancy in 9 eyes, and idiopathic in 30 eyes. Mean visual acuity improved significantly in the first 6 months after DVx. Visual acuity improved in 60% of eyes, with 37.8% of eyes improving by 3 lines or more. Analysis of vitreous fluid by widely available tests is useful in identifying intraocular infection or malignancy. Most patients experienced a substantial improvement in vision.

Hearing loss is negatively related to episodic and semantic long-term memory but not to short-term memory.

PubMed

Rönnberg, Jerker; Danielsson, Henrik; Rudner, Mary; Arlinger, Stig; Sternäng, Ola; Wahlin, Ake; Nilsson, Lars-Göran

2011-04-01

To test the relationship between degree of hearing loss and different memory systems in hearing aid users. Structural equation modeling (SEM) was used to study the relationship between auditory and visual acuity and different cognitive and memory functions in an age-hetereogenous subsample of 160 hearing aid users without dementia, drawn from the Swedish prospective cohort aging study known as Betula (L.-G. Nilsson et al., 1997). Hearing loss was selectively and negatively related to episodic and semantic long-term memory (LTM) but not short-term memory (STM) performance. This held true for both ears, even when age was accounted for. Visual acuity alone, or in combination with auditory acuity, did not contribute to any acceptable SEM solution. The overall relationships between hearing loss and memory systems were predicted by the ease of language understanding model (J. Rönnberg, 2003), but the exact mechanisms of episodic memory decline in hearing aid users (i.e., mismatch/disuse, attentional resources, or information degradation) remain open for further experiments. The hearing aid industry should strive to design signal processing algorithms that are cognition friendly.

Virtual reality method to analyze visual recognition in mice.

PubMed

Young, Brent Kevin; Brennan, Jayden Nicole; Wang, Ping; Tian, Ning

2018-01-01

Behavioral tests have been extensively used to measure the visual function of mice. To determine how precisely mice perceive certain visual cues, it is necessary to have a quantifiable measurement of their behavioral responses. Recently, virtual reality tests have been utilized for a variety of purposes, from analyzing hippocampal cell functionality to identifying visual acuity. Despite the widespread use of these tests, the training requirement for the recognition of a variety of different visual targets, and the performance of the behavioral tests has not been thoroughly characterized. We have developed a virtual reality behavior testing approach that can essay a variety of different aspects of visual perception, including color/luminance and motion detection. When tested for the ability to detect a color/luminance target or a moving target, mice were able to discern the designated target after 9 days of continuous training. However, the quality of their performance is significantly affected by the complexity of the visual target, and their ability to navigate on a spherical treadmill. Importantly, mice retained memory of their visual recognition for at least three weeks after the end of their behavioral training.

Vision, Training Hours, and Road Testing Results in Bioptic Drivers

PubMed Central

Dougherty, Bradley E.; Flom, Roanne E.; Bullimore, Mark A.; Raasch, Thomas W.

2015-01-01

Purpose Bioptic telescopic spectacles (BTS) can be used by people with central visual acuity that does not meet the state standards to obtain an unrestricted driver’s license. The purpose of this study was to examine the relationships among visual and demographic factors, training hours, and the results of road testing for bioptic drivers. Methods A retrospective study of patients who received an initial daylight bioptic examination at the Ohio State University and subsequently received a bioptic license was conducted. Data were collected on vision including visual acuity, contrast sensitivity, and visual field. Hours of driver training and results of Highway Patrol road testing were extracted from records. Relationships among vision, training hours, and road testing were analyzed. Results Ninety-seven patients who completed a vision examination between 2004 and 2008 and received daylight licensure with BTS were included. Results of the first Highway Patrol road test were available for 74 patients. The median interquartile range (IQR) hours of training prior to road testing was 21±17 hours, (range of 9 to 75 hours). Candidates without previous licensure were younger (p< 0.001) and had more documented training (p< 0.001). Lack of previous licensure and more training were significantly associated with having failed a portion of the Highway Patrol test and points deducted on the road test. Conclusions New bioptic drivers without previous non-bioptic driving experience required more training and performed more poorly on road testing for licensure than those who had previous non-bioptic licensure. No visual factor was predictive of road testing results after adjustment for previous experience. The hours of training received remained predictive of road testing outcome even with adjustment for previous experience. These results suggest that previous experience and trainer assessments should be investigated as potential predictors of road safety in bioptic drivers in future studies. PMID:25946098

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.

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.

Time to first treatment: The significance of early treatment of exudative age-related macular degeneration.

PubMed

Rauch, Renate; Weingessel, Birgit; Maca, Saskia M; Vecsei-Marlovits, Pia V

2012-07-01

To determine whether the time span between initial symptoms and treatment with ranibizumab in patients with neovascular age-related macular degeneration has an effect on visual outcome. In this retrospective study, 45 patients with exudative age-related macular degeneration were split into 3 groups depending on the duration of visual symptoms--Group I: <1 month, Group II: 1 month to 6 months, and Group III: >6 months. Best-corrected visual acuity, clinical ophthalmologic examination, and central retinal thickness as measured by optical coherence tomography were recorded at baseline and 2 months later. Fluorescein angiography was performed at baseline. Treatment consisted of 2 intravitreal injections of 1.25 mg of ranibizumab at baseline and after 4 weeks. The mean time span between initial symptoms and treatment was 59 ± 62 days. In all groups, a reduction of retinal thickness was observed. Shorter disease duration, as estimated by persistence of visual symptoms, was correlated with a better visual outcome after treatment. Patients in Group I demonstrated a significant increase in best-corrected visual acuity (P = 0.007). Patients of Group II (P = 0.095) and Group III (P = 0.271) still achieved a visual improvement in best-corrected visual acuity, albeit not significant. The mean change in best-corrected visual acuity was 0.08 ± 0.1 in all patients and was not statistically significant between groups (P = 0.87). Duration of visual symptoms <1 month before treatment is associated with a better visual outcome. Treatment of new-onset wet age-related macular degeneration should be initiated as soon as possible.

Vision Test in Seconds

NASA Technical Reports Server (NTRS)

1976-01-01

Acuity Systems, Inc. developed an electro-optical instrument under a grant from NASA to measure the visual performance of pilots. Transferred from Ames Research Center, this instrument now allows you to have your eyes tested in seconds by relatively unskilled operators. The device automatically measures refractive error of eye and prints out proper prescription for glasses. The unit also detects cataracts and glaucoma.

Optical Radiation: Susceptibility and Countermeasures

DTIC Science & Technology

1998-12-01

1995). "Early Visual Acuity Side Effects After Laser Retinal Photocoagulation in Diabetic Retinopathy ," W.D. Kosnik, L. Marouf, and M. Myers...tests. The automatic positioner (AMPS) coupled with the automatic optical test system (PEATS) permits timely and consistent evaluation of candidate...Science and Engineering OR:S&C Optical Radiation: Susceptibility and Countermeasures OSADS Optical Signature, Acquisition, and Detection System

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.

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

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.

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.

The Mark 3 Haploscope

NASA Technical Reports Server (NTRS)

Decker, T. A.; Williams, R. E.; Kuether, C. L.; Logar, N. D.; Wyman-Cornsweet, D.

1975-01-01

A computer-operated binocular vision testing device was developed as one part of a system designed for NASA to evaluate the visual function of astronauts during spaceflight. This particular device, called the Mark 3 Haploscope, employs semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phoria, fixation disparity, refractive state and accommodation/convergence relationships. Test procedures are self-administered and can be used repeatedly without subject memorization. The Haploscope was designed as one module of the complete NASA Vision Testing System. However, it is capable of stand-alone operation. Moreover, the compactness and portability of the Haploscope make possible its use in a broad variety of testing environments.

Multiparameter vision testing apparatus

NASA Technical Reports Server (NTRS)

Hunt, S. R., Jr.; Homkes, R. J.; Poteate, W. B.; Sturgis, A. C. (Inventor)

1975-01-01

Compact vision testing apparatus is described for testing a large number of physiological characteristics of the eyes and visual system of a human subject. The head of the subject is inserted into a viewing port at one end of a light-tight housing containing various optical assemblies. Visual acuity and other refractive characteristics and ocular muscle balance characteristics of the eyes of the subject are tested by means of a retractable phoroptor assembly carried near the viewing port and a film cassette unit carried in the rearward portion of the housing (the latter selectively providing a variety of different visual targets which are viewed through the optical system of the phoroptor assembly). The visual dark adaptation characteristics and absolute brightness threshold of the subject are tested by means of a projector assembly which selectively projects one or both of a variable intensity fixation target and a variable intensity adaptation test field onto a viewing screen located near the top of the housing.

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

Clinical Outcomes of an Optimized Prolate Ablation Procedure for Correcting Residual Refractive Errors Following Laser Surgery.

PubMed

Chung, Byunghoon; Lee, Hun; Choi, Bong Joon; Seo, Kyung Ryul; Kim, Eung Kwon; Kim, Dae Yune; Kim, Tae-Im

2017-02-01

The purpose of this study was to investigate the clinical efficacy of an optimized prolate ablation procedure for correcting residual refractive errors following laser surgery. We analyzed 24 eyes of 15 patients who underwent an optimized prolate ablation procedure for the correction of residual refractive errors following laser in situ keratomileusis, laser-assisted subepithelial keratectomy, or photorefractive keratectomy surgeries. Preoperative ophthalmic examinations were performed, and uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction values (sphere, cylinder, and spherical equivalent), point spread function, modulation transfer function, corneal asphericity (Q value), ocular aberrations, and corneal haze measurements were obtained postoperatively at 1, 3, and 6 months. Uncorrected distance visual acuity improved and refractive errors decreased significantly at 1, 3, and 6 months postoperatively. Total coma aberration increased at 3 and 6 months postoperatively, while changes in all other aberrations were not statistically significant. Similarly, no significant changes in point spread function were detected, but modulation transfer function increased significantly at the postoperative time points measured. The optimized prolate ablation procedure was effective in terms of improving visual acuity and objective visual performance for the correction of persistent refractive errors following laser surgery.

Refractive errors and binocular dysfunctions in a population of university students.

PubMed

Risovic, D J; Misailovic, K R; Eric-Marinkovic, J M; Kosanovic-Jakovic, N G; Milenkovic, S M; Petrovic, L Z

2008-01-01

This clinical study was performed to determine the presence of refractive errors and binocular dysfunctions in a population of university students. Refraction and binocular function were evaluated in a young patient population (230 students and 234 nonstudent subjects, aged 18-27 years). Distance visual acuity (DVA) and near visual acuity (NVA), refraction, cover test (CT), ocular motility, near-point of convergence, horizontal phoria measurement by Maddox wing, negative and positive vergence amplitude in prism diopters, fusion amplitude in synoptophore, as well as stereoacuity (Titmus test) were tested. Emmetropia was the most frequent refractive status in our student and nonstudent groups (78.7%). Myopia was the most frequent refractive disorder in the whole population (13.1%). Myopia and hypermetropia were significantly more frequent in the students than in nonstudents (chi-square emp 47.55). Exophoria is significantly more frequent in myopic subjects. Vergence amplitude (t test 0.000) and fusion amplitude (t test 0.005) show significantly lower values in student population. Results of Titmus test in the student group is significantly worse than in the nonstudent group (t test 0.000). Maddox wing resulted in significantly higher degree of heterophoria in the student population (t test 0.000). Myopic subjects, in the student group (t test 0.002) as well as in the nonstudent group (t test 0.001), show significantly better results in Titmus test. High near visual demand could be the most important factor for higher incidence of myopia, worse convergence and fusion amplitude, higher degree of exophoria, and worse results in Titmus test in the student population.

Identifying at-risk drivers : a survey of state programs : final report.

DOT National Transportation Integrated Search

1990-01-01

Motor vehicle administrators have long realized that certain drivers present more of safety problem than others. Tests of static visual acuity, knowledge of the rules of the road, and on-the-road driving performance are used to ensure that each drive...

Power profiles and short-term visual performance of soft contact lenses.

PubMed

Papas, Eric; Dahms, Anne; Carnt, Nicole; Tahhan, Nina; Ehrmann, Klaus

2009-04-01

To investigate the manner in which contemporary soft contact lenses differ in the distribution of optical power within their optic zones and establish if these variations affect the vision of wearers or the prescribing procedure for back vertex power (BVP). By using a Visionix VC 2001 contact lens power analyzer, power profiles were measured across the optic zones of the following contemporary contact lenses ACUVUE 2, ACUVUE ADVANCE, O2OPTIX, NIGHT & DAY and PureVision. Single BVP measures were obtained using a Nikon projection lensometer. Visual performance was assessed in 28 masked subjects who wore each lens type in random order. Measurements taken were high and low contrast visual acuity in normal illumination (250 Cd/m), high contrast acuity in reduced illumination (5 Cd/m), subjective visual quality using a numerical rating scale, and visual satisfaction rating using a Likert scale. Marked differences in the distribution of optical power across the optic zone were evident among the lens types. No significant differences were found for any of the visual performance variables (p > 0.05, analysis of variance with repeated measures and Friedman test). Variations in power profile between contemporary soft lens types exist but do not, in general, result in measurable visual performance differences in the short term, nor do they substantially influence the BVP required for optimal correction.