Visual loss after spine surgery: a population-based study.

PubMed

Patil, Chirag G; Lad, Eleonora M; Lad, Shivanand P; Ho, Chris; Boakye, Maxwell

2008-06-01

Retrospective cohort study using National inpatient sample administrative data. To determine national estimates of visual impairment and ischemic optic neuropathy after spine surgery. Loss of vision after spine surgery is rare but has devastating complications that has gained increasing recognition in the recent literature. National population-based studies of visual complications after spine surgery are lacking. All patients from 1993 to 2002 who underwent spine surgery (Clinical Classifications software procedure code: 3, 158) and who had ischemic optic neuropathy (ION) (ICD9-CM code 377.41), central retinal artery occlusion (CRAO) (ICD9-CM code 362.31) or non-ION, non-CRAO perioperative visual impairment (ICD9-CM codes: 369, 368.4, 368.8-9368.11-13) were included. Univariate and multivariate analysis were performed to identify potential risk factors. The overall incidence of visual disturbance after spine surgery was 0.094%. Spine surgery for scoliosis correction and posterior lumbar fusion had the highest rates of postoperative visual loss of 0.28% and 0.14% respectively. Pediatric patients (<18 years) were 5.8 times and elderly patients (>84 years) were 3.2 times more likely than, patients 18 to 44 years of age to develop non-ION, non-CRAO visual loss after spine surgery. Patients with peripheral vascular disease (OR = 2.0), hypertension (OR = 1.3), and those who received blood transfusion (OR = 2.2) were more likely to develop non-ION, non-CRAO vision loss after spine surgery. Ischemic optic neuropathy was present in 0.006% of patients. Hypotension (OR = 10.1), peripheral vascular disease (OR = 6.3) and anemia (OR = 5.9) were the strongest risk factors identified for the development of ION. We used multivariate analysis to identify significant risk factors for visual loss after spine surgery. National population-based estimate of visual impairment after spine surgery confirms that ophthalmic complications after spine surgery are rare. Since visual loss may be reversible in the early stages, awareness, evaluation and prompt management of this rare but potentially devastating complication is critical.

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

Long-term visual outcomes of craniopharyngioma in children.

PubMed

Wan, Michael J; Zapotocky, Michal; Bouffet, Eric; Bartels, Ute; Kulkarni, Abhaya V; Drake, James M

2018-05-01

Visual function is a critical factor in the diagnosis, monitoring, and prognosis of craniopharyngiomas in children. The aim of this study was to report the long-term visual outcomes in a cohort of pediatric patients with craniopharyngioma. The study design is a retrospective chart review of craniopharyngioma patients from a single tertiary-care pediatric hospital. 59 patients were included in the study. Mean age at presentation was 9.4 years old (range 0.7-18.0 years old). The most common presenting features were headache (76%), nausea/vomiting (32%), and vision loss (31%). Median follow-up was 5.2 years (range 1.0-17.2 years). During follow-up, visual decline occurred in 17 patients (29%). On Kaplan Meier survival analysis, 47% of the cases of visual decline occurred within 4 months of diagnosis, with the remaining cases occurring sporadically during follow-up (up to 8 years after diagnosis). In terms of risk factors, younger age at diagnosis, optic nerve edema at presentation, and tumor recurrence were found to have statistically significant associations with visual decline. At final follow-up, 58% of the patients had visual impairment in at least one eye but only 10% were legally blind in both eyes (visual acuity 20/200 or worse or < 20° of visual field). Vision loss is a common presenting symptom of craniopharyngiomas in children. After diagnosis, monitoring vision is important as about 30% of patients will experience significant visual decline. Long-term vision loss occurs in the majority of patients, but severe binocular visual impairment is uncommon.

Vision Function in HIV-infected Individuals without Retinitis; Report of the Studies of Ocular Complications of AIDS Research Group

PubMed Central

Freeman, William R.; Van Natta, Mark L.; Jabs, Douglas; Sample, Pamela A.; Sadun, Alfredo A.; Thorne, Jennifer; Shah, Kayur H.; Holland, Gary N.

2008-01-01

Purpose To evaluate the prevalence and risk factors for vision loss in patients with clinical or immunologic AIDS without infectious retinitis. Design A prospective multicentered cohort study of patients with AIDS. Methods 1,351 patients (2,671 eyes) at 19 clinical trials centers diagnosed with AIDS but without major ocular complications of HIV. Standardized measurements of visual acuity, automated perimetry, and contrast sensitivity were analyzed and correlated with measurements of patients’ health and medical data relating to HIV infection. We evaluated correlations between vision function testing and HIV-related risk factors and medical testing. Results There were significant (p<0.05) associations between measures of decreasing vision function and indices of increasing disease severity including Karnofsky score and hemoglobin. A significant relationship was seen between low contrast sensitivity and decreasing levels of CD4+ T-cell count. Three percent of eyes had a visual acuity worse than 20/40 Snellen equivalents, which was significantly associated with a history of opportunistic infections and low Karnofsky score. When compared to external groups with normal vision, 39% of eyes had abnormal mean deviation on automated perimetry, 33% had abnormal pattern standard deviation, and 12% of eyes had low contrast sensitivity. Conclusions This study confirms that visual dysfunction is common in patients with AIDS but without retinitis. The most prevalent visual dysfunction is loss of visual field; nearly 40% of patients have some abnormal visual field. There is an association between general disease severity and less access to care and vision loss. The pathophysiology of this vision loss is unknown but is consistent with retinovascular disease or optic nerve disease. PMID:18191094

Interocular asymmetry of the visual field defects in newly diagnosed normal-tension glaucoma, primary open-angle glaucoma, and chronic angle-closure glaucoma.

PubMed

Huang, Ping; Shi, Yan; Wang, Xin; Liu, Mugen; Zhang, Chun

2014-09-01

To compare the interocular asymmetry of visual field loss in newly diagnosed normal-tension glaucoma (NTG), primary open-angle glaucoma (POAG), and chronic angle-closure glaucoma (CACG) patients. Visual field results of 117 newly diagnosed, treatment-naive glaucoma patients (42 NTG, 38 POAG, and 37 CACG) were studied retrospectively. The following 3 visual field defect parameters were used to evaluate the interocular asymmetry: (1) global indices; (2) local mean deviations (MDs) of 6 predefined visual field areas; and (3) stage designated by glaucoma staging system 2. The differences of the above parameters between the trial eye (the eye with greater MDs) and the fellow eye in each subject were defined as interocular asymmetry scores. Interocular asymmetry of visual field loss was presented in all the 3 groups (all P<0.05). CACG group had greater total MD interocular asymmetry score compared with the NTG and POAG groups (among groups, P=0.008; NTG vs. CACG, P=0.005; POAG vs. CACG, P=0.009). CACG also presented with significantly higher local MD interocular asymmetry scores at central, inferior, and temporal areas compared with those of the POAG group and at inferior area compared with that of NTG group. No significant difference in either total or local MDs was detected between NTG and POAG (all P>0.05). Interocular asymmetry scores of glaucoma staging system 2 had no significant difference among the 3 groups (P=0.068). All CACG, POAG, and NTG groups presented with interocular asymmetric visual field loss at the time of diagnosis. CACG had greater interocular asymmetry compared with NTG and POAG. No significant interocular asymmetry difference was observed between NTG and POAG.

Longterm visual prognosis in Usher syndrome types 1 and 2.

PubMed

Sadeghi, André M; Eriksson, Kristina; Kimberling, William J; Sjöström, Anders; Möller, Claes

2006-08-01

To estimate the age at diagnosis of retinitis pigmentosa and to determine visual acuity deterioration, visual field impairment and the frequency of cataracts in Usher syndrome types 1 and 2. We carried out a retrospective study of 328 affected subjects with Usher syndrome types 1 and 2. Study subjects were divided into seven different age groups by decade. Data were analysed using descriptive statistics, general linear model anova and survival analysis. Retinitis pigmentosa was diagnosed significantly earlier in subjects with Usher syndrome type 1 than in those with type 2. Visual acuity was significantly more impaired in affected subjects with Usher syndrome type 1 than in those with type 2 from 50 years of age onwards. Survival analysis revealed a significant difference in visual field loss (

Medically unexplained visual loss in a specialist clinic: a retrospective case-control comparison.

PubMed

O'Leary, Éanna D; McNeillis, Benjamin; Aybek, Selma; Riordan-Eva, Paul; David, Anthony S

2016-02-15

To compare the clinical and demographic characteristics of adult patients with nonorganic or medically unexplained visual loss (MUVL) to those with other common conditions presenting to a neuro-ophthalmology clinic. Case-control design: a retrospective review of medical notes on a consecutive case series of 49 patients assessed at the King's College Hospital neuro-ophthalmology clinic with unexplained visual loss and matched with the next assessed patient identified from clinic records. Patients presented post-symptom onset with a mean clinical course of 30 months (SD=67 months) and standard clinical examination used to confirm diagnoses, alongside ancillary investigations if required. Seventy-two percent (n=36) of MUVL patients were female. In comparison with patients with organic visual disorders, MUVL cases presented with significantly higher rates of bilateral (cf. unilateral) visual impairment (41%, n=20), premorbid psychiatric (27%, n=13) as well as functional (24%, n=12) diagnoses and psychotropic medication usage (22%, n=11). Medically unexplained cases were significantly more likely to report preceding psychological stress (n=9; 18%). Medically unexplained visual impairment may be regarded as part of the spectrum of medically unexplained disorders seen in the general hospital setting. Research is needed to determine long-term outcomes and effective tailored interventions. Copyright © 2016 Elsevier B.V. All rights reserved.

[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.

Markers of Alzheimer's Disease in Primary Visual Cortex in Normal Aging in Mice.

PubMed

Hernández-Zimbrón, Luis Fernando; Perez-Hernández, Montserrat; Torres-Romero, Abigail; Gorostieta-Salas, Elisa; Gonzalez-Salinas, Roberto; Gulias-Cañizo, Rosario; Quiroz-Mercado, Hugo; Zenteno, Edgar

2017-01-01

Aging is the principal risk factor for the development of Alzheimer's disease (AD). The hallmarks of AD are accumulation of the amyloid- β peptide 1-42 (A β 42) and abnormal hyperphosphorylation of Tau (p-Tau) protein in different areas of the brain and, more recently reported, in the visual cortex. Recently, A β 42 peptide overproduction has been involved in visual loss. Similar to AD, in normal aging, there is a significant amyloid deposition related to the overactivation of the aforementioned mechanisms. However, the mechanisms associated with visual loss secondary to age-induced visual cortex affectation are not completely understood. Young and aged mice were used as model to analyze the presence of A β 42, p-Tau, glial-acidic fibrillary protein (GFAP), and presenilin-2, one of the main enzymes involved in A β 42 production. Our results show a significant increase of A β 42 deposition in aged mice in the following cells and/or tissues: endothelial cells and blood vessels and neurons of the visual cortex; they also show an increase of the expression of GFAP and presenilin-2 in this region. These results provide a comprehensive framework for the role of A β 42 in visual loss due to inflammation present with aging and offer some clues for fruitful avenues for the study of healthy aging.

Effects of sensorineural hearing loss on visually guided attention in a multitalker environment.

PubMed

Best, Virginia; Marrone, Nicole; Mason, Christine R; Kidd, Gerald; Shinn-Cunningham, Barbara G

2009-03-01

This study asked whether or not listeners with sensorineural hearing loss have an impaired ability to use top-down attention to enhance speech intelligibility in the presence of interfering talkers. Listeners were presented with a target string of spoken digits embedded in a mixture of five spatially separated speech streams. The benefit of providing simple visual cues indicating when and/or where the target would occur was measured in listeners with hearing loss, listeners with normal hearing, and a control group of listeners with normal hearing who were tested at a lower target-to-masker ratio to equate their baseline (no cue) performance with the hearing-loss group. All groups received robust benefits from the visual cues. The magnitude of the spatial-cue benefit, however, was significantly smaller in listeners with hearing loss. Results suggest that reduced utility of selective attention for resolving competition between simultaneous sounds contributes to the communication difficulties experienced by listeners with hearing loss in everyday listening situations.

Attitudes towards and perceptions of visual loss and its causes among Hong Kong Chinese adults.

PubMed

Lau, Joseph Tak Fai; Lee, Vincent; Fan, Dorothy; Lau, Mason; Michon, John

2004-06-01

As part of a study of visual function among Hong Kong Chinese adults, their attitudes and perceptions related to visual loss were examined. These included fear of visual loss, negative functional impacts of visual loss, the relationship between ageing and visual loss and help-seeking behaviours related to visual loss. Demographic factors associated with these variables were also studied. The study population were people aged 40 and above randomly selected from the Shatin district of Hong Kong. The participants underwent eye examinations that included visual acuity, intraocular pressure measurement, visual field, slit-lamp biomicroscopy and ophthalmoscopy. The primary cause of visual disability was recorded. The participants were also asked about their attitudes and perceptions regarding visual loss using a structured questionnaire. The prevalence of bilateral visual disability was 2.2% among adults aged 40 or above and 6.4% among adults aged 60 or above. Nearly 36% of the participants selected blindness as the most feared disabling medical condition, which was substantially higher than conditions such as dementia, loss of limbs, deafness or aphasia. Inability to take care of oneself (21.0%), inconvenience related to mobility (20.2%) and inability to work (14.8%) were the three most commonly mentioned 'worst impact' effects of visual loss. Fully 68% of the participants believed that loss of vision is related to ageing. A majority of participants would seek help and advice from family members in case of visual loss. Visual function is perceived to be very important by Hong Kong Chinese adults. The fear of visual loss is widespread and particularly affects self-care and functional abilities. Visual loss is commonly seen as related to ageing. Attitudes and perceptions in this population may be modified by educational and outreach efforts in order to take advantage of preventive measures.

Objective Analysis of Performance of Activities of Daily Living in People With Central Field Loss.

PubMed

Pardhan, Shahina; Latham, Keziah; Tabrett, Daryl; Timmis, Matthew A

2015-11-01

People with central visual field loss (CFL) adopt various strategies to complete activities of daily living (ADL). Using objective movement analysis, we compared how three ADLs were completed by people with CFL compared with age-matched, visually healthy individuals. Fourteen participants with CFL (age 81 ± 10 years) and 10 age-matched, visually healthy (age 75 ± 5 years) participated. Three ADLs were assessed: pick up food from a plate, pour liquid from a bottle, and insert a key in a lock. Participants with CFL completed each ADL habitually (as they would in their home). Data were compared with visually healthy participants who were asked to complete the tasks as they would normally, but under specified experimental conditions. Movement kinematics were compared using three-dimension motion analysis (Vicon). Visual functions (distance and near acuities, contrast sensitivity, visual fields) were recorded. All CFL participants were able to complete each ADL. However, participants with CFL demonstrated significantly (P < 0.05) longer overall movement times, shorter minimum viewing distance, and, for two of the three ADL tasks, needed more online corrections in the latter part of the movement. Results indicate that, despite the adoption of various habitual strategies, participants with CFL still do not perform common daily living tasks as efficiently as healthy subjects. Although indices suggesting feed-forward planning are similar, they made more movement corrections and increased time for the latter portion of the action, indicating a more cautious/uncertain approach. Various kinematic indices correlated significantly to visual function parameters including visual acuity and midperipheral visual field loss.

A prospective profile of visual field loss following stroke: prevalence, type, rehabilitation, and outcome.

PubMed

Rowe, Fiona J; Wright, David; Brand, Darren; Jackson, Carole; Harrison, Shirley; Maan, Tallat; Scott, Claire; Vogwell, Linda; Peel, Sarah; Akerman, Nicola; Dodridge, Caroline; Howard, Claire; Shipman, Tracey; Sperring, Una; Macdiarmid, Sonia; Freeman, Cicely

2013-01-01

To profile site of stroke/cerebrovascular accident, type and extent of field loss, treatment options, and outcome. Prospective multicentre cohort trial. Standardised referral and investigation protocol of visual parameters. 915 patients were recruited with a mean age of 69 years (SD 14). 479 patients (52%) had visual field loss. 51 patients (10%) had no visual symptoms. Almost half of symptomatic patients (n = 226) complained only of visual field loss: almost half (n = 226) also had reading difficulty, blurred vision, diplopia, and perceptual difficulties. 31% (n = 151) had visual field loss as their only visual impairment: 69% (n = 328) had low vision, eye movement deficits, or visual perceptual difficulties. Occipital and parietal lobe strokes most commonly caused visual field loss. Treatment options included visual search training, visual awareness, typoscopes, substitutive prisms, low vision aids, refraction, and occlusive patches. At followup 15 patients (7.5%) had full recovery, 78 (39%) had improvement, and 104 (52%) had no recovery. Two patients (1%) had further decline of visual field. Patients with visual field loss had lower quality of life scores than stroke patients without visual impairment. Stroke survivors with visual field loss require assessment to accurately define type and extent of loss, diagnose coexistent visual impairments, and offer targeted treatment.

Ganglion Cell Loss and Age-Related Visual Loss: A Cortical Pooling Analysis

PubMed Central

SCHMIDT, LAURA A.; LY-SCHROEDER, EMILY; SWANSON, WILLIAM H.

2006-01-01

Purpose To evaluate the ability of the cortical pooling model to predict the effects of random, mild ganglion cell loss, we compared the predictions of the model with the age-related loss and variability in achromatic and chromatic contrast sensitivity. Methods The relative sensitivity to small (0.5°) and large (3.0°) stimuli was compared in older (mean = 67 years, n = 27) and younger (mean = 23 years, n = 32) adults. Contrast sensitivity for modulations along the luminance, equiluminant L-cone, and equiluminant S-cone axes was assessed at the fovea and at four peripheral locations (12°). Results When the stimuli were large, threshold measurements obtained from all participants were reliable and well within the range of modulations along the chromatic axes that could be produced by the phosphors of the CRT. For the large stimuli, neither long- nor short-term variability increased as a function of age. Increasing the size of the stimulus did not decrease the magnitude of the age-related losses when the stimulus was chromatic, and visual losses observed with large chromatic stimuli were not different from those obtained with small achromatic stimuli. Moreover, chromatic contrast sensitivity assessments identified significant visual losses in four individuals who were not identified by achromatic contrast sensitivity assessments and only missed identifying one individual with significant losses in achromatic contrast sensitivity. Conclusions The declines in achromatic and chromatic sensitivity as a function of age (0.4 – 0.7 dB per decade) were similar to those obtained in previous studies of achromatic and chromatic perimetry and are consistent with the loss of retinal ganglion cells reported in histologic studies. The results of this study are consistent with the predictions the cortical pooling model makes for both variability and contrast sensitivity. These findings emphasize that selective visual impairments do not necessarily reflect preferential damage to a single ganglion cell class and that it is important to include the influence of higher cortical processing when quantifying the relation between ganglion cells and visual function. PMID:16840870

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.

'I didn't see that coming': simulated visual fields and driving hazard perception test performance.

PubMed

Glen, Fiona C; Smith, Nicholas D; Jones, Lee; Crabb, David P

2016-09-01

Evidence is limited regarding specific types of visual field loss associated with unsafe driving. We use novel gaze-contingent software to examine the effect of simulated visual field loss on computer-based driving hazard detection with the specific aim of testing the impact of scotomata located to the right and left of fixation. The 'hazard perception test' is a component of the UK driving licence examination, which measures speed of detecting 15 different hazards in a series of real-life driving films. We have developed a novel eye-tracking and computer set up capable of generating a realistic gaze-contingent scotoma simulation (GazeSS) overlaid on film content. Thirty drivers with healthy vision completed three versions of the hazard perception test in a repeated measures experiment. In two versions, GazeSS simulated a scotoma in the binocular field of view to the left or right of fixation. A third version was unmodified to establish baseline performance. Participants' mean baseline hazard perception test score was 51 ± 7 (out of 75). This reduced to 46 ± 9 and 46 ± 11 when completing the task with a binocular visual field defect located to the left and right of fixation, respectively. While the main effect of simulated visual field loss on performance was statistically significant (p = 0.007), there were no average differences in the experimental conditions where a scotoma was located in the binocular visual field to the right or left of fixation. Simulated visual field loss impairs driving hazard detection on a computer-based test. There was no statistically significant difference in average performance when the simulated scotoma was located to the right or left of fixation of the binocular visual field, but certain types of hazard caused more difficulties than others. © 2016 Optometry Australia.

Working Memory and Speech Recognition in Noise Under Ecologically Relevant Listening Conditions: Effects of Visual Cues and Noise Type Among Adults With Hearing Loss.

PubMed

Miller, Christi W; Stewart, Erin K; Wu, Yu-Hsiang; Bishop, Christopher; Bentler, Ruth A; Tremblay, Kelly

2017-08-16

This study evaluated the relationship between working memory (WM) and speech recognition in noise with different noise types as well as in the presence of visual cues. Seventy-six adults with bilateral, mild to moderately severe sensorineural hearing loss (mean age: 69 years) participated. Using a cross-sectional design, 2 measures of WM were taken: a reading span measure, and Word Auditory Recognition and Recall Measure (Smith, Pichora-Fuller, & Alexander, 2016). Speech recognition was measured with the Multi-Modal Lexical Sentence Test for Adults (Kirk et al., 2012) in steady-state noise and 4-talker babble, with and without visual cues. Testing was under unaided conditions. A linear mixed model revealed visual cues and pure-tone average as the only significant predictors of Multi-Modal Lexical Sentence Test outcomes. Neither WM measure nor noise type showed a significant effect. The contribution of WM in explaining unaided speech recognition in noise was negligible and not influenced by noise type or visual cues. We anticipate that with audibility partially restored by hearing aids, the effects of WM will increase. For clinical practice to be affected, more significant effect sizes are needed.

Long-term follow-up of patients with retinitis pigmentosa (RP) receiving intraocular ciliary neurotrophic factor implants

PubMed Central

Birch, David G.; Bennett, Lea D.; Duncan, Jacque L.; Weleber, Richard G.; Pennesi, Mark E.

2016-01-01

Purpose To evaluate the long-term efficacy of ciliary neurotrophic factor delivered via an intraocular encapsulated cell implant for the treatment of retinitis pigmentosa (RP). Design Long-term follow up of a multicenter, sham-controlled study. Methods Thirty-six patients at three CNTF4 sites were randomly assigned to receive a high- or low- dose implant in one eye and sham surgery in the fellow eye. The primary endpoint (change in visual field sensitivity at 12 months) has been reported previously.1 Here we report long-term visual acuity, visual field and optical coherence tomography (OCT) outcomes in 24 patients either retaining or explanting the device at 24 months relative to sham-treated eyes. Results Eyes retaining the implant showed significantly greater visual field loss from baseline than either explanted eyes or sham eyes through 42 months. By 60 months and continuing through 96 months, visual field loss was comparable among sham-treated eyes, eyes retaining the implant and explanted eyes, as was visual acuity and OCT macular volume. Conclusions Over the short term, ciliary neurotrophic factor released continuously from an intra-vitreal implant lead to loss of total visual field sensitivity that was greater than the natural progression in the sham-treated eye. This additional loss of sensitivity related to the active implant was reversible when the implant was removed. Over the long term (60 – 96 months), there was no evidence of efficacy for visual acuity, visual field sensitivity or OCT measures of retinal structure. PMID:27457255

[Analysis of the changes in the causes of blindness and significant vision loss among children and young adults born between 1974 and 2004].

PubMed

Seroczyńska, Małgorzata; Grałek, Mirosława; Kanigowska, Krystyna

2007-01-01

Visual impairment develops serious medical, psychological, social and economical problems. Thus, of most importance is improvement in prophylaxis, early diagnosis and treatment. THE AIM of this paper is to define the reasons of blindness and significant loss of vision in children and youths in Poland, and changes in them among children and youths under the age of 24, born between 1974-2004, with classification by age. Included in the study were the records of 2,518 children and youths under the age of 24, associates of the Polski Zwiazek Niewidomych (PZN, Polish Association of the Blind); these were analyzed for the prevalence of each cause of vision loss. There were two groups. The first group were files of 1,504 students and pupils in the institutions for blind and visually impaired children, and the archives of PZN, describing the members who joined it between year 1974 and 1998. The second, comparative group, was based on files of 1,014 children and students, who joined PZN between year 1999 and 2004. Each group was also analysed within different age groups. The most important causes of visual impairment are: optic nerve atrophy, retinopathy of prematurity (ROP), high myopia, congenital cataract and retinal degradations. Changes in them between 1998-2004 introduce a percentage growth of optic nerve atrophy from 21.66% to 25.41% and decrement in vision degrading stages of ROP from 14.14% to 10.71%, in development disorders from 8.09% to 7.10%. There is an alarming growth in congenital toxoplasmosis percentage, from 1.06% to 2.39%, and of congenital cataract, from 3.02% to 4.47%. High myopia among the visually impaired remains at the same level. There is a big growth in the percentage of heavy (bilateral) injuries, which cause significant vision loss. Less often, the cause of serious vision damage are uveitis, secondary glaucoma and toxocariasis. The study conducted between 1998-2004 revealed changes in the causes of blindness and significantly vision loss in children and youths under the age of 24, as compared to a similar study conducted between 1974-1998. There is constant increase of the optic nerve atrophy as a cause of vision loss, and decrease among vision impairments caused by vision damaging stages of ROP. Cataract and congenital abnormalities are more frequent among youngest children. Cortical blindness, formerly rarely diagnosed, is becoming a significant factor. The results of our study, describing the changes in blindness and significant vision loss factors, should provide a proper rationale for developing a strategy for control of visual impairment in children and youths.

Auditory, visual, and auditory-visual perceptions of emotions by young children with hearing loss versus children with normal hearing.

PubMed

Most, Tova; Michaelis, Hilit

2012-08-01

This study aimed to investigate the effect of hearing loss (HL) on emotion-perception ability among young children with and without HL. A total of 26 children 4.0-6.6 years of age with prelingual sensory-neural HL ranging from moderate to profound and 14 children with normal hearing (NH) participated. They were asked to identify happiness, anger, sadness, and fear expressed by an actress when uttering the same neutral nonsense sentence. Their auditory, visual, and auditory-visual perceptions of the emotional content were assessed. The accuracy of emotion perception among children with HL was lower than that of the NH children in all 3 conditions: auditory, visual, and auditory-visual. Perception through the combined auditory-visual mode significantly surpassed the auditory or visual modes alone in both groups, indicating that children with HL utilized the auditory information for emotion perception. No significant differences in perception emerged according to degree of HL. In addition, children with profound HL and cochlear implants did not perform differently from children with less severe HL who used hearing aids. The relatively high accuracy of emotion perception by children with HL may be explained by their intensive rehabilitation, which emphasizes suprasegmental and paralinguistic aspects of verbal communication.

SOURCES OF BINOCULAR SUPRATHRESHOLD VISUAL FIELD LOSS IN A COHORT OF OLDER WOMEN BEING FOLLOWED FOR RISK OF FALLS (AN AMERICAN OPHTHALMOLOGICAL SOCIETY THESIS)

PubMed Central

Coleman, Anne Louise

2007-01-01

Purpose To determine the sources of binocular visual field loss most strongly associated with falls in a cohort of older women. Methods In the Study of Osteoporotic Fractures, women with severe binocular visual field loss had an increased risk of two or more falls during the 12 months following the eye examination. The lens and fundus photographs of the 422 women with severe binocular visual field loss, plus a random sample of 141 white women with no, mild, or moderate binocular visual field loss—47 white women with no binocular visual field loss, 46 white women with mild binocular visual field loss, and 48 white women with moderate binocular visual field loss —were evaluated for lens opacities, glaucomatous optic nerve damage, age-related macular degeneration, and diabetic retinopathy. Results Eighty-four percent of the women with severe binocular visual field loss had ocular disease in one or both eyes. Bilateral cataracts and glaucomatous optic nerve damage were the most common sources of this severe binocular visual field loss. Approximately 15.2% of women had no evidence of lens opacities, glaucomatous optic nerve damage, age-related macular degeneration, or diabetic retinopathy. Conclusion Severe binocular visual field loss due primarily to cataracts, glaucoma, and age-related macular degeneration explains 33.3% of the falls among women who fell frequently. Because binocular visual field loss may be treatable and/or preventable, screening programs for binocular visual field loss and subsequent referral for intervention and treatment are recommended as a strategy for preventing falls among the elderly. PMID:18427619

Multifocal Visual Evoked Potential in Eyes With Temporal Hemianopia From Chiasmal Compression: Correlation With Standard Automated Perimetry and OCT Findings.

PubMed

Sousa, Rafael M; Oyamada, Maria K; Cunha, Leonardo P; Monteiro, Mário L R

2017-09-01

To verify whether multifocal visual evoked potential (mfVEP) can differentiate eyes with temporal hemianopia due to chiasmal compression from healthy controls. To assess the relationship between mfVEP, standard automated perimetry (SAP), and Fourier domain-optical coherence tomography (FD-OCT) macular and peripapillary retinal nerve fiber layer (RNFL) thickness measurements. Twenty-seven eyes with permanent temporal visual field (VF) defects from chiasmal compression on SAP and 43 eyes of healthy controls were submitted to mfVEP and FD-OCT scanning. Multifocal visual evoked potential was elicited using a stimulus pattern of 60 sectors and the responses were averaged for the four quadrants and two hemifields. Optical coherence tomography macular measurements were averaged in quadrants and halves, while peripapillary RNFL thickness was averaged in four sectors around the disc. Visual field loss was estimated in four quadrants and each half of the 24-2 strategy test points. Multifocal visual evoked potential measurements in the two groups were compared using generalized estimated equations, and the correlations between mfVEP, VF, and OCT findings were quantified. Multifocal visual evoked potential-measured temporal P1 and N2 amplitudes were significantly smaller in patients than in controls. No significant difference in amplitude was observed for nasal parameters. A significant correlation was found between mfVEP amplitudes and temporal VF loss, and between mfVEP amplitudes and the corresponding OCT-measured macular and RNFL thickness parameters. Multifocal visual evoked potential amplitude parameters were able to differentiate eyes with temporal hemianopia from controls and were significantly correlated with VF and OCT findings, suggesting mfVEP is a useful tool for the detection of visual abnormalities in patients with chiasmal compression.

M&S Smart System Contrast Sensitivity Measurements Compared With Standard Visual Function Measurements in Primary Open-Angle Glaucoma Patients.

PubMed

Liu, Jessica L; McAnany, J Jason; Wilensky, Jacob T; Aref, Ahmad A; Vajaranant, Thasarat S

2017-06-01

To evaluate the nature and extent of letter contrast sensitivity (CS) deficits in glaucoma patients using a commercially available computer-based system (M&S Smart System II) and to compare the letter CS measurements to standard clinical measures of visual function. Ninety-four subjects with primary open-angle glaucoma participated. Each subject underwent visual acuity, letter CS, and standard automated perimetry testing (Humphrey SITA 24-2). All subjects had a best-corrected visual acuity (BCVA) of 0.3 log MAR (20/40 Snellen equivalent) or better and reliable standard automated perimetry (fixation losses, false positives, and false negatives <33%). CS functions were estimated from the letter CS and BCVA measurements. The area under the CS function (AUCSF), which is a combined index of CS and BCVA, was derived and analyzed. The mean (± SD) BCVA was 0.08±0.10 log MAR (∼20/25 Snellen equivalent), the mean CS was 1.38±0.17, and the mean Humphrey Visual Field mean deviation (HVF MD) was -7.22±8.10 dB. Letter CS and HVF MD correlated significantly (r=0.51, P<0.001). BCVA correlated significantly with letter CS (r=-0.22, P=0.03), but not with HVF MD (r=-0.12, P=0.26). A subset of the subject sample (∼20%) had moderate to no field loss (≤-6 dB MD) and minimal to no BCVA loss (≤0.3 log MAR), but had poor letter CS. AUCSF was correlated significantly with HVF MD (r=0.46, P<0.001). The present study is the first to evaluate letter CS in glaucoma using the digital M&S Smart System II display. Letter CS correlated significantly with standard HVF MD measurements, suggesting that letter CS may provide a useful adjunct test of visual function for glaucoma patients. In addition, the significant correlation between HVF MD and the combined index of CS and BCVA (AUCSF) suggests that this measure may also be useful for quantifying visual dysfunction in glaucoma patients.

Contrast Enhancement Algorithm Based on Gap Adjustment for Histogram Equalization

PubMed Central

Chiu, Chung-Cheng; Ting, Chih-Chung

2016-01-01

Image enhancement methods have been widely used to improve the visual effects of images. Owing to its simplicity and effectiveness histogram equalization (HE) is one of the methods used for enhancing image contrast. However, HE may result in over-enhancement and feature loss problems that lead to unnatural look and loss of details in the processed images. Researchers have proposed various HE-based methods to solve the over-enhancement problem; however, they have largely ignored the feature loss problem. Therefore, a contrast enhancement algorithm based on gap adjustment for histogram equalization (CegaHE) is proposed. It refers to a visual contrast enhancement algorithm based on histogram equalization (VCEA), which generates visually pleasing enhanced images, and improves the enhancement effects of VCEA. CegaHE adjusts the gaps between two gray values based on the adjustment equation, which takes the properties of human visual perception into consideration, to solve the over-enhancement problem. Besides, it also alleviates the feature loss problem and further enhances the textures in the dark regions of the images to improve the quality of the processed images for human visual perception. Experimental results demonstrate that CegaHE is a reliable method for contrast enhancement and that it significantly outperforms VCEA and other methods. PMID:27338412

Visual loss in a school for the blind in Nigeria.

PubMed

Okoye, O I; Aghaji, A E; Ikojo, I N

2009-01-01

There are an estimated 1.4 million blind children worldwide, it has been observed that almost 90% of the so-called blind population (children inclusive) do not have total loss of visual function, but retain a degree of usable residual vision. The study aims to determined the sites and causes of visual loss in the students of a school for the blind in Nigeria, and also the proportion of those students who could benefit from low vision devices. Forty-five students of the school were examined using the standard World Health Organization/Prevention of blindness examination record for childhood blindness. Refraction and assessment for low vision devices were conducted, where necessary. Glaucoma/buphthalmos (22.2%) and corneal lesions (20%) were the major causes of vision loss. Six students (13.3%) benefited from spectacles and/or low vision devices. Glaucoma/buphthalmos is assuming great significance in this study population, though most of the causes of vision loss are avoidable (77.7%). There is need for low vision service in the schools for the blind in South East Nigeria.

Visual brain plasticity induced by central and peripheral visual field loss.

PubMed

Sanda, Nicolae; Cerliani, Leonardo; Authié, Colas N; Sabbah, Norman; Sahel, José-Alain; Habas, Christophe; Safran, Avinoam B; Thiebaut de Schotten, Michel

2018-06-23

Disorders that specifically affect central and peripheral vision constitute invaluable models to study how the human brain adapts to visual deafferentation. We explored cortical changes after the loss of central or peripheral vision. Cortical thickness (CoTks) and resting-state cortical entropy (rs-CoEn), as a surrogate for neural and synaptic complexity, were extracted in 12 Stargardt macular dystrophy, 12 retinitis pigmentosa (tunnel vision stage), and 14 normally sighted subjects. When compared to controls, both groups with visual loss exhibited decreased CoTks in dorsal area V3d. Peripheral visual field loss also showed a specific CoTks decrease in early visual cortex and ventral area V4, while central visual field loss in dorsal area V3A. Only central visual field loss exhibited increased CoEn in LO-2 area and FG1. Current results revealed biomarkers of brain plasticity within the dorsal and the ventral visual streams following central and peripheral visual field defects.

Visual loss in Takayasu Arteritis - Look Beyond the Eye.

PubMed

Peter, Jayanthi; Joseph, George; Mathew, Vivek; Peter, John Victor

2014-08-01

Patients with Takayasu arteritis often present with reduced vision related either to the disease per se or due to complications of therapy. We report a patient with Takayasu arteritis who developed acute onset bilateral visual loss 6wks following percutaneous revascularization of occluded aortic arch branches. No ocular cause for the visual loss was evident. The reason for visual loss in this patient was an extraocular cause. Ocular and extraocular causes of visual loss in Takayasu arteritis are discussed.

Impact of Visual Field Loss on Health-Related Quality of Life in Glaucoma

PubMed Central

McKean-Cowdin, Roberta; Wang, Ying; Wu, Joanne; Azen, Stanley P.; Varma, Rohit

2016-01-01

Purpose To examine the association between health-related quality of life (HRQOL) and visual field (VF) loss in participants with open-angle glaucoma (OAG) in the Los Angeles Latino Eye Study (LALES). Design Population-based cross-sectional study. Participants Two hundred thirteen participants with OAG and 2821 participants without glaucoma or VF loss. Methods Participants in the LALES—a population-based prevalence study of eye disease in Latinos 40 years and older, residing in Los Angeles, California—underwent a detailed eye examination including an assessment of their VF using the Humphrey Automated Field Analyzer (Swedish interactive thresholding algorithm Standard 24-2). Open-angle glaucoma was determined by clinical examination. Mean deviation scores were used to assess severity of VF loss. Health-related QOL was assessed by the Medical Outcomes Study 12-item Short-Form Health Survey (SF-12) and 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). Linear regression and analysis of covariance were used to assess the relationship between HRQOL scores and VF loss after adjusting for sociodemographic variables and visual acuity. Main Outcome Measures The 25-item NEI-VFQ and SF-12 scores. Results A trend of worse NEI-VFQ-25 scores for most subscales was observed with worse VF loss (using both monocular and calculated binocular data). Open-angle glaucoma participants with VF loss had lower scores than participants with no VF loss. This association was also present in participants who were previously undiagnosed and untreated for OAG (N = 160). Participants with any central VF loss had lower NEI-VFQ-25 scores than those with unilateral or bilateral peripheral VF loss. There was no significant impact of severity or location of VF loss on SF-12 scores. Conclusion Greater severity of VF loss in persons with OAG impacts vision-related QOL. This impact was present in persons who were previously unaware that they had glaucoma. Prevention of VF loss in persons with glaucoma is likely to reduce loss of vision-related QOL. PMID:17997485

Working Memory and Speech Recognition in Noise Under Ecologically Relevant Listening Conditions: Effects of Visual Cues and Noise Type Among Adults With Hearing Loss

PubMed Central

Stewart, Erin K.; Wu, Yu-Hsiang; Bishop, Christopher; Bentler, Ruth A.; Tremblay, Kelly

2017-01-01

Purpose This study evaluated the relationship between working memory (WM) and speech recognition in noise with different noise types as well as in the presence of visual cues. Method Seventy-six adults with bilateral, mild to moderately severe sensorineural hearing loss (mean age: 69 years) participated. Using a cross-sectional design, 2 measures of WM were taken: a reading span measure, and Word Auditory Recognition and Recall Measure (Smith, Pichora-Fuller, & Alexander, 2016). Speech recognition was measured with the Multi-Modal Lexical Sentence Test for Adults (Kirk et al., 2012) in steady-state noise and 4-talker babble, with and without visual cues. Testing was under unaided conditions. Results A linear mixed model revealed visual cues and pure-tone average as the only significant predictors of Multi-Modal Lexical Sentence Test outcomes. Neither WM measure nor noise type showed a significant effect. Conclusion The contribution of WM in explaining unaided speech recognition in noise was negligible and not influenced by noise type or visual cues. We anticipate that with audibility partially restored by hearing aids, the effects of WM will increase. For clinical practice to be affected, more significant effect sizes are needed. PMID:28744550

Visual prompt poster for promoting patient-physician conversations on weight loss.

PubMed

Stephens, Gillian S; Blanken, Stephanie E; Greiner, K Allen; Chumley, Heidi S

2008-01-01

This study investigated the effect of a simple visual prompt in the form of a poster on the occurrence of patient-physician weight loss conversations during routine office encounters in a primary care outpatient clinic. We conducted a 2-phase study in a family medicine residency program outpatient clinic in August and September 2006. During the first phase, lasting 5 days, we surveyed all nonpregnant adult patients (preintervention group) about weight loss. We then implemented a visual prompt in the form of a colorful poster (11 x 17 inches) in both English and Spanish. The poster read "Do you want to lose weight? Ask your doctor today!" and included a picture of a bathroom scale. During the second phase, also lasting 5 days, we again surveyed all nonpregnant adult patients (postintervention group). Analyses were based on 283 patients in the preintervention group and 386 patients in the postintervention group. The mean body mass index, obtained from medical records, did not differ significantly between groups (31 vs 32 kg/m2, respectively). Fully 60% of patients in the postintervention group recalled seeing the poster during their visit; however, the percentage of patients who reported discussing weight loss with their physician did not differ between the preintervention and postintervention groups overall (29% vs 27%), among the two-thirds of patients who wanted to lose weight (26% vs 23%), or when only postintervention patients who saw the poster were included in the comparison (29% vs 29%). The large majority of patients in both groups who had such discussions--82% and 77%--indicated that they found them useful; the difference between groups was not significant. A simple visual prompt in the form of a poster directed at patients did not increase the occurrence of conversations between patients and their physicians about weight loss.

Scanning laser polarimetry, but not optical coherence tomography predicts permanent visual field loss in acute nonarteritic anterior ischemic optic neuropathy.

PubMed

Kupersmith, Mark J; Anderson, Susan; Durbin, Mary; Kardon, Randy

2013-08-15

Scanning laser polarimetry (SLP) reveals abnormal retardance of birefringence in locations of the edematous peripapillary retinal nerve fiber layer (RNFL), which appear thickened by optical coherence tomography (OCT), in nonarteritic anterior ischemic optic neuropathy (NAION). We hypothesize initial sector SLP RNFL abnormalities will correlate with long-term regional visual field loss due to ischemic injury. We prospectively performed automated perimetry, SLP, and high definition OCT (HD-OCT) of the RNFL in 25 eyes with acute NAION. We grouped visual field threshold and RNFL values into Garway-Heath inferior/superior disc sectors and corresponding superior/inferior field regions. We compared sector SLP RNFL thickness with corresponding visual field values at presentation and at >3 months. At presentation, 12 eyes had superior sector SLP reduction, 11 of which had inferior field loss. Six eyes, all with superior field loss, had inferior sector SLP reduction. No eyes had reduced OCT-derived RNFL acutely. Eyes with abnormal field regions had corresponding SLP sectors thinner (P = 0.003) than for sectors with normal field regions. During the acute phase, the SLP-derived sector correlated with presentation (r = 0.59, P = 0.02) and with >3-month after presentation (r = 0.44, P = 0.02) corresponding superior and inferior field thresholds. Abnormal RNFL birefringence occurs in sectors corresponding to regional visual field loss during acute NAION when OCT-derived RNFL shows thickening. Since the visual field deficits show no significant recovery, SLP can be an early marker for axonal injury, which may be used to assess recovery potential at RNFL locations with respect to new treatments for acute NAION.

Visual estimation versus gravimetric measurement of postpartum blood loss: a prospective cohort study.

PubMed

Al Kadri, Hanan M F; Al Anazi, Bedayah K; Tamim, Hani M

2011-06-01

One of the major problems in international literature is how to measure postpartum blood loss with accuracy. We aimed in this research to assess the accuracy of visual estimation of postpartum blood loss (by each of two main health-care providers) compared with the gravimetric calculation method. We carried out a prospective cohort study at King Abdulaziz Medical City, Riyadh, Saudi Arabia between 1 November 2009 and 31 December 2009. All women who were admitted to labor and delivery suite and delivered vaginally were included in the study. Postpartum blood loss was visually estimated by the attending physician and obstetrics nurse and then objectively calculated by a gravimetric machine. Comparison between the three methods of blood loss calculation was carried out. A total of 150 patients were included in this study. There was a significant difference between the gravimetric calculated blood loss and both health-care providers' estimation with a tendency to underestimate the loss by about 30%. The background and seniority of the assessing health-care provider did not affect the accuracy of the estimation. The corrected incidence of postpartum hemorrhage in Saudi Arabia was found to be 1.47%. Health-care providers tend to underestimate the volume of postpartum blood loss by about 30%. Training and continuous auditing of the diagnosis of postpartum hemorrhage is needed to avoid missing cases and thus preventing associated morbidity and mortality.

Loss of calretinin immunoreactive fibers in subcortical visual recipient structures of the RCS dystrophic rat.

PubMed

Vugler, Anthony A; Coffey, Peter J

2003-11-01

The retinae of dystrophic Royal College of Surgeons (RCS) rats exhibit progressive photoreceptor degeneration accompanied by pathology of ganglion cells. To date, little work has examined the consequences of retinal degeneration for central visual structures in dystrophic rats. Here, we use immunohistochemistry for calretinin (CR) to label retinal afferents in the superior colliculus (SC), lateral geniculate nucleus, and olivary pretectal nucleus of RCS rats aged between 2 and 26 months of age. Early indications of fiber loss in the medial dystrophic SC were apparent between 9 and 13 months. Quantitative methods reveal a significant reduction in the level of CR immunoreactivity in visual layers of the medial dystrophic SC at 13 months (P < 0.02). In dystrophic animals aged 19-26 months the loss of CR fibers in SC was dramatic, with well-defined patches of fiber degeneration predominating in medial aspects of the structure. This fiber degeneration in SC was accompanied by increased detection of cells immunoreactive for CR. In several animals, regions of fiber loss were also found to contain strongly parvalbumin-immunoreactive cells. Loss of CR fibers was also observed in the lateral geniculate nucleus and olivary pretectal nucleus. Patterns of fiber loss in the dystrophic SC compliment reports of ganglion cell degeneration in these animals and the response of collicular neurons to degeneration is discussed in terms of plasticity of the dystrophic visual system and properties of calcium binding proteins.

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

PubMed

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

2007-07-01

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

Retinopathy of prematurity: inflammation, choroidal degeneration, and novel promising therapeutic strategies.

PubMed

Rivera, José Carlos; Holm, Mari; Austeng, Dordi; Morken, Tora Sund; Zhou, Tianwei Ellen; Beaudry-Richard, Alexandra; Sierra, Estefania Marin; Dammann, Olaf; Chemtob, Sylvain

2017-08-22

Retinopathy of prematurity (ROP) is an important cause of childhood blindness globally, and the incidence is rising. The disease is characterized by initial arrested retinal vascularization followed by neovascularization and ensuing retinal detachment causing permanent visual loss. Although neovascularization can be effectively treated via retinal laser ablation, it is unknown which children are at risk of entering this vision-threatening phase of the disease. Laser ablation may itself induce visual field deficits, and there is therefore a need to identify targets for novel and less destructive treatments of ROP. Inflammation is considered a key contributor to the pathogenesis of ROP. A large proportion of preterm infants with ROP will have residual visual loss linked to loss of photoreceptor (PR) and the integrity of the retinal pigment epithelium (RPE) in the macular region. Recent studies using animal models of ROP suggest that choroidal degeneration may be associated with a loss of integrity of the outer retina, a phenomenon so far largely undescribed in ROP pathogenesis. In this review, we highlight inflammatory and neuron-derived factors related to ROP progression, as well, potential targets for new treatment strategies. We also introduce choroidal degeneration as a significant cause of residual visual loss following ROP. We propose that ROP should no longer be considered an inner retinal vasculopathy only, but also a disease of choroidal degeneration affecting both retinal pigment epithelium and photoreceptor integrity.

A 6‐month telephone‐based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension

PubMed Central

Kovacs, Betty; Miller, Neil; McDermott, Michael P.; Wall, Michael; Kupersmith, Mark; Pi‐Sunyer, F. Xavier

2016-01-01

Summary Objectives The purpose of this paper is to measure the change in body weight after a 6‐month telephone‐based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension (IIH) and mild visual loss randomized to receive either acetazolamide or placebo. Methods One hundred sixty‐five subjects with IIH, aged 29.1 ± 7.5 (mean ± SD) and BMI 39.9 + 8.3 kg/m2, enrolled at 38 academic and private practice sites in North America, participated in this trial. This was a randomized, double‐masked, placebo‐controlled trial of acetazolamide in subjects with IIH and mild visual loss. All participants received a reduced‐sodium, weight‐reduction diet and a 6‐month telephone‐based weight loss intervention. Six‐month changes from baseline in body weight, perimetric mean deviation as assessed by automated perimetry and quality of life using the National Eye Institute Visual Function Questionnaire 25 and the 36‐item Short Form Health Survey were measured. Results Mean percent weight change at 6 months was −5.9% ± 6.7% of initial body weight overall, −3.5% ± 5.9% in the placebo group and −7.8% ± 6.8% in the acetazolamide group. Weight change was not associated with changes in either mean deviation or quality of life scores. Conclusion Patients with IIH and mild visual loss assigned to either acetazolamide or placebo, all of whom received a 6‐month telephone‐based weight loss intervention, lost an average of 5.9% of initial body weight, consistent with NHLBI guidelines of 5% to 10% of body weight loss for clinically significant health benefit. PMID:29071096

A 6-month telephone-based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension.

PubMed

Weil, Richard; Kovacs, Betty; Miller, Neil; McDermott, Michael P; Wall, Michael; Kupersmith, Mark; Pi-Sunyer, F Xavier

2016-06-01

The purpose of this paper is to measure the change in body weight after a 6-month telephone-based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension (IIH) and mild visual loss randomized to receive either acetazolamide or placebo. One hundred sixty-five subjects with IIH, aged 29.1 ± 7.5 (mean ± SD) and BMI 39.9 + 8.3 kg/m 2 , enrolled at 38 academic and private practice sites in North America, participated in this trial. This was a randomized, double-masked, placebo-controlled trial of acetazolamide in subjects with IIH and mild visual loss. All participants received a reduced-sodium, weight-reduction diet and a 6-month telephone-based weight loss intervention. Six-month changes from baseline in body weight, perimetric mean deviation as assessed by automated perimetry and quality of life using the National Eye Institute Visual Function Questionnaire 25 and the 36-item Short Form Health Survey were measured. Mean percent weight change at 6 months was -5.9% ± 6.7% of initial body weight overall, -3.5% ± 5.9% in the placebo group and -7.8% ± 6.8% in the acetazolamide group. Weight change was not associated with changes in either mean deviation or quality of life scores. Patients with IIH and mild visual loss assigned to either acetazolamide or placebo, all of whom received a 6-month telephone-based weight loss intervention, lost an average of 5.9% of initial body weight, consistent with NHLBI guidelines of 5% to 10% of body weight loss for clinically significant health benefit.

Ocular injuries from pressurised bottled drinks in China.

PubMed

Zhu, Lili; Lou, Dinghua

2014-01-01

The objective of this study is to provide a systematic review on ocular injuries induced by glass bottles containing carbonated drinks in China, which emphasised the injury circumstance and visual function loss. We performed a literature-based retrospective analysis using predetermined inclusion and exclusion criteria. Demographic characteristics of pressurised bottled drinks-related eye injuries were obtained and vision loss was calculated. A total of 26 relevant articles were found suitable for investigation of causative agent and patient demographics, of which 19 articles could be used for calculating vision loss and injury circumstance. Victims were often pertinent workers (46.0%). Most of the trauma was serious and even devastating. Final visual acuity was >10/20 in 29.2%, with severe final vision loss (<10/200) in 30.8%. Visual acuity can improve significantly with treatment (P<0.05). One in three ocular injuries from glass bottles containing carbonated drinks show severe vision loss. Relevant workers are most frequently injured, followed by inappropriate handlers or openers. Besides manufacturing standards being strictly implemented, many ocular traumas related to bottled carbonated drinks should be prevented through health education. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vision and quality-of-life.

PubMed Central

Brown, G C

1999-01-01

OBJECTIVE: To determine the relationship of visual acuity loss to quality of life. DESIGN: Three hundred twenty-five patients with visual loss to a minimum of 20/40 or greater in at least 1 eye were interviewed in a standardized fashion using a modified VF-14, questionnaire. Utility values were also obtained using both the time trade-off and standard gamble methods of utility assessment. MAIN OUTCOME MEASURES: Best-corrected visual acuity was correlated with the visual function score on the modified VF-14 questionnaire, as well as with utility values obtained using both the time trade-off and standard gamble methods. RESULTS: Decreasing levels of vision in the eye with better acuity correlated directly with decreasing visual function scores on the modified VF-14 questionnaire, as did decreasing utility values using the time trade-off method of utility evaluation. The standard gamble method of utility evaluation was not as directly correlated with vision as the time trade-off method. Age, level of education, gender, race, length of time of visual loss, and the number of associated systemic comorbidities did not significantly affect the time trade-off utility values associated with visual loss in the better eye. The level of reduced vision in the better eye, rather than the specific disease process causing reduced vision, was related to mean utility values. The average person with 20/40 vision in the better seeing eye was willing to trade 2 of every 10 years of life in return for perfect vision (utility value of 0.8), while the average person with counting fingers vision in the better eye was willing to trade approximately 5 of every 10 remaining years of life (utility value of 0.52) in return for perfect vision. CONCLUSIONS: The time trade-off method of utility evaluation appears to be an effective method for assessing quality of life associated with visual loss. Time trade-off utility values decrease in direct conjunction with decreasing vision in the better-seeing eye. Unlike the modified VF-14 test and its counterparts, utility values allow the quality of life associated with visual loss to be more readily compared to the quality of life associated with other health (disease) states. This information can be employed for cost-effective analyses that objectively compare evidence-based medicine, patient-based preferences and sound econometric principles across all specialties in health care. PMID:10703139

[Clinico-statistical study on availability of Esterman disability score for assessment of mobility difficulty in patients with visual field loss].

PubMed

Yamagata, Yoshitaka; Terada, Yuko; Suzuki, Atsushi; Mimura, Osamu

2010-01-01

The visual efficiency scale currently adopted to determine the legal grade of visual disability associated with visual field loss in Japan is not appropriate for the evaluation of disability regarding daily living activities. We investigated whether Esterman disability score (EDS) is suitable for the assessment of mobility difficulty in patients with visual field loss. The correlation between the EDS calculated from Goldmann's kinetic visual field and the degree of subjective mobility difficulty determined by a questionnaire was investigated in 164 patients with visual field loss. The correlation between the EDS determined using a program built into the Humphrey field analyzer and that calculated from Goldmann's kinetic visual field was also investigated. The EDS based on the kinetic visual field was correlated well with the degree of subjective mobility difficulty, and the EDS measured using the Humphrey field analyzer could be estimated from the kinetic visual field-based EDS. Instead of the currently adopted visual efficiency scale, EDS should be employed for the assessment of mobility difficulty in patients with visual field loss, also to establish new judgment criteria concerning the visual field.

The effect of sildenafil citrate (Viagra) on visual sensitivity.

PubMed

Stockman, Andrew; Sharpe, Lindsay T; Tufail, Adnan; Kell, Philip D; Ripamonti, Caterina; Jeffery, Glen

2007-06-08

The erectile dysfunction medicine sildenafil citrate (Viagra) inhibits phosphodiesterase type 6 (PDE6), an essential enzyme involved in the activation and modulation of the phototransduction cascade. Although Viagra might thus be expected to impair visual performance, reports of deficits following its ingestion have so far been largely inconclusive or anecdotal. Here, we adopt tests sensitive to the slowing of the visual response likely to result from the inhibition of PDE6. We measured temporal acuity (critical fusion frequency) and modulation sensitivity in four subjects before and after the ingestion of a 100-mg dose of Viagra under conditions chosen to isolate the responses of either their short-wavelength-sensitive (S-) cone photoreceptors or their long- and middle-wavelength-sensitive (L- and M-) cones. When vision was mediated by S-cones, all subjects exhibited some statistically significant losses in sensitivity, which varied from mild to moderate. The two individuals who showed the largest S-cone sensitivity losses also showed comparable losses when their vision was mediated by the L- and M-cones. Some of the losses appear to increase with frequency, which is broadly consistent with Viagra interfering with the ability of PDE6 to shorten the time over which the visual system integrates signals as the light level increases. However, others appear to represent a roughly frequency-independent attenuation of the visual signal, which might also be consistent with Viagra lengthening the integration time (because it has the effect of increasing the effectiveness of steady background lights), but such changes are also open to other interpretations. Even for the more affected observers, however, Viagra is unlikely to impair common visual tasks, except under conditions of reduced visibility when objects are already near visual threshold.

Binocular Glaucomatous Visual Field Loss and Its Impact on Visual Exploration - A Supermarket Study

PubMed Central

Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as “passed” or “failed” with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p<0.001). Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD) area than patients who failed (t-test, p<0.05). According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a “time-effective” compensatory mechanism during the present supermarket task. PMID:25162522

Binocular glaucomatous visual field loss and its impact on visual exploration--a supermarket study.

PubMed

Sippel, Katrin; Kasneci, Enkelejda; Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as "passed" or "failed" with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p < 0.001). Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD) area than patients who failed (t-test, p < 0.05). According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a "time-effective" compensatory mechanism during the present supermarket task.

Laser-Assisted Subepithelial Keratectomy versus Laser In Situ Keratomileusis in Myopia: A Systematic Review and Meta-Analysis

PubMed Central

Zhao, Li-Quan; Zhu, Huang; Li, Liang-Mao

2014-01-01

This systematic review was to compare the clinical outcomes between laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK) for myopia. Primary parameters included mean manifest refraction spherical equivalent (MRSE), MRSE within ±0.50 diopters, uncorrected visual acuity (UCVA) ≥20/20, and loss of ≥1 line of best-corrected visual acuity (BCVA). Secondary parameters included flap complications and corneal haze. Twelve clinical controlled trials were identified and used for comparing LASEK (780 eyes) to LASIK (915 eyes). There were no significant differences in visual and refractive outcomes between the two surgeries for low to moderate myopia. The incidence of loss of ≥1 line of BCVA was significantly higher in moderate to high myopia treated by LASEK than LASIK in the mid-term and long-term followup. The efficacy (MRSE and UCVA) of LASEK appeared to be a significant worsening trend in the long-term followup. Corneal haze was more severe in moderate to high myopia treated by LASEK than LASIK in the mid-term and long-term followup. The flap-related complications still occurred in LASIK, but the incidence was not significantly higher than that in LASEK. LASEK and LASIK were safe and effective for low to moderate myopia. The advantage of LASEK was the absence of flap-related complications, and such procedure complication may occur in LASIK and affect the visual results. The increased incidence of stromal haze and regression in LASEK significantly affected the visual and refractive results for high myopia. PMID:24977054

Impact of Glaucoma and Dry Eye on Text-Based Searching.

PubMed

Sun, Michelle J; Rubin, Gary S; Akpek, Esen K; Ramulu, Pradeep Y

2017-06-01

We determine if visual field loss from glaucoma and/or measures of dry eye severity are associated with difficulty searching, as judged by slower search times on a text-based search task. Glaucoma patients with bilateral visual field (VF) loss, patients with clinically significant dry eye, and normally-sighted controls were enrolled from the Wilmer Eye Institute clinics. Subjects searched three Yellow Pages excerpts for a specific phone number, and search time was recorded. A total of 50 glaucoma subjects, 40 dry eye subjects, and 45 controls completed study procedures. On average, glaucoma patients exhibited 57% longer search times compared to controls (95% confidence interval [CI], 26%-96%, P < 0.001), and longer search times were noted among subjects with greater VF loss ( P < 0.001), worse contrast sensitivity ( P < 0.001), and worse visual acuity ( P = 0.026). Dry eye subjects demonstrated similar search times compared to controls, though worse Ocular Surface Disease Index (OSDI) vision-related subscores were associated with longer search times ( P < 0.01). Search times showed no association with OSDI symptom subscores ( P = 0.20) or objective measures of dry eye ( P > 0.08 for Schirmer's testing without anesthesia, corneal fluorescein staining, and tear film breakup time). Text-based visual search is slower for glaucoma patients with greater levels of VF loss and dry eye patients with greater self-reported visual difficulty, and these difficulties may contribute to decreased quality of life in these groups. Visual search is impaired in glaucoma and dry eye groups compared to controls, highlighting the need for compensatory strategies and tools to assist individuals in overcoming their deficiencies.

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

Demographic Characteristics and Impairments of Louisiana Students with Usher's Syndrome.

ERIC Educational Resources Information Center

Brown, S. C.

1987-01-01

Of 51 Louisiana students with Usher's Syndrome (a genetic condition characterized by hearing loss and progressive blindness), 71 percent manifested visual impairment and hearing loss, 9 percent had neither, 10 percent had visual impairments but a less-than-profound hearing loss, and 10 percent had profound hearing loss and no visual impairment.…

Prevalence and Causes of Visual Loss Among the Indigenous Peoples of the World: A Systematic Review.

PubMed

Foreman, Joshua; Keel, Stuart; van Wijngaarden, Peter; Bourne, Rupert A; Wormald, Richard; Crowston, Jonathan; Taylor, Hugh R; Dirani, Mohamed

2018-05-01

Studies have documented a higher disease burden in indigenous compared with nonindigenous populations, but no global data on the epidemiology of visual loss in indigenous peoples are available. A systematic review of literature on visual loss in the world's indigenous populations could identify major gaps and inform interventions to reduce their burden of visual loss. To conduct a systematic review on the prevalence and causes of visual loss among the world's indigenous populations. A search of databases and alternative sources identified literature on the prevalence and causes of visual loss (visual impairment and blindness) and eye diseases in indigenous populations. Studies from January 1, 1990, through August 1, 2017, that included clinical eye examinations of indigenous participants and, where possible, compared findings with those of nonindigenous populations were included. Methodologic quality of studies was evaluated to reveal gaps in the literature. Limited data were available worldwide. A total of 85 articles described 64 unique studies from 24 countries that examined 79 598 unique indigenous participants. Nineteen studies reported comparator data on 42 085 nonindigenous individuals. The prevalence of visual loss was reported in 13 countries, with visual impairment ranging from 0.6% in indigenous Australian children to 48.5% in native Tibetans 50 years or older. Uncorrected refractive error was the main cause of visual impairment (21.0%-65.1%) in 5 of 6 studies that measured presenting visual acuity. Cataract was the main cause of visual impairment in all 6 studies measuring best-corrected acuity (25.4%-72.2%). Cataract was the leading cause of blindness in 13 studies (32.0%-79.2%), followed by uncorrected refractive error in 2 studies (33.0% and 35.8%). Most countries with indigenous peoples do not have data on the burden of visual loss in these populations. Although existing studies vary in methodologic quality and reliability, they suggest that most visual loss in indigenous populations is avoidable. Improvements in quality and frequency of research into the eye health of indigenous communities appear to be required, and coordinated eye care programs should be implemented to specifically target the indigenous peoples of the world.

Visual loss after corrective surgery for pediatric scoliosis: incidence and risk factors from a nationwide database.

PubMed

De la Garza-Ramos, Rafael; Samdani, Amer F; Sponseller, Paul D; Ain, Michael C; Miller, Neil R; Shaffrey, Christopher I; Sciubba, Daniel M

2016-04-01

Perioperative visual loss (POVL) after spinal deformity surgery is an uncommon but severe complication. Data on the incidence and risk factors of this complication after corrective surgery in the pediatric population are limited. The present study aimed to investigate nationwide estimates of POVL after corrective surgery for pediatric scoliosis. This is a retrospective study that uses a nationwide database. The sample includes 42,339 patients under the age of 18 who underwent surgery for idiopathic scoliosis. The outcome measures were incidence of POVL and risk factors. Patients under the age of 18 who underwent elective surgery for idiopathic scoliosis between 2002 and 2011 were identified using the Nationwide Inpatient Sample database. The incidence of POVL (ischemic optic neuropathy, central retinal artery occlusion, or cortical blindness) was estimated after application of discharge weights. Demographics, comorbidities, and operative parameters were compared between patients with and without visual loss. A multivariate logistic regression was performed to identify significant risk factors for POVL development. No funds were received in support of this work. The incidence of POVL was 1.6 per 1,000 procedures (0.16%). Patients with visual loss were significantly more likely to be younger and male, have Medicaid as insurance, and undergo fusion of eight or more spinal levels compared with patients without visual loss. Following multivariate analysis, older patients (odds ratio [OR]: 0.84; 95% confidence interval [CI]: 0.77-0.91) and female patients (OR: 0.08; 95% CI: 0.04-0.14) were significantly less likely to develop POVL compared with younger and male patients. On the other hand, having Medicaid as insurance (OR: 2.13;95% CI: 1.32-3.45), history of deficiency anemia (OR: 8.64; 95% CI: 5.46-14.31), and fusion of eight or more spinal levels (OR: 2.40; 95% CI: 1.34-4.30) were all independently associated with POVL. In this nationwide study, the incidence of POVL after scoliosis surgery in patients under the age of 18 was estimated at 0.16%, similar to the rate reported in adult patients. Cortical blindness accounted for all cases of POVL in the present study. Younger patients, patients with history of deficiency anemia, and patients undergoing long-segment fusions may be at increased risk of POVL after corrective surgery for pediatric scoliosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Dry eye disease and work productivity loss in visual display users: the Osaka study.

PubMed

Uchino, Miki; Uchino, Yuichi; Dogru, Murat; Kawashima, Motoko; Yokoi, Norihiko; Komuro, Aoi; Sonomura, Yukiko; Kato, Hiroaki; Kinoshita, Shigeru; Schaumberg, Debra A; Tsubota, Kazuo

2014-02-01

To estimate the impact of dry eye disease (DED) on work performance and productivity in office workers using visual display terminals (VDTs). Cross-sectional study. Six hundred seventy-two Japanese young and middle-aged office workers using VDTs completed a questionnaire that was designed to measured at-work performance deficits and productivity losses using the Japanese version of the Work Limitations Questionnaire, completed by e-mail. Using the Japanese dry eye diagnostic criteria, respondents were classified into 3 groups: definite DED, probable DED, and non DED. Of the 672 office workers, 553 subjects (82.3%), including 366 men and 187 women, completed the questionnaire and underwent clinical evaluation. As for the total workplace productivity loss, the non DED group demonstrated a loss of 3.56%, those with probable DED demonstrated a loss of 4.06%, and those with definite DED demonstrated a loss of 4.82%, indicating significantly worse performance and productivity (P = .014, trend test). For the 4 subscales, DED was associated with significantly lower on-the-job time management (P = .009, trend test) and combined mental performance and interpersonal functioning (P = .011, trend test). After controlling for age, sex, VDT working hours, and diagnosis of DED, time management, physical demands, and mental and interpersonal functioning showed a significant relationship to DED (each P > .05). Annual DED productivity losses were estimated to be $6160 per employee when measured by total production and $1178 per employee calculated by wage. This study indicated that there is a significant impact of DED on the total productivity of Japanese VDT users. Copyright © 2014 Elsevier Inc. All rights reserved.

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

PubMed

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

2017-04-01

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

Medical review licensing outcomes in drivers with visual field loss in Victoria, Australia

PubMed Central

Muir, Carlyn; Charlton, Judith L; Odell, Morris; Keeffe, Jill; Wood, Joanne; Bohensky, Megan; Fildes, Brian; Oxley, Jennifer; Bentley, Sharon; Rizzo, Matthew

2017-01-01

Background Good vision is essential for safe driving and studies have associated visual impairment with an increased crash risk. Currently, there is little information about the medical review of drivers with visual field loss. This study examines the prevalence of visual field loss among drivers referred for medical review in one Australian jurisdiction and investigates factors associated with licence outcome in this group. Methods A random sample of 10,000 (31.25 per cent) medical review cases was extracted for analysis from the Victorian licensing authority. Files were screened for the presence of six visual field-related medical conditions. Data were captured on a range of variables, including referral source, age, gender, health status, crash history and licence outcome. Prevalence analyses were univariate and descriptive. Logistic regression was used to assess factors associated with licence outcomes in the visual field loss group. Results Approximately 1.9 per cent of the 10,000 medical review cases screened had a visual field loss condition identified (n=194). Among the visual field loss group, 57.2 per cent were permitted to continue driving (conditional/unconditional licence). Primary referral sources were the police, self-referrals and general medical practitioners. Key factors associated with licence test outcomes were visual field condition, age group, crash involvement and referral to the Driver Licensing Authority’s Medical Advisors. Those who were younger had a crash involvement triggering referral and those who were referred to the Medical Advisors were more likely to have a positive licensing outcome. Conclusion The evidence base for making licensing decisions is complicated by the variable causes, patterns, progressions and measuring technologies for visual field loss. This study highlighted that the involvement of an expert medical advisory service in Victoria resulted in an increased likelihood that drivers with visual field loss will be allowed to continue driving. Further research is warranted to explore issues relating to severity of field loss and the capacity for compensation. PMID:27530283

Pediatric and adult vision restoration after optic nerve sheath decompression for idiopathic intracranial hypertension.

PubMed

Bersani, Thomas A; Meeker, Austin R; Sismanis, Dimitrios N; Carruth, Bryant P

2016-06-01

To compare presentations of idiopathic intracranial hypertension and efficacy of optic nerve sheath decompression between adult and pediatric patients, a retrospective cohort study was completed All idiopathic intracranial hypertension patients undergoing optic nerve sheath decompression by one surgeon between 1991 and 2012 were included. Pre-operative and post-operative visual fields, visual acuity, color vision, and optic nerve appearance were compared between adult and pediatric (<18 years) populations. Outcome measures included percentage of patients with complications or requiring subsequent interventions. Thirty-one adults (46 eyes) and eleven pediatric patients (18 eyes) underwent optic nerve sheath decompression for vision loss from idiopathic intracranial hypertension. Mean deviation on visual field, visual acuity, color vision, and optic nerve appearance significantly improved across all subjects. Pre-operative mean deviation was significantly worse in children compared to adults (p=0.043); there was no difference in mean deviation post-operatively (p=0.838). Significantly more pediatric eyes (6) presented with light perception only or no light perception than adult eyes (0) (p=0.001). Pre-operative color vision performance in children (19%) was significantly worse than in adults (46%) (p=0.026). Percentage of patients with complications or requiring subsequent interventions did not differ between groups. The consistent improvement after surgery and low rate of complications suggest optic nerve sheath decompression is safe and effective in managing vision loss due to adult and pediatric idiopathic intracranial hypertension. Given the advanced pre-operative visual deficits seen in children, one might consider a higher index of suspicion in diagnosing, and earlier surgical intervention in treating pediatric idiopathic intracranial hypertension.

Ranibizumab for the treatment of neovascular AMD.

PubMed

Kaiser, P K; Do, D V

2007-03-01

Age-related macular degeneration (AMD) is the leading cause of adult blindness among individuals aged 50 and older in the Western world, with the neovascular form of AMD responsible for the most severe and rapid visual loss. Although monotherapy with currently available treatments can slow the rate of loss of vision in eyes with neovascular AMD, they do not significantly improve vision. Vascular endothelial growth factor-A (VEGF-A) plays a critical role in the pathogenesis of neovascular AMD, and ranibizumab is a promising new treatment that targets all VEGF-A isoforms and their biologically active degradation products. Clinical trials have reported that ranibizumab treatment resulted in greater proportions of patients achieving a < 15 letter loss of visual acuity and improved vision at 12 and 24 months than control groups. The incidence of serious ocular and systemic adverse events was low in all ranibizumab trials to date. Currently, ranibizumab is the only treatment for neovascular AMD to demonstrate significant improvement in vision for many patients and represents a major advance in treating neovascular AMD.

Retrieval analysis of ceramic-coated metal-on-polyethylene total hip replacements.

PubMed

Khatkar, Harman; Hothi, Harry; de Villiers, Danielle; Lausmann, Christian; Kendoff, Daniel; Gehrke, Thorsten; Skinner, John; Hart, Alister

2017-06-01

Ceramic coatings have been used in metal-on-polyethylene (MOP) hips to reduce the risk of wear and also infection; the clinical efficacy of this remains unclear. This retrieval study sought to better understand the performance of coated bearing surfaces. Forty-three coated MOP components were analysed post-retrieval for evidence of coating loss and gross polyethylene wear. Coating loss was graded using a visual semi-quantitative protocol. Evidence of gross polyethylene wear was determined by radiographic analysis and visual inspection of the retrieved implants. All components with gross polyethylene wear (n = 10) were revised due to a malfunctioning acetabular component; 35 % (n = 15) of implants exhibited visible coating loss and the incidence of polyethylene wear in samples with coating loss was 54 %, significantly (p = 0.02) elevated compared to samples with intact coatings (14 %). In this study we found evidence of coating loss on metal femoral heads which was associated with increased wear of the corresponding polyethylene acetabular cups.

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.

Impact of Glaucoma and Dry Eye on Text-Based Searching

PubMed Central

Sun, Michelle J.; Rubin, Gary S.; Akpek, Esen K.; Ramulu, Pradeep Y.

2017-01-01

Purpose We determine if visual field loss from glaucoma and/or measures of dry eye severity are associated with difficulty searching, as judged by slower search times on a text-based search task. Methods Glaucoma patients with bilateral visual field (VF) loss, patients with clinically significant dry eye, and normally-sighted controls were enrolled from the Wilmer Eye Institute clinics. Subjects searched three Yellow Pages excerpts for a specific phone number, and search time was recorded. Results A total of 50 glaucoma subjects, 40 dry eye subjects, and 45 controls completed study procedures. On average, glaucoma patients exhibited 57% longer search times compared to controls (95% confidence interval [CI], 26%–96%, P < 0.001), and longer search times were noted among subjects with greater VF loss (P < 0.001), worse contrast sensitivity (P < 0.001), and worse visual acuity (P = 0.026). Dry eye subjects demonstrated similar search times compared to controls, though worse Ocular Surface Disease Index (OSDI) vision-related subscores were associated with longer search times (P < 0.01). Search times showed no association with OSDI symptom subscores (P = 0.20) or objective measures of dry eye (P > 0.08 for Schirmer's testing without anesthesia, corneal fluorescein staining, and tear film breakup time). Conclusions Text-based visual search is slower for glaucoma patients with greater levels of VF loss and dry eye patients with greater self-reported visual difficulty, and these difficulties may contribute to decreased quality of life in these groups. Translational Relevance Visual search is impaired in glaucoma and dry eye groups compared to controls, highlighting the need for compensatory strategies and tools to assist individuals in overcoming their deficiencies. PMID:28670502

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.

Amaurosis fugax

MedlinePlus

... other symptoms with the vision loss, seek medical attention right away. Alternative Names Transient monocular blindness; Transient monocular visual loss; TMLV; Transient monocular visual loss; Transient binocular ...

Eccentric correction for off-axis vision in central visual field loss.

PubMed

Gustafsson, Jörgen; Unsbo, Peter

2003-07-01

Subjects with absolute central visual field loss use eccentric fixation and magnifying devices to utilize their residual vision. This preliminary study investigated the importance of an accurate eccentric correction of off-axis refractive errors to optimize the residual visual function for these subjects. Photorefraction using the PowerRefractor instrument was used to evaluate the ametropia in eccentric fixation angles. Methods were adapted for measuring visual acuity outside the macula using filtered optotypes from high-pass resolution perimetry. Optical corrections were implemented, and the visual function of subjects with central visual field loss was measured with and without eccentric correction. Of the seven cases reported, five experienced an improvement in visual function in their preferred retinal locus with eccentric refraction. The main result was that optical correction for better image quality on the peripheral retina is important for the vision of subjects with central visual field loss, objectively as well as subjectively.

Blindsight and Unconscious Vision: What They Teach Us about the Human Visual System

PubMed Central

Ajina, Sara; Bridge, Holly

2017-01-01

Damage to the primary visual cortex removes the major input from the eyes to the brain, causing significant visual loss as patients are unable to perceive the side of the world contralateral to the damage. Some patients, however, retain the ability to detect visual information within this blind region; this is known as blindsight. By studying the visual pathways that underlie this residual vision in patients, we can uncover additional aspects of the human visual system that likely contribute to normal visual function but cannot be revealed under physiological conditions. In this review, we discuss the residual abilities and neural activity that have been described in blindsight and the implications of these findings for understanding the intact system. PMID:27777337

Traits and causes of environmental loss-related chemical accidents in China based on co-word analysis.

PubMed

Wu, Desheng; Song, Yu; Xie, Kefan; Zhang, Baofeng

2018-04-25

Chemical accidents are major causes of environmental losses and have been debated due to the potential threat to human beings and environment. Compared with the single statistical analysis, co-word analysis of chemical accidents illustrates significant traits at various levels and presents data into a visual network. This study utilizes a co-word analysis of the keywords extracted from the Web crawling texts of environmental loss-related chemical accidents and uses the Pearson's correlation coefficient to examine the internal attributes. To visualize the keywords of the accidents, this study carries out a multidimensional scaling analysis applying PROXSCAL and centrality identification. The research results show that an enormous environmental cost is exacted, especially given the expected environmental loss-related chemical accidents with geographical features. Meanwhile, each event often brings more than one environmental impact. Large number of chemical substances are released in the form of solid, liquid, and gas, leading to serious results. Eight clusters that represent the traits of these accidents are formed, including "leakage," "poisoning," "explosion," "pipeline crack," "river pollution," "dust pollution," "emission," and "industrial effluent." "Explosion" and "gas" possess a strong correlation with "poisoning," located at the center of visualization map.

Modality specific semantic knowledge loss for unique items.

PubMed

Kartsounis, L D; Shallice, T

1996-03-01

We report the case of a man who, following a major myocardial infarction, suffered anoxia followed by significant event memory impairment. Investigations indicated that his semantic memory for word concepts and object meanings was well preserved. However, he had great difficulty in identifying in the visual (but not verbal) modality historically known people, such as Queen Elizabeth I and Napoleon, and well known world and London landmarks, such as the Parthenon and Buckingham Palace. This selective impairment could not be accounted for in terms of prosopagnosia or high level visual perceptual deficits and we interpret it as a modality specific semantic memory loss for unique objects.

Visual and proprioceptive interaction in patients with bilateral vestibular loss.

PubMed

Cutfield, Nicholas J; Scott, Gregory; Waldman, Adam D; Sharp, David J; Bronstein, Adolfo M

2014-01-01

Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular function in BVL patients.

Correlation of Retinal Nerve Fiber Layer Thickness and Visual Fields in Glaucoma: A broken stick model

PubMed Central

Alasil, Tarek; Wang, Kaidi; Yu, Fei; Field, Matthew G.; Lee, Hang; Baniasadi, Neda; de Boer, Johannes F.; Coleman, Anne L.; Chen, Teresa C.

2015-01-01

Purpose To determine the retinal nerve fiber layer (RNFL) thickness at which visual field (VF) damage becomes detectable and associated with structural loss. Design Retrospective cross-sectional study. Methods Eighty seven healthy and 108 glaucoma subjects (one eye per subject) were recruited from an academic institution. All patients had VF examinations (Swedish Interactive Threshold Algorithm 24-2 test of the Humphrey visual field analyzer 750i; Carl Zeiss Meditec, Dublin, CA) and spectral domain optical coherence tomography RNFL scans (Spectralis, Heidelberg Engineering, Heidelberg, Germany). Comparison of RNFL thicknesses values with VF threshold values showed a plateau of VF threshold values at high RNFL thickness values and then a sharp decrease at lower RNFL thickness values. A broken stick statistical analysis was utilized to estimate the tipping point at which RNFL thickness values are associated with VF defects. The slope for the association between structure and function was computed for data above and below the tipping point. Results The mean RNFL thickness value that was associated with initial VF loss was 89 μm. The superior RNFL thickness value that was associated with initial corresponding inferior VF loss was 100 μm. The inferior RNFL thickness value that was associated with initial corresponding superior VF loss was 73 μm. The differences between all the slopes above and below the aforementioned tipping points were statistically significant (p<0.001). Conclusions In open angle glaucoma, substantial RNFL thinning or structural loss appears to be necessary before functional visual field defects become detectable. PMID:24487047

Screening methods for post-stroke visual impairment: a systematic review.

PubMed

Hanna, Kerry Louise; Hepworth, Lauren Rachel; Rowe, Fiona

2017-12-01

To provide a systematic overview of the various tools available to screen for post-stroke visual impairment. A review of the literature was conducted including randomised controlled trials, controlled trials, cohort studies, observational studies, systematic reviews and retrospective medical note reviews. All languages were included and translation was obtained. Participants included adults ≥18 years old diagnosed with a visual impairment as a direct cause of a stroke. We searched a broad range of scholarly online resources and hand-searched articles registers of published, unpublished and on-going trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Study selection was performed by two authors independently. The quality of the evidence and risk of bias were assessed using the STROBE, GRACE and PRISMA statements. A total of 25 articles (n = 2924) were included in this review. Articles appraised reported on tools screening solely for visual impairments or for general post-stroke disabilities inclusive of vision. The majority of identified tools screen for visual perception including visual neglect (VN), with few screening for visual acuity (VA), visual field (VF) loss or ocular motility (OM) defects. Six articles reported on nine screening tools which combined visual screening assessment alongside screening for general stroke disabilities. Of these, three included screening for VA; three screened for VF loss; three screened for OM defects and all screened for VN. Two tools screened for all visual impairments. A further 19 articles were found which reported on individual vision screening tests in stroke populations; two for VF loss; 11 for VN and six for other visual perceptual defects. Most tools cannot accurately account for those with aphasia or communicative deficits, which are common problems following a stroke. There is currently no standardised visual screening tool which can accurately assess all potential post-stroke visual impairments. The current tools screen for only a number of potential stroke-related impairments, which means many visual defects may be missed. The sensitivity of those which screen for all impairments is significantly lowered when patients are unable to report their visual symptoms. Future research is required to develop a tool capable of assessing stroke patients which encompasses all potential visual deficits and can also be easily performed by both the patients and administered by health care professionals in order to ensure all stroke survivors with visual impairment are accurately identified and managed. Implications for Rehabilitation Over 65% of stroke survivors will suffer from a visual impairment, whereas 45% of stroke units do not assess vision. Visual impairment significantly reduces the quality of life, such as being unable to return to work, driving and depression. This review outlines the available screening methods to accurately identify stroke survivors with visual impairments. Identifying visual impairment after stroke can aid general rehabilitation and thus, improve the quality of life for these patients.

Accidental human laser retinal injuries from military laser systems

NASA Astrophysics Data System (ADS)

Stuck, Bruce E.; Zwick, Harry; Molchany, Jerome W.; Lund, David J.; Gagliano, Donald A.

1996-04-01

The time course of the ophthalmoscopic and functional consequences of eight human laser accident cases from military laser systems is described. All patients reported subjective vision loss with ophthalmoscopic evidence of retinal alteration ranging from vitreous hemorrhage to retinal burn. Five of the cases involved single or multiple exposures to Q-switched neodymium radiation at close range whereas the other three incidents occur over large ranges. Most exposures were within 5 degrees of the foveola, yet none directly in the foveola. High contrast visual activity improved with time except in the cases with progressive retinal fibrosis between lesion sites or retinal hole formation encroaching the fovea. In one patient the visual acuity recovered from 20/60 at one week to 20/25 in four months with minimal central visual field loss. Most cases showed suppression of high and low spatial frequency contrast sensitivity. Visual field measurements were enlarged relative to ophthalmoscopic lesion size observations. Deep retinal scar formation and retinal traction were evident in two of the three cases with vitreous hemorrhage. In one patient, nerve fiber layer damage to the papillo-macular bundle was clearly evident. Visual performance measured with a pursuit tracking task revealed significant performance loss relative to normal tracking observers even in cases where acuity returned to near normal levels. These functional and performance deficits may reflect secondary effects of parafoveal laser injury.

The Economic Burden of Visual Impairment and Comorbid Fatigue: A Cost-of-Illness Study (From a Societal Perspective).

PubMed

Schakel, Wouter; van der Aa, Hilde P A; Bode, Christina; Hulshof, Carel T J; van Rens, Ger H M B; van Nispen, Ruth M A

2018-04-01

To investigate the burden of visual impairment and comorbid fatigue in terms of impact on daily life, by estimating societal costs (direct medical costs and indirect non-health care costs) accrued by these conditions. This cost-of-illness study was performed from a societal perspective. Cross-sectional data of visually impaired adults and normally sighted adults were collected through structured telephone interviews and online surveys, respectively. Primary outcomes were fatigue severity (FAS), impact of fatigue on daily life (MFIS), and total societal costs. Cost differences between participants with and without vision loss, and between participants with and without fatigue, were examined by (adjusted) multivariate regression analyses, including bootstrapped confidence intervals. Severe fatigue (FAS ≥ 22) and high fatigue impact (MFIS ≥ 38) was present in 57% and 40% of participants with vision loss (n = 247), respectively, compared to 22% (adjusted odds ratio [OR] 4.6; 95% confidence interval [CI] [2.7, 7.6]) and 11% (adjusted OR 4.8; 95% CI [2.7, 8.7]) in those with normal sight (n = 233). A significant interaction was found between visual impairment and high fatigue impact for total societal costs (€449; 95% CI [33, 1017]). High fatigue impact was associated with significantly increased societal costs for participants with visual impairment (mean difference €461; 95% CI [126, 797]), but this effect was not observed for participants with normal sight (€12; 95% CI [-527, 550]). Visual impairment is associated with an increased prevalence of high fatigue impact that largely determines the economic burden of visual impairment. The substantial costs of visual impairment and comorbid fatigue emphasize the need for patient-centered interventions aimed at decreasing its impact.

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.

The cost of misremembering: Inferring the loss function in visual working memory.

PubMed

Sims, Chris R

2015-03-04

Visual working memory (VWM) is a highly limited storage system. A basic consequence of this fact is that visual memories cannot perfectly encode or represent the veridical structure of the world. However, in natural tasks, some memory errors might be more costly than others. This raises the intriguing possibility that the nature of memory error reflects the costs of committing different kinds of errors. Many existing theories assume that visual memories are noise-corrupted versions of afferent perceptual signals. However, this additive noise assumption oversimplifies the problem. Implicit in the behavioral phenomena of visual working memory is the concept of a loss function: a mathematical entity that describes the relative cost to the organism of making different types of memory errors. An optimally efficient memory system is one that minimizes the expected loss according to a particular loss function, while subject to a constraint on memory capacity. This paper describes a novel theoretical framework for characterizing visual working memory in terms of its implicit loss function. Using inverse decision theory, the empirical loss function is estimated from the results of a standard delayed recall visual memory experiment. These results are compared to the predicted behavior of a visual working memory system that is optimally efficient for a previously identified natural task, gaze correction following saccadic error. Finally, the approach is compared to alternative models of visual working memory, and shown to offer a superior account of the empirical data across a range of experimental datasets. © 2015 ARVO.

Arterial spin labeling fMRI measurements of decreased blood flow in primary visual cortex correlates with decreased visual function in human glaucoma.

PubMed

Duncan, Robert O; Sample, Pamela A; Bowd, Christopher; Weinreb, Robert N; Zangwill, Linda M

2012-05-01

Altered metabolic activity has been identified as a potential contributing factor to the neurodegeneration associated with primary open angle glaucoma (POAG). Consequently, we sought to determine whether there is a relationship between the loss of visual function in human glaucoma and resting blood perfusion within primary visual cortex (V1). Arterial spin labeling (ASL) functional magnetic resonance imaging (fMRI) was conducted in 10 participants with POAG. Resting cerebral blood flow (CBF) was measured from dorsal and ventral V1. Behavioral measurements of visual function were obtained using standard automated perimetry (SAP), short-wavelength automated perimetry (SWAP), and frequency-doubling technology perimetry (FDT). Measurements of CBF were compared to differences in visual function for the superior and inferior hemifield. Differences in CBF between ventral and dorsal V1 were correlated with differences in visual function for the superior versus inferior visual field. A statistical bootstrapping analysis indicated that the observed correlations between fMRI responses and measurements of visual function for SAP (r=0.49), SWAP (r=0.63), and FDT (r=0.43) were statistically significant (all p<0.05). Resting blood perfusion in human V1 is correlated with the loss of visual function in POAG. Altered CBF may be a contributing factor to glaucomatous optic neuropathy, or it may be an indication of post-retinal glaucomatous neurodegeneration caused by damage to the retinal ganglion cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Image gathering and restoration - Information and visual quality

NASA Technical Reports Server (NTRS)

Mccormick, Judith A.; Alter-Gartenberg, Rachel; Huck, Friedrich O.

1989-01-01

A method is investigated for optimizing the end-to-end performance of image gathering and restoration for visual quality. To achieve this objective, one must inevitably confront the problems that the visual quality of restored images depends on perceptual rather than mathematical considerations and that these considerations vary with the target, the application, and the observer. The method adopted in this paper is to optimize image gathering informationally and to restore images interactively to obtain the visually preferred trade-off among fidelity resolution, sharpness, and clarity. The results demonstrate that this method leads to significant improvements in the visual quality obtained by the traditional digital processing methods. These traditional methods allow a significant loss of visual quality to occur because they treat the design of the image-gathering system and the formulation of the image-restoration algorithm as two separate tasks and fail to account for the transformations between the continuous and the discrete representations in image gathering and reconstruction.

Social Inequality and Visual Impairment in Older People.

PubMed

Whillans, Jennifer; Nazroo, James

2018-03-02

Visual impairment is the leading cause of age-related disability, but the social patterning of loss of vision in older people has received little attention. This study's objective was to assess the association between social position and onset of visual impairment, to empirically evidence health inequalities in later life. Visual impairment was measured in 2 ways: self-reporting fair vision or worse (moderate) and self-reporting poor vision or blindness (severe). Correspondingly, 2 samples were drawn from the English Longitudinal Study on Ageing (ELSA). First, 7,483 respondents who had good vision or better at Wave 1; second, 8,487 respondents who had fair vision or better at Wave 1. Survival techniques were used. Cox proportional hazards models showed wealth and subjective social status (SSS) were significant risk factors associated with the onset of visual impairment. The risk of onset of moderate visual impairment was significantly higher for the lowest and second lowest wealth quintiles, whereas the risk of onset of severe visual impairment was significantly higher for the lowest, second, and even middle wealth quintiles, compared with the highest wealth quintile. Independently, lower SSS was associated with increased risk of onset of visual impairment (both measures), particularly so for those placing themselves on the lowest rungs of the social ladder. The high costs of visual impairment are disproportionately felt by the worst off elderly. Both low wealth and low SSS significantly increase the risk of onset of visual impairment.

Driving habits in older patients with central vision loss.

PubMed

Sengupta, Sabyasachi; van Landingham, Suzanne W; Solomon, Sharon D; Do, Diana V; Friedman, David S; Ramulu, Pradeep Y

2014-03-01

To determine if central visual loss is associated with driving cessation, driving restriction, or other-driver preference. Cross-sectional study. Sixty-four subjects with bilateral visual loss (<20/32 in better eye) or severe unilateral visual loss (<20/200) from age-related macular degeneration (AMD) and 58 normally sighted controls between 60 and 80 years of age. Participants self-reported driving habits. Other-driver preference was defined as preferring that another drive when there is more than 1 driver in the car. Subjects reporting 2 or more driving limitations were considered to have restricted their driving. Self-reported driving cessation, other-driver preference, and driving restriction. Age-related macular degeneration subjects were older (74.7 vs. 69.7 years), had worse visual acuity (VA; mean better-eye VA, 0.43 vs. 0.08 logarithm of minimum angle of resolution [logMAR]) and contrast sensitivity (CS; 1.4 vs. 1.9 log units of CS [logCS]), and were more likely to be white when compared with controls (P<0.001 for all). Drivers with AMD-related vision loss were more likely to avoid driving over longer distances, beyond 1 hour, at night, and in unfamiliar conditions (P < 0.05 for all). In multivariate models, driving cessation was associated with worse better-eye VA (odds ratio [OR], 1.5 per 1-line decrement in VA; P<0.001) and worse binocular CS (OR, 1.36 per 0.1 logCS increment; P = 0.005); however, AMD group status was not associated with driving cessation (OR, 1.9; P = 0.35). Factors predicting driving restriction were AMD (OR, 9.0; P = 0.004), worse vision (OR, 2.5 per line of VA loss; P<0.001), lower CS (OR, 2.2 per 0.1-logCS increment; P<0.001), and female gender (OR, 27.9; P = 0.002). Other-driver preference was more common with worse vision (OR, 1.6 per 0.1-logMAR increment; P = 0.003), female gender (OR, 4.5; P = 0.02), and being married (OR, 3.8; P = 0.04). Most patients with AMD-related central vision loss continue to drive, but demonstrate significant driving restrictions, especially with more severe VA and CS loss. Future work should determine which driving adaptations the visually impaired best balance safety and independence. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Progression of asymptomatic optic disc swelling to non-arteritic anterior ischaemic optic neuropathy.

PubMed

Subramanian, Prem S; Gordon, Lynn K; Bonelli, Laura; Arnold, Anthony C

2017-05-01

The time of onset of optic disc swelling in non-arteritic anterior ischaemic optic neuropathy (NAION) is not known, and it is commonly assumed to arise simultaneously with vision loss. Our goal is to report the presence and persistence of optic disc swelling without initial vision loss and its subsequent evolution to typical, symptomatic NAION. Clinical case series of patients with optic disc swelling and normal visual acuity and visual fields at initial presentation who progressed to have vision loss typical of NAION. All subjects underwent automated perimetry, disc photography and optic coherence tomography and/or fluorescein angiography to evaluate optic nerve function and perfusion. Four patients were found to have sectoral or diffuse optic disc swelling without visual acuity or visual field loss; the fellow eye of all four had either current or prior NAION or a 'disc at risk' configuration. Over several weeks of clinical surveillance, each patient experienced sudden onset of visual field and/or visual acuity loss typical for NAION. Current treatment options for NAION once vision loss occurs are limited and may not alter the natural history of the disorder. Subjects with NAION may have disc swelling for 2-10 weeks prior to the occurrence of visual loss, and with the development of new therapeutic agents, treatment at the time of observed disc swelling could prevent vision loss from NAION. 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/.

Relationship among visual field, blood flow, and neural structure measurements in glaucoma.

PubMed

Hwang, John C; Konduru, Ranjith; Zhang, Xinbo; Tan, Ou; Francis, Brian A; Varma, Rohit; Sehi, Mitra; Greenfield, David S; Sadda, Srinivas R; Huang, David

2012-05-17

To determine the relationship among visual field, neural structural, and blood flow measurements in glaucoma. Case-control study. Forty-seven eyes of 42 patients with perimetric glaucoma were age-matched with 27 normal eyes of 27 patients. All patients underwent Doppler Fourier-domain optical coherence tomography to measure retinal blood flow and standard glaucoma evaluation with visual field testing and quantitative structural imaging. Linear regression analysis was performed to analyze the relationship among visual field, blood flow, and structure, after all variables were converted to logarithmic decibel scale. Retinal blood flow was reduced in glaucoma eyes compared to normal eyes (P < 0.001). Visual field loss was correlated with both reduced retinal blood flow and structural loss of rim area and retinal nerve fiber layer (RNFL). There was no correlation or paradoxical correlation between blood flow and structure. Multivariate regression analysis revealed that reduced blood flow and structural loss are independent predictors of visual field loss. Each dB decrease in blood flow was associated with at least 1.62 dB loss in mean deviation (P ≤ 0.001), whereas each dB decrease in rim area and RNFL was associated with 1.15 dB and 2.56 dB loss in mean deviation, respectively (P ≤ 0.03). There is a close link between reduced retinal blood flow and visual field loss in glaucoma that is largely independent of structural loss. Further studies are needed to elucidate the causes of the vascular dysfunction and potential avenues for therapeutic intervention. Blood flow measurement may be useful as an independent assessment of glaucoma severity.

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.

Frequency of Testing to Detect Visual Field Progression Derived Using a Longitudinal Cohort of Glaucoma Patients.

PubMed

Wu, Zhichao; Saunders, Luke J; Daga, Fábio B; Diniz-Filho, Alberto; Medeiros, Felipe A

2017-06-01

To determine the time required to detect statistically significant progression for different rates of visual field loss using standard automated perimetry (SAP) when considering different frequencies of testing using a follow-up scheme that resembles clinical practice. Observational cohort study. One thousand seventy-two eyes of 665 patients with glaucoma followed up over an average of 4.3±0.9 years. Participants with 5 or more visual field tests over a 2- to 5-year period were included to derive the longitudinal measurement variability of SAP mean deviation (MD) using linear regressions. Estimates of variability then were used to reconstruct real-world visual field data by computer simulation to evaluate the time required to detect progression for various rates of visual field loss and different frequencies of testing. The evaluation was performed using a follow-up scheme that resembled clinical practice by requiring a set of 2 baseline tests and a confirmatory test to identify progression. Time (in years) required to detect progression. The time required to detect a statistically significant negative MD slope decreased as the frequency of testing increased, albeit not proportionally. For example, 80% of eyes with an MD loss of -2 dB/year would be detected after 3.3, 2.4, and 2.1 years when testing is performed once, twice, and thrice per year, respectively. For eyes with an MD loss of -0.5 dB/year, progression can be detected with 80% power after 7.3, 5.7, and 5.0 years, respectively. This study provides information on the time required to detect progression using MD trend analysis in glaucoma eyes when different testing frequencies are used. The smaller gains in the time to detect progression when testing is increased from twice to thrice per year suggests that obtaining 2 reliable tests at baseline followed by semiannual testing and confirmation of progression through repeat testing in the initial years of follow-up may provide a good compromise for detecting progression, while minimizing the burden on health care resources in clinical practice. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

[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.

Light-Emitting Diode (LED) therapy improves occipital cortex damage by decreasing apoptosis and increasing BDNF-expressing cells in methanol-induced toxicity in rats.

PubMed

Ghanbari, Amir; Ghareghani, Majid; Zibara, Kazem; Delaviz, Hamdallah; Ebadi, Elham; Jahantab, Mohammad Hossein

2017-05-01

Methanol-induced retinal toxicity, frequently associated with elevated free radicals and cell edema, is characterized by progressive retinal ganglion cell (RGC) death and vision loss. Previous studies investigated the effect of photomodulation on RGCs, but not the visual cortex. In this study, the effect of 670nm Light-Emitting Diode (LED) therapy on RGCs and visual cortex recovery was investigated in a seven-day methanol-induced retinal toxicity protocol in rats. Methanol administration showed a reduction in the number of RGCs, loss of neurons (neuronal nuclear antigen, NeuN+), activation of glial fibrillary acidic protein (GFAP+) expressing cells, suppression of brain-derived neurotrophic factor (BDNF+) positive cells, increase in apoptosis (caspase 3+) and enhancement of nitric oxide (NO) release in serum and brain. On the other hand, LED therapy significantly reduced RGC death, in comparison to the methanol group. In addition, the number of BDNF positive cells was significantly higher in the visual cortex of LED-treated group, in comparison to methanol-intoxicated and control groups. Moreover, LED therapy caused a significant decrease in cell death (caspase 3+ cells) and a significant reduction in the NO levels, both in serum and brain tissue, in comparison to methanol-intoxicated rats. Overall, LED therapy demonstrated a number of beneficial effects in decreasing oxidative stress and in functional recovery of RGCs and visual cortex. Our data suggest that LED therapy could be a potential condidate as a non-invasive approach for treatment of retinal damage, which needs further clinicl studies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Experience-induced interocular plasticity of vision in infancy.

PubMed

Tschetter, Wayne W; Douglas, Robert M; Prusky, Glen T

2011-01-01

Animal model studies of amblyopia have generally concluded that enduring effects of monocular deprivation (MD) on visual behavior (i.e., loss of visual acuity) are limited to the deprived eye, and are restricted to juvenile life. We have previously reported, however, that lasting effects of MD on visual function can be elicited in adulthood by stimulating visuomotor experience through the non-deprived eye. To test whether stimulating experience would also induce interocular plasticity of vision in infancy, we assessed in rats from eye-opening on postnatal day (P) 15, the effect of pairing MD with the daily experience of measuring thresholds for optokinetic tracking (OKT). MD with visuomotor experience from P15 to P25 led to a ~60% enhancement of the spatial frequency threshold for OKT through the non-deprived eye during the deprivation, which was followed by loss-of-function (~60% below normal) through both eyes when the deprived eye was opened. Reduced thresholds were maintained into adulthood with binocular OKT experience from P25 to P30. The ability to generate the plasticity and maintain lost function was dependent on visual cortex. Strictly limiting the period of deprivation to infancy by opening the deprived eye at P19 resulted in a comparable loss-of-function. Animals with reduced OKT responses also had significantly reduced visual acuity, measured independently in a discrimination task. Thus, experience-dependent cortical plasticity that can lead to amblyopia is present earlier in life than previously recognized.

Is the Charcot and Bernard case (1883) of loss of visual imagery really based on neurological impairment?

PubMed

Zago, Stefano; Allegri, Nicola; Cristoffanini, Marta; Ferrucci, Roberta; Porta, Mauro; Priori, Alberto

2011-11-01

INTRODUCTION. The Charcot and Bernard case of visual imagery, Monsieur X, is a classic case in the history of neuropsychology. Published in 1883, it has been considered the first case of visual imagery loss due to brain injury. Also in recent times a neurological valence has been given to it. However, the presence of analogous cases of loss of visual imagery in the psychiatric field have led us to hypothesise functional origins rather than organic. METHODS. In order to assess the validity of such an inference, we have compared the symptomatology of Monsieur X with that found in cases of loss of visual mental images, both psychiatric and neurological, presented in literature. RESULTS. The clinical findings show strong assonances of the Monsieur X case with the symptoms manifested over time by the patients with functionally based loss of visual imagery. CONCLUSION. Although Monsieur X's damage was initially interpreted as neurological, reports of similar symptoms in the psychiatric field lead us to postulate a functional cause for his impairment as well.

A comparison of patient pain and visual outcome using topical anesthesia versus regional anesthesia during cataract surgery.

PubMed

Hosoda, Yoshikatsu; Kuriyama, Shoji; Jingami, Yoko; Hattori, Hidetsugu; Hayashi, Hisako; Matsumoto, Miho

2016-01-01

The purpose of this study was to compare the level of patient pain during the phacoemulsification and implantation of foldable intraocular lenses while under topical, intracameral, or sub-Tenon lidocaine. This was a retrospective study. Three hundred and one eyes subjected to cataract surgery were included in this study. All eyes underwent phacoemulsification surgery and intraocular lens implantation using topical, sub-Tenon, or intracameral anesthesia. The topical group received 4% lidocaine drops, and the intracameral group received a 0.1-0.2 cc infusion of 1% preservative-free lidocaine into the anterior chamber through the side port combined with topical drops of lidocaine. The sub-Tenon group received 2% lidocaine. Best-corrected visual acuity, corneal endothelial cell loss, and intraoperative pain level were evaluated. Pain level was assessed on a visual analog scale (range 0-2). There were no significant differences in visual outcome and corneal endothelial cell loss between the three groups. The mean pain score in the sub-Tenon group was significantly lower than that in the topical and intracameral groups (P=0.0009 and P=0.0055, respectively). In 250 eyes without high myopia (< -6D), there were no significant differences in mean pain score between the sub-Tenon and intracameral groups (P=0.1417). No additional anesthesia was required in all groups. Intracameral lidocaine provides sufficient pain suppressive effects in eyes without high myopia, while sub-Tenon anesthesia is better for cataract surgery in eyes with high myopia.

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.

Spatial contrast sensitivity vision loss in children with cortical visual impairment.

PubMed

Good, William V; Hou, Chuan; Norcia, Anthony M

2012-11-19

Although cortical visual impairment (CVI) is the leading cause of bilateral vision impairment in children in Western countries, little is known about the effects of CVI on visual function. The aim of this study was to compare visual evoked potential measures of contrast sensitivity and grating acuity in children with CVI with those of age-matched typically developing controls. The swept parameter visual evoked potential (sVEP) was used to measure contrast sensitivity and grating acuity in 34 children with CVI at 5 months to 5 years of age and in 16 age-matched control children. Contrast thresholds and spatial frequency thresholds (grating acuities) were derived by extrapolating the tuning functions to zero amplitude. These thresholds and maximal suprathreshold response amplitudes were compared between groups. Among 34 children with CVI, 30 had measurable but reduced contrast sensitivity with a median threshold of 10.8% (range 5.0%-30.0% Michelson), and 32 had measurable but reduced grating acuity with median threshold 0.49 logMAR (9.8 c/deg, range 5-14 c/deg). These thresholds were significantly reduced, compared with age-matched control children. In addition, response amplitudes over the entire sweep range for both measures were significantly diminished in children with CVI compared with those of control children. Our results indicate that spatial contrast sensitivity and response amplitudes are strongly affected by CVI. The substantial degree of loss in contrast sensitivity suggests that contrast is a sensitive measure for evaluating vision deficits in patients with CVI.

A Small Disc Area Is a Risk Factor for Visual Field Loss Progression in Primary Open-Angle Glaucoma: The Glaucoma Stereo Analysis Study.

PubMed

Kitaoka, Yasushi; Tanito, Masaki; Yokoyama, Yu; Nitta, Koji; Katai, Maki; Omodaka, Kazuko; Nakazawa, Toru

2018-01-01

The Glaucoma Stereo Analysis Study, a cross-sectional multicenter collaborative study, used a stereo fundus camera (nonmyd WX) to assess various morphological parameters of the optic nerve head (ONH) in glaucoma patients. We compared the associations of each parameter between the visual field loss progression group and no-progression group. The study included 187 eyes of 187 patients with primary open-angle glaucoma or normal-tension glaucoma. We divided the mean deviation (MD) slope values of all patients into the progression group (<-0.3 dB/year) and no-progression group (≧-0.3 dB/year). ONH morphological parameters were calculated with prototype analysis software. The correlations between glaucomatous visual field progression and patient characteristics or each ONH parameter were analyzed with Spearman's rank correlation coefficient. The MD slope averages in the progression group and no-progression group were -0.58 ± 0.28 dB/year and 0.05 ± 0.26 dB/year, respectively. Among disc parameters, vertical disc width (diameter), disc area, cup area, and cup volume in the progression group were significantly less than those in the no-progression group. Logistic regression analysis revealed a significant association between the visual field progression and disc area (odds ratio 0.49/mm 2 disc area). A smaller disc area may be associated with more rapid glaucomatous visual field progression.

Diving-related visual loss in the setting of angioid streaks: report of two cases.

PubMed

Angulo Bocco, Maria I; Spielberg, Leigh; Coppens, Greet; Catherine, Janet; Verougstraete, Claire; Leys, Anita M

2012-01-01

The purpose of this study was to report diving-related visual loss in the setting of angioid streaks. Observational case reports of two patients with angioid streaks suffering sudden visual loss immediately after diving. Two young adult male patients presented with visual loss after diving headfirst. Funduscopy revealed angioid streaks, peau d'orange, subretinal hemorrhages, and ruptures of Bruch membrane. Choroidal neovascularization developed during follow-up. Both patients had an otherwise uneventful personal and familial medical history. In patients with angioid streaks, diving headfirst can lead to subretinal hemorrhages and traumatic ruptures in Bruch membrane and increase the risk of maculopathy. Ophthalmologists should caution patients with angioid streaks against diving headfirst.

Clinical outcomes of trabeculectomy vs. Ahmed glaucoma valve implantation in patients with penetrating keratoplasty : (Trabeculectomy vs. Ahmed galucoma valve in patients with penetrating keratoplasty).

PubMed

Akdemir, Mehmet Orcun; Acar, Banu Torun; Kokturk, Furuzan; Acar, Suphi

2016-08-01

The aim of this study was to compare the visual outcomes, intraocular pressure (IOP), and endothelial cell loss caused by trabeculectomy (TRAB) and Ahmed glaucoma valve (AGV) implantation in patients who had previously undergone penetrating keratoplasty (PKP). The data from all patients who underwent surgical treatment of glaucoma after PKP were reviewed at the Cornea Department of Haydarpasa Numune Education and Research Hospital. Eighteen patients who had undergone surgical treatment of glaucoma after PKP were included in this retrospective study. Time between PKP and glaucoma surgeries, visual acuity results, IOP results, endothelial cell counts (ECC) before the surgery, at 1st, 6th, and 12th month of surgery were recorded. Differences between two groups were evaluated. Mean loss of ECC was 315 cells/mm(2) in the AGV group and 197 cells/mm(2) in TRAB group at 12th month of glaucoma surgery. The difference between endothelial cell loss at 12th month of surgery was statistically significant and higher in AGV group (p < 0.001). The decrease in IOP was 64.2 % in AGV group and 46.9 % in TRAB group at 12th month of surgery. Both differences were statistically significant between 2 groups (p = 0.001, 0.001). TRAB successfully decreased both the IOP and endothelial cell loss in patients with post-PKP glaucoma. Ahmed glaucoma valve had a significantly better IOP lowering but higher endothelial cell loss effect.

Relationship between Structural and Functional Assessment of the Visual System in Mildly Disabled Relapsing-Remitting Multiple Sclerosis Patients

PubMed Central

Huseyinoglu, Nergiz; Ekinci, Metin; Ozben, Serkan; Buyukuysal, Cagatay

2014-01-01

Abstract Studies that explored the anterior visual pathway in the patients with multiple sclerosis (MS) have demonstrated contradictory results about the correlation between structural and functional status of optic nerve and retina. We aimed to investigate the functional and structural findings in our cohort of mildly disabled relapsing-remitting MS patients. A total of 134 eyes (80 eyes of the patients with MS and 54 eyes of the control group) were investigated. Eyes of MS patients were divided into two groups—as eyes with history of optic neuritis (ON group) and without history of optic neuritis (NON group). Ophthalmological investigation including visual evoked potentials, standard automated perimetry, and optical coherence tomography were performed for all participants. Retinal and macular thicknesses were significantly decreased in ON and NON groups compared with controls. Also, visual evoked potential latencies and visual field loss were worse in the both MS groups compared with control group. We did not find any correlation between visual evoked potentials and retinal or macular thickness values but visual field parameters were correlated between retinal and macular layer loss in the NON group. According to our results and some previous studies, although both functional and structural changes were detected in patients with MS, functional status markers do not always show parallelism (or synchrony) with structural changes, especially in eyes with history of optic neuritis. PMID:27928266

[Neuro-ophthalmology: the eye as a window to the brain].

PubMed

Kesler, Anat

2013-02-01

Neuro-ophthalmology focuses on the diagnosis and treatment of visual disorders related to the neurological system rather than the globe itself. Being a subspecialty of both neurology and ophthalmology, it requires specialized training and expertise in diseases of the eye, brain, nerves and muscles. Commonly encountered pathologies in neuro-ophthalmology include: optic neuropathies (such as optic neuritis and ischemic optic neuropathy), visual field loss (transient, constant, unexplained), transient visual loss, unspecified visual disturbances, diplopia, abnormal eye movements, thyroid eye disease, myasthenia gravis, anisocoria, and eyelid abnormalities. The current issue of "Harefuah" is dedicated to contemporary knowledge in neuro-opthalmology, and spans from studies of neuromyelitis optica (NMO), ischemic optic neuropathies, and optic neuropathies induced by phosphodiesterase inhibitors, to the management of sight-threatening carotid-cavernous fistulas, and more. These studies emphasize the importance of an interdisciplinary treatment team consisting of a neuro-ophthalmologist, a neuro-radiologist, and sometimes, even a neuro-surgeon. Such an approach may prove to be beneficial to the patient, by optimizing follow-up and treatment decisions. This issue emphasizes how a correct and timely diagnosis is of paramount significance in patients with neuro-ophthalmological disorders.

Audiovisual sentence repetition as a clinical criterion for auditory development in Persian-language children with hearing loss.

PubMed

Oryadi-Zanjani, Mohammad Majid; Vahab, Maryam; Rahimi, Zahra; Mayahi, Anis

2017-02-01

It is important for clinician such as speech-language pathologists and audiologists to develop more efficient procedures to assess the development of auditory, speech and language skills in children using hearing aid and/or cochlear implant compared to their peers with normal hearing. So, the aim of study was the comparison of the performance of 5-to-7-year-old Persian-language children with and without hearing loss in visual-only, auditory-only, and audiovisual presentation of sentence repetition task. The research was administered as a cross-sectional study. The sample size was 92 Persian 5-7 year old children including: 60 with normal hearing and 32 with hearing loss. The children with hearing loss were recruited from Soroush rehabilitation center for Persian-language children with hearing loss in Shiraz, Iran, through consecutive sampling method. All the children had unilateral cochlear implant or bilateral hearing aid. The assessment tool was the Sentence Repetition Test. The study included three computer-based experiments including visual-only, auditory-only, and audiovisual. The scores were compared within and among the three groups through statistical tests in α = 0.05. The score of sentence repetition task between V-only, A-only, and AV presentation was significantly different in the three groups; in other words, the highest to lowest scores belonged respectively to audiovisual, auditory-only, and visual-only format in the children with normal hearing (P < 0.01), cochlear implant (P < 0.01), and hearing aid (P < 0.01). In addition, there was no significant correlationship between the visual-only and audiovisual sentence repetition scores in all the 5-to-7-year-old children (r = 0.179, n = 92, P = 0.088), but audiovisual sentence repetition scores were found to be strongly correlated with auditory-only scores in all the 5-to-7-year-old children (r = 0.943, n = 92, P = 0.000). According to the study's findings, audiovisual integration occurs in the 5-to-7-year-old Persian children using hearing aid or cochlear implant during sentence repetition similar to their peers with normal hearing. Therefore, it is recommended that audiovisual sentence repetition should be used as a clinical criterion for auditory development in Persian-language children with hearing loss. Copyright © 2016. Published by Elsevier B.V.

[Analysis of the Effect of Non-phacoemulsification Cataract Operation on Corneal Endothelial Cell Nucleus Division].

PubMed

Huang, Zufeng; Miao, Xiaoqing

2015-09-01

To investigate the effect of non-phacoemulsification cataract operation in two different patterns of nucleus delivery on the quantity and morphology of corneal endothelial cells and postoperative visual acuity. Forty patients diagnosed with cataract underwent cataract surgery and were assigned into the direct nuclear delivery and semi-nuclear delivery groups. Lens density was measured and divided into the hard and soft lenses according to Emery-little lens nucleus grading system. Non-phacoemulsification cataract operation was performed. At 3 d after surgery, the quantity and morphology of corneal endothelium were counted and observed under corneal endothelial microscope. During 3-month postoperative follow-up, the endothelial cell loss rate, morphological changes and visual acuity were compared among four groups. Corneal endothelial cell loss rate in the direct delivery of hard nucleus group significantly differed from those in the other three groups before and 3 months after operation (P < 0.01), whereas no statistical significance was found among the direct delivery of soft nucleus, semi-delivery of hard nucleus and semi-delivery soft nucleus groups (all P > 0.05). Preoperative and postoperative 2-d visual acuity did not differ between the semi-delivery of hard nucleus and direct delivery of soft nucleus groups (P = 0.49), significantly differed from those in the semi-delivery of soft nucleus (P = 0.03) and direct delivery of hard nucleus groups (P = 0.14). Visual acuity at postoperative four months did not differ among four groups (P = 0.067). During non-phacoemulsification cataract surgery, direct delivery of hard nucleus caused severe injury to corneal endothelium and semi-delivery of soft nucleus yielded mild corneal endothelial injury. Slight corneal endothelial injury exerted no apparent effect upon visual acuity and corneal endothelial morphology at three months after surgery.

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

PubMed

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

2010-06-01

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

The relationship between 3D morphology of optic disc and spatial patterns of visual field loss in glaucoma

NASA Astrophysics Data System (ADS)

Wang, Mengyu; Wang, Hui; Baniasadi, Neda; Elze, Tobias

2017-02-01

Purpose: Optic disc tilt defined over 3D optic disc morphology has been shown to be associated with the location of initial glaucomatous damages. In this work, we study the impact of optic cup depth (OCD) on spatial patterns of visual field loss in glaucoma. Methods: Pairs of reliable Cirrus OCT scans around optic disc and Humphrey visual fields of glaucoma patients without visually significant cataract and age-related macular degeneration were selected. The most recent visit of a randomly selected eye of each patient was chosen. The OCD was automatically calculated on the superior-inferior cross sectional image passing through the optic disc center. The correlations between the mean pattern deviation (PD) of each sector in glaucoma hemifield test (GHT) and Garway-Heath scheme and OCD were evaluated for all severities glaucoma and mild glaucoma (mean deviation >= -5 dB), respectively. Results: 424 eyes of 424 patients passed the data reliability criteria with 346 mild glaucoma patients. For all severities glaucoma, there was no significant correlation between the mean sector PD and OCD. For mild glaucoma, OCD was uniquely correlated to the mean PD of the inferior pericentral sector (r=-0.18, p=0.01) in GHT, which was independent of mean deviation and retinal nerve fiber layer thickness (p<0.001 for both). Conclusion: OCD was uniquely correlated to the vision loss of the inferior pericentral sector in GHT and Garway- Health scheme for mild glaucoma. Future advancement of OCT imaging techniques may provide better clinical diagnosis for early glaucoma by focusing on 3D morphological variation of the optic disc.

Electropysiologic evaluation of the visual pathway in patients with multiple sclerosis.

PubMed

Rodriguez-Mena, Diego; Almarcegui, Carmen; Dolz, Isabel; Herrero, Raquel; Bambo, Maria P; Fernandez, Javier; Pablo, Luis E; Garcia-Martin, Elena

2013-08-01

To evaluate the ability of visual evoked potentials and pattern electroretinograms (PERG) to detect subclinical axonal damage in patients during the early diagnostic stage of multiple sclerosis (MS). The authors also compared the ability of optical coherence tomography (OCT), PERG, and visual evoked potentials to detect axonal loss in MS patients and correlated the functional and structural properties of the retinal nerve fiber layer. Two hundred twenty-eight eyes of 114 subjects (57 MS patients and 57 age- and sex-matched healthy controls) were included. The visual pathway was evaluated based on functional and structural assessments. All patients underwent a complete ophthalmic examination that included assessment of visual acuity, ocular motility, intraocular pressure, visual field, papillary morphology, OCT, visual evoked potentials, and PERG. Visual evoked potentials (P100 latency and amplitude), PERG (N95 amplitude and N95/P50 ratio), and OCT parameters differed significantly between MS patients and healthy subjects. Moderate significant correlations were found between visual evoked potentials or PERG parameters and OCT measurements. Axonal damage in ganglion cells of the visual pathway can be detected based on structural measures provided by OCT in MS patients and by the N95 component and N95/P50 index of PERG, thus providing good correlation between function and structure.

Intraorbital foreign body projectile as a consideration for unilateral pupillary defect

PubMed Central

2012-01-01

Intraorbital foreign bodies are frequently the result of high-velocity injuries with varying clinical presentations. The resultant diagnosis, management, and outcome depend on the type of foreign body present, anatomical location, tissue disruption, and symptomatology. A patient who presented to the Emergency Department with a large intraorbital foreign body projectile that was not evident clinically, but found incidentally on computed tomography and subsequent plain films is reported. The emergency room physician needs to be aware of the differential diagnosis of a unilateral irregular pupil with or without visual acuity changes. The differential diagnosis for any trauma patient with an irregular pupil with significant visual loss must include intraorbital foreign body and associated injury to the optic nerve directly or via orbital compartment syndrome secondary to hemorrhage and/or edema. Patients with significantly decreased visual acuity may benefit from emergent surgical intervention. In patients with intact visual acuity, the patient must be monitored closely for any visual changes as this may require emergent surgical intervention. PMID:22390406

Superior visual performance in nocturnal insects: neural principles and bio-inspired technologies

NASA Astrophysics Data System (ADS)

Warrant, Eric J.

2016-04-01

At night, our visual capacities are severely reduced, with a complete loss in our ability to see colour and a dramatic loss in our ability to see fine spatial and temporal details. This is not the case for many nocturnal animals, notably insects. Our recent work, particularly on fast-flying moths and bees and on ball-rolling dung beetles, has shown that nocturnal animals are able to distinguish colours, to detect faint movements, to learn visual landmarks, to orient to the faint pattern of polarised light produced by the moon and to navigate using the stars. These impressive visual abilities are the result of exquisitely adapted eyes and visual systems, the product of millions of years of evolution. Nocturnal animals typically have highly sensitive eye designs and visual neural circuitry that is optimised for extracting reliable information from dim and noisy visual images. Even though we are only at the threshold of understanding the neural mechanisms responsible for reliable nocturnal vision, growing evidence suggests that the neural summation of photons in space and time is critically important: even though vision in dim light becomes necessarily coarser and slower, it also becomes significantly more reliable. We explored the benefits of spatiotemporal summation by creating a computer algorithm that mimicked nocturnal visual processing strategies. This algorithm dramatically increased the reliability of video collected in dim light, including the preservation of colour, strengthening evidence that summation strategies are essential for nocturnal vision.

Driving with visual field loss : an exploratory simulation study

DOT National Transportation Integrated Search

2009-01-01

The goal of this study was to identify the influence of peripheral visual field loss (VFL) on driving performance in a motion-based driving simulator. Sixteen drivers (6 with VFL and 10 with normal visual fields) completed a 14 km simulated drive. Th...

Cognitive Performance as Predictor and Outcome of Adolescent Bariatric Surgery: A Nonrandomized Pilot Study.

PubMed

Mackey, Eleanor R; Jacobs, Marni; Nadler, Evan P; Olson, Alexandra; Pearce, Alaina; Cherry, J Bradley C; Magge, Sheela N; Mietus-Snyer, Michele; Vaidya, Chandan

2018-05-16

Evidence in adults suggests that improvements in cognitive performance may follow weight loss resulting from bariatric surgery, and baseline cognitive performance may be associated with weight loss following surgery. This has not been evaluated in adolescents. Participants were 38 adolescents of age 14-21 years composed of three groups: (1) 12 adolescents with severe obesity who received vertical sleeve gastrectomy during the study (VSG); (2) 14 adolescents with severe obesity who were wait-listed for VSG (WL); and (3) 12 healthy weight controls (HC). Participants completed testing of visual memory, verbal memory, and executive functioning at baseline (T1), which occurred presurgery for the VSG group, and approximately 4 months after baseline (T2). Body mass index (BMI) was assessed at T1, T2, and additionally at 6 months following VSG for the adolescents who received surgery. Although there was evidence of greater improvement for the VSG as compared with WL and HC groups in visual and verbal memory, group differences did not reach significance and effect sizes were small (η2 < 0.01). There was a significant positive association between indices of baseline executive functioning and excess BMI loss at 6 months postsurgery. This small pilot study showed no significant differences by group in cognitive performance post-VSG. There was a significant association of baseline cognitive performance with weight loss outcomes. Given the very preliminary nature of these results in a small sample, future research should examine these relationships in a larger sample and evaluate mechanisms of these associations (e.g., insulin resistance, sleep, physical activity).

Blindness and visual impairment in the Americas and the Caribbean

PubMed Central

Muñoz, B; West, S K

2002-01-01

Aim: To summarise available data on the prevalence and causes of visual impairment and blindness in the Americas and the Caribbean. Methods: The published literature was searched in Medline and LILACS using the following key words: blindness, visual impairment, prevalence. Articles were reviewed, and the references of the articles were also searched for relevant articles, which were also reviewed. Results: Using the mortality in children under the age of 5 as an indicator, the overall prevalence of childhood blindness (in the under age 15 group) for the region was estimated at 0.45/1000, with the majority (67%) living in countries with mortality of children under age 5 above 30/1000 live births. Corneal opacities were more common in countries where the under 5 year mortality are above 30/1000 live births and retinopathy of prematurity (ROP) was an important cause in countries with intermediate death rates. For adults, overall blindness rates were not estimated because of the social, economic, and ethnic diversity in the region. The primary causes of visual loss in adults in the Americas were age related eye diseases, notably cataract and glaucoma in the African-American and Hispanic populations, and age related macular degeneration in the white population. Uncorrected refractive error was a significant cause of decreased vision across ages, ethnic groups, and countries. Conclusion: More data are needed on the magnitude and causes of visual loss for the Caribbean and Latin American countries. Rates of blindness and visual loss from available data within these countries are widely disparate. Prevention and control of avoidable blindness needs to be an ongoing focus in this region. PMID:11973241

What Do Patients With Glaucoma See? Visual Symptoms Reported by Patients With Glaucoma

PubMed Central

Hu, Cindy X.; Zangalli, Camila; Hsieh, Michael; Gupta, Lalita; Williams, Alice L.; Richman, Jesse

2014-01-01

Abstract: Background: Vision loss from glaucoma has traditionally been described as loss of “peripheral vision.” In this prospective study, we aimed to improve our clinical understanding of the visual symptoms caused by glaucoma by asking patients specific detailed questions about how they see. Methods: Patients who were clinically diagnosed with various types and stages of glaucoma were included. All had a comprehensive ocular examination, including Octopus visual field testing. Patients were excluded if they had other ocular conditions that affected their vision, including cornea, lens or retina pathologies. Patients responded to an oral questionnaire about their visual symptoms. We investigated the visual symptoms described by patients with glaucoma and correlated the severity of visual field loss with visual symptoms reported. Results: Ninety-nine patients completed the questionnaire. Most patients (76%) were diagnosed with primary open-angle glaucoma. The most common symptoms reported by all patients, including patients with early or moderate glaucoma, were needing more light and blurry vision. Patients with a greater amount of field loss (Octopus mean defect >+9.4 dB) were more likely to report difficulty seeing objects to one or both sides, as if looking through dirty glasses and trouble differentiating boundaries and colors. Conclusions: Vision loss in patients with glaucoma is not as simple as the traditional view of loss of peripheral vision. Needing more light and blurry vision were the most common symptoms reported by patients with glaucoma. PMID:24992392

Geographical and genetic factors do not account for significant differences in the clinical spectrum of giant cell arteritis in southern europe.

PubMed

Gonzalez-Gay, Miguel A; Boiardi, Luigi; Garcia-Porrua, Carlos; Macchioni, Pierluigi; Amor-Dorado, Juan C; Salvarani, Carlo

2004-03-01

To investigate whether genetic and geographical differences may influence the clinical spectrum of giant cell arteritis (GCA), we compared the demographic and clinical features of patients with biopsy-proven GCA from Reggio Emilia (Northern Italy) and Lugo (Northwest Spain) during a 15-year period. We performed a retrospective review of the case records of all patients diagnosed with biopsy-proven GCA at Hospital Xeral-Calde (Lugo, Spain) and Hospital Santa Maria Nuova (Reggio Emilia, Italy) between 1 January 1986 and 31 December 2001. Both hospitals are the only referral centers for populations living in central Galicia and central Emilia Romagna, respectively. During the period of study, 194 Lugo residents and 126 Reggio Emilia residents were diagnosed with biopsy proven GCA. Reggio Emilia patients were more likely to be female (74% vs 54%; p = 0.0001). Although Lugo patients complained of headache (86%) more commonly than did those from Reggio Emilia (77%), the difference was only marginally significant (p = 0.05). The proportion of patients with visual manifestations or visual loss was remarkably similar (22% for visual manifestations and 17% for visual loss in Lugo and 29% and 21% for Reggio Emilia residents). The mean erythrocyte sedimentation rate prior to the onset of therapy was also similar. Apart from differences in sex, the clinical spectrum of GCA in these 2 Southern European regions was similar.

Working memory, short-term memory and reading proficiency in school-age children with cochlear implants.

PubMed

Bharadwaj, Sneha V; Maricle, Denise; Green, Laura; Allman, Tamby

2015-10-01

The objective of the study was to examine short-term memory and working memory through both visual and auditory tasks in school-age children with cochlear implants. The relationship between the performance on these cognitive skills and reading as well as language outcomes were examined in these children. Ten children between the ages of 7 and 11 years with early-onset bilateral severe-profound hearing loss participated in the study. Auditory and visual short-term memory, auditory and visual working memory subtests and verbal knowledge measures were assessed using the Woodcock Johnson III Tests of Cognitive Abilities, the Wechsler Intelligence Scale for Children-IV Integrated and the Kaufman Assessment Battery for Children II. Reading outcomes were assessed using the Woodcock Reading Mastery Test III. Performance on visual short-term memory and visual working memory measures in children with cochlear implants was within the average range when compared to the normative mean. However, auditory short-term memory and auditory working memory measures were below average when compared to the normative mean. Performance was also below average on all verbal knowledge measures. Regarding reading outcomes, children with cochlear implants scored below average for listening and passage comprehension tasks and these measures were positively correlated to visual short-term memory, visual working memory and auditory short-term memory. Performance on auditory working memory subtests was not related to reading or language outcomes. The children with cochlear implants in this study demonstrated better performance in visual (spatial) working memory and short-term memory skills than in auditory working memory and auditory short-term memory skills. Significant positive relationships were found between visual working memory and reading outcomes. The results of the study provide support for the idea that WM capacity is modality specific in children with hearing loss. Based on these findings, reading instruction that capitalizes on the strengths in visual short-term memory and working memory is suggested for young children with early-onset hearing loss. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Visual field loss and accelerometer-measured physical activity in the United States.

PubMed

van Landingham, Suzanne W; Willis, Jeffrey R; Vitale, Susan; Ramulu, Pradeep Y

2012-12-01

To determine whether visual field (VF) loss is associated with lower levels of accelerometer-defined walking or physical activity in a nationally representative sample of American adults. Cross-sectional study. A total of 2934 adults aged 40 years or older who participated in the examination component of the 2005-2006 National Health and Nutritional Examination Survey. Frequency-doubling technology (FDT) testing was performed in both eyes and used to categorize subjects as having no VF loss, unilateral VF loss, or bilateral VF loss. Accelerometer data were collected over 7 days of normal activity. Steps per day and daily minutes of moderate or vigorous physical activity (MVPA). A total of 1468 participants (50.0%) had complete FDT and accelerometer data. Individuals without VF loss averaged 9751 steps/day and 20.8 minutes/day of MVPA, compared with 8023 steps/day and 14.5 minutes/day for subjects with unilateral VF loss (age-adjusted P = 0.11 and P = 0.51) and 6840 steps/day and 10.1 minutes/day for subjects with bilateral VF loss (age-adjusted P = 0.02 and 0.09, respectively). In multivariable models adjusted for age, sex, race/ethnicity, education, and several comorbid illnesses, individuals with bilateral VF loss took 17% fewer steps per day (P < 0.01) and engaged in 30% less MVPA (P = 0.02) than individuals without VF loss. No significant difference in steps per day or MVPA was observed between individuals with unilateral VF loss and no VF loss (P > 0.05). In addition to VF loss, older age, female sex, arthritis, diabetes, congestive heart failure (CHF), and stroke were significantly associated with fewer daily steps and minutes of MVPA (P < 0.05). Bilateral VF loss is associated with less walking and physical activity in American adults. Patients with bilateral VF loss should be encouraged to engage safely in more physical activity. 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.

Colour vision and contrast sensitivity losses of mercury intoxicated industry workers in Brazil.

PubMed

Ventura, D F; Simões, A L; Tomaz, S; Costa, M F; Lago, M; Costa, M T V; Canto-Pereira, L H M; de Souza, J M; Faria, M A M; Silveira, L C L

2005-05-01

We evaluated vision loss in workers from fluorescent lamp industries (n=39) who had retired due to intoxication with mercury vapour and had been away from the work situation for several years (mean=6.32 years). An age-matched control group was submitted to the same tests for comparison. The luminance contrast sensitivity (CSF) was measured psychophysically and with the sweep visual evoked potential (sVEP) method. Chromatic red-green and blue-yellow CSFs were measured psychophysically. Colour discrimination was assessed with the Farnsworth-Munsell 100-hue test, Lanthony D-15d test and Cambridge Colour Vision Test. Patient data showed significantly lower scores in all colour tests compared to controls (p<.001). The behavioural luminance CSF of the patients was lower than that of controls (p<.001 at all frequencies tested). This result was confirmed by the electrophysiologically measured sweep VEP luminance CSF except at the highest frequencies-a difference that might be related to stimulus differences in the two situations. Chromatic CSFs were also statistically significantly lower for the patients than for the controls, for both chromatic equiluminant stimuli: red-green (p<.005) and blue-yellow (p<.04 for all frequencies, except 2 cycles per degree (cpd), the highest spatial frequency tested) spatial gratings. We conclude that exposure to elemental mercury vapour is associated with profound and lasting losses in achromatic and chromatic visual functions, affecting the magno-, parvo- and koniocellular visual pathways.

Reproducibility of retinal nerve fiber layer thickness measures using eye tracking in children with nonglaucomatous optic neuropathy.

PubMed

Rajjoub, Raneem D; Trimboli-Heidler, Carmelina; Packer, Roger J; Avery, Robert A

2015-01-01

To determine the intra- and intervisit reproducibility of circumpapillary retinal nerve fiber layer (RNFL) thickness measures using eye tracking-assisted spectral-domain optical coherence tomography (SD OCT) in children with nonglaucomatous optic neuropathy. Prospective longitudinal study. Circumpapillary RNFL thickness measures were acquired with SD OCT using the eye-tracking feature at 2 separate study visits. Children with normal and abnormal vision (visual acuity ≥ 0.2 logMAR above normal and/or visual field loss) who demonstrated clinical and radiographic stability were enrolled. Intra- and intervisit reproducibility was calculated for the global average and 9 anatomic sectors by calculating the coefficient of variation and intraclass correlation coefficient. Forty-two subjects (median age 8.6 years, range 3.9-18.2 years) met inclusion criteria and contributed 62 study eyes. Both the abnormal and normal vision cohort demonstrated the lowest intravisit coefficient of variation for the global RNFL thickness. Intervisit reproducibility remained good for those with normal and abnormal vision, although small but statistically significant increases in the coefficient of variation were observed for multiple anatomic sectors in both cohorts. The magnitude of visual acuity loss was significantly associated with the global (ß = 0.026, P < .01) and temporal sector coefficient of variation (ß = 0.099, P < .01). SD OCT with eye tracking demonstrates highly reproducible RNFL thickness measures. Subjects with vision loss demonstrate greater intra- and intervisit variability than those with normal vision. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of hemifield sector analysis protocol in multifocal visual evoked potential objective perimetry for the diagnosis and early detection of glaucomatous field defects.

PubMed

Mousa, Mohammad F; Cubbidge, Robert P; Al-Mansouri, Fatima; Bener, Abdulbari

2014-02-01

Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.

Evaluation of Hemifield Sector Analysis Protocol in Multifocal Visual Evoked Potential Objective Perimetry for the Diagnosis and Early Detection of Glaucomatous Field Defects

PubMed Central

Mousa, Mohammad F.; Cubbidge, Robert P.; Al-Mansouri, Fatima

2014-01-01

Purpose Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. Methods Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. Results Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. Conclusions The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss. PMID:24511212

Social capital, social relationships and adults with acquired visual impairment: a nigerian perspective.

PubMed

Bassey, Emmanuel; Ellison, Caroline; Walker, Ruth

2018-01-31

This study investigates the social capital implications of vision loss among working-age adults in Nigeria. The study explores the challenges of acquiring and maintaining social relationships post-vision loss, and investigates the extent to which visual rehabilitation services support social goals. A qualitative study using a phenomenological approach was undertaken. Eight adults (18-59 years) were recruited from disability service organizations in Nigeria. Telephone interviews were recorded and transcribed, and thematic content analysis was used to analyze the data gathered in this study. Three broad themes were developed from participants' accounts of their experiences: (1) changes to relationships with friends and others; (2) finding strength in family relationships; and (3) rehabilitation and the confidence to interact. The findings indicate that the relationship between participants and their family members improved post vision impairment, enhancing bonding social capital. However, participants experienced reduced bridging and linking social capital due to diminished or broken relationships with managers, coworkers, friends, and others in the community. As social connectedness and relationships are highly valued in Nigeria's diverse society, we suggest that adults with visual impairment would significantly benefit from visual rehabilitation services placing greater emphasis on addressing the social goals of participants. Implications for Rehabilitation Visual impairment in working-age adults can strengthen family relationships (homogenous groups), creating bonding capital that is associated with access to important resources including emotional and moral support, and some financial and material resources. Visual impairment can negatively impact relationships with managers, coworkers, and others in the community (heterogeneous groups), resulting in diminished bridging and linking capital. Visual impairment can reduce access to resources such as an income, social status, and reduces participation in the wider community. Visual Rehabilitation Services could significantly benefit participants by placing greater emphasis on social goals, such as building and maintaining social networks, particularly with diverse (heterogeneous groups), which are valued in Nigeria's diverse cultural climate.

Intralaminar nuclei of the thalamus in Lewy body diseases.

PubMed

Brooks, Daniel; Halliday, Glenda M

2009-02-16

Although the intralaminar thalamus is a target of alpha-synuclein pathology in Parkinson's disease, the degree of neuronal loss in Lewy body diseases has not been assessed. We have used unbiased stereological techniques to quantify neuronal loss in intralaminar thalamic nuclei concentrating alpha-synuclein pathology (the anterodorsal, cucullar, parataenial, paraventricular, central medial, central lateral and centre-median/parafascicular complex) in different clinical forms of Lewy body disease (Parkinson's disease with and without dementia, and dementia with Lewy bodies, N=21) compared with controls (N=5). Associations were performed in the Lewy body cases between intralaminar cell loss and the main diagnostic clinical (parkinsonism, dementia, fluctuation in consciousness, and visual hallucinations) and pathological (Braak stage of Parkinson's disease) features of these diseases, as well as between cell loss and the scaled severity of the alpha-synuclein deposition within the intralaminar thalamus. As expected, significant alpha-synuclein accumulation occurred in the intralaminar thalamus in the cases with Lewy body disease. Pathology concentrated anteriorly and in the central lateral and paraventricular nuclei was related to the Braak stage of Parkinson's disease, ageing, and the presence of dementia. Across all types of Lewy body cases there was substantial atrophy and neuronal loss in the central lateral, cucullar and parataenial nuclei, and neuronal loss without atrophy in the centre-median/parafascicular complex. Cases with visual hallucinations showed a greater degree of atrophy of the cucullar nucleus, possibly due to amygdala denervation. The significant degeneration demonstrated in the intralaminar thalamus is likely to contribute to the movement and cognitive dysfunction observed in Lewy body disorders.

Visual Memory for Objects Following Foveal Vision Loss

ERIC Educational Resources Information Center

Geringswald, Franziska; Herbik, Anne; Hofmüller, Wolfram; Hoffmann, Michael B.; Pollmann, Stefan

2015-01-01

Allocation of visual attention is crucial for encoding items into visual long-term memory. In free vision, attention is closely linked to the center of gaze, raising the question whether foveal vision loss entails suboptimal deployment of attention and subsequent impairment of object encoding. To investigate this question, we examined visual…

Effect of field of view and monocular viewing on angular size judgements in an outdoor scene

NASA Technical Reports Server (NTRS)

Denz, E. A.; Palmer, E. A.; Ellis, S. R.

1980-01-01

Observers typically overestimate the angular size of distant objects. Significantly, overestimations are greater in outdoor settings than in aircraft visual-scene simulators. The effect of field of view and monocular and binocular viewing conditions on angular size estimation in an outdoor field was examined. Subjects adjusted the size of a variable triangle to match the angular size of a standard triangle set at three greater distances. Goggles were used to vary the field of view from 11.5 deg to 90 deg for both monocular and binocular viewing. In addition, an unrestricted monocular and binocular viewing condition was used. It is concluded that neither restricted fields of view similar to those present in visual simulators nor the restriction of monocular viewing causes a significant loss in depth perception in outdoor settings. Thus, neither factor should significantly affect the depth realism of visual simulators.

Detection of Visual Field Loss in Pituitary Disease: Peripheral Kinetic Versus Central Static

PubMed Central

Rowe, Fiona J.; Cheyne, Christopher P.; García-Fiñana, Marta; Noonan, Carmel P.; Howard, Claire; Smith, Jayne; Adeoye, Joanne

2015-01-01

Abstract Visual field assessment is an important clinical evaluation for eye disease and neurological injury. We evaluated Octopus semi-automated kinetic peripheral perimetry (SKP) and Humphrey static automated central perimetry for detection of neurological visual field loss in patients with pituitary disease. We carried out a prospective cross-sectional diagnostic accuracy study comparing Humphrey central 30-2 SITA threshold programme with a screening protocol for SKP on Octopus perimetry. Humphrey 24-2 data were extracted from 30-2 results. Results were independently graded for presence/absence of field defect plus severity of defect. Fifty patients (100 eyes) were recruited (25 males and 25 females), with mean age of 52.4 years (SD = 15.7). Order of perimeter assessment (Humphrey/Octopus first) and order of eye tested (right/left first) were randomised. The 30-2 programme detected visual field loss in 85%, the 24-2 programme in 80%, and the Octopus combined kinetic/static strategy in 100% of eyes. Peripheral visual field loss was missed by central threshold assessment. Qualitative comparison of type of visual field defect demonstrated a match between Humphrey and Octopus results in 58%, with a match for severity of defect in 50%. Tests duration was 9.34 minutes (SD = 2.02) for Humphrey 30-2 versus 10.79 minutes (SD = 4.06) for Octopus perimetry. Octopus semi-automated kinetic perimetry was found to be superior to central static testing for detection of pituitary disease-related visual field loss. Where reliant on Humphrey central static perimetry, the 30-2 programme is recommended over the 24-2 programme. Where kinetic perimetry is available, this is preferable to central static programmes for increased detection of peripheral visual field loss. PMID:27928344

Galvanic vestibular stimulation speeds visual memory recall.

PubMed

Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

2008-08-01

The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

All-optical recording and stimulation of retinal neurons in vivo in retinal degeneration mice

PubMed Central

Strazzeri, Jennifer M.; Williams, David R.; Merigan, William H.

2018-01-01

Here we demonstrate the application of a method that could accelerate the development of novel therapies by allowing direct and repeatable visualization of cellular function in the living eye, to study loss of vision in animal models of retinal disease, as well as evaluate the time course of retinal function following therapeutic intervention. We use high-resolution adaptive optics scanning light ophthalmoscopy to image fluorescence from the calcium sensor GCaMP6s. In mice with photoreceptor degeneration (rd10), we measured restored visual responses in ganglion cell layer neurons expressing the red-shifted channelrhodopsin ChrimsonR over a six-week period following significant loss of visual responses. Combining a fluorescent calcium sensor, a channelrhodopsin, and adaptive optics enables all-optical stimulation and recording of retinal neurons in the living eye. Because the retina is an accessible portal to the central nervous system, our method also provides a novel non-invasive method of dissecting neuronal processing in the brain. PMID:29596518

Predicting progression of glaucoma from rates of frequency doubling technology perimetry change.

PubMed

Meira-Freitas, Daniel; Tatham, Andrew J; Lisboa, Renato; Kuang, Tung-Mei; Zangwill, Linda M; Weinreb, Robert N; Girkin, Christopher A; Liebmann, Jeffrey M; Medeiros, Felipe A

2014-02-01

To evaluate the ability of longitudinal frequency doubling technology (FDT) to predict the development of glaucomatous visual field loss on standard automated perimetry (SAP) in glaucoma suspects. Prospective, observational cohort study. The study included 587 eyes of 367 patients with suspected glaucoma at baseline selected from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). These eyes had an average of 6.7 ± 1.9 FDT tests during a mean follow-up time of 73.1 ± 28.0 months. Glaucoma suspects had intraocular pressure (IOP) >21 mmHg or an optic disc appearance suspicious of glaucoma. All patients had normal or nonrepeatable abnormal SAP at baseline. Humphrey Matrix FDT (Carl Zeiss Meditec, Inc, Dublin, CA) testing was performed within 6 months of SAP testing. The study end point was the development of 3 consecutive abnormal SAP test results. Joint longitudinal survival models were used to evaluate the ability of rates of FDT pattern standard deviation (PSD) change to predict the development of visual field loss on SAP, adjusting for confounding variables (baseline age, mean IOP, corneal thickness, and follow-up measurements of SAP PSD). The R(2) index was used to evaluate and compare the predictive abilities of the model containing longitudinal FDT PSD data with the model containing only baseline data. Sixty-three of 587 eyes (11%) developed SAP visual field loss during follow-up. The mean rate of FDT PSD change in eyes that developed SAP visual field loss was 0.07 dB/year versus 0.02 dB/year in those that did not (P < 0.001). Baseline FDT PSD and slopes of FDT PSD change were significantly predictive of progression, with hazard ratios of 1.11 per 0.1 dB higher (95% confidence interval [CI], 1.04-1.18; P = 0.002) and 4.40 per 0.1 dB/year faster (95% CI, 1.08-17.96; P = 0.04), respectively. The longitudinal model performed significantly better than the baseline model with an R(2) of 82% (95% CI, 74-89) versus 11% (95% CI, 2-24), respectively. Rates of FDT PSD change were highly predictive of the development of SAP visual field loss in glaucoma suspects. This finding suggests that longitudinal FDT evaluation may be useful for risk stratification of patients with suspected glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Design Considerations for Attitude State Awareness and Prevention of Entry into Unusual Attitudes

NASA Technical Reports Server (NTRS)

Ellis, Kyle K. E.; Prinzel, Lawrence J., III; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel; Verstynen, Harry; Hubbs, Clay; Wilkerson, James

2017-01-01

Loss of control - inflight (LOC-I) has historically represented the largest category of commercial aviation fatal accidents. A review of the worldwide transport airplane accidents (2001-2010) evinced that loss of attitude or energy state awareness was responsible for a large majority of the LOC-I events. A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that flight crew loss of attitude awareness or energy state awareness due to lack of external visual reference cues was a significant causal factor in 17 of the 18 reviewed flights. CAST recommended that "Virtual Day-Visual Meteorological Condition" (Virtual Day-VMC) displays be developed to provide the visual cues necessary to prevent loss-of-control resulting from flight crew spatial disorientation and loss of energy state awareness. Synthetic vision or equivalent systems (SVS) were identified for a design "safety enhancement" (SE-200). Part of this SE involves the conduct of research for developing minimum aviation system performance standards (MASPS) for these flight deck display technologies to aid flight crew attitude and energy state awareness similar to that of a virtual day-VMC-like environment. This paper will describe a novel experimental approach to evaluating a flight crew's ability to maintain attitude awareness and to prevent entry into unusual attitudes across several SVS optical flow design considerations. Flight crews were subjected to compound-event scenarios designed to elicit channelized attention and startle/surprise within the crew. These high-fidelity scenarios, designed from real-world events, enable evaluation of the efficacy of SVS at improving flight crew attitude awareness to reduce the occurrence of LOC-I incidents in commercial flight operations.

Wayfinding and Glaucoma: A Virtual Reality Experiment.

PubMed

Daga, Fábio B; Macagno, Eduardo; Stevenson, Cory; Elhosseiny, Ahmed; Diniz-Filho, Alberto; Boer, Erwin R; Schulze, Jürgen; Medeiros, Felipe A

2017-07-01

Wayfinding, the process of determining and following a route between an origin and a destination, is an integral part of everyday tasks. The purpose of this study was to investigate the impact of glaucomatous visual field loss on wayfinding behavior using an immersive virtual reality (VR) environment. This cross-sectional study included 31 glaucomatous patients and 20 healthy subjects without evidence of overall cognitive impairment. Wayfinding experiments were modeled after the Morris water maze navigation task and conducted in an immersive VR environment. Two rooms were built varying only in the complexity of the visual scene in order to promote allocentric-based (room A, with multiple visual cues) versus egocentric-based (room B, with single visual cue) spatial representations of the environment. Wayfinding tasks in each room consisted of revisiting previously visible targets that subsequently became invisible. For room A, glaucoma patients spent on average 35.0 seconds to perform the wayfinding task, whereas healthy subjects spent an average of 24.4 seconds (P = 0.001). For room B, no statistically significant difference was seen on average time to complete the task (26.2 seconds versus 23.4 seconds, respectively; P = 0.514). For room A, each 1-dB worse binocular mean sensitivity was associated with 3.4% (P = 0.001) increase in time to complete the task. Glaucoma patients performed significantly worse on allocentric-based wayfinding tasks conducted in a VR environment, suggesting visual field loss may affect the construction of spatial cognitive maps relevant to successful wayfinding. VR environments may represent a useful approach for assessing functional vision endpoints for clinical trials of emerging therapies in ophthalmology.

Photorefractive keratectomy with a small spot laser and tracker.

PubMed

Pallikaris, I G; Koufala, K I; Siganos, D S; Papadaki, T G; Katsanevaki, V J; Tourtsan, V; McDonald, M B

1999-01-01

The Autonomous Technologies LADARVision excimer laser system utilizes an eye tracking mechanism and a small spot for photorefractive keratectomy. One hundred and two eyes of 102 patients were treated for -1.50 to -6.25 D of spherical myopia at the spectacle plane using a 6-mm diameter ablation zone. One year follow-up was available for 93 eyes (91%). Uncorrected visual acuity for eyes treated for distance vision was 20/40 or better in 99% (n = 90), and 20/20 or better in 70% (n = 64) of eyes at 12 months. Spectacle-corrected visual acuity was 20/25 or better in all 92 eyes reported; no eye lost more than 2 lines of spectacle-corrected visual acuity, and only 1 eye (1.0%) experienced a loss of 2 lines (20/12.5 to 20/20) at 1 year. The refractive result was within +/- 0.50 D of the desired correction in 75% (n = 70), and within +/- 1.00 D in 93% (n = 86) of eyes at 12 months. Refractive stability was achieved between 3 and 6 months. Corneal haze was graded as trace or less in 100% of the 93 eyes. No significant reductions were noted in contrast sensitivity or endothelial cell density. Patients treated with the Autonomous Technologies LADARVision excimer laser system for -1.50 to -6.25 D of spherical myopia with 1 year follow-up had uncorrected visual acuity of 20/20 or better in 70%, no significant loss of spectacle-corrected visual acuity, no reduction of endothelial cell density or contrast sensitivity, and low levels of corneal haze.

Unconscious Imagination and the Mental Imagery Debate

PubMed Central

Brogaard, Berit; Gatzia, Dimitria Electra

2017-01-01

Traditionally, philosophers have appealed to the phenomenological similarity between visual experience and visual imagery to support the hypothesis that there is significant overlap between the perceptual and imaginative domains. The current evidence, however, is inconclusive: while evidence from transcranial brain stimulation seems to support this conclusion, neurophysiological evidence from brain lesion studies (e.g., from patients with brain lesions resulting in a loss of mental imagery but not a corresponding loss of perception and vice versa) indicates that there are functional and anatomical dissociations between mental imagery and perception. Assuming that the mental imagery and perception do not overlap, at least, to the extent traditionally assumed, then the question arises as to what exactly mental imagery is and whether it parallels perception by proceeding via several functionally distinct mechanisms. In this review, we argue that even though there may not be a shared mechanism underlying vision for perception and conscious imagery, there is an overlap between the mechanisms underlying vision for action and unconscious visual imagery. On the basis of these findings, we propose a modification of Kosslyn’s model of imagery that accommodates unconscious imagination and explore possible explanations of the quasi-pictorial phenomenology of conscious visual imagery in light of the fact that its underlying neural substrates and mechanisms typically are distinct from those of visual experience. PMID:28588527

Bilateral nanophthalmos and pigmentary retinal dystrophy--an unusual syndrome.

PubMed

Proença, Helena; Castanheira-Dinis, A; Monteiro-Grillo, M

2006-09-01

To report the clinical picture of the rare association of nanophthalmos and pigmentary retinal dystrophy and its cataract surgery outcome. We report a case of a 60-year-old female who presented with bilateral slowly progressive visual loss. The patient presented with bilateral light perception visual acuity, exotropia, brunescent cataract hindering fundus examination and hypodontia. Ultrasonography revealed bilateral nanophthalmos. A visual-evoked potential was also performed preoperatively. Cataract surgery with +40D IOL implantation was uneventful. Postoperative fundus examination revealed pigmentary retinal dystrophy, confirmed by electrophysiologic tests. Glycosaminoglycan urinary excretion was normal. Congenital bilateral nanophthalmos may rarely be associated with pigmentary retinal dystrophy. We suggest thorough preoperative evaluation in nanophthalmic eyes for the exclusion of significant features concerning visual prognosis.

Visual Acuity Change over 12 Months in the Prospective Progression of Atrophy Secondary to Stargardt Disease (ProgStar) Study: ProgStar Report Number 6.

PubMed

Kong, Xiangrong; Strauss, Rupert W; Cideciyan, Artur V; Michaelides, Michel; Sahel, José-Alain; Munoz, Beatriz; Ahmed, Mohamed; Ervin, Ann M; West, Sheila K; Cheetham, Janet K; Scholl, Hendrik P N

2017-11-01

To estimate the yearly rate of change of best-corrected visual acuity (BCVA) and the risk of loss 1 line or more over 1 year and to identify risk factors for BCVA loss in patients with Stargardt disease (STGD1). Multicenter, prospective cohort study. Two hundred fifty-nine patients (489 eyes) with molecularly confirmed STGD1 enrolled at 9 centers in the United States and Europe. Participants were followed up every 6 months, and data at the baseline and 6- and 12-month visits were analyzed. Best-corrected visual acuity was measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Standardized reporting forms were used to collect participants' characteristics and clinical observations. Linear mixed effects models were used to estimate the rate of BCVA loss. Linear models with generalized estimating equations were used to identify risk factors for BCVA loss of 1 line or more over 1 year. Change in BCVA over 1 year. Cross-sectional analysis at baseline showed that earlier symptom onset and longer duration since onset was associated with worse BCVA. Longitudinal analysis showed no overall significant change of BCVA within 12 months, but the rate of BCVA change was significantly different by baseline BCVA (P < 0.001). The BCVA of eyes with baseline BCVA of 20/25 or better declined at a rate of 2.8 ETDRS letters per year (P = 0.10), eyes with baseline BCVA between 20/25 and 20/70 declined at a rate of 2.3 ETDRS letters per year (P = 0.002), eyes with baseline BCVA between 20/70 and 20/200 declined at a rate of 0.8 ETDRS letters per year (P = 0.08), and eyes with baseline BCVA worse than 20/200 showed a significant improvement of 2.3 ETDRS letters per year (P < 0.001). Overall, 12.9% of eyes lost 1 line or more, and the risk of such BCVA loss was different by baseline BCVA level (P = 0.016). Smoking and vitamin A use was not associated significantly with baseline BCVA, nor with rate of BCVA loss over 1 year. Change in BCVA in STGD1 patients over a 12-month period was small, but varied depending on baseline BCVA. Given the slow change during 1 year, BCVA is unlikely to be a sensitive outcome measure for STGD1 treatment trials with 1 year's duration. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Assistive Technologies for Visually Impaired Persons : Developing Situational Awareness and Guidance Solutions for People with Vision Impairment and Other Disabilities

DOT National Transportation Integrated Search

2015-02-15

There are approximately 2 million adults with reported vision loss in the United States. Independent travel and active interactions with the surrounding environment present significant daily challenges for these individuals, ultimately reducing quali...

Effects of Spaceflight on Venous and Arterial Compliance

NASA Technical Reports Server (NTRS)

Platts, S. H.; Pibeiro, L. C.; Laurie, S. S.; Lee, S. M. C.; Martin, D. S.; Ploutz-Snyder, R.; Stenger, M. B.

2016-01-01

The visual impairment and intracranial pressure (VIIP) syndrome is a spaceflight-associated medical condition consisting of a constellation of symptoms affecting less than 70% of American astronauts who have flown International Space Station (ISS) missions. VIIP is defined primarily by visual acuity deficits and anatomical changes to eye structures and is hypothesized to be related to elevated intracranial pressure secondary to spaceflight-induced cephalad fluid shifts, although other space flight factors (e.g., diet, environmental factors) may contribute. Loss of visual acuity could be a significant threat to crew health and performance during and after an exploration mission and may have implications for years postflight.

Auditory preferences of young children with and without hearing loss for meaningful auditory-visual compound stimuli.

PubMed

Zupan, Barbra; Sussman, Joan E

2009-01-01

Experiment 1 examined modality preferences in children and adults with normal hearing to combined auditory-visual stimuli. Experiment 2 compared modality preferences in children using cochlear implants participating in an auditory emphasized therapy approach to the children with normal hearing from Experiment 1. A second objective in both experiments was to evaluate the role of familiarity in these preferences. Participants were exposed to randomized blocks of photographs and sounds of ten familiar and ten unfamiliar animals in auditory-only, visual-only and auditory-visual trials. Results indicated an overall auditory preference in children, regardless of hearing status, and a visual preference in adults. Familiarity only affected modality preferences in adults who showed a strong visual preference to unfamiliar stimuli only. The similar degree of auditory responses in children with hearing loss to those from children with normal hearing is an original finding and lends support to an auditory emphasis for habilitation. Readers will be able to (1) Describe the pattern of modality preferences reported in young children without hearing loss; (2) Recognize that differences in communication mode may affect modality preferences in young children with hearing loss; and (3) Understand the role of familiarity in modality preferences in children with and without hearing loss.

The order of information processing alters economic gain-loss framing effects.

PubMed

Kwak, Youngbin; Huettel, Scott

2018-01-01

Adaptive decision making requires analysis of available information during the process of choice. In many decisions that information is presented visually - which means that variations in visual properties (e.g., salience, complexity) can potentially influence the process of choice. In the current study, we demonstrate that variation in the left-right positioning of risky and safe decision options can influence the canonical gain-loss framing effect. Two experiments were conducted using an economic framing task in which participants chose between gambles and certain outcomes. The first experiment demonstrated that the magnitude of the gain-loss framing effect was greater when the certain option signaling the current frame was presented on the left side of the visual display. Eye-tracking data during task performance showed a left-gaze bias for initial fixations, suggesting that the option presented on the left side was processed first. Combination of eye-tracking and choice data revealed that there was a significant effect of direction of first gaze (i.e. left vs. right) as well as an interaction between gaze direction and identity of the first fixated information (i.e. certain vs. gamble) regardless of frame. A second experiment presented the gamble and certain options in a random order, with a temporal delay between their presentations. We found that the magnitude of gain-loss framing was larger when the certain option was presented first, regardless of left and right positioning, only in individuals with lower risk-taking tendencies. The effect of presentation order on framing was not present in high risk-takers. These results suggest that the sequence of visual information processing as well as their left-right positioning can bias choices by changing the impact of the presented information during risky decision making. Copyright © 2017 Elsevier B.V. All rights reserved.

Correlation between local glaucomatous visual field defects and loss of nerve fiber layer thickness measured with polarimetry and spectral domain OCT.

PubMed

Horn, Folkert K; Mardin, Christian Y; Laemmer, Robert; Baleanu, Delia; Juenemann, Anselm M; Kruse, Friedrich E; Tornow, Ralf P

2009-05-01

To study the correlation between local perimetric field defects and glaucoma-induced thickness reduction of the nerve layer measured in the peripapillary area with scanning laser polarimetry (SLP) and spectral domain optical coherence tomography (SOCT) and to compare the results with those of a theoretical model. The thickness of the retinal nerve fiber layer was determined in 32 sectors (11.25 degrees each) by using SLP with variable cornea compensation (GDxVCC; Laser Diagnostics, San Diego, CA) and the newly introduced high-resolution SOCT (Spectralis; Heidelberg Engineering, Heidelberg, Germany). Eighty-eight healthy subjects served as control subjects, to determine the thickness deviation in patients with glaucoma. The relationship between glaucomatous nerve fiber reduction and visual field losses was calculated in six nerve fiber bundle-related areas. Sixty-four patients at different stages of open-angle glaucoma and 26 patients with ocular hypertension underwent perimetry (Octopus G1; Haag-Streit, Köniz, Switzerland) and measurements with the two morphometric techniques. Sector-shaped analyses between local perimetric losses and reduction of the retinal nerve fiber layer thickness showed a significant association for corresponding areas except for the central visual field in SLP. Correlation coefficients were highest in the area of the nasal inferior visual field (SOCT, -0.81; SLP, -0.57). A linear model describes the association between structural and functional damage. Localized perimetric defects can be explained by reduced nerve fiber layer thickness. The data indicate that the present SOCT is useful for determining the functional-structural relationship in peripapillary areas and that association between perimetric defects and corresponding nerve fiber losses is stronger for SOCT than for the present SLP. (ClinicalTrials.gov number, NCT00494923.).

Emergent risk factors associated with eyeball loss and ambulatory vision loss after globe injuries.

PubMed

Hyun Lee, Seung; Ahn, Jae Kyoun

2010-07-01

The objective of this study was to evaluate risk factors associated with eyeball loss and ambulatory vision loss on emergent examination of patients with ocular trauma. We reviewed the medical records of 1,875 patients hospitalized in a single tertiary referral center between January 2003 and December 2007. Emergent examinations included a history of trauma, elapsed time between injury and hospital arrival, visible intraocular tissues, and initial visual acuity (VA) using a penlight. The main outcome measures were ocular survival and ambulatory vision survival (>20/200) at 1 year after trauma using univariate and multivariate regression analysis. The ocular trauma scores were significantly higher in open globe injuries than in closed globe injuries (p < 0.01). In open globe injuries, initial VA less than light perception (LP) and a history of golf ball injury were the significant risk factors associated with eyeball loss. Elapsed time more than 12 hours and visible intraocular tissues were the significant risk factors associated with ambulatory vision loss. The most powerful predictor of eyeball loss and ambulatory vision loss was eyeball rupture. In closed globe injuries, there were no significant risk factors of eyeball loss, whereas initial vision less than LP and the presence of relative afferent pupillary defect were the significant risk factors associated with ambulatory vision loss. An initial VA less than LP using a penlight, a history of golf ball injury, and elapsed time more than 12 hours between ocular trauma and hospital arrival were associated with eyeball loss and ambulatory vision loss. Physicians should bear these factors in mind so that they can more effectively counsel patients with such injuries.

Central and Peripheral Vision Loss Differentially Affects Contextual Cueing in Visual Search

ERIC Educational Resources Information Center

Geringswald, Franziska; Pollmann, Stefan

2015-01-01

Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental…

Baseline 24-2 Central Visual Field Damage Is Predictive of Global Progressive Field Loss.

PubMed

Garg, Aakriti; De Moraes, C Gustavo; Cioffi, George A; Girkin, Christopher A; Medeiros, Felipe A; Weinreb, Robert N; Zangwill, Linda M; Liebmann, Jeffrey M

2018-03-01

Central visual field (VF) damage in glaucoma patients can significantly hinder daily activities. The present study investigates whether the presence of localized baseline damage to the central 10 degrees of the VF is predictive of faster global mean deviation (MD) progression. Prospective cohort study. Eyes from the multicenter African Descent and Glaucoma Evaluation Study (ADAGES) with established glaucoma and VF loss and a minimum of 5 24-2 VFs were eligible. Baseline central 24-2 damage was defined as any of the 12 central-most points with total deviation (TD) values at P < 0.5% on 2 consecutive examinations. Progression was determined using trend-based and event-based criteria: (1) rates of MD change significantly faster than zero and (2) >-5 dB MD loss over the entire follow-up. A total of 827 eyes of 584 patients were studied. Mean rate of MD change of the entire sample was -0.15 dB/year (95% CI: -0.19 to -0.12, P < .001). Eyes with baseline central damage progressed faster than those without (difference: β central  = -0.07 dB/year, 95% CI: -0.11 to -0.01, P = .011) and were more likely to experience MD loss greater than 5 dB (hazard ratio = 3.0 [95% CI: 2.1-4.1, P < .001]). These differences remained significant after adjusting for confounders. The presence of central VF damage at baseline is significantly associated with more rapid global progression. Detection of central VF damage aids in stratification of high-risk patients who may need intensive surveillance and aggressive treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Synaptic noise is an information bottleneck in the inner retina during dynamic visual stimulation

PubMed Central

Freed, Michael A; Liang, Zhiyin

2014-01-01

In daylight, noise generated by cones determines the fidelity with which visual signals are initially encoded. Subsequent stages of visual processing require synapses from bipolar cells to ganglion cells, but whether these synapses generate a significant amount of noise was unknown. To characterize noise generated by these synapses, we recorded excitatory postsynaptic currents from mammalian retinal ganglion cells and subjected them to a computational noise analysis. The release of transmitter quanta at bipolar cell synapses contributed substantially to the noise variance found in the ganglion cell, causing a significant loss of fidelity from bipolar cell array to postsynaptic ganglion cell. Virtually all the remaining noise variance originated in the presynaptic circuit. Circuit noise had a frequency content similar to noise shared by ganglion cells but a very different frequency content from noise from bipolar cell synapses, indicating that these synapses constitute a source of independent noise not shared by ganglion cells. These findings contribute a picture of daylight retinal circuits where noise from cones and noise generated by synaptic transmission of cone signals significantly limit visual fidelity. PMID:24297850

Comparing the Impact of Refractive and Nonrefractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation.

PubMed

Zebardast, Nazlee; Swenor, Bonnielin K; van Landingham, Suzanne W; Massof, Robert W; Munoz, Beatriz; West, Sheila K; Ramulu, Pradeep Y

2015-06-01

To compare the effects of uncorrected refractive error (URE) and nonrefractive visual impairment (VI) on performance and disability measures. Cross-sectional, population-based study. A total of 2469 individuals with binocular presenting visual acuity (PVA) of ≥ 20/80 who participated in the first round of the Salisbury Eye Evaluation study. The URE was defined as binocular PVA of ≤ 20/30, improving to >20/30 with subjective refraction. The VI was defined as post-refraction binocular best-corrected visual acuity (BCVA) of ≤ 20/30. The visual acuity decrement due to VI was calculated as the difference between BCVA and 20/30, whereas visual acuity due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of (1) vision status (VI, URE, or normal vision) using the group with normal vision as reference and (2) a 1-line decrement in acuity due to VI or URE. Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. The ADV responses were analyzed using Rasch analysis to determine visual ability. Compared with individuals with normal vision, subjects with VI (n = 191) had significantly poorer objective and subjective visual functioning in all metrics examined (P < 0.05), whereas subjects with URE (n = 132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation, and lower ADV scores (P < 0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a 1-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared with a 1-line VA decrement due to URE. Visual impairment is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and nonrefractive vision loss should be distinguished in studies evaluating visual disability and be understood to have differing consequences. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Framing and visual type: Effect on future Zika vaccine uptake intent

PubMed Central

Guidry, Jeanine P.D.; Carlyle, Kellie E.; LaRose, Jessica G.; Perrin, Paul; Ryan, Mark; Messner, Marcus; Adams, Jay

2018-01-01

Introduction The Zika virus is associated with the birth defect microcephaly, and while a vaccine was not available in early- 2017, several were under development. This study’s purpose was to identify effective communication strategies to promote uptake of a new vaccine, particularly among women of reproductive age. Design and methods In order to study the effects of Zika message framing (gain vs. loss) and visual type (photo vs. infographic) on future Zika vaccine uptake intent, a 2×2 between-subjects experiment was performed via an online survey in 2017 among 339 U.S. women of reproductive age (18-49 years). Participants were exposed to one of four messages, all resembling Instagram posts: gain-framed vs. loss-framed infographic, and gain-framed vs. loss-framed photo. These messages were followed by questions about Zika vaccine uptake intent as well as intermediate psychosocial variables that could lead to intent. Results There was no interaction between framing and visual type (P=0.116), and there was no effect for framing (P=0.185) or visual type (P=0.724) on future Zika vaccine uptake intent, which is likely indicative of insufficient dosage of the intervention. However, when focusing on intermediate psychosocial constructs that are known to influence behavior and intent, gain-framed messages were more effective in increasing subjective norms (P=0.005) as related to a future Zika vaccine, as well as perceived benefits (P=0.016) and self-efficacy (P=0.032). Conclusions Gain-framed messages seem to be more effective than loss-framed messages to increase several constructs that could, in turn, affect future Zika vaccine uptake intent. This is a novel finding since, traditionally, loss-framed messages are considered more beneficial in promoting vaccine-related health behaviors. Significance for public healthThe study described in this paper is significant for the field of public health for several reasons: It takes a proactive approach in studying messaging focused on the Zika vaccine before that vaccine is available, allowing for quick implementation of its limited results. In addition, this study centers on messaging in the form of realistic images consistent with those that could be posted on Instagram, thereby focusing on a relatively new yet immensely popular communications platform that few are focusing on presently. PMID:29780762

Detection of Progressive Retinal Nerve Fiber Layer Loss in Glaucoma Using Scanning Laser Polarimetry with Variable Corneal Compensation

PubMed Central

Medeiros, Felipe A.; Alencar, Luciana M.; Zangwill, Linda M.; Bowd, Christopher; Vizzeri, Gianmarco; Sample, Pamela A.; Weinreb, Robert N.

2010-01-01

Purpose To evaluate the ability of scanning laser polarimetry with variable corneal compensation to detect progressive retinal nerve fiber layer (RNFL) loss in glaucoma patients and patients suspected of having the disease. Methods This was an observational cohort study that included 335 eyes of 195 patients. Images were obtained annually with the GDx VCC scanning laser polarimeter, along with optic disc stereophotographs and standard automated perimetry (SAP) visual fields. The median follow-up time was 3.94 years. Progression was determined using commercial software for SAP and by masked assessment of optic disc stereophotographs performed by expert graders. Random coefficient models were used to evaluate the relationship between RNFL thickness measurements over time and progression as determined by SAP and/or stereophotographs. Results From the 335 eyes, 34 (10%) showed progression over time by stereophotographs and/or SAP. Average GDx VCC measurements decreased significantly over time for both progressors as well as non-progressors. However, the rate of decline was significantly higher in the progressing group (−0.70 μm/year) compared to the non-progressing group (−0.14 μm/year; P = 0.001). Black race and male sex were significantly associated with higher rates of RNFL loss during follow-up. Conclusions The GDx VCC scanning laser polarimeter was able to identify longitudinal RNFL loss in eyes that showed progression in optic disc stereophotographs and/or visual fields. These findings suggest that this technology could be useful to detect and monitor progressive disease in patients with established diagnosis of glaucoma or suspected of having the disease. PMID:19029038

Usher's syndrome--case report.

PubMed

Kwiecień, Sława; Sulak, Robert; Szaflik, Jerzy

2008-01-01

The aim of this study is to present a case of coincidence of sensorineural hearing loss with chronic recurrent bilateral cystoid macular oedema in a 32-year-old woman, who was admitted to the clinic for deterioration of visual acuity of four months' duration. The patient gave a history of hearing loss for 29 years. Visual field examination disclosed peripheral ring scotoma. Electrophysiological examination was performed: pattern visual evoked response was within normal limits and electroretinogram displayed diminished both photopic and scotopic response. As ophthalmoscopy demonstrated no pigment in the fundus of the eye, the findings were consisted with diagnosis of retinitis pigmentosis sine pigmento. The presence of loss of hearing indicated the necessity of performing the genetic examination for Usher's syndrome. In order to establish a final diagnosis of Usher's syndrome genetic examination must be performed, but family history is relevant. Early investigation for Usher's syndrome in children with sensorineural hearing impairment is of a great significance. The patient may develop symptoms of retinitis pigmentosa in second or even third decade of his life. The necessity of thorough investigation for detecting other systemic abnormalities should be emphasized. There is no effective treatment of this syndrome. A child with Usher's syndrome requires a comprehensive care of different medical specialties. Psychological, educational and sociological attitude is also of a great importance in the child development.

The Advanced Glaucoma Intervention Study (AGIS): 13. Comparison of treatment outcomes within race: 10-year results.

PubMed

Ederer, Fred; Gaasterland, Douglas A; Dally, Leonard G; Kim, Jonghyeon; VanVeldhuisen, Paul C; Blackwell, Beth; Prum, Bruce; Shafranov, George; Allen, Robert C; Beck, Allen

2004-04-01

To present for black and white patients with medically uncontrolled glaucoma 10-year results of treatment with 1 of 2 randomly assigned surgical intervention sequences. Randomized clinical trial. Three hundred thirty-two black patients (451 eyes) and 249 white patients (325 eyes). Eyes had glaucoma that could not be controlled with medications alone. Eyes were randomly assigned to 1 of 2 sequences: argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy (ATT) or trabeculectomy-ALT-trabeculectomy (TAT). Second and third interventions were offered after failure of the preceding intervention. Minimum required intraocular pressure (IOP) for intervention failure ranged upward from 18 mmHg, the value depending on whether recent optic disc or visual field (VF) deterioration occurred, and on the magnitude of the field defect. Patients were observed every 6 months, with total potential follow-up ranging from 8 years, 4 months to 13 years. The averages over follow-up of (1) the percentage of eyes having moderate loss of VF and (2) the percentage of eyes having moderate loss of visual acuity (VA). Race-treatment interactions in VF and VA loss are significant for the 2 main outcome measures; therefore, results of treatment sequence differences are presented by race. In black patients the average percent of eyes with VF loss was less in the ATT sequence than in the TAT sequence, a difference that is not statistically significant at any visit. In white patients, conversely, after 18 months the average percent of eyes with VF loss was less in the TAT sequence, a difference that increases and is statistically significant in years 8 to 10. In both black and white patients, the average percent of eyes with VA loss was less in the ATT sequence; this difference is statistically significant throughout 10 follow-up years in black patients and is statistically significant only for the first year in white patients. In both black and white patients, average IOP reductions were greater in the TAT sequence, though the TAT-ATT difference was substantially greater in white patients. In both black and white patients, first-intervention failure rates were substantially lower for trabeculectomy than for trabeculoplasty. Ten-year cumulative incidence of unilateral VF impairment comparable to legal blindness was modest in eyes of black (ATT 11.9%, TAT 18.5%) and white (ATT 9.9%, TAT 7.3%) patients. Although IOP was lowered in both sequences in black and white patients with medically uncontrolled glaucoma, long-term visual function outcomes were better for the ATT sequence in black patients and better for the TAT sequence in white patients.

Predictors of visual outcomes following Boston type 1 keratoprosthesis implantation.

PubMed

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

2015-04-01

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

[Brief video-assisted observation of visual attention, facial expression, and motor skills for diagnosis of attention deficit/hyperactivity disorder (ADHD)].

PubMed

Kühle, H J; Hoch, C; Rautzenberg, P; Jansen, F

2001-10-01

Can video assisted observation of visual attention, facial expression and motor skills contribute to the diagnosis of attention deficit/hyperactivity disorder (ADHD)? 20 children from 6 to 10 years of age, diagnosed for ADHD following the DSM-IV criteria, and an age and sex matched control group of 20 children with harmless upper airway infections were filmed during 3 minutes playing cards with their mothers and 7 minutes of oral arithmetic exercises. Two persons were trained for eight hours in recognizing 22 signs for visual attention loss, alterated facial expression like oversized and sustained smile and abnormal motor skills in ADHD-patient videos. Then they viewed minutes 2 and 3 and 3 and 4 of the 40 children in a randomized sequence and scored the signs. 8 of the 22 signs showed high (r > .75) and 9 showed medium (r > .6) interrater correlations. The presence of signs in the ADHD and in the control group was highly significantly different (a = 0.01, U-Test of Mann and Whitney) for 10 of the 22 signs and significantly different for other 4 signs (a = 0.05). The four field table comparison between the frequency of the signs showed correct positioning in 80% of all cases. The loss of visual attention was the most frequent sign in ADHD children. The signs of alterated facial expression were also among the highly correlated signs. These are used by us to find the individual dose for stimulant medication.

Screening in Primary Care for Diabetic Retinopathy, Maculopathy and Visual Loss in South Africa.

PubMed

Webb, Elizabeth M; Rheeder, Paul; Roux, Polla

2016-01-01

The aim of the study was to determine the prevalence of diabetic retinopathy, maculopathy and visual loss in primary care patients and to identify associated risk factors. We conducted a cluster randomised trial at primary care clinics in the Tshwane district in South Africa. Grades of retinopathy and maculopathy (with fundus camera) and visual acuity (Snellen chart) were assessed and, using mobile screening and teleophthalmology, clinical and biochemical testing was conducted to obtain information about glycaemic control and microvascular complications. The prevalence rates for any retinopathy, preproliferative retinopathy and proliferative retinopathy were 24.9, 19.5 and 5.5%, respectively. The prevalence rates of diabetic maculopathy, observable maculopathy and referable maculopathy were 20.8, 11.8 and 9.0%, respectively. The presence of retinopathy was associated with high body mass index, systolic blood pressure, being on insulin treatment, high HbA1c and the presence of neuropathy. High systolic blood pressure, being on insulin treatment, high HbA1c level and high low-density lipoprotein cholesterol level as well as the presence of albuminuria were significant in predicting any diabetic maculopathy. Laser photocoagulation was given to 8.3% of patients from the mobile unit and 12% of patients were referred to the nearest hospital with an outpatient eye clinic for follow-up treatment of various other eye conditions. Using the WHO categories, the study found that 78.1% of diabetes patients had normal vision, 19.3% were visually impaired and 2.2% were severely impaired or blind. High prevalence rates for diabetic retinopathy, maculopathy and visual loss were found and associations were identified. © 2016 S. Karger AG, Basel.

Childhood blindness: a new form for recording causes of visual loss in children.

PubMed Central

Gilbert, C.; Foster, A.; Négrel, A. D.; Thylefors, B.

1993-01-01

The new standardized form for recording the causes of visual loss in children is accompanied by coding instructions and by a database for statistical analysis. The aim is to record the causes of childhood visual loss, with an emphasis on preventable and treatable causes, so that appropriate control measures can be planned. With this standardized methodology, it will be possible to monitor the changing patterns of childhood blindness over a period of time in response to changes in health care services, specific interventions, and socioeconomic development. PMID:8261552

Visual impairment and depression among socially vulnerable older adults in Armenia.

PubMed

Giloyan, Aida; Harutyunyan, Tsovinar; Petrosyan, Varduhi

2015-01-01

Visual impairment in older adults is a major public health problem. Untreated visual impairment might negatively impact physical and psychological health. This study assessed the association between visual impairment and depression among socially vulnerable older adults (those aged 50 and above) in Armenia. The survey and eye screenings were carried out among 339 participants who were the residents of retirement homes and single older adults in the households. The study team used Golovin-Sivtsev chart and cycloplegic skiascopy to measure visual impairment and Center for Epidemiologic Studies Depression scale to measure depression. The prevalence of visual impairment in the sample was 13.3%. Almost 24.0% of participants reported depression symptoms. Participants living in the retirement homes had substantially higher rates of visual impairment (21.5%) and depression (28.0%) than those living in households (9.3% and 15.0%, respectively). The odds of having depression were higher among those with visual impairment compared to those without after adjusting for confounders (OR = 2.75; 95% CI: 1.29-5.87). Having at least one non-communicable disease was associated with depression (OR = 2.47; 95% CI: 1.28-4.75). Living in the retirement home was marginally significantly associated with having depression. Other confounders included age, gender, education, physical activity, and smoking. Visual impairment was significantly associated with depression in socially vulnerable older adults in Armenia. Timely eye screenings in similar population groups could lead to early detection of visual impairment and prevention of visual loss and associated mental health problems.

Modulation of working memory function by motivation through loss-aversion.

PubMed

Krawczyk, Daniel C; D'Esposito, Mark

2013-04-01

Cognitive performance is affected by motivation. Few studies, however, have investigated the neural mechanisms of the influence of motivation through potential monetary punishment on working memory. We employed functional MRI during a delayed recognition task that manipulated top-down control demands with added monetary incentives to some trials in the form of potential losses of bonus money. Behavioral performance on the task was influenced by loss-threatening incentives in the form of faster and more accurate performance. As shown previously, we found enhancement of activity for relevant stimuli occurs throughout all task periods (e.g., stimulus encoding, maintenance, and response) in both prefrontal and visual association cortex. Further, these activation patterns were enhanced for trials with possible monetary loss relative to nonincentive trials. During the incentive cue, the amygdala and striatum showed significantly greater activation when money was at a possible loss on the trial. We also evaluated patterns of functional connectivity between regions responsive to monetary consequences and prefrontal areas responsive to the task. This analysis revealed greater delay period connectivity between and the left insula and prefrontal cortex with possible monetary loss relative to nonincentive trials. Overall, these results reveal that incentive motivation can modulate performance on working memory tasks through top-down signals via amplification of activity within prefrontal and visual association regions selective to processing the perceptual inputs of the stimuli to be remembered. Copyright © 2011 Wiley Periodicals, Inc.

Modulation of working memory function by motivation through loss-aversion

PubMed Central

Krawczyk, Daniel C.; D’Esposito, Mark

2012-01-01

Cognitive performance is affected by motivation. Few studies, however, have investigated the neural mechanisms of the influence of motivation through potential monetary punishment on working memory. We employed functional MRI during a delayed recognition task that manipulated top-down control demands with added monetary incentives to some trials in the form of potential losses of bonus money. Behavioral performance on the task was influenced by loss-threatening incentives in the form of faster and more accurate performance. As shown previously, we found enhancement of activity for relevant stimuli occurs throughout all task periods (e.g. stimulus encoding, maintenance, and response) in both prefrontal and visual association cortex. Further, these activation patterns were enhanced for trials with possible monetary loss relative to non-incentive trials. During the incentive cue, the amygdala and striatum showed significantly greater activation when money was at a possible loss on the trial. We also evaluated patterns of functional connectivity between regions responsive to monetary consequences and prefrontal areas responsive to the task. This analysis revealed greater delay period connectivity between and the left insula and prefrontal cortex with possible monetary loss relative to non-incentive trials. Overall, these results reveal that incentive motivation can modulate performance on working memory tasks through top-down signals via amplification of activity within prefrontal and visual association regions selective to processing the perceptual inputs of the stimuli to be remembered. PMID:22113962

Accuracy of Blood Loss Measurement during Cesarean Delivery.

PubMed

Doctorvaladan, Sahar V; Jelks, Andrea T; Hsieh, Eric W; Thurer, Robert L; Zakowski, Mark I; Lagrew, David C

2017-04-01

Objective  This study aims to compare the accuracy of visual, quantitative gravimetric, and colorimetric methods used to determine blood loss during cesarean delivery procedures employing a hemoglobin extraction assay as the reference standard. Study Design  In 50 patients having cesarean deliveries blood loss determined by assays of hemoglobin content on surgical sponges and in suction canisters was compared with obstetricians' visual estimates, a quantitative gravimetric method, and the blood loss determined by a novel colorimetric system. Agreement between the reference assay and other measures was evaluated by the Bland-Altman method. Results  Compared with the blood loss measured by the reference assay (470 ± 296 mL), the colorimetric system (572 ± 334 mL) was more accurate than either visual estimation (928 ± 261 mL) or gravimetric measurement (822 ± 489 mL). The correlation between the assay method and the colorimetric system was more predictive (standardized coefficient = 0.951, adjusted R 2  = 0.902) than either visual estimation (standardized coefficient = 0.700, adjusted R 2  = 00.479) or the gravimetric determination (standardized coefficient = 0.564, adjusted R 2  = 0.304). Conclusion  During cesarean delivery, measuring blood loss using colorimetric image analysis is superior to visual estimation and a gravimetric method. Implementation of colorimetric analysis may enhance the ability of management protocols to improve clinical outcomes.

Accuracy of Blood Loss Measurement during Cesarean Delivery

PubMed Central

Doctorvaladan, Sahar V.; Jelks, Andrea T.; Hsieh, Eric W.; Thurer, Robert L.; Zakowski, Mark I.; Lagrew, David C.

2017-01-01

Objective This study aims to compare the accuracy of visual, quantitative gravimetric, and colorimetric methods used to determine blood loss during cesarean delivery procedures employing a hemoglobin extraction assay as the reference standard. Study Design In 50 patients having cesarean deliveries blood loss determined by assays of hemoglobin content on surgical sponges and in suction canisters was compared with obstetricians' visual estimates, a quantitative gravimetric method, and the blood loss determined by a novel colorimetric system. Agreement between the reference assay and other measures was evaluated by the Bland–Altman method. Results Compared with the blood loss measured by the reference assay (470 ± 296 mL), the colorimetric system (572 ± 334 mL) was more accurate than either visual estimation (928 ± 261 mL) or gravimetric measurement (822 ± 489 mL). The correlation between the assay method and the colorimetric system was more predictive (standardized coefficient = 0.951, adjusted R2 = 0.902) than either visual estimation (standardized coefficient = 0.700, adjusted R2 = 00.479) or the gravimetric determination (standardized coefficient = 0.564, adjusted R2 = 0.304). Conclusion During cesarean delivery, measuring blood loss using colorimetric image analysis is superior to visual estimation and a gravimetric method. Implementation of colorimetric analysis may enhance the ability of management protocols to improve clinical outcomes. PMID:28497007

Role of somatosensory and vestibular cues in attenuating visually induced human postural sway

NASA Technical Reports Server (NTRS)

Peterka, Robert J.; Benolken, Martha S.

1993-01-01

The purpose was to determine the contribution of visual, vestibular, and somatosensory cues to the maintenance of stance in humans. Postural sway was induced by full field, sinusoidal visual surround rotations about an axis at the level of the ankle joints. The influences of vestibular and somatosensory cues were characterized by comparing postural sway in normal and bilateral vestibular absent subjects in conditions that provided either accurate or inaccurate somatosensory orientation information. In normal subjects, the amplitude of visually induced sway reached a saturation level as stimulus amplitude increased. The saturation amplitude decreased with increasing stimulus frequency. No saturation phenomena was observed in subjects with vestibular loss, implying that vestibular cues were responsible for the saturation phenomenon. For visually induced sways below the saturation level, the stimulus-response curves for both normal and vestibular loss subjects were nearly identical implying that (1) normal subjects were not using vestibular information to attenuate their visually induced sway, possibly because sway was below a vestibular-related threshold level, and (2) vestibular loss subjects did not utilize visual cues to a greater extent than normal subjects; that is, a fundamental change in visual system 'gain' was not used to compensate for a vestibular deficit. An unexpected finding was that the amplitude of body sway induced by visual surround motion could be almost three times greater than the amplitude of the visual stimulus in normals and vestibular loss subjects. This occurred in conditions where somatosensory cues were inaccurate and at low stimulus amplitudes. A control system model of visually induced postural sway was developed to explain this finding. For both subject groups, the amplitude of visually induced sway was smaller by a factor of about four in tests where somatosensory cues provided accurate versus inaccurate orientation information. This implied that (1) the vestibular loss subjects did not utilize somatosensory cues to a greater extent than normal subjects; that is, changes in somatosensory system 'gain' were not used to compensate for a vestibular deficit, and (2) the threshold for the use of vestibular cues in normals was apparently lower in test conditions where somatosensory cues were providing accurate orientation information.

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

Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of "Green" Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex.

PubMed

Rauscher, Franziska G; Plant, Gordon T; James-Galton, Merle; Barbur, John L

2011-01-01

Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d'Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength ("red") and middle wavelength ("green") regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient's results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both "red/green" and "yellow/blue" directions in colour space, the subject's lower left quadrant showed a marked asymmetry in "red/green" thresholds with the greatest loss of sensitivity towards the "green" region of the spectrum locus. This spatially localized asymmetric loss of "green" but not "red" sensitivity has not been reported previously in human vision. Such loss is consistent with selective damage of neural substrates in the visual cortex that process colour information, but are spectrally non-opponent.

Compromised Integrity of Central Visual Pathways in Patients With Macular Degeneration.

PubMed

Malania, Maka; Konrad, Julia; Jägle, Herbert; Werner, John S; Greenlee, Mark W

2017-06-01

Macular degeneration (MD) affects the central retina and leads to gradual loss of foveal vision. Although, photoreceptors are primarily affected in MD, the retinal nerve fiber layer (RNFL) and central visual pathways may also be altered subsequent to photoreceptor degeneration. Here we investigate whether retinal damage caused by MD alters microstructural properties of visual pathways using diffusion-weighted magnetic resonance imaging. Six MD patients and six healthy control subjects participated in the study. Retinal images were obtained by spectral-domain optical coherence tomography (SD-OCT). Diffusion tensor images (DTI) and high-resolution T1-weighted structural images were collected for each subject. We used diffusion-based tensor modeling and probabilistic fiber tractography to identify the optic tract (OT) and optic radiations (OR), as well as nonvisual pathways (corticospinal tract and anterior fibers of corpus callosum). Fractional anisotropy (FA) and axial and radial diffusivity values (AD, RD) were calculated along the nonvisual and visual pathways. Measurement of RNFL thickness reveals that the temporal circumpapillary retinal nerve fiber layer was significantly thinner in eyes with macular degeneration than normal. While we did not find significant differences in diffusion properties in nonvisual pathways, patients showed significant changes in diffusion scalars (FA, RD, and AD) both in OT and OR. The results indicate that the RNFL and the white matter of the visual pathways are significantly altered in MD patients. Damage to the photoreceptors in MD leads to atrophy of the ganglion cell axons and to corresponding changes in microstructural properties of central visual pathways.

Macular function and morphological features in juvenile Stargardt disease: Longitudinal study

PubMed Central

Testa, Francesco; Melillo, Paolo; Iorio, Valentina Di; Orrico, Ada; Attanasio, Marcella; Rossi, Settimio; Simonelli, Francesca

2014-01-01

Purpose to evaluate disease progression in a cohort of patients with clinical and genetic diagnosis of Stargardt disease. Design longitudinal cohort study. Subjects 56 selected patients with a clinical and molecular diagnosis of Stargardt disease, an early age of onset and a median follow-up length of two years. Methods patients underwent routine examination including full-field electroretinography, microperimetry and optical coherence tomography. Main Outcome Measures best corrected visual acuity, mean retinal sensitivity, fixation stability, preferred retinal locus, inner-outer segment (IS/OS) junction loss, atrophic lesion area. Results 56 patients with a mean age of disease onset of 15.3 years (range: 3 - 28 years), a mean disease length of 12.1 years and a mean age at baseline of 27.4 years were analyzed. The median best corrected visual acuity was 20/200 in both eyes. Optical coherence tomography parameters (IS/OS alteration and retinal pigment epithelium lesion area) were obtained in 49 patients because signal quality was poor in the remaining 7 patients. Optical coherence tomography revealed a mean retinal pigment epithelium lesion area of 2.6 mm2, preserved foveal IS/OS in 4.1% of patients, loss of foveal IS/OS in 59.2%, and extensive loss of macular IS/OS in 36.7%. Microperimetric findings showed a reduced macular sensitivity (mean 10 dB) and an unstable fixation in half of the patient cohort. The longitudinal analysis showed a significant progressive reduction of best corrected visual acuity and macular sensitivity (at an estimated rate of 0.04 decimals and 1.19 dB per year, respectively) associated with a significant enlargement of retinal pigment epithelium lesion area (0.282 mm2 per year). No significant changes in ophthalmoscopic findings and electroretinographic responses were detected. Conclusions this study highlights the importance of microperimetry and optical coherence tomography in monitoring Stargardt patients. In fact, quantifying the decline of visual functionality and detecting morphological macular changes proves useful to evaluate disease progression over a short-term follow-up and should be taken into account for the design of future gene therapy clinical trials to treat retinal dystrophy. PMID:25097154

Predictors of visual outcome in patients operated for craniopharyngioma - a Danish national study.

PubMed

Jacobsen, Mads Forslund; Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Doroudian, Ghazaleh; Nissen, Kamilla Rothe; Fugleholm, Kåre; Poulsgaard, Lars; Siersma, Volkert; Heegaard, Steffen

2018-02-01

Craniopharyngioma often causes visual loss due to the close relation to the anterior visual pathways. This study investigates the incidence and predictors of visual outcomes in patients with craniopharyngioma. Data from sixty-six patients who underwent surgery for craniopharyngioma from 2009 to 2013 in Denmark were reviewed. Primary outcomes were visual acuity (VA) and visual field (VF) defects from pre-and postoperative visits. Secondary outcomes were optic nerve atrophy (OA) and papilledema. Fifty-eight patients were included. The VA of the patients 1-year after surgery improved by -0.16 log(MAR) (95%CI: -0.30 to -0.02; p = 0.0266). Visual field (VF) defects worsened in 17 eyes (30%), remained stable in 21 eyes (37%) and improved in 19 eyes (33%). The presence of papilledema and the absence of OA were significantly correlated with an improvement in VA postoperatively (p = 0.011 and p = 0.011, respectively). Patients undergoing surgery within a week or less after their first ophthalmological examination had a significant improvement in VA (-0.36; 95%CI: -0.62 to -0.09; p = 0.0099). Patients undergoing surgery using a subfrontal approach also showed improvement in VA (p = 0.048). Tumour recurrence had a significantly worse VA outcome (p = 0.0074). Patients show a slight improvement in VA 1-year after operation for craniopharyngioma. The presence of papilledema and early surgical intervention is associated with a significant improvement in VA. Early involvement of a dedicated ophthalmologist is recommended to secure an early detection of a visual decline and potential tumour recurrence. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

The ophthalmological course of Usher syndrome type III.

PubMed

Pakarinen, L; Tuppurainen, K; Laippala, P; Mäntyjärvi, M; Puhakka, H

Usher syndrome is a recessive hereditary disease group with clinical and genetical heterogeneity leading to handicapped hearing and visual loss until middle age. It is the most common cause for deaf-blindness. Three distinct phenotypes and five distinct genotypes are already known. In Finland the distribution of known Usher types is different than elsewhere. Usher syndrome type III (USH3) is common in Finland and it is thought to include 40% of patients. Progressive hearing loss is characteristic of USH3. Elsewhere USH3 has been regarded as a rarity covering only several percent of the whole Usher population. The aim of this paper is to describe, for the first time, the course of visual handicap and typical refractive errors in USH3 and compare it with other USH types. From a total patient sample consisting of 229 Finnish USH patients, 200 patients' visual findings were analyzed in a multicenter retrospective follow-up study. The average progress rate during a 10-year follow-up period in different USH types was similar. The essential progress occurred below the age of 40 and was continuous up to that age. Visual acuity dropped below 0.05 (severely impaired) at the age of 37 and the visual fields were of tubular shape without any peripheric islands at the average age of 30. Clinically significant hypermetropia with astigmatism seems to be a pathognomonic clinical sign of USH3.

[Acute visual loss in pregnancy caused by craniopharyngioma].

PubMed

Grillo-Mallo, E; Jiménez-Benito, J; Diéz-Feijóo, E; Alonso Alonso, I; Ferrero Collado, A; Muñoz Quiñones, S

2014-04-01

A 38-year-old female, at 20-weeks gestation, experienced a sudden visual loss and visual-field abnormalities. The neuroimaging tests showed a craniopharyngioma. Surgical removal was performed with a successful outcome as regards the pregnancy and visual function. It is known that pituitary adenomas may grow during pregnancy; however this is unusual in craniopharyngiomas. They usually present with visual problems due to their suprasellar topography. Surgery is the treatment of choice, the outcome essentially depending on its complete resection. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Visual and proprioceptive interaction in patients with bilateral vestibular loss☆

PubMed Central

Cutfield, Nicholas J.; Scott, Gregory; Waldman, Adam D.; Sharp, David J.; Bronstein, Adolfo M.

2014-01-01

Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular function in BVL patients. PMID:25061564

Visual Field Outcomes for the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT).

PubMed

Wall, Michael; Johnson, Chris A; Cello, Kimberly E; Zamba, K D; McDermott, Michael P; Keltner, John L

2016-03-01

The Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) showed that acetazolamide provided a modest, significant improvement in mean deviation (MD). Here, we further analyze visual field changes over the 6-month study period. Of 165 subjects with mild visual loss in the IIHTT, 125 had perimetry at baseline and 6 months. We evaluated pointwise linear regression of visual sensitivity versus time to classify test locations in the worst MD (study) eye as improving or not; pointwise changes from baseline to month 6 in decibels; and clinical consensus of change from baseline to 6 months. The average study eye had 36 of 52 test locations with improving sensitivity over 6 months using pointwise linear regression, but differences between the acetazolamide and placebo groups were not significant. Pointwise results mostly improved in both treatment groups with the magnitude of the mean change within groups greatest and statistically significant around the blind spot and the nasal area, especially in the acetazolamide group. The consensus classification of visual field change from baseline to 6 months in the study eye yielded percentages (acetazolamide, placebo) of 7.2% and 17.5% worse, 35.1% and 31.7% with no change, and 56.1% and 50.8% improved; group differences were not statistically significant. In the IIHTT, compared to the placebo group, the acetazolamide group had a significant pointwise improvement in visual field function, particularly in the nasal and pericecal areas; the latter is likely due to reduction in blind spot size related to improvement in papilledema. (ClinicalTrials.gov number, NCT01003639.).

Braille Reading Accuracy of Students Who Are Visually Impaired: The Effects of Gender, Age at Vision Loss, and Level of Education

ERIC Educational Resources Information Center

Argyropoulos, Vassilis; Papadimitriou, Vassilios

2015-01-01

Introduction: The present study assesses the performance of students who are visually impaired (that is, those who are blind or have low vision) in braille reading accuracy and examines potential correlations among the error categories on the basis of gender, age at loss of vision, and level of education. Methods: Twenty-one visually impaired…

[Case of pediatric chronic myeloid leukemia with bilateral visual loss onset].

PubMed

Hara, Yusuke; Kamura, Yumi; Oikawa, Aki; Shichino, Hiroyuki; Mugishima, Hideo; Goto, Hiroshi

2010-05-01

Chronic myeloid leukemia (CML) during childhood is rare, and only been a few cases showed visual disturbances as an initial symptom. We report a pediatric CML case diagnosed by bilateral visual loss. An 11-year-old boy complained of visual loss in both eyes. His best corrected visual acuity was 0.5 in the right eye and 0.2 in the left. Fundus examination showed disc swelling, dilated and tortuous retinal veins and multiple elevated retinal lesions with hemorrhages of various size from one-forth to four disc diameters in both eyes. He was diagnosed as having CML by leucocytosis and systematic work-up including Philadelphia chromosome-positive, BCR-ABL kinase domain in peripheral blood and bone marrow. The ocular findings improved after treatment with hydroxyurea, leukocytaphresis and imatinib. His best corrected visual acuity improved to 0.7 in both eyes. Recent leukemia therapy including imatinib is effective not only for ocular lesions but also to induce hematological remission in childhood CML.

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant.

PubMed

Ye, Clara; Patel, Cajal K; Momont, Anna C; Liu, Yao

2018-06-01

We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL) (Visian ICL™, Staar Inc., Monrovia, CA) implant that resulted in advanced visual field loss. A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL) placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP) in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss.

Improved retinal and visual function following panmacular subthreshold diode micropulse laser for retinitis pigmentosa.

PubMed

Luttrull, Jeffrey K

2018-06-01

To examine the effect of subthreshold diode micropulse laser (SDM) on pattern electroretinography (PERG) and visual function in retinitis pigmentosa (RP). The records of all patients (pts) undergoing SDM in a vitreoretinal subspecialty practice were reviewed. Inclusion criteria included the presence of RP evaluated before and after SDM by PERG. As a secondary outcome measure, the results of automated omnifield resolution perimetry (ORP) were also reviewed. All eyes undergoing SDM for RP were eligible study, including 26 eyes of 15 pts; seven male and eight female, aged 16-69 (avg. 47) years. Retinal function by PERG improved by all indices, with significant improvements in the 24° field signal latency measures; the MagD(µV)/ Mag(µV) ratio (P < 0.0001) and the MagD(µV) amplitude (P = 0.0003). ORP significantly improved by all indices (p = 0.02-0.002). Average best-corrected chart visual acuities improved from 0.6 to 0.4 logMAR units (p = 0.02). There were no adverse treatment effects. SDM significantly improved chart visual acuity, mesopic logMAR visual acuity perimetry, and retinal function by PERG in RP without adverse treatment effects. Treatment responses indicate a significant capacity for rescue of dysfunctional retina. These results suggest that early and periodic treatment with SDM might slow disease progression and reduce long-term vision loss.

Long Term Results of Visual Field Progression Analysis in Open Angle Glaucoma Patients Under Treatment.

PubMed

Kocatürk, Tolga; Bekmez, Sinan; Katrancı, Merve; Çakmak, Harun; Dayanır, Volkan

2015-01-01

To evaluate visual field progression with trend and event analysis in open angle glaucoma patients under treatment. Fifteen year follow-up results of 408 eyes of 217 glaucoma patients who were followed at Adnan Menderes University, Department of Ophthalmology between 1998 and 2013 were analyzed retrospectively. Visual field data were collected for Mean Deviation (MD), Visual Field Index (VFI), and event occurrence. There were 146 primary open-angle glaucoma (POAG), 123 pseudoexfoliative glaucoma (XFG) and 139 normal tension glaucoma (NTG) eyes. MD showed significant change in all diagnostic groups (p<0.001). The difference of VFI between first and last examinations were significantly different in POAG (p<0.001), and XFG (p<0.003) but not in NTG. VFI progression rates were -0.3, -0.43, and -0.2 % loss/year in treated POAG, XFG, and NTG, respectively. The number of empty triangles were statistically different between POAG-NTG (p=0.001), and XFG-NTG (p=0.002) groups. The number of half-filled (p=0.002), and full-filled (p=0.010) triangles were significantly different between XFG-NTG groups. Functional long-term follow-up of glaucoma patients can be monitored with visual field indices. We herein report our fifteen year follow-up results in open angle glaucoma.

The effect of static scanning and mobility training on mobility in people with hemianopia after stroke: A randomized controlled trial comparing standardized versus non-standardized treatment protocols

PubMed Central

2011-01-01

Background Visual loss following stroke impacts significantly on activities of daily living and is an independent risk factor for becoming dependent. Routinely, allied health clinicians provide training for visual field loss, mainly with eye movement based therapy. The effectiveness of the compensatory approach to rehabilitation remains inconclusive largely due to difficulty in validating functional outcome with the varied type and dosage of therapy received by an individual patient. This study aims to determine which treatment is more effective, a standardized approach or individualized therapy in patients with homonymous hemianopia post stroke. Methods/Design This study is a double-blind randomized controlled, multicenter trial. A standardised scanning rehabilitation program (Neuro Vision Technology (NVT) program) of 7 weeks at 3 times per week, is compared to individualized therapy recommended by clinicians. Discussion The results of the trial will provide information that could potentially inform the allocation of resources in visual rehabilitation post stroke. Trial Registration Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12610000494033 PMID:21767413

Effects of aging on audio-visual speech integration.

PubMed

Huyse, Aurélie; Leybaert, Jacqueline; Berthommier, Frédéric

2014-10-01

This study investigated the impact of aging on audio-visual speech integration. A syllable identification task was presented in auditory-only, visual-only, and audio-visual congruent and incongruent conditions. Visual cues were either degraded or unmodified. Stimuli were embedded in stationary noise alternating with modulated noise. Fifteen young adults and 15 older adults participated in this study. Results showed that older adults had preserved lipreading abilities when the visual input was clear but not when it was degraded. The impact of aging on audio-visual integration also depended on the quality of the visual cues. In the visual clear condition, the audio-visual gain was similar in both groups and analyses in the framework of the fuzzy-logical model of perception confirmed that older adults did not differ from younger adults in their audio-visual integration abilities. In the visual reduction condition, the audio-visual gain was reduced in the older group, but only when the noise was stationary, suggesting that older participants could compensate for the loss of lipreading abilities by using the auditory information available in the valleys of the noise. The fuzzy-logical model of perception confirmed the significant impact of aging on audio-visual integration by showing an increased weight of audition in the older group.

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

PubMed

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

2018-05-01

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

Prevalence of visual impairment and blindness in Upper Egypt: a gender-based perspective.

PubMed

Mousa, Ahmed; Courtright, Paul; Kazanjian, Arminee; Bassett, Ken

2014-06-01

To estimate the prevalence, causes of and risk factors for vision loss in Upper Egypt. In this cross-sectional study, four villages in Upper Egypt were randomly selected; within these four villages, households were randomly selected and within the selected households all residents aged ≥ 40 years were enumerated and enrolled. Door-to-door eye examinations of household members were conducted. Data on relevant demographic and socioeconomic characteristics were collected. The prevalence and causes of vision loss and associated risk factors were assessed. Sex differences in prevalence and determinants were also evaluated. The prevalence of best eye presenting visual impairment, severe visual impairment, and blindness were 23.9%, 6.4%, and 9.3% respectively. The prevalence of blindness among women significantly exceeded that among men (11.8% vs. 5.4%, respectively, p = 0.021). The prevalence of cataract was 22.9% (higher in women, 26.5% than men 17.2%, p = 0.018). The prevalence of trachomatous trichiasis was 9.7% (higher among women, 12.5%, than men, 5.4%, p = 0.012). The principal causes of blindness were cataract (60%), uncorrected refractive errors (16%) and corneal opacities (12%). Age, sex, family size, illiteracy, unemployment, water source and sanitation methods and living conditions were the major risk factors for vision loss. The prevalence of visual impairment remains high in Egypt, particularly among women. Risk factors for blindness may differ between men and women. There is a need for qualitative investigations to better understand the causes behind the excess in prevalence of blindness among women.

Effect of visual experience on structural organization of the human brain: a voxel based morphometric study using DARTEL.

PubMed

Modi, Shilpi; Bhattacharya, Manisha; Singh, Namita; Tripathi, Rajendra Prasad; Khushu, Subash

2012-10-01

To investigate structural reorganization in the brain with differential visual experience using Voxel-Based Morphometry with Diffeomorphic Anatomic Registration Through Exponentiated Lie algebra algorithm (DARTEL) approach. High resolution structural MR images were taken in fifteen normal sighted healthy controls, thirteen totally blind subjects and six partial blind subjects. The analysis was carried out using SPM8 software on MATLAB 7.6.0 platform. VBM study revealed gray matter volume atrophy in the cerebellum and left inferior parietal cortex in total blind subjects and in left inferior parietal cortex, right caudate nucleus, and left primary visual cortex in partial blind subjects as compared to controls. White matter volume loss was found in calcarine gyrus in total blind subjects and Thlamus-somatosensory region in partially blind subjects as compared to controls. Besides, an increase in Gray Matter volume was also found in left middle occipital and middle frontal gyrus and right entorhinal cortex, and an increase in White Matter volume was found in superior frontal gyrus, left middle temporal gyrus and right Heschl's gyrus in totally blind subjects as compared to controls. Comparison between total and partial blind subjects revealed a greater Gray Matter volume in left cerebellum of partial blinds and left Brodmann area 18 of total blind subjects. Results suggest that, loss of vision at an early age can induce significant structural reorganization on account of the loss of visual input. These plastic changes are different in early onset of total blindness as compared to partial blindness. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Optical coherence tomography detects characteristic retinal nerve fiber layer thickness corresponding to band atrophy of the optic discs.

PubMed

Kanamori, Akiyasu; Nakamura, Makoto; Matsui, Noriko; Nagai, Azusa; Nakanishi, Yoriko; Kusuhara, Sentaro; Yamada, Yuko; Negi, Akira

2004-12-01

To analyze retinal nerve fiber layer (RNFL) thickness in eyes with band atrophy by use of optical coherence tomography (OCT) and to evaluate the ability of OCT to detect this characteristic pattern of RNFL loss. Cross-sectional, retrospective study. Thirty-four eyes of 18 patients with bitemporal hemianopia caused by optic chiasm compression by chiasmal tumors were studied. All eyes were divided into 3 groups according to visual field loss grading after Goldmann perimetry. Retinal nerve fiber layer thickness measurements with OCT. Retinal nerve fiber layer thickness around the optic disc was measured by OCT (3.4-mm diameter circle). Calculation of the changes in OCT parameters, including the horizontal (nasal + temporal quadrant RNFL thickness) and vertical values (superior + inferior quadrant RNFL thickness) was based on data from 160 normal eyes. Comparison between the 3 visual field grading groups was done with the analysis of variance test. The receiver operating characteristic (ROC) curve for the horizontal and vertical value were calculated, and the areas under the curve (AUC) were compared. Retinal nerve fiber layer thickness in eyes with band atrophy decreased in all OCT parameters. The reduction rate in average and temporal RNFL thickness and horizontal value was correlated with visual field grading. The AUC of horizontal value was 0.970+/-0.011, which was significantly different from AUC of vertical value (0.903+/-0.022). The degree of RNFL thickness reduction correlated with that of visual field defects. Optical coherence tomography was able to identify the characteristic pattern of RNFL loss in these eyes.

Assessing disease stress and modeling yield losses in alfalfa

NASA Astrophysics Data System (ADS)

Guan, Jie

Alfalfa is the most important forage crop in the U.S. and worldwide. Fungal foliar diseases are believed to cause significant yield losses in alfalfa, yet, little quantitative information exists regarding the amount of crop loss. Different fungicides and application frequencies were used as tools to generate a range of foliar disease intensities in Ames and Nashua, IA. Visual disease assessments (disease incidence, disease severity, and percentage defoliation) were obtained weekly for each alfalfa growth cycle (two to three growing cycles per season). Remote sensing assessments were performed using a hand-held, multispectral radiometer to measure the amount and quality of sunlight reflected from alfalfa canopies. Factors such as incident radiation, sun angle, sensor height, and leaf wetness were all found to significantly affect the percentage reflectance of sunlight reflected from alfalfa canopies. The precision of visual and remote sensing assessment methods was quantified. Precision was defined as the intra-rater repeatability and inter-rater reliability of assessment methods. F-tests, slopes, intercepts, and coefficients of determination (R2) were used to compare assessment methods for precision. Results showed that among the three visual disease assessment methods (disease incidence, disease severity, and percentage defoliation), percentage defoliation had the highest intra-rater repeatability and inter-rater reliability. Remote sensing assessment method had better precision than the percentage defoliation assessment method based upon higher intra-rater repeatability and inter-rater reliability. Significant linear relationships between canopy reflectance (810 nm), percentage defoliation and yield were detected using linear regression and percentage reflectance (810 nm) assessments were found to have a stronger relationship with yield than percentage defoliation assessments. There were also significant linear relationships between percentage defoliation, dry weight, percentage reflectance (810 nm), and green leaf area index (GLAI). Percentage reflectance (810 nm) assessments had a stronger relationship with dry weight and green leaf area index than percentage defoliation assessments. Our research conclusively demonstrates that percentage reflectance measurements can be used to nondestructively assess green leaf area index which is a direct measure of plant health and an indirect measure of productivity. This research conclusively demonstrates that remote sensing is superior to visual assessment method to assess alfalfa stress and to model yield and GLAI in the alfalfa foliar disease pathosystem.

Comparing the Impact of Refractive and Non-Refractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation

PubMed Central

Zebardast, Nazlee; Swenor, Bonnielin K.; van Landingham, Suzanne W.; Massof, Robert W.; Munoz, Beatriz; West, Sheila K.; Ramulu, Pradeep Y.

2015-01-01

Purpose To compare the effects of uncorrected refractive error (URE) and non-refractive visual impairment (VI) on performance and disability measures. Design Cross-sectional population-based study. Participants 2469 individuals with binocular presenting visual acuity (PVA) of 20/80 or better who participated in the first round of the Salisbury Eye Evaluation study. Methods URE was defined as binocular PVA of 20/30 or worse, improving to better than 20/30 with subjective refraction. VI was defined as post-refraction binocular best corrected visual acuity (BCVA) of 20/30 or worse. The visual acuity decrement attributable to VI was calculated as the difference between BCVA and 20/30 while that due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of 1) vision status (VI, URE, or normal vision) using the group with normal vision as reference, and 2) a one-line decrement in acuity due to VI or URE. Main Outcome Measures Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. ADV responses were analyzed using Rasch analysis to determine visual ability. Results Compared to individuals with normal vision, subjects with VI (n=191) had significantly poorer objective and subjective visual functioning in all metrics examined (p<0.05) while subjects with URE (n=132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation and lower ADV scores (p<0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a one-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared to a one-line VA decrement due to URE. Conclusions VI is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and non-refractive vision loss should be distinguished in studies evaluating visual disability, and should be understood to have differing consequences. PMID:25813453

Retinal Structures and Visual Cortex Activity are Impaired Prior to Clinical Vision Loss in Glaucoma.

PubMed

Murphy, Matthew C; Conner, Ian P; Teng, Cindy Y; Lawrence, Jesse D; Safiullah, Zaid; Wang, Bo; Bilonick, Richard A; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S; Chan, Kevin C

2016-08-11

Glaucoma is the second leading cause of blindness worldwide and its pathogenesis remains unclear. In this study, we measured the structure, metabolism and function of the visual system by optical coherence tomography and multi-modal magnetic resonance imaging in healthy subjects and glaucoma patients with different degrees of vision loss. We found that inner retinal layer thinning, optic nerve cupping and reduced visual cortex activity occurred before patients showed visual field impairment. The primary visual cortex also exhibited more severe functional deficits than higher-order visual brain areas in glaucoma. Within the visual cortex, choline metabolism was perturbed along with increasing disease severity in the eye, optic radiation and visual field. In summary, this study showed evidence that glaucoma deterioration is already present in the eye and the brain before substantial vision loss can be detected clinically using current testing methods. In addition, cortical cholinergic abnormalities are involved during trans-neuronal degeneration and can be detected non-invasively in glaucoma. The current results can be of impact for identifying early glaucoma mechanisms, detecting and monitoring pathophysiological events and eye-brain-behavior relationships, and guiding vision preservation strategies in the visual system, which may help reduce the burden of this irreversible but preventable neurodegenerative disease.

Retinal Structures and Visual Cortex Activity are Impaired Prior to Clinical Vision Loss in Glaucoma

PubMed Central

Murphy, Matthew C.; Conner, Ian P.; Teng, Cindy Y.; Lawrence, Jesse D.; Safiullah, Zaid; Wang, Bo; Bilonick, Richard A.; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S.; Chan, Kevin C.

2016-01-01

Glaucoma is the second leading cause of blindness worldwide and its pathogenesis remains unclear. In this study, we measured the structure, metabolism and function of the visual system by optical coherence tomography and multi-modal magnetic resonance imaging in healthy subjects and glaucoma patients with different degrees of vision loss. We found that inner retinal layer thinning, optic nerve cupping and reduced visual cortex activity occurred before patients showed visual field impairment. The primary visual cortex also exhibited more severe functional deficits than higher-order visual brain areas in glaucoma. Within the visual cortex, choline metabolism was perturbed along with increasing disease severity in the eye, optic radiation and visual field. In summary, this study showed evidence that glaucoma deterioration is already present in the eye and the brain before substantial vision loss can be detected clinically using current testing methods. In addition, cortical cholinergic abnormalities are involved during trans-neuronal degeneration and can be detected non-invasively in glaucoma. The current results can be of impact for identifying early glaucoma mechanisms, detecting and monitoring pathophysiological events and eye-brain-behavior relationships, and guiding vision preservation strategies in the visual system, which may help reduce the burden of this irreversible but preventable neurodegenerative disease. PMID:27510406

Evidence for Non-Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of “Green” Sensitivity in a Subject with Damaged Ventral Occipito-Temporal Cortex

PubMed Central

Rauscher, Franziska G.; Plant, Gordon T.; James-Galton, Merle; Barbur, John L.

2011-01-01

Damage to ventral occipito-temporal extrastriate visual cortex leads to the syndrome of prosopagnosia often with coexisting cerebral achromatopsia. A patient with this syndrome resulting in a left upper homonymous quadrantanopia, prosopagnosia, and incomplete achromatopsia is described. Chromatic sensitivity was assessed at a number of locations in the intact visual field using a dynamic luminance contrast masking technique that isolates the use of colour signals. In normal subjects chromatic detection thresholds form an elliptical contour when plotted in the Commission Internationale d’Eclairage, (x-y), chromaticity diagram. Because the extraction of colour signals in early visual processing involves opponent mechanisms, subjects with Daltonism (congenital red/green loss of sensitivity) show symmetric increase in thresholds towards the long wavelength (“red”) and middle wavelength (“green”) regions of the spectrum locus. This is also the case with acquired loss of chromatic sensitivity as a result of retinal or optic nerve disease. Our patient’s results were an exception to this rule. Whilst his chromatic sensitivity in the central region of the visual field was reduced symmetrically for both “red/green” and “yellow/blue” directions in colour space, the subject’s lower left quadrant showed a marked asymmetry in “red/green” thresholds with the greatest loss of sensitivity towards the “green” region of the spectrum locus. This spatially localized asymmetric loss of “green” but not “red” sensitivity has not been reported previously in human vision. Such loss is consistent with selective damage of neural substrates in the visual cortex that process colour information, but are spectrally non-opponent. PMID:27956924

[Spontaneous peeling of the epimacular membrane after cryotherapy of retinal vasoproliferative tumors: report of a case].

PubMed

Coulier, J; Gribomont, A C; De Potter, P

2013-01-01

Epimacular membranes when responsible for a significant loss of visual acuity, generally require treatment by vitrectomy and peeling of the membrane. We report the case of a spontaneous peeling of a macular pucker after cryotherapy of peripheral retinal vasoproliferative tumors. Review of the literature.

The Glenn A. Fry Award Lecture 2012: Plasticity of the visual system following central vision loss.

PubMed

Chung, Susana T L

2013-06-01

Following the onset of central vision loss, most patients develop an eccentric retinal location outside the affected macular region, the preferred retinal locus (PRL), as their new reference for visual tasks. The first goal of this article is to present behavioral evidence showing the presence of experience-dependent plasticity in people with central vision loss. The evidence includes the presence of oculomotor re-referencing of fixational saccades to the PRL; the characteristics of the shape of the crowding zone (spatial region within which the presence of other objects affects the recognition of a target) at the PRL are more "foveal-like" instead of resembling those of the normal periphery; and the change in the shape of the crowding zone at a para-PRL location that includes a component referenced to the PRL. These findings suggest that there is a shift in the referencing locus of the oculomotor and the sensory visual system from the fovea to the PRL for people with central vision loss, implying that the visual system for these individuals is still plastic and can be modified through experiences. The second goal of the article is to demonstrate the feasibility of applying perceptual learning, which capitalizes on the presence of plasticity, as a tool to improve functional vision for people with central vision loss. Our finding that visual function could improve with perceptual learning presents an exciting possibility for the development of an alternative rehabilitative strategy for people with central vision loss.

Detecting Glaucoma With a Portable Brain-Computer Interface for Objective Assessment of Visual Function Loss.

PubMed

Nakanishi, Masaki; Wang, Yu-Te; Jung, Tzyy-Ping; Zao, John K; Chien, Yu-Yi; Diniz-Filho, Alberto; Daga, Fabio B; Lin, Yuan-Pin; Wang, Yijun; Medeiros, Felipe A

2017-06-01

The current assessment of visual field loss in diseases such as glaucoma is affected by the subjectivity of patient responses and the lack of portability of standard perimeters. To describe the development and initial validation of a portable brain-computer interface (BCI) for objectively assessing visual function loss. This case-control study involved 62 eyes of 33 patients with glaucoma and 30 eyes of 17 healthy participants. Glaucoma was diagnosed based on a masked grading of optic disc stereophotographs. All participants underwent testing with a BCI device and standard automated perimetry (SAP) within 3 months. The BCI device integrates wearable, wireless, dry electroencephalogram and electrooculogram systems and a cellphone-based head-mounted display to enable the detection of multifocal steady state visual-evoked potentials associated with visual field stimulation. The performances of global and sectoral multifocal steady state visual-evoked potentials metrics to discriminate glaucomatous from healthy eyes were compared with global and sectoral SAP parameters. The repeatability of the BCI device measurements was assessed by collecting results of repeated testing in 20 eyes of 10 participants with glaucoma for 3 sessions of measurements separated by weekly intervals. Receiver operating characteristic curves summarizing diagnostic accuracy. Intraclass correlation coefficients and coefficients of variation for assessing repeatability. Among the 33 participants with glaucoma, 19 (58%) were white, 12 (36%) were black, and 2 (6%) were Asian, while among the 17 participants with healthy eyes, 9 (53%) were white, 8 (47%) were black, and none were Asian. The receiver operating characteristic curve area for the global BCI multifocal steady state visual-evoked potentials parameter was 0.92 (95% CI, 0.86-0.96), which was larger than for SAP mean deviation (area under the curve, 0.81; 95% CI, 0.72-0.90), SAP mean sensitivity (area under the curve, 0.80; 95% CI, 0.69-0.88; P = .03), and SAP pattern standard deviation (area under the curve, 0.77; 95% CI, 0.66-0.87; P = .01). No statistically significant differences were seen for the sectoral measurements between the BCI and SAP. Intraclass coefficients for global and sectoral parameters ranged from 0.74 to 0.92, and mean coefficients of variation ranged from 3.03% to 7.45%. The BCI device may be useful for assessing the electrical brain responses associated with visual field stimulation. The device discriminated eyes with glaucomatous neuropathy from healthy eyes in a clinically based setting. Further studies should investigate the feasibility of the BCI device for home-based testing as well as for detecting visual function loss over time.

Causes and anatomical site of blindness and severe visual loss in Isfahan, Islamic Republic of Iran.

PubMed

Dehghan, A; Kianersi, F; Moazam, E; Ghanbari, H

2010-02-01

This study in 2005 evaluated the causes and major anatomical site of blindness and severe visual loss at a school for blind children in Isfahan province, Islamic Republic of Iran. All 211 students were examined according to the modified WHO/PBL eye examination record: 70.4% were blind, 24.3% had severe visual loss and 5.3% were visually impaired. The major causes of abnormality were hereditary factors (42.7%), prenatal/neonatal (18.5%) and unknown etiology (35.5%). The main sites of abnormality were the retina (62.6%), whole globe (17.5%), lens (7.1%) and optic nerve (7.1%). A high proportion of parents were in a consanguineous marriage (49.2%). The pattern of blindness in Isfahan encompasses characteristics of both developed and developing countries.

The physiotherapeutic context of loss of dominant arm function due to occupational accidents.

PubMed

Kostiukow, Anna; Kaluga, Elżbieta; Samborski, Włodzimierz; Rostkowska, Elżbieta

2016-12-23

The study examines the problem of dominant arm function loss in rural adult patients due to work-related accidents. The types of risks involved in farmyard work include falling from a height, manually moving loads, overturning/accident whilst driving an agricultural tractor, noise and vibration, use of pesticides, and the risk of being cut or injured. The study focuses on adaptation of the non-dominant arm. The main aim of the study was evaluation of visual-motor coordination on the basis of performance of the non-dominant hand in patients after the loss of function of the dominant arm. The research sample consisted of 52 patients with a permanent or temporary loss of function or severely limited function of the dominant arm. The subjects were patients with arm amputations due to various occupational injuries sustained while operating agricultural and construction machinery and forestry equipment, following traumas or complicated medical surgeries of the arm, or due to car accidents. The following tests were applied in the analysis: I) Dufour cross-shaped apparatus test for assessing visual motor-coordination; II) paper-and-pencil tests and the Relay Baton motor fitness test; III) anthropometric measurements; IV) Edinburgh Handedness Inventory; and V) a questionnaire survey. The results of the apparatus and motor tests indicate the same tendency: reaction to stimuli measured on the basis of performance of the non-dominant arm is longer in shorter and older patients. Visual-motor coordination, as measured by the performance of the non-dominant arm, is significantly affected by the subject's body height and arm length.

The Effect of Conventional and Transparent Surgical Masks on Speech Understanding in Individuals with and without Hearing Loss.

PubMed

Atcherson, Samuel R; Mendel, Lisa Lucks; Baltimore, Wesley J; Patro, Chhayakanta; Lee, Sungmin; Pousson, Monique; Spann, M Joshua

2017-01-01

It is generally well known that speech perception is often improved with integrated audiovisual input whether in quiet or in noise. In many health-care environments, however, conventional surgical masks block visual access to the mouth and obscure other potential facial cues. In addition, these environments can be noisy. Although these masks may not alter the acoustic properties, the presence of noise in addition to the lack of visual input can have a deleterious effect on speech understanding. A transparent ("see-through") surgical mask may help to overcome this issue. To compare the effect of noise and various visual input conditions on speech understanding for listeners with normal hearing (NH) and hearing impairment using different surgical masks. Participants were assigned to one of three groups based on hearing sensitivity in this quasi-experimental, cross-sectional study. A total of 31 adults participated in this study: one talker, ten listeners with NH, ten listeners with moderate sensorineural hearing loss, and ten listeners with severe-to-profound hearing loss. Selected lists from the Connected Speech Test were digitally recorded with and without surgical masks and then presented to the listeners at 65 dB HL in five conditions against a background of four-talker babble (+10 dB SNR): without a mask (auditory only), without a mask (auditory and visual), with a transparent mask (auditory only), with a transparent mask (auditory and visual), and with a paper mask (auditory only). A significant difference was found in the spectral analyses of the speech stimuli with and without the masks; however, no more than ∼2 dB root mean square. Listeners with NH performed consistently well across all conditions. Both groups of listeners with hearing impairment benefitted from visual input from the transparent mask. The magnitude of improvement in speech perception in noise was greatest for the severe-to-profound group. Findings confirm improved speech perception performance in noise for listeners with hearing impairment when visual input is provided using a transparent surgical mask. Most importantly, the use of the transparent mask did not negatively affect speech perception performance in noise. American Academy of Audiology

aCNViewer: Comprehensive genome-wide visualization of absolute copy number and copy neutral variations.

PubMed

Renault, Victor; Tost, Jörg; Pichon, Fabien; Wang-Renault, Shu-Fang; Letouzé, Eric; Imbeaud, Sandrine; Zucman-Rossi, Jessica; Deleuze, Jean-François; How-Kit, Alexandre

2017-01-01

Copy number variations (CNV) include net gains or losses of part or whole chromosomal regions. They differ from copy neutral loss of heterozygosity (cn-LOH) events which do not induce any net change in the copy number and are often associated with uniparental disomy. These phenomena have long been reported to be associated with diseases and particularly in cancer. Losses/gains of genomic regions are often correlated with lower/higher gene expression. On the other hand, loss of heterozygosity (LOH) and cn-LOH are common events in cancer and may be associated with the loss of a functional tumor suppressor gene. Therefore, identifying recurrent CNV and cn-LOH events can be important as they may highlight common biological components and give insights into the development or mechanisms of a disease. However, no currently available tools allow a comprehensive whole-genome visualization of recurrent CNVs and cn-LOH in groups of samples providing absolute quantification of the aberrations leading to the loss of potentially important information. To overcome these limitations, we developed aCNViewer (Absolute CNV Viewer), a visualization tool for absolute CNVs and cn-LOH across a group of samples. aCNViewer proposes three graphical representations: dendrograms, bi-dimensional heatmaps showing chromosomal regions sharing similar abnormality patterns, and quantitative stacked histograms facilitating the identification of recurrent absolute CNVs and cn-LOH. We illustrated aCNViewer using publically available hepatocellular carcinomas (HCCs) Affymetrix SNP Array data (Fig 1A). Regions 1q and 8q present a similar percentage of total gains but significantly different copy number gain categories (p-value of 0.0103 with a Fisher exact test), validated by another cohort of HCCs (p-value of 5.6e-7) (Fig 2B). aCNViewer is implemented in python and R and is available with a GNU GPLv3 license on GitHub https://github.com/FJD-CEPH/aCNViewer and Docker https://hub.docker.com/r/fjdceph/acnviewer/. aCNViewer@cephb.fr.

The Spectrum of Optic Disc Ischemia in Patients Younger than 50 Years (An Amercian Ophthalmological Society Thesis)

PubMed Central

Arnold, Anthony C.; Costa, Roberta M. S.; Dumitrascu, Oana M.

2013-01-01

Purpose: To identify the spectrum of clinical and fluorescein angiographic features of optic disc ischemia in patients younger than 50 years. Methods: This retrospective comparative case series from a university consultative neuro-ophthalmology practice consisted of two phases. The first compared 108 cases of nonarteritic anterior ischemic optic neuropathy in patients younger than 50 years (NAIONy) to a cohort of 108 cases in patients 50 years or older (NAIONo). Predisposing risk factors, fluorescein angiographic features, and clinical course were compared. In the second phase, 12 cases of diabetic papillopathy under age 50 were assessed by fluorescein angiographic criteria for evidence of optic disc ischemia and compared to patients with NAIONy. Results: NAIONy comprised 108 (12.7%) of 848 NAION cases reviewed. Chronic renal failure with dialysis and migraine were more common in NAIONy. Fellow eye involvement rate was significantly higher for NAIONy patients (46/108, 42.6%) than for NAIONo patients (32/108, 29.6%). Fluorescein angiographic features of ischemia were documented in 44 (81.5%) of 54 eyes studied. In one case, these features were documented in pre-NAION edema. Diabetic papillopathy demonstrated delayed filling consistent with ischemia in 7 of 10 (70.0%), without significant visual field loss. Conclusions: Ischemic optic neuropathy in patients younger than 50 years is not rare. Fellow eye involvement is more frequent in younger patients. Fluorescein angiography confirmation of impaired perfusion in multiple syndromes of optic neuropathy corroborates a spectrum of optic disc ischemia ranging from perfusion delay without visual loss to severely impaired perfusion and visual loss and incorporates optic neuropathies previously considered nonischemic. PMID:24167327

Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease.

PubMed

Kokona, Despina; Georgiou, Panagiota-Christina; Kounenidakis, Mihalis; Kiagiadaki, Foteini; Thermos, Kyriaki

2016-01-01

The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago. In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma. The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss. Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness. The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease.

Quality changes and nutrient retention in fresh-cut versus whole fruits during storage.

PubMed

Gil, María I; Aguayo, Encarna; Kader, Adel A

2006-06-14

The influences of processing and storage on the quality indices and nutritional content of fresh-cut fruits were evaluated in comparison to whole fruits stored for the same duration but prepared on the day of sampling. Fresh-cut pineapples, mangoes, cantaloupes, watermelons, strawberries, and kiwifruits and whole fruits were stored for up to 9 days in air at 5 degrees C. The postcutting life based on visual appearance was shorter than 6 days for fresh-cut kiwifruit and shorter than 9 days for fresh-cut pineapple, cantaloupe, and strawberry. On the other hand, fresh-cut watermelon and mango pieces were still marketable after 9 days at 5 degrees C. Losses in vitamin C after 6 days at 5 degrees C were < or = 5% in mango, strawberry, and watermelon pieces, 10% in pineapple pieces, 12% in kiwifruit slices, and 25% in cantaloupe cubes. No losses in carotenoids were found in kiwifruit slices and watermelon cubes, whereas losses in pineapples were the highest at 25% followed by 10-15% in cantaloupe, mango, and strawberry pieces after 6 days at 5 degrees C. No significant losses in total phenolics were found in any of the fresh-cut fruit products tested after 6 days at 5 degrees C. Light exposure promoted browning in pineapple pieces and decreased vitamin C content in kiwifruit slices. Total carotenoids contents decreased in cantaloupe cubes and kiwifruit slices, but increased in mango and watermelon cubes in response to light exposure during storage at 5 degrees C for up to 9 days. There was no effect of exposure to light on the content of phenolics. In general, fresh-cut fruits visually spoil before any significant nutrient loss occurs.

Network-based H.264/AVC whole frame loss visibility model and frame dropping methods.

PubMed

Chang, Yueh-Lun; Lin, Ting-Lan; Cosman, Pamela C

2012-08-01

We examine the visual effect of whole frame loss by different decoders. Whole frame losses are introduced in H.264/AVC compressed videos which are then decoded by two different decoders with different common concealment effects: frame copy and frame interpolation. The videos are seen by human observers who respond to each glitch they spot. We found that about 39% of whole frame losses of B frames are not observed by any of the subjects, and over 58% of the B frame losses are observed by 20% or fewer of the subjects. Using simple predictive features which can be calculated inside a network node with no access to the original video and no pixel level reconstruction of the frame, we developed models which can predict the visibility of whole B frame losses. The models are then used in a router to predict the visual impact of a frame loss and perform intelligent frame dropping to relieve network congestion. Dropping frames based on their visual scores proves superior to random dropping of B frames.

Comparison of the effect of web-based, simulation-based, and conventional training on the accuracy of visual estimation of postpartum hemorrhage volume on midwifery students: A randomized clinical trial

PubMed Central

Kordi, Masoumeh; Fakari, Farzaneh Rashidi; Mazloum, Seyed Reza; Khadivzadeh, Talaat; Akhlaghi, Farideh; Tara, Mahmoud

2016-01-01

Introduction: Delay in diagnosis of bleeding can be due to underestimation of the actual amount of blood loss during delivery. Therefore, this research aimed to compare the efficacy of web-based, simulation-based, and conventional training on the accuracy of visual estimation of postpartum hemorrhage volume. Materials and Methods: This three-group randomized clinical trial study was performed on 105 midwifery students in Mashhad School of Nursing and Midwifery in 2013. The samples were selected by the convenience method and were randomly divided into three groups of web-based, simulation-based, and conventional training. The three groups participated before and 1 week after the training course in eight station practical tests, then, the students of the web-based group were trained on-line for 1 week, the students of the simulation-based group were trained in the Clinical Skills Centre for 4 h, and the students of the conventional group were trained for 4 h presentation by researchers. The data gathering tool was a demographic questionnaire designed by the researchers and objective structured clinical examination. Data were analyzed by software version 11.5. Results: The accuracy of visual estimation of postpartum hemorrhage volume after training increased significantly in the three groups at all stations (1, 2, 4, 5, 6 and 7 (P = 0.001), 8 (P = 0.027)) except station 3 (blood loss of 20 cc, P = 0.095), but the mean score of blood loss estimation after training did not significantly different between the three groups (P = 0.95). Conclusion: Training increased the accuracy of estimation of postpartum hemorrhage, but no significant difference was found among the three training groups. We can use web-based training as a substitute or supplement of training along with two other more common simulation and conventional methods. PMID:27500175

Role of somatosensory and vestibular cues in attenuating visually induced human postural sway

NASA Technical Reports Server (NTRS)

Peterka, R. J.; Benolken, M. S.

1995-01-01

The purpose of this study was to determine the contribution of visual, vestibular, and somatosensory cues to the maintenance of stance in humans. Postural sway was induced by full-field, sinusoidal visual surround rotations about an axis at the level of the ankle joints. The influences of vestibular and somatosensory cues were characterized by comparing postural sway in normal and bilateral vestibular absent subjects in conditions that provided either accurate or inaccurate somatosensory orientation information. In normal subjects, the amplitude of visually induced sway reached a saturation level as stimulus amplitude increased. The saturation amplitude decreased with increasing stimulus frequency. No saturation phenomena were observed in subjects with vestibular loss, implying that vestibular cues were responsible for the saturation phenomenon. For visually induced sways below the saturation level, the stimulus-response curves for both normal subjects and subjects experiencing vestibular loss were nearly identical, implying (1) that normal subjects were not using vestibular information to attenuate their visually induced sway, possibly because sway was below a vestibular-related threshold level, and (2) that subjects with vestibular loss did not utilize visual cues to a greater extent than normal subjects; that is, a fundamental change in visual system "gain" was not used to compensate for a vestibular deficit. An unexpected finding was that the amplitude of body sway induced by visual surround motion could be almost 3 times greater than the amplitude of the visual stimulus in normal subjects and subjects with vestibular loss. This occurred in conditions where somatosensory cues were inaccurate and at low stimulus amplitudes. A control system model of visually induced postural sway was developed to explain this finding. For both subject groups, the amplitude of visually induced sway was smaller by a factor of about 4 in tests where somatosensory cues provided accurate versus inaccurate orientation information. This implied (1) that the subjects experiencing vestibular loss did not utilize somatosensory cues to a greater extent than normal subjects; that is, changes in somatosensory system "gain" were not used to compensate for a vestibular deficit, and (2) that the threshold for the use of vestibular cues in normal subjects was apparently lower in test conditions where somatosensory cues were providing accurate orientation information.

Screening for hearing, visual and dual sensory impairment in older adults using behavioural cues: a validation study.

PubMed

Roets-Merken, Lieve M; Zuidema, Sytse U; Vernooij-Dassen, Myrra J F J; Kempen, Gertrudis I J M

2014-11-01

This study investigated the psychometric properties of the Severe Dual Sensory Loss screening tool, a tool designed to help nurses and care assistants to identify hearing, visual and dual sensory impairment in older adults. Construct validity of the Severe Dual Sensory Loss screening tool was evaluated using Crohnbach's alpha and factor analysis. Interrater reliability was calculated using Kappa statistics. To evaluate the predictive validity, sensitivity and specificity were calculated by comparison with the criterion standard assessment for hearing and vision. The criterion used for hearing impairment was a hearing loss of ≥40 decibel measured by pure-tone audiometry, and the criterion for visual impairment was a visual acuity of ≤0.3 diopter or a visual field of ≤0.3°. Feasibility was evaluated by the time needed to fill in the screening tool and the clarity of the instruction and items. Prevalence of dual sensory impairment was calculated. A total of 56 older adults receiving aged care and 12 of their nurses and care assistants participated in the study. Crohnbach's alpha was 0.81 for the hearing subscale and 0.84 for the visual subscale. Factor analysis showed two constructs for hearing and two for vision. Kappa was 0.71 for the hearing subscale and 0.74 for the visual subscale. The predictive validity showed a sensitivity of 0.71 and a specificity of 0.72 for the hearing subscale; and a sensitivity of 0.69 and a specificity of 0.78 for the visual subscale. The optimum cut-off point for each subscale was score 1. The nurses and care assistants reported that the Severe Dual Sensory Loss screening tool was easy to use. The prevalence of hearing and vision impairment was 55% and 29%, respectively, and that of dual sensory impairment was 20%. The Severe Dual Sensory Loss screening tool was compared with the criterion standards for hearing and visual impairment and was found a valid and reliable tool, enabling nurses and care assistants to identify hearing, visual and dual sensory impairment among older adults. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of Visual Information Presentation for Visual Prosthesis.

PubMed

Guo, Fei; Yang, Yuan; Gao, Yong

2018-01-01

Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis.

Optimization of Visual Information Presentation for Visual Prosthesis

PubMed Central

Gao, Yong

2018-01-01

Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis. PMID:29731769

Two-year visual results for older Asian women treated with photodynamic therapy or bevacizumab for myopic choroidal neovascularization.

PubMed

Ikuno, Yasushi; Nagai, Yoshimi; Matsuda, Satoshi; Arisawa, Akiko; Sho, Kenichiro; Oshita, Takashi; Takahashi, Kanji; Uchihori, Yasutaka; Gomi, Fumi

2010-01-01

To compare the long-term visual and anatomic outcome of treatment with photodynamic therapy (PDT) or intravitreal bevacizumab (IVB; Avastin; Genentech Inc, South San Francisco, California, USA) for choroidal neovascularization attributable to pathologic myopia (mCNV). An open-label, interventional case series. Multi-institutional. Thirty-one eyes of Japanese women who received either PDT or IVB for mCNV. Inclusion criteria were age 50 years or older, greatest linear dimension (GLD) 1200 to 3000 microm, and baseline best-corrected visual acuity (BCVA) 20/200 to 20/40. INTERVENTION PROCEDURES: Patients received either PDT or IVB (1 mg/40 microL) throughout the study, with re-treatment when necessary. BCVA and visual gain/loss at 3, 6, 12, 18, and 24 months after the initial treatment. Age, BCVA, location of CNV, refractive error, and symptom duration at baseline did not differ significantly between groups. BCVA was significantly improved at 3 to 12 months (P < .05); however, the significance was lost at 18 and 24 months in the IVB group. The PDT group showed no significant improvement within the first year, and vision slowly worsened after 12 months, becoming significantly worse at 18 and 24 months compared to baseline (P< .01). BCVA was significantly higher in the IVB group at 6 months (P< .05), and 12 months or further (P < .01). Visual gain was significantly greater in the IVB group at 6, 12, 18, and 24 months (P < .05 for 6, 18, and 24 months and P < .01 for 12 months). These findings indicate that the effects of PDT and IVB have a different time course, and that IVB provides a significantly better BCVA than PDT for mCNV over the long-term. Copyright 2010 Elsevier Inc. All rights reserved.

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

Clinical Features of Pregnancy-associated Retinal and Choroidal Diseases Causing Acute Visual Disturbance.

PubMed

Park, Young Joo; Park, Kyu Hyung; Woo, Se Joon

2017-08-01

To report clinical features of patients with retinal and choroidal diseases presenting with acute visual disturbance during pregnancy. In this retrospective case series, patients who developed acute visual loss during pregnancy (including puerperium) and visited a tertiary hospital from July 2007 to June 2015, were recruited by searching electronic medical records. Patients were categorized according to the cause of visual loss. Clinical features and required diagnostic modalities were analyzed in the retinal and choroidal disease group. Acute visual loss occurred in 147 patients; 49 (38.9%) were classified into the retinal and choroidal group. The diagnoses included central serous chorioretinopathy (22.4%), hypertensive retinopathy with or without pre-eclampsia (22.4%), retinal tear with or without retinal detachment (18.4%), diabetic retinopathy progression (10.2%), Vogt-Koyanagi-Harada disease (4.1%), retinal artery occlusion (4.1%), multiple evanescent white dot syndrome (4.1%), and others (14.3%). Visual symptoms first appeared at gestational age 25.9 ± 10.3 weeks. The initial best-corrected visual acuity (BCVA) was 0.27 ± 0.39 logarithm of the minimum angle of resolution (logMAR); the final BCVA after delivery improved to 0.13 ± 0.35 logMAR. Serious visual deterioration (BCVA worth than 20 / 200) developed in two patients. Differential diagnoses were established with characteristic fundus and spectral-domain optical coherence tomography findings in all cases. In pregnant women with acute visual loss, retinal and choroidal diseases are common and could be vision threatening. Physicians should be aware of pregnancy-associated retinal and choroidal diseases and their clinical features. The differential diagnosis can be established with non-invasive techniques. © 2017 The Korean Ophthalmological Society

[Postoperative visual loss due to conversion disorder after spine surgery: a case report].

PubMed

Bezerra, Dailson Mamede; Bezerra, Eglantine Mamede; Silva Junior, Antonio Jorge; Amorim, Marco Aurélio Soares; Miranda, Denismar Borges de

Patients undergoing spinal surgeries may develop postoperative visual loss. We present a case of total bilateral visual loss in a patient who, despite having clinical and surgical risk factors for organic lesion, evolved with visual disturbance due to conversion disorder. A male patient, 39 years old, 71kg, 1.72 m, ASA I, admitted to undergo fusion and discectomy at L4-L5 and L5-S1. Venoclysis, cardioscopy, oximetry, NIBP; induction with remifentanil, propofol and rocuronium; intubation with ETT (8.0mm) followed by capnography and urinary catheterization for diuresis. Maintenance with full target-controlled intravenous anesthesia. During fixation and laminectomy, the patient developed severe bleeding and hypovolemic shock. After 30minutes, hemostasis and hemodynamic stability was achieved with infusion of norepinephrine, volume expansion, and blood products. In the ICU, the patient developed mental confusion, weakness in the limbs, and bilateral visual loss. It was not possible to identify clinical, laboratory or image findings of organic lesion. He evolved with episodes of anxiety, emotional lability, and language impairment; the hypothesis of conversion syndrome with visual component was raised after psychiatric evaluation. The patient had complete resolution of symptoms after visual education and introduction of low doses of antipsychotic, antidepressant, and benzodiazepine. Other symptoms also regressed, and the patient was discharged 12 days after surgery. After 60 days, the patient had no more symptoms. Conversion disorders may have different signs and symptoms of non-organic origin, including visual component. It is noteworthy that the occurrence of this type of visual dysfunction in the postoperative period of spinal surgery is a rare event and should be remembered as a differential diagnosis. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Functional visual fields: relationship of visual field areas to self-reported function.

PubMed

Subhi, Hikmat; Latham, Keziah; Myint, Joy; Crossland, Michael D

2017-07-01

The aim of this study is to relate areas of the visual field to functional difficulties to inform the development of a binocular visual field assessment that can reflect the functional consequences of visual field loss. Fifty-two participants with peripheral visual field loss undertook binocular assessment of visual fields using the 30-2 and 60-4 SITA Fast programs on the Humphrey Field Analyser, and mean thresholds were derived. Binocular visual acuity, contrast sensitivity and near reading performance were also determined. Self-reported overall and mobility function were assessed using the Dutch ICF Activity Inventory. Greater visual field loss (0-60°) was associated with worse self-reported function both overall (R 2 = 0.50; p < 0.0001), and for mobility (R 2 = 0.64; p < 0.0001). Central (0-30°) and peripheral (30-60°) visual field areas were similarly related to mobility function (R 2 = 0.61, p < 0.0001 and R 2 = 0.63, p < 0.0001 respectively), although the peripheral (30-60°) visual field was the best predictor of mobility self-reported function in multiple regression analyses. Superior and inferior visual field areas related similarly to mobility function (R 2 = 0.56, p < 0.0001 and R 2 = 0.67, p < 0.0001 respectively). The inferior field was found to be the best predictor of mobility function in multiple regression analysis. Mean threshold of the binocular visual field to 60° eccentricity is a good predictor of self-reported function overall, and particularly of mobility function. Both the central (0-30°) and peripheral (30-60°) mean threshold are good predictors of self-reported function, but the peripheral (30-0°) field is a slightly better predictor of mobility function, and should not be ignored when considering functional consequences of field loss. The inferior visual field is a slightly stronger predictor of perceived overall and mobility function than the superior field. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

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.

Progressive Decrease of Peripapillary Angioflow Vessel Density During Structural and Visual Field Progression in Early Primary Open-angle Glaucoma.

PubMed

Holló, Gábor

2017-07-01

To present a case of early primary open-angle glaucoma in which retinal nerve fiber layer thickness (RNFLT), ganglion cell complex (GCC), and visual field progression were accompanied with significant progression of peripapillary angioflow vessel density (PAFD) measured with optical coherence tomographic angiography. A 68-year-old female patient who was under topical intraocular pressure (IOP) lowering medication for 20 years for ocular hypertension of the right and preperimetric primary open-angle glaucoma of the left eye (with reproducible inferotemporal and superotemporal neuroretinal rim and RNFL loss) was prospectively imaged with the AngioVue OCT for RNFLT, GCC thickness, and PAFD, and investigated with the Octopus Normal G2 visual field test on the same days at 6-month intervals for 18 months, while the IOP of the left eye escaped from control. IOP of the left eye fluctuated between 14 and 30 mm Hg in the study period. RNFLT, GCC thickness, and peripapillary PAFD all decreased significantly (linear regression analysis, P=0.030, 0.040, and 0.020, respectively), and a significant 2.1 dB/y progression was seen for a superior visual field cluster. The RNFLT, peripapillary PAFD, and visual field of the right eye remained normal and unchanged. In our case IOP elevation, glaucomatous visual field conversion, and structural progression were accompanied with significant progressive decrease of peripapillary PAFD. The simultaneous thinning of RNFLT and GCC and decrease of peripapillary PAFD suggest that PAFD may potentially be an additional indicator of early progression in primary open-angle glaucoma.

Using a visual discrimination model for the detection of compression artifacts in virtual pathology images.

PubMed

Johnson, Jeffrey P; Krupinski, Elizabeth A; Yan, Michelle; Roehrig, Hans; Graham, Anna R; Weinstein, Ronald S

2011-02-01

A major issue in telepathology is the extremely large and growing size of digitized "virtual" slides, which can require several gigabytes of storage and cause significant delays in data transmission for remote image interpretation and interactive visualization by pathologists. Compression can reduce this massive amount of virtual slide data, but reversible (lossless) methods limit data reduction to less than 50%, while lossy compression can degrade image quality and diagnostic accuracy. "Visually lossless" compression offers the potential for using higher compression levels without noticeable artifacts, but requires a rate-control strategy that adapts to image content and loss visibility. We investigated the utility of a visual discrimination model (VDM) and other distortion metrics for predicting JPEG 2000 bit rates corresponding to visually lossless compression of virtual slides for breast biopsy specimens. Threshold bit rates were determined experimentally with human observers for a variety of tissue regions cropped from virtual slides. For test images compressed to their visually lossless thresholds, just-noticeable difference (JND) metrics computed by the VDM were nearly constant at the 95th percentile level or higher, and were significantly less variable than peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) metrics. Our results suggest that VDM metrics could be used to guide the compression of virtual slides to achieve visually lossless compression while providing 5-12 times the data reduction of reversible methods.

Contextual cueing impairment in patients with age-related macular degeneration.

PubMed

Geringswald, Franziska; Herbik, Anne; Hoffmann, Michael B; Pollmann, Stefan

2013-09-12

Visual attention can be guided by past experience of regularities in our visual environment. In the contextual cueing paradigm, incidental learning of repeated distractor configurations speeds up search times compared to random search arrays. Concomitantly, fewer fixations and more direct scan paths indicate more efficient visual exploration in repeated search arrays. In previous work, we found that simulating a central scotoma in healthy observers eliminated this search facilitation. Here, we investigated contextual cueing in patients with age-related macular degeneration (AMD) who suffer from impaired foveal vision. AMD patients performed visual search using only their more severely impaired eye (n = 13) as well as under binocular viewing (n = 16). Normal-sighted controls developed a significant contextual cueing effect. In comparison, patients showed only a small nonsignificant advantage for repeated displays when searching with their worse eye. When searching binocularly, they profited from contextual cues, but still less than controls. Number of fixations and scan pattern ratios showed a comparable pattern as search times. Moreover, contextual cueing was significantly correlated with acuity in monocular search. Thus, foveal vision loss may lead to impaired guidance of attention by contextual memory cues.

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.

Sunglasses with thick temples and frame constrict temporal visual field.

PubMed

Denion, Eric; Dugué, Audrey Emmanuelle; Augy, Sylvain; Coffin-Pichonnet, Sophie; Mouriaux, Frédéric

2013-12-01

Our aim was to compare the impact of two types of sunglasses on visual field and glare: one ("thick sunglasses") with a thick plastic frame and wide temples and one ("thin sunglasses") with a thin metal frame and thin temples. Using the Goldmann perimeter, visual field surface areas (cm²) were calculated as projections on a 30-cm virtual cupola. A V4 test object was used, from seen to unseen, in 15 healthy volunteers in the primary position of gaze ("base visual field"), then allowing eye motion ("eye motion visual field") without glasses, then with "thin sunglasses," followed by "thick sunglasses." Visual field surface area differences greater than the 14% reproducibility error of the method and having a p < 0.05 were considered significant. A glare test was done using a surgical lighting system pointed at the eye(s) at different incidence angles. No significant "base visual field" or "eye motion visual field" surface area variations were noted when comparing tests done without glasses and with the "thin sunglasses." In contrast, a 22% "eye motion visual field" surface area decrease (p < 0.001) was noted when comparing tests done without glasses and with "thick sunglasses." This decrease was most severe in the temporal quadrant (-33%; p < 0.001). All subjects reported less lateral glare with the "thick sunglasses" than with the "thin sunglasses" (p < 0.001). The better protection from lateral glare offered by "thick sunglasses" is offset by the much poorer ability to use lateral space exploration; this results in a loss of most, if not all, of the additional visual field gained through eye motion.

Perceptual deficits of object identification: apperceptive agnosia.

PubMed

Milner, A David; Cavina-Pratesi, Cristiana

2018-01-01

It is argued here that apperceptive object agnosia (generally now known as visual form agnosia) is in reality not a kind of agnosia, but rather a form of "imperception" (to use the term coined by Hughlings Jackson). We further argue that its proximate cause is a bilateral loss (or functional loss) of the visual form processing systems embodied in the human lateral occipital cortex (area LO). According to the dual-system model of cortical visual processing elaborated by Milner and Goodale (2006), area LO constitutes a crucial component of the ventral stream, and indeed is essential for providing the figural qualities inherent in our normal visual perception of the world. According to this account, the functional loss of area LO would leave only spared visual areas within the occipito-parietal dorsal stream - dedicated to the control of visually-guided actions - potentially able to provide some aspects of visual shape processing in patients with apperceptive agnosia. We review the relevant evidence from such individuals, concentrating particularly on the well-researched patient D.F. We conclude that studies of this kind can provide useful pointers to an understanding of the processing characteristics of parietal-lobe visual mechanisms and their interactions with occipitotemporal perceptual systems in the guidance of action. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparison of Diagnostic Accuracy between Octopus 900 and Goldmann Kinetic Visual Fields

PubMed Central

Rowe, Fiona J.; Rowlands, Alison

2014-01-01

Purpose. To determine diagnostic accuracy of kinetic visual field assessment by Octopus 900 perimetry compared with Goldmann perimetry. Methods. Prospective cross section evaluation of 40 control subjects with full visual fields and 50 patients with known visual field loss. Comparison of test duration and area measurement of isopters for Octopus 3, 5, and 10°/sec stimulus speeds. Comparison of test duration and type of visual field classification for Octopus versus Goldmann perimetry. Results were independently graded for presence/absence of field defect and for type and location of defect. Statistical evaluation comprised of ANOVA and paired t test for evaluation of parametric data with Bonferroni adjustment. Bland Altman and Kappa tests were used for measurement of agreement between data. Results. Octopus 5°/sec perimetry had comparable test duration to Goldmann perimetry. Octopus perimetry reliably detected type and location of visual field loss with visual fields matched to Goldmann results in 88.8% of results (K = 0.775). Conclusions. Kinetic perimetry requires individual tailoring to ensure accuracy. Octopus perimetry was reproducible for presence/absence of visual field defect. Our screening protocol when using Octopus perimetry is 5°/sec for determining boundaries of peripheral isopters and 3°/sec for blind spot mapping with further evaluation of area of field loss for defect depth and size. PMID:24587983

Does Central Vision Loss Impair Visual Search Performance of Adults More than Children?

PubMed

Satgunam, PremNandhini; Luo, Gang

2018-05-01

In general, young adults with normal vision show the best visual search performance when compared with children and older adults. Through our study, we show that this trend is not observed in individuals with vision impairment. An interaction effect of vision impairment with visual development and aging is observed. Performance in many visual tasks typically shows improvement with age until young adulthood and then declines with aging. Using a visual search task, this study investigated whether a similar age effect on performance is present in people with central vision loss. A total of 98 participants, 37 with normal sight (NS) and 61 with visual impairment (VI) searched for targets in 150 real-world digital images. Search performance was quantified by an integrated measure combining speed and accuracy. Participant ages ranged from 5 to 74 years, visual acuity from -0.14 (20/14.5) to 1.16 logMAR (20/290), and log contrast sensitivity (CS) from 0.48 to 2.0. Data analysis was performed with participants divided into three age groups: children (aged <14 years, n = 25), young adults (aged 14 to 45 years, n = 47), and older adults (aged >45 years, n = 26). Regression (r = 0.7) revealed CS (P < .001) and age (P = .003) were significant predictors of search performance. Performance of VI participants was normalized to the age-matched average performance of the NS group. In the VI group, it was found that children's normalized performance (52%) was better than both young (39%, P = .05) and older (40%, P = .048) adults. Unlike NS participants, young adults in the VI group may not have search ability superior to children with VI, despite having the same level of visual functions (quantified by visual acuity and CS). This could be because of vision impairment limiting the developmental acquisition of the age dividend for peak performance. Older adults in the VI group had the worst performance, indicating an interaction of aging.

On the losses of dissolved CO(2) during champagne serving.

PubMed

Liger-Belair, Gérard; Bourget, Marielle; Villaume, Sandra; Jeandet, Philippe; Pron, Hervé; Polidori, Guillaume

2010-08-11

Pouring champagne into a glass is far from being consequenceless with regard to its dissolved CO(2) concentration. Measurements of losses of dissolved CO(2) during champagne serving were done from a bottled Champagne wine initially holding 11.4 +/- 0.1 g L(-1) of dissolved CO(2). Measurements were done at three champagne temperatures (i.e., 4, 12, and 18 degrees C) and for two different ways of serving (i.e., a champagne-like and a beer-like way of serving). The beer-like way of serving champagne was found to impact its concentration of dissolved CO(2) significantly less. Moreover, the higher the champagne temperature is, the higher its loss of dissolved CO(2) during the pouring process, which finally constitutes the first analytical proof that low temperatures prolong the drink's chill and helps it to retain its effervescence during the pouring process. The diffusion coefficient of CO(2) molecules in champagne and champagne viscosity (both strongly temperature-dependent) are suspected to be the two main parameters responsible for such differences. Besides, a recently developed dynamic-tracking technique using IR thermography was also used in order to visualize the cloud of gaseous CO(2) which flows down from champagne during the pouring process, thus visually confirming the strong influence of champagne temperature on its loss of dissolved CO(2).

Optic nerve compression as a late complication of a hydrogel explant with silicone encircling band.

PubMed

Crama, Niels; Kluijtmans, Leo; Klevering, B Jeroen

2018-06-01

To present a complication of compressive optic neuropathy caused by a swollen hydrogel explant and posteriorly displaced silicone encircling band. A 72-year-old female patient presented with progressive visual loss and a tilted optic disc. Her medical history included a retinal detachment in 1993 that was treated with a hydrogel explant under a solid silicone encircling band. Visual acuity had decreased from 6/10 to 6/20 and perimetry showed a scotoma in the temporal superior quadrant. On Magnetic Resonance Imaging (MRI), compression of the optic nerve by a displaced silicone encircling band inferior nasally in combination with a swollen episcleral hydrogel explant was observed. Surgical removal of the hydrogel explant and silicone encircling band was uneventful and resulted in improvement of visual acuity and visual field loss. This is the first report on compressive optic neuropathy caused by swelling of a hydrogel explant resulting in a dislocated silicone encircling band. The loss of visual function resolved upon removal of the explant and encircling band.

Progressive Chronic Retinal Axonal Loss Following Acute Methanol-Induced Optic Neuropathy: Four-Year Prospective Cohort Study.

PubMed

Nurieva, Olga; Diblik, Pavel; Kuthan, Pavel; Sklenka, Petr; Meliska, Martin; Bydzovsky, Jan; Heissigerova, Jarmila; Urban, Pavel; Kotikova, Katerina; Navratil, Tomas; Komarc, Martin; Seidl, Zdenek; Vaneckova, Manuela; Pelclova, Daniela; Zakharov, Sergey

2018-04-27

To study the dynamics and clinical determinants of chronic retinal nerve fiber layer thickness (RNFL) loss after methanol-induced optic neuropathy. Prospective cohort study. All patients underwent complete ophthalmic evaluation including SD-OCT three times during four years of observation:4.9[±0.6], 25.0[±0.6], and 49.9[±0.5] months after discharge. Eighty-four eyes of 42 survivors of methanol poisoning; mean age (standard deviation) of 45.7[±4.4] years, and 82 eyes of 41 controls; mean age 44.0[±4.2] years. global and temporal RNFL loss. Abnormal RNFL thickness was registered in 13/42(31%) survivors of methanol poisoning and chronic axonal loss in 10/42(24%) patients. Significant decrease of global/temporal RNFL thickness during the observation period was found in the study population compared to the controls (p<0.001). The risk estimate of chronic global RNFL loss for arterial blood pH<7.3 at admission was: 11.65(1.91-71.12;95%CI) after adjusting for age and sex. The patients with chronic axonal degeneration demonstrated progressive visual loss in 7/10 cases. The patients with abnormal RNFL thickness had magnetic resonance signs of brain damage in 10/13 versus 8/29 cases with normal RNFL thickness (p=0.003). Signs of brain hemorrhages were present in 7/13 patients with abnormal RNFL thickness versus 5/29 cases with normal RNFL thickness (p=0.015). Methanol-induced optic neuropathy may lead to chronic retinal axonal loss during the following years. Arterial blood pH on admission is the strongest predictor of chronic RNFL thickness decrease. Chronic retinal neurodegeneration is associated with the progressive loss of visual functions and necrotic brain lesions. Copyright © 2018. Published by Elsevier Inc.

The Glenn A. Fry Award Lecture 2012: Plasticity of the Visual System Following Central Vision Loss

PubMed Central

Chung, Susana T. L.

2013-01-01

Following the onset of central vision loss, most patients develop an eccentric retinal location outside the affected macular region, the preferred retinal locus (PRL), as their new reference for visual tasks. The first goal of this paper is to present behavioral evidence showing the presence of experience-dependent plasticity in people with central vision loss. The evidence includes (1) the presence of oculomotor re-referencing of fixational saccades to the PRL; (2) the characteristics of the shape of the crowding zone (spatial region within which the presence of other objects affects the recognition of a target) at the PRL are more “foveal-like” instead of resembling those of the normal periphery; and (3) the change in the shape of the crowding zone at a para-PRL location that includes a component referenced to the PRL. These findings suggest that there is a shift in the referencing locus of the oculomotor and the sensory visual system from the fovea to the PRL for people with central vision loss, implying that the visual system for these individuals is still plastic and can be modified through experiences. The second goal of the paper is to demonstrate the feasibility of applying perceptual learning, which capitalizes on the presence of plasticity, as a tool to improve functional vision for people with central vision loss. Our finding that visual function could improve with perceptual learning presents an exciting possibility for the development of an alternative rehabilitative strategy for people with central vision loss. PMID:23670125

Inhibition of Stat3 by a Small Molecule Inhibitor Slows Vision Loss in a Rat Model of Diabetic Retinopathy

PubMed Central

Vanlandingham, Phillip A.; Nuno, Didier J.; Quiambao, Alexander B.; Phelps, Eric; Wassel, Ronald A.; Ma, Jian-Xing; Farjo, Krysten M.; Farjo, Rafal A.

2017-01-01

Purpose Diabetic retinopathy is a leading cause of vision loss. Previous studies have shown signaling pathways mediated by Stat3 (signal transducer and activator of transcription 3) play a primary role in diabetic retinopathy progression. This study tested CLT-005, a small molecule inhibitor of Stat3, for its dose-dependent therapeutic effects on vision loss in a rat model of diabetic retinopathy. Methods Brown Norway rats were administered streptozotocin (STZ) to induce diabetes. CLT-005 was administered daily by oral gavage for 16 weeks at concentrations of 125, 250, or 500 mg/kg, respectively, beginning 4 days post streptozotocin administration. Systemic and ocular drug concentration was quantified with mass spectrometry. Visual function was monitored at 2-week intervals from 6 to 16 weeks using optokinetic tracking to measure visual acuity and contrast sensitivity. The presence and severity of cataracts was visually monitored and correlated to visual acuity. The transcription and translation of multiple angiogenic factors and inflammatory cytokines were measured by real-time polymerase chain reaction and Multiplex immunoassay. Results Streptozotocin-diabetic rats sustain progressive vision loss over 16 weeks, and this loss in visual function is rescued in a dose-dependent manner by CLT-005. This positive therapeutic effect correlates to the positive effects of CLT-005 on vascular leakage and the presence of inflammatory cytokines in the retina. Conclusions The present study indicates that Stat3 inhibition has strong therapeutic potential for the treatment of vision loss in diabetic retinopathy. PMID:28395025

Visual impairment and road traffic accidents among drivers in Jimma Town, Southwest Ethiopia.

PubMed

Biza, Mohamed; Mossie, Andualem; Woldemichael, Kifle; Gelaw, Yeshigeta

2013-04-01

Vision play a vital role in driving where good and efficient visual functioning of the driver is essential. Any significant loss of visual function will diminish a driver's ability to operate a motor vehicle safely and will thus contribute to road traffic injury. However, there is little evidence indicating that defects of vision alone cause road traffic accidents. To determine the impact of visual impairment and other factors on road traffic accident among vehicle drivers. A cross-sectional descriptive study was conducted on 249 sampled drivers in Southwest Ethiopia. A pretested interviewer led questionnaire was used for interview and vision tests were done using Snellen's acuity chart and Ishihara pseudo-isochromatic plates. Statistical analyses were performed using SPSS version 16.0. The mean age of drivers was 33.6 years (SD +/- 10.3). The relative frequency of self reported road traffic accident was 15.3%. The prevalence of uncorrected binocular visual impairment was 1.6% and there was a significant association between visual impairment and road traffic accident (P < 0.05). Uncorrected refractive error was seen in 7.6% and 8.8% of drivers in the right and left eyes respectively, and 3.2% of them had vision less than what is required to obtain driving license (visual acuity of 6/12). None of the drivers with refractive errors were wearing appropriate corrections. Color vision impairment was seen in 1.6% of the drivers. A significant proportion (9.6%) of the drivers did not have eye exam for their driving license. Uncorrected binocular visual impairment was strongly associated with road traffic accident. There is need for consistent inspection and screening, strict rules and regulations of licensing and health education for drivers to minimize road traffic accident.

Lack of degradation in visuospatial perception of line orientation after one night of sleep loss.

PubMed

Killgore, William D S; Kendall, Athena P; Richards, Jessica M; McBride, Sharon A

2007-08-01

Sleep deprivation impairs a variety of cognitive abilities including vigilance, attention, and executive function. Although sleep loss has been shown to impair tasks requiring visual attention and spatial perception, it is not clear whether these deficits are exclusively a function of reduced attention and vigilance or if there are also alterations in visuospatial perception. Visuospatial perception and sustained vigilance performance were therefore examined in 54 healthy volunteers at rested baseline and again after one night of sleep deprivation using the Judgment of Line Orientation Test and a computerized test of psychomotor vigilance. Whereas psychomotor vigilance declined significantly from baseline to sleep-deprived testing, scores on the Judgment of Line Orientation did not change significantly. Results suggest that documented performance deficits associated with sleep loss are unlikely to be the result of dysfunction within systems of the brain responsible for simple visuospatial perception and processing of line angles.

Rapid Forgetting Results from Competition over Time between Items in Visual Working Memory

ERIC Educational Resources Information Center

Pertzov, Yoni; Manohar, Sanjay; Husain, Masud

2017-01-01

Working memory is now established as a fundamental cognitive process across a range of species. Loss of information held in working memory has the potential to disrupt many aspects of cognitive function. However, despite its significance, the mechanisms underlying rapid forgetting remain unclear, with intense recent debate as to whether it is…

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.

Rates of retinal nerve fiber layer thinning in glaucoma suspect eyes

PubMed Central

Miki, Atsuya; Medeiros, Felipe A.; Weinreb, Robert N.; Jain, Sonia; He, Feng; Sharpsten, Lucie; Khachatryan, Naira; Hammel, Na’ama; Liebmann, Jeffrey M.; Girkin, Christopher A.; Sample, Pamela A.; Zangwill, Linda M.

2015-01-01

Purpose To compare the rates of retinal nerve fiber layer (RNFL) loss in patients suspect of having glaucoma who developed visual field damage (VFD) to those who did not develop VFD, and to determine whether the rate of RNFL loss can be used to predict who will develop VFD.. Design Prospective observational cohort study Participants Glaucoma suspects, defined as having glaucomatous optic neuropathy or ocular hypertension (Intraocular pressure (IOP)>21 mmHg) without repeatable VFD at baseline from the Diagnostic Innovations in Glaucoma Study, and the African Descent and Glaucoma Evaluation Study. Methods Global and quadrant RNFL thickness (RNFLT) were measured with the Spectralis spectral-domain optical coherence tomography (SD-OCT). VFD was defined as having 3 consecutive abnormal visual fields. The rate of RNFL loss in eyes developing VFD was compared with eyes not developing VFD using multivariable linear mixed-effects models. A joint longitudinal survival model utilized the estimated RNFLT slope to predict the risk of developing VFD, while adjusting for potential confounding variables. Main Outcome Measures The rate of RNFL thinning and the probability of developing VFD. Results Four hundred and fifty-four eyes of 294 glaucoma suspects were included. The average number of SD-OCT examinations was 4.6 (range, 2–9) with median follow-up time of 2.2 (0.4–4.1) years. Forty eyes (8.8%) developed VFD. The estimated mean rate of global RNFL loss was significantly faster in eyes developing VFD compared with eyes that did not (−2.02μm/year vs. −0.82μm/year, P<0.001). The joint longitudinal survival model showed that each 1μm/year faster rate of global RNFL loss corresponded to a 2.05 times higher risk of developing VFD (Hazards Ratio (HR)=2.05, 95% Confidence Interval (CI): 1.14–3.71; p=0.017). Conclusions The rate of global RNFL loss was more than twice as fast in eyes developing VFD compared with eyes that did not develop them. Joint longitudinal survival model showed that a 1μm/year faster rate of RNFLT loss corresponded to a 2.05 times higher risk of developing VFD. These results suggest that measuring the rate of SD-OCT RNFL loss may be a useful tool to help identify patients who are at a high risk of developing visual field loss. PMID:24629619

Structural and functional changes across the visual cortex of a patient with visual form agnosia.

PubMed

Bridge, Holly; Thomas, Owen M; Minini, Loredana; Cavina-Pratesi, Cristiana; Milner, A David; Parker, Andrew J

2013-07-31

Loss of shape recognition in visual-form agnosia occurs without equivalent losses in the use of vision to guide actions, providing support for the hypothesis of two visual systems (for "perception" and "action"). The human individual DF received a toxic exposure to carbon monoxide some years ago, which resulted in a persisting visual-form agnosia that has been extensively characterized at the behavioral level. We conducted a detailed high-resolution MRI study of DF's cortex, combining structural and functional measurements. We present the first accurate quantification of the changes in thickness across DF's occipital cortex, finding the most substantial loss in the lateral occipital cortex (LOC). There are reduced white matter connections between LOC and other areas. Functional measures show pockets of activity that survive within structurally damaged areas. The topographic mapping of visual areas showed that ordered retinotopic maps were evident for DF in the ventral portions of visual cortical areas V1, V2, V3, and hV4. Although V1 shows evidence of topographic order in its dorsal portion, such maps could not be found in the dorsal parts of V2 and V3. We conclude that it is not possible to understand fully the deficits in object perception in visual-form agnosia without the exploitation of both structural and functional measurements. Our results also highlight for DF the cortical routes through which visual information is able to pass to support her well-documented abilities to use visual information to guide actions.

Glaucoma Severity and Participation in Diverse Social Roles: Does Visual Field Loss Matter?

PubMed

Yang, Yelin; Trope, Graham E; Buys, Yvonne M; Badley, Elizabeth M; Gignac, Monique A M; Shen, Carl; Jin, Ya-Ping

2016-07-01

To assess the association between glaucoma severity and participation in diverse social roles. Cross-sectional survey. Individuals with glaucoma, 50+, with visual acuity in the better eye >20/50 were enrolled. They were classified into 3 groups based on visual field loss in the better eye: mild [mean deviation (MD)>-6 dB], moderate (MD, -6 to -12 dB), and severe (MD<-12 dB). The validated Social Role Participation Questionnaire assessed respondents' perceptions of the importance, difficulty, and satisfaction with participation in 11 social role domains (eg, community events, travel). Differences between groups were examined using multivariate linear regression analyses. A total of 118 participants (52% female) were included: 60 mild, 29 moderate, and 29 severe. All social role domains were rated as important by all participants except for education and employment. Women (P<0.01), those with a partner (P<0.01), and those who were less depressed (P=0.03) reported higher scores of perceived importance of participating in social activities. Compared with those with mild glaucoma, individuals with severe glaucoma reported significantly more difficulty participating in community/religious/cultural events (P<0.01), travelling (P<0.01), and relationships with family members (P=0.01). They also reported less satisfaction with travelling (P=0.01) and social events (P=0.04). Participation in diverse social roles is valued by individuals with glaucoma. Severe visual field loss impedes involvement in and satisfaction with activities in community/religious/cultural events, travelling, and relationships with family members. Appropriate community and targeted interventions are needed to allow people with severe glaucoma to maintain active social participation-a key component to successful aging.

Alterations of sodium and potassium channels of RGCs in RCS rat with the development of retinal degeneration.

PubMed

Chen, Zhongshan; Song, Yanping; Yao, Junping; Weng, Chuanhuang; Yin, Zheng Qin

2013-11-01

All know that retinitis pigmentosa (RP) is a group of hereditary retinal degenerative diseases characterized by progressive dysfunction of photoreceptors and associated with progressive cells loss; nevertheless, little is known about how rods and cones loss affects the surviving inner retinal neurons and networks. Retinal ganglion cells (RGCs) process and convey visual information from retina to visual centers in the brain. The healthy various ion channels determine the normal reception and projection of visual signals from RGCs. Previous work on the Royal College of Surgeons (RCS) rat, as a kind of classical RP animal model, indicated that, at late stages of retinal degeneration in RCS rat, RGCs were also morphologically and functionally affected. Here, retrograde labeling for RGCs with Fluorogold was performed to investigate the distribution, density, and morphological changes of RGCs during retinal degeneration. Then, patch clamp recording, western blot, and immunofluorescence staining were performed to study the channels of sodium and potassium properties of RGCs, so as to explore the molecular and proteinic basis for understanding the alterations of RGCs membrane properties and firing functions. We found that the resting membrane potential, input resistance, and capacitance of RGCs changed significantly at the late stage of retinal degeneration. Action potential could not be evoked in a part of RGCs. Inward sodium current and outward potassium current recording showed that sodium current was impaired severely but only slightly in potassium current. Expressions of sodium channel protein were impaired dramatically at the late stage of retinal degeneration. The results suggested that the density of RGCs decreased, process ramification impaired, and sodium ion channel proteins destructed, which led to the impairment of electrophysiological functions of RGCs and eventually resulted in the loss of visual function.

A cane reduces loss of balance in patients with peripheral neuropathy: results from a challenging unipedal balance test.

PubMed

Ashton-Miller, J A; Yeh, M W; Richardson, J K; Galloway, T

1996-05-01

To test the hypothesis that use of a cane in the nondominant hand during challenging balance tasks would significantly decrease loss of balance in patients with peripheral neuropathy while transferring from bipedal to unipedal stance on an unsteady surface. Nonrandomized control study. Tertiary-care institution. Eight consecutive patients with peripheral neuropathy (PN) and eight age- and gender-matched controls (C) with a mean (SD) age of 65 (8.2) years. Subjects were asked to transfer their weight onto their right foot, despite a rapid +/- 2 degrees or +/- 4 degrees frontal plane tilt of the support surface at 70% of weight transfer, and balance unipedally for at least 3 seconds. The efficacy of their weight transfer was evaluated over 112 consecutive randomized and blocked trials by calculating loss of balance as failure rates (%FR) with and without visual feedback, and with and without use of a cane in the nondominant (left) hand. Results were analyzed using a 2 x 2 x 2 x 2 x 2 repeated-measures analysis of variance (rm-ANOVA) and post hoc t tests. The rm-ANOVA showed that the FR of the PN subjects (47.6% [18.1%]) was significantly higher than C (29.2% [15.2%], p = .036). Removing visual feedback, simulating the dark of night, increased the FR fourfold (p = .000). Use of a cane in the contralateral nondominant hand significantly reduced the FR (p = .000), particularly in the PN group (cane x disease interaction: p = .055). Post hoc t tests showed that with or without visual feedback, the cane reduced the FR of the PN group fourfold and enabled them to perform more reliably than matched controls not using a cane (p = .011). An inversion perturbation resulted in a higher FR than an eversion perturbation (p = .007). The PN group employed larger mean peak cane forces (21.9% BW) than C (13.6% BW) in restoring their balance (p = .000). Use of a cane by PN patients significantly reduced their risk of losing balance on unstable surfaces, especially under low-light conditions.

Wide-Field Fundus Autofluorescence for Retinitis Pigmentosa and Cone/Cone-Rod Dystrophy.

PubMed

Oishi, Akio; Oishi, Maho; Ogino, Ken; Morooka, Satoshi; Yoshimura, Nagahisa

2016-01-01

Retinitis pigmentosa and cone/cone-rod dystrophy are inherited retinal diseases characterized by the progressive loss of rod and/or cone photoreceptors. To evaluate the status of rod/cone photoreceptors and visual function, visual acuity and visual field tests, electroretinogram, and optical coherence tomography are typically used. In addition to these examinations, fundus autofluorescence (FAF) has recently garnered attention. FAF visualizes the intrinsic fluorescent material in the retina, which is mainly lipofuscin contained within the retinal pigment epithelium. While conventional devices offer limited viewing angles in FAF, the recently developed Optos machine enables recording of wide-field FAF. With wide-field analysis, an association between abnormal FAF areas and visual function was demonstrated in retinitis pigmentosa and cone-rod dystrophy. In addition, the presence of "patchy" hypoautofluorescent areas was found to be correlated with symptom duration. Although physicians should be cautious when interpreting wide-field FAF results because the peripheral parts of the image are magnified significantly, this examination method provides previously unavailable information.

Comparison of Risk Factor Profiles for Primary Open-Angle Glaucoma Subtypes Defined by Pattern of Visual Field Loss: A Prospective Study.

PubMed

Kang, Jae H; Loomis, Stephanie J; Rosner, Bernard A; Wiggs, Janey L; Pasquale, Louis R

2015-04-01

We explored whether risk factor associations differed by primary open-angle glaucoma (POAG) subtypes defined by visual field (VF) loss pattern (i.e., paracentral or peripheral). We included 77,157 women in the Nurses' Health Study (NHS) and 42,773 men in the Health Professionals Follow-up Study (HPFS 1986-2010), and incident medical record confirmed cases of paracentral (n = 440) and peripheral (n = 865) POAG subtypes. We evaluated African heritage, glaucoma family history, body mass index (BMI), mean arterial blood pressure, diabetes mellitus, physical activity, smoking, caffeine intake, and alcohol intake. We used competing risk Cox regression analyses modeling age as the metameter and stratified by age, cohort, and event type. We sequentially identified factors with the least significant differences in associations with POAG subtypes ("stepwise down" approach with P for heterogeneity [P-het] < 0.10 as threshold). Body mass index was more inversely associated with the POAG paracentral VF loss subtype than the peripheral VF loss subtype (per 10 kg/m2; hazard ratio [HR] = 0.67 [95% confidence interval (CI): 0.52, 0.86] versus HR = 0.93 [95% CI: 0.78, 1.10]; P-het = 0.03) as was smoking (per 10 pack-years; HR = 0.92 [95% CI: 0.87, 0.98] versus HR = 0.98 [95% CI: 0.94, 1.01]; P-het = 0.09). These findings were robust in sensitivity analyses using a "stepwise up" approach (identify factors that showed the most significant differences). Nonheterogeneous (P-het > 0.10) adverse associations with both POAG subtypes were observed with glaucoma family history, diabetes, African heritage, greater caffeine intake, and higher mean arterial pressure. These data indicate that POAG with early paracentral VF loss has distinct as well as common determinants compared with POAG with peripheral VF loss.

Experience-dependent plasticity from eye opening enables lasting, visual cortex-dependent enhancement of motion vision.

PubMed

Prusky, Glen T; Silver, Byron D; Tschetter, Wayne W; Alam, Nazia M; Douglas, Robert M

2008-09-24

Developmentally regulated plasticity of vision has generally been associated with "sensitive" or "critical" periods in juvenile life, wherein visual deprivation leads to loss of visual function. Here we report an enabling form of visual plasticity that commences in infant rats from eye opening, in which daily threshold testing of optokinetic tracking, amid otherwise normal visual experience, stimulates enduring, visual cortex-dependent enhancement (>60%) of the spatial frequency threshold for tracking. The perceptual ability to use spatial frequency in discriminating between moving visual stimuli is also improved by the testing experience. The capacity for inducing enhancement is transitory and effectively limited to infancy; however, enhanced responses are not consolidated and maintained unless in-kind testing experience continues uninterrupted into juvenile life. The data show that selective visual experience from infancy can alone enable visual function. They also indicate that plasticity associated with visual deprivation may not be the only cause of developmental visual dysfunction, because we found that experientially inducing enhancement in late infancy, without subsequent reinforcement of the experience in early juvenile life, can lead to enduring loss of function.

Managing daily life with age-related sensory loss: cognitive resources gain in importance.

PubMed

Heyl, Vera; Wahl, Hans-Werner

2012-06-01

This paper investigates the role of cognitive resources in everyday functioning, comparing visually impaired, hearing impaired, and sensory unimpaired older adults. According to arguments that cognitive resources are of increased importance and a greater awareness of cognitive restrictions exists among sensory impaired individuals, in particular among visually impaired individuals, we hypothesized differential relationships between resources and outcomes when comparing sensory impaired and sensory unimpaired older adults. Findings are based on samples of 121 visually impaired, 116 hearing impaired, and 150 sensory unimpaired older adults (M = 82 years). Results from a sample of 43 dual sensory impaired older adults are reported for comparison. Assessment relied on established instruments (e.g., WAIS-R, ADL/IADL). Structural equation modeling showed that cognitive resources and behavior-related everyday functioning were more strongly related in the sensory impaired groups as compared to the sensory unimpaired group. Cognitive resources and evaluation of everyday functioning were significantly linked only among the sensory impaired groups. When medical condition was controlled for, these effects persisted. It is concluded that both cognitive training as well as psychosocial support may serve as important additions to classic vision and hearing loss rehabilitation. PsycINFO Database Record (c) 2012 APA, all rights reserved

Role of Visual Speech in Phonological Processing by Children with Hearing Loss

ERIC Educational Resources Information Center

Jerger, Susan; Tye-Murray, Nancy; Abdi, Herve

2009-01-01

Purpose: This research assessed the influence of visual speech on phonological processing by children with hearing loss (HL). Method: Children with HL and children with normal hearing (NH) named pictures while attempting to ignore auditory or audiovisual speech distractors whose onsets relative to the pictures were either congruent, conflicting in…

Sensory Temporal Processing in Adults with Early Hearing Loss

ERIC Educational Resources Information Center

Heming, Joanne E.; Brown, Lenora N.

2005-01-01

This study examined tactile and visual temporal processing in adults with early loss of hearing. The tactile task consisted of punctate stimulations that were delivered to one or both hands by a mechanical tactile stimulator. Pairs of light emitting diodes were presented on a display for visual stimulation. Responses consisted of YES or NO…

The Secret Club Project: Exploring Miscarriage through the Visual Arts.

ERIC Educational Resources Information Center

Seftel, Laura

2001-01-01

Examines art as a means to understand the physical and emotional loss of miscarriage. "The Secret Club Project," an innovative exhibit featuring 10 women artists' visual responses to miscarriage, is described. Rituals related to pregnancy loss are reviewed, as well as artists' and art therapists' use of the creative process to move…

Comparing Auditory-Only and Audiovisual Word Learning for Children with Hearing Loss.

PubMed

McDaniel, Jena; Camarata, Stephen; Yoder, Paul

2018-05-15

Although reducing visual input to emphasize auditory cues is a common practice in pediatric auditory (re)habilitation, the extant literature offers minimal empirical evidence for whether unisensory auditory-only (AO) or multisensory audiovisual (AV) input is more beneficial to children with hearing loss for developing spoken language skills. Using an adapted alternating treatments single case research design, we evaluated the effectiveness and efficiency of a receptive word learning intervention with and without access to visual speechreading cues. Four preschool children with prelingual hearing loss participated. Based on probes without visual cues, three participants demonstrated strong evidence for learning in the AO and AV conditions relative to a control (no-teaching) condition. No participants demonstrated a differential rate of learning between AO and AV conditions. Neither an inhibitory effect predicted by a unisensory theory nor a beneficial effect predicted by a multisensory theory for providing visual cues was identified. Clinical implications are discussed.

Spatial interactions reveal inhibitory cortical networks in human amblyopia.

PubMed

Wong, Erwin H; Levi, Dennis M; McGraw, Paul V

2005-10-01

Humans with amblyopia have a well-documented loss of sensitivity for first-order, or luminance defined, visual information. Recent studies show that they also display a specific loss of sensitivity for second-order, or contrast defined, visual information; a type of image structure encoded by neurons found predominantly in visual area A18/V2. In the present study, we investigate whether amblyopia disrupts the normal architecture of spatial interactions in V2 by determining the contrast detection threshold of a second-order target in the presence of second-order flanking stimuli. Adjacent flanks facilitated second-order detectability in normal observers. However, in marked contrast, they suppressed detection in each eye of the majority of amblyopic observers. Furthermore, strabismic observers with no loss of visual acuity show a similar pattern of detection suppression. We speculate that amblyopia results in predominantly inhibitory cortical interactions between second-order neurons.

The onset of visual experience gates auditory cortex critical periods

PubMed Central

Mowery, Todd M.; Kotak, Vibhakar C.; Sanes, Dan H.

2016-01-01

Sensory systems influence one another during development and deprivation can lead to cross-modal plasticity. As auditory function begins before vision, we investigate the effect of manipulating visual experience during auditory cortex critical periods (CPs) by assessing the influence of early, normal and delayed eyelid opening on hearing loss-induced changes to membrane and inhibitory synaptic properties. Early eyelid opening closes the auditory cortex CPs precociously and dark rearing prevents this effect. In contrast, delayed eyelid opening extends the auditory cortex CPs by several additional days. The CP for recovery from hearing loss is also closed prematurely by early eyelid opening and extended by delayed eyelid opening. Furthermore, when coupled with transient hearing loss that animals normally fully recover from, very early visual experience leads to inhibitory deficits that persist into adulthood. Finally, we demonstrate a functional projection from the visual to auditory cortex that could mediate these effects. PMID:26786281

Radiation-induced optic neuropathy: A magnetic resonance imaging study

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

Guy, J.; Mancuso, A.; Beck, R.

1991-03-01

Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence ofmore » both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.« less

Metamorphopsia Score and Central Visual Field Outcomes in Diabetic Cystoid Macular Edema

PubMed Central

Brzozowska, Agnieszka; Maciejewski, Ryszard

2018-01-01

Aim To detect abnormality of the visual function in naïve patients with cystoid diabetic macular edema (DME) using M-charts, Amsler test, and white on white (W/W) and blue on yellow (B/Y) perimetry. Methods There were 64 eyes included in the study: 30 eyes with DME, 22 eyes with diabetes without DME, and 12 eyes of normal subjects. Conventional W/W perimetry and B/Y perimetry were performed within the central 10° of the visual field. To assess metamorphopsia, Amsler test and M-charts were used. Results The rate of detection of metamorphopsia was 37% with Amsler test examination and 50% with M-charts. Specificity of both tests was 100%. We found a significant difference between vertical scores of M-charts in all groups, but not in horizontal scores (p < 0.0001). Mean defect (MD) was 8.9 dB and 3.6 dB and loss variance (LV) 4.8 dB and 3.3 dB (p < 0.0001). Conclusions M-chart is more sensitive than Amsler test method for detection of metamorphopsia. The MD and LV are higher in b/y in comparison to W/W perimetry. B/Y perimetry and M-charts are more sensitive than conventional methods for detecting the visual function loss in cystoid DME. PMID:29744359

The use of different concentrations of betaine as a reducing irritation agent in soaps monitored visually and non-invasively.

PubMed

Nicander, Ingrid; Aberg, Peter; Ollmar, Stig

2003-02-01

Products containing detergents can damage the skin and give rise to irritant contact dermatitis. Therefore, attempts have been made to find less irritating detergents as well as substances decreasing undesired side-effects of detergents, and a novel approach is offered by betaine. The aim of the study has been to determine the irritating properties of some liquid soaps for personal hygiene and to map the effect of different concentrations of betaine using electrical impedance, trans-epidermal water loss and visual inspection. Twenty-eight healthy subjects were patch tested with different commercial soaps with and without betaine and sodium lauryl sulphate on both volar forearms for 24 h. A site with distilled water and an unoccluded area were used as references. Responses of the skin reactions were evaluated by visual inspection and by measuring trans-epidermal water loss and electrical impedance before application and 24 h after removal of the chambers. Significant skin reactions were found for all soaps tested but the soaps containing betaine were the least irritating. However, the skin irritation did not decrease with increasing concentrations of betaine in the tested range. On the whole the differences between the products were not large. The non-invasive methods used were more sensitive than visual assessment for evaluation of invisible or barely visible skin responses. Copyright Blackwell Munksgaard 2003

Disturbed temporal dynamics of brain synchronization in vision loss.

PubMed

Bola, Michał; Gall, Carolin; Sabel, Bernhard A

2015-06-01

Damage along the visual pathway prevents bottom-up visual input from reaching further processing stages and consequently leads to loss of vision. But perception is not a simple bottom-up process - rather it emerges from activity of widespread cortical networks which coordinate visual processing in space and time. Here we set out to study how vision loss affects activity of brain visual networks and how networks' activity is related to perception. Specifically, we focused on studying temporal patterns of brain activity. To this end, resting-state eyes-closed EEG was recorded from partially blind patients suffering from chronic retina and/or optic-nerve damage (n = 19) and healthy controls (n = 13). Amplitude (power) of oscillatory activity and phase locking value (PLV) were used as measures of local and distant synchronization, respectively. Synchronization time series were created for the low- (7-9 Hz) and high-alpha band (11-13 Hz) and analyzed with three measures of temporal patterns: (i) length of synchronized-/desynchronized-periods, (ii) Higuchi Fractal Dimension (HFD), and (iii) Detrended Fluctuation Analysis (DFA). We revealed that patients exhibit less complex, more random and noise-like temporal dynamics of high-alpha band activity. More random temporal patterns were associated with worse performance in static (r = -.54, p = .017) and kinetic perimetry (r = .47, p = .041). We conclude that disturbed temporal patterns of neural synchronization in vision loss patients indicate disrupted communication within brain visual networks caused by prolonged deafferentation. We propose that because the state of brain networks is essential for normal perception, impaired brain synchronization in patients with vision loss might aggravate the functional consequences of reduced visual input. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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

Miller, R.W.

1962-08-01

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

Cross-Domain Shoe Retrieval with a Semantic Hierarchy of Attribute Classification Network.

PubMed

Zhan, Huijing; Shi, Boxin; Kot, Alex C

2017-08-04

Cross-domain shoe image retrieval is a challenging problem, because the query photo from the street domain (daily life scenario) and the reference photo in the online domain (online shop images) have significant visual differences due to the viewpoint and scale variation, self-occlusion, and cluttered background. This paper proposes the Semantic Hierarchy Of attributE Convolutional Neural Network (SHOE-CNN) with a three-level feature representation for discriminative shoe feature expression and efficient retrieval. The SHOE-CNN with its newly designed loss function systematically merges semantic attributes of closer visual appearances to prevent shoe images with the obvious visual differences being confused with each other; the features extracted from image, region, and part levels effectively match the shoe images across different domains. We collect a large-scale shoe dataset composed of 14341 street domain and 12652 corresponding online domain images with fine-grained attributes to train our network and evaluate our system. The top-20 retrieval accuracy improves significantly over the solution with the pre-trained CNN features.

Visual impairment, coping strategies and impact on daily life: a qualitative study among working-age UK ex-service personnel.

PubMed

Stevelink, Sharon A M; Malcolm, Estelle M; Fear, Nicola T

2015-11-12

Sustaining a visual impairment may have a substantial impact on various life domains such as work, interpersonal relations, mobility and social and mental well-being. How to adjust to the loss of vision and its consequences might be a challenge for the visually impaired person. The purpose of the current study was to explore how younger male ex-Service personnel cope with becoming visually impaired and how this affects their daily life. Semi-structured interviews with 30 visually impaired male ex-Service personnel, all under the age of 55, were conducted. All participants are members of the charity organisation Blind Veterans UK. Interviews were analysed thematically. Younger ex-Service personnel applied a number of different strategies to overcome their loss of vision and its associated consequences. Coping strategies varied from learning new skills, goal setting, integrating the use of low vision aids in their daily routine, to social withdrawal and substance misuse. Vision loss affected on all aspects of daily life and ex-Service personnel experienced an on-going struggle to accept and adjust to becoming visually impaired. Health care professionals, family and friends of the person with the visual impairment need to be aware that coping with a visual impairment is a continuous struggle; even after a considerable amount of time has passed, needs for emotional, social, practical and physical support may still be present.

Periorbital Scar Correction.

PubMed

Chambers, Christopher B; Moe, Kristen S

2017-02-01

Periorbital scarring with eyelid retraction can have serious visual effects and can lead to loss of vision or even loss of the eye. Understanding of eyelid anatomy and the delicate balance of its structural supports is critical for the identification of the eyelid disorder responsible for the cicatrix and helps to guide treatment. The 2-finger test and lateral distraction of the lid can also be of significant help in proper diagnosis of the underlying disorder. Proper reconstruction with respect to the anterior and posterior lamellae helps to ensure a favorable outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

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

PubMed

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

2016-12-01

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

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.

Child's play: the creativity of older adults.

PubMed

Capps, Donald

2012-09-01

In this article, I discuss Paul W. Pruyser's view presented in his article "An Essay on Creativity" (Pruyser in Bull Menninger Clin 43:294-353, 1979) that creative persons manifest early childhood qualities of playfulness, curiosity, and pleasure seeking and that adaptation is itself a form of creativity. I then discuss his article "Creativity in Aging Persons" (Pruyser in Bull Menninger Clin 51:425-435, 1987) in which he presents his view that aging itself is a potentially creative process, that creativity among older adults is not limited to the talented few, and that older adulthood has several specific features that are conducive to creativity. Significant among these features are object loss (especially involving human relationships) and functional loss (due to the vicissitudes of aging). Noting his particular emphasis on object loss and its role in late-life creativity, I focus on functional loss, and I emphasize the importance of adaptation in sustaining the creativity of older adults who experience such loss. I illustrate this adaptation by considering well-known painters who in late life suffered visual problems common to older adults. I suggest that in adapting to their visual problems these artists drew on the early childhood qualities (playfulness, curiosity and pleasure seeking) that all creative persons possess and that they are therefore illustrative for other older adults who are experiencing functional losses. I conclude with Erik H. Erikson's (Toys and reasons: stages in the ritualization of experience, W. W. Norton, New York, 1977) and Paul W. Pruyser's (Pastor Psychol 35:120-131, 1986) reflections on the relationship between seeing and hoping.

Longitudinal study of visual function in patients with relapsing-remitting multiple sclerosis with and without a history of optic neuritis.

PubMed

González Gómez, A; García-Ben, A; Soler García, A; García-Basterra, I; Padilla Parrado, F; García-Campos, J M

2017-03-15

The contrast sensitivity test determines the quality of visual function in patients with multiple sclerosis (MS). The purpose of this study is to analyse changes in visual function in patients with relapsing-remitting MS with and without a history of optic neuritis (ON). We conducted a longitudinal study including 61 patients classified into 3 groups as follows: a) disease-free patients (control group); b) patients with MS and no history of ON; and c) patients with MS and a history of unilateral ON. All patients underwent baseline and 6-year follow-up ophthalmologic examinations, which included visual acuity and monocular and binocular Pelli-Robson contrast sensitivity tests. Monocular contrast sensitivity was significantly lower in MS patients with and without a history of ON than in controls both at baseline (P=.00 and P=.01, respectively) and at 6 years (P=.01 and P=.02). Patients with MS and no history of ON remained stable throughout follow-up whereas those with a history of ON displayed a significant loss of contrast sensitivity (P=.01). Visual acuity and binocular contrast sensitivity at baseline and at 6 years was significantly lower in the group of patients with a history of ON than in the control group (P=.003 and P=.002 vs P=.006 and P=.005) and the group with no history of ON (P=.04 and P=.038 vs P=.008 and P=.01). However, no significant differences were found in follow-up results (P=.1 and P=.5). Monocular Pelli-Robson contrast sensitivity test may be used to detect changes in visual function in patients with ON. Copyright © 2017 The Author(s). Publicado por Elsevier España, S.L.U. All rights reserved.

Auditory biofeedback substitutes for loss of sensory information in maintaining stance.

PubMed

Dozza, Marco; Horak, Fay B; Chiari, Lorenzo

2007-03-01

The importance of sensory feedback for postural control in stance is evident from the balance improvements occurring when sensory information from the vestibular, somatosensory, and visual systems is available. However, the extent to which also audio-biofeedback (ABF) information can improve balance has not been determined. It is also unknown why additional artificial sensory feedback is more effective for some subjects than others and in some environmental contexts than others. The aim of this study was to determine the relative effectiveness of an ABF system to reduce postural sway in stance in healthy control subjects and in subjects with bilateral vestibular loss, under conditions of reduced vestibular, visual, and somatosensory inputs. This ABF system used a threshold region and non-linear scaling parameters customized for each individual, to provide subjects with pitch and volume coding of their body sway. ABF had the largest effect on reducing the body sway of the subjects with bilateral vestibular loss when the environment provided limited visual and somatosensory information; it had the smallest effect on reducing the sway of subjects with bilateral vestibular loss, when the environment provided full somatosensory information. The extent that all subjects substituted ABF information for their loss of sensory information was related to the extent that each subject was visually dependent or somatosensory-dependent for their postural control. Comparison of postural sway under a variety of sensory conditions suggests that patients with profound bilateral loss of vestibular function show larger than normal information redundancy among the remaining senses and ABF of trunk sway. The results support the hypothesis that the nervous system uses augmented sensory information differently depending both on the environment and on individual proclivities to rely on vestibular, somatosensory or visual information to control sway.

Isolated cortical visual loss with subtle brain MRI abnormalities in a case of hypoxic-ischemic encephalopathy.

PubMed

Margolin, Edward; Gujar, Sachin K; Trobe, Jonathan D

2007-12-01

A 16-year-old boy who was briefly asystolic and hypotensive after a motor vehicle accident complained of abnormal vision after recovering consciousness. Visual acuity was normal, but visual fields were severely constricted without clear hemianopic features. The ophthalmic examination was otherwise normal. Brain MRI performed 11 days after the accident showed no pertinent abnormalities. At 6 months after the event, brain MRI demonstrated brain volume loss in the primary visual cortex and no other abnormalities. One year later, visual fields remained severely constricted; neurologic examination, including formal neuropsychometric testing, was normal. This case emphasizes the fact that hypoxic-ischemic encephalopathy (HIE) may cause enduring damage limited to primary visual cortex and that the MRI abnormalities may be subtle. These phenomena should be recognized in the management of patients with HIE.

The first rapid assessment of avoidable blindness (RAAB) in Thailand.

PubMed

Isipradit, Saichin; Sirimaharaj, Maytinee; Charukamnoetkanok, Puwat; Thonginnetra, Oraorn; Wongsawad, Warapat; Sathornsumetee, Busaba; Somboonthanakij, Sudawadee; Soomsawasdi, Piriya; Jitawatanarat, Umapond; Taweebanjongsin, Wongsiri; Arayangkoon, Eakkachai; Arame, Punyawee; Kobkoonthon, Chinsuchee; Pangputhipong, Pannet

2014-01-01

The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB) study in Thailand. A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. The age and sex adjusted prevalence of blindness (presenting visual acuity (VA) <20/400), severe visual impairment (VA <20/200 but ≥20/400), and moderate visual impairment (VA <20/70 but ≥20/200) were 0.6% (95% CI: 0.5-0.8), 1.3% (95% CI: 1.0-1.6), 12.6% (95% CI: 10.8-14.5). There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system.

The accuracy of confrontation visual field test in comparison with automated perimetry.

PubMed Central

Johnson, L. N.; Baloh, F. G.

1991-01-01

The accuracy of confrontation visual field testing was determined for 512 visual fields using automated static perimetry as the reference standard. The sensitivity of confrontation testing excluding patchy defects was 40% for detecting anterior visual field defects, 68.3% for posterior defects, and 50% for both anterior and posterior visual field defects combined. The sensitivity within each group varied depending on the type of visual field defect encountered. Confrontation testing had a high sensitivity (75% to 100%) for detecting altitudinal visual loss, central/centrocecal scotoma, and homonymous hemianopsia. Confrontation testing was fairly insensitive (20% to 50% sensitivity) for detecting arcuate scotoma and bitemporal hemianopsia. The specificity of confrontation testing was high at 93.4%. The high positive predictive value (72.6%) and negative predictive value (75.7%) would indicate that visual field defects identified during confrontation testing are often true visual field defects. However, the many limitations of confrontation testing should be remembered, particularly its low sensitivity for detecting visual field loss associated with parasellar tumors, glaucoma, and compressive optic neuropathies. PMID:1800764

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT AT 2-MONTH INTERVALS REDUCES FOVEAL AVASCULAR ZONE ENLARGEMENT AND VISION LOSS IN RADIATION MACULOPATHY: A Pilot Study.

PubMed

Daruich, Alejandra; Matet, Alexandre; Schalenbourg, Ann; Zografos, Leonidas

2018-05-03

To evaluate, in eyes with radiation maculopathy, the effect of 2-month-interval anti-vascular endothelial growth factor therapy on best-corrected visual acuity and foveal avascular zone (FAZ) enlargement using optical coherence tomography angiography. Consecutive treatment-naive patients with radiation maculopathy after proton beam irradiation for choroidal melanoma were retrospectively included. Clinical and optical coherence tomography angiography data at baseline and the 6-month visit were recorded. Two independent observers measured FAZ area manually on 3 × 3-mm optical coherence tomography angiography images of the superficial capillary plexus and deep capillary plexus. Patients were encouraged to follow strictly a 2-month-interval intravitreal anti-vascular endothelial growth factor treatment by either bevacizumab or ranibizumab. Findings were analyzed based on the adherence to the treatment scheme. According to the adherence to the bimonthly anti-vascular endothelial growth factor treatment protocol, patients were categorized into 3 groups: treatment protocol (n = 19, strict adherence), variable intervals (n = 11, intervals other than 2 months), and no treatment (n = 11). The estimated radiation dose to the foveola in each group was 49 ± 16, 46 ± 17, and 46 ± 18 cobalt gray equivalent, respectively (P = 0.85). For the entire cohort, best-corrected visual acuity loss (P < 0.02) and FAZ enlargement (P < 0.0001) were observed over 6 months. Best-corrected visual acuity loss was significantly less pronounced in the treatment-protocol group than in the variable-interval and no-treatment groups (P = 0.007 and P = 0.004). The FAZ enlargement was lower in the treatment-protocol group compared with the variable-interval group for both superficial capillary plexus (P = 0.029) and deep capillary plexus (P = 0.03), and to the no-treatment group for the deep capillary plexus only (P = 0.016). Decrease in best-corrected visual acuity and FAZ enlargement on optical coherence tomography angiography occurred over 6 months in eyes with radiation maculopathy and were significantly reduced under 2-month-interval anti-vascular endothelial growth factor therapy.

Effects of Sleep Loss on Subjective Complaints and Objective Neurocognitive Performance as Measured by the Immediate Post-Concussion Assessment and Cognitive Testing.

PubMed

Stocker, Ryan P J; Khan, Hassen; Henry, Luke; Germain, Anne

2017-05-01

This study examined the effects of total and partial sleep deprivation on subjective symptoms and objective neurocognitive performance, as measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in a sample of healthy adults. One-hundred and two, right-handed, healthy participants (between ages 18 and 30 years old) completed three consecutive nights in the sleep laboratory with concurrent continuous polysomnography monitoring. Night 1 served as a baseline night. Prior to Night 2, they were randomly assigned to one of three sleep conditions: undisrupted normal sleep (N = 34), sleep restriction (50% of habitual sleep, N = 37), or total sleep deprivation (N = 31). Participants slept undisturbed on Night 3. ImPACT was administered on three separate occasions. Sleep loss was associated with increased severity of subjectively reported affective, cognitive, physical, and sleep symptoms. Although objective neurocognitive task scores derived from the ImPACT battery did not corroborate subjective complaints, sleep loss was associated with significant differences on tasks of visual memory, reaction time, and visual motor speed over time. While self-report measures suggested marked impairments following sleep loss, deficits in neurocognitive performance were observed only on three domains measured with ImPACT. ImPACT may capture subtle changes in neurocognitive performance following sleep loss; however, independent and larger validation studies are needed to determine its sensitivity to acute sleep loss and recovery sleep. Neurocognitive screening batteries may be useful for detecting the effects of more severe or chronic sleep loss under high-stress conditions that mimic high-risk occupations. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Management of neovascular age-related macular degeneration: current state-of-the-art care for optimizing visual outcomes and therapies in development

PubMed Central

Agarwal, Aniruddha; Rhoades, William R; Hanout, Mostafa; Soliman, Mohamed Kamel; Sarwar, Salman; Sadiq, Mohammad Ali; Sepah, Yasir Jamal; Do, Diana V; Nguyen, Quan Dong

2015-01-01

Contemporary management of neovascular age-related macular degeneration (AMD) has evolved significantly over the last few years. The goal of treatment is shifting from merely salvaging vision to maintaining a high quality of life. There have been significant breakthroughs in the identification of viable drug targets and gene therapies. Imaging tools with near-histological precision have enhanced our knowledge about pathophysiological mechanisms that play a role in vision loss due to AMD. Visual, social, and vocational rehabilitation are all important treatment goals. In this review, evidence from landmark clinical trials is summarized to elucidate the optimum modern-day management of neovascular AMD. Therapeutic strategies currently under development, such as gene therapy and personalized medicine, are also described. PMID:26089632

Intervention Practices in the Retention of Competitive Employment among Individuals Who Are Blind or Visually Impaired.

ERIC Educational Resources Information Center

Sikka, Anjoo; Stephens, Barry C.

This report discusses the results of a national study of 89 rehabilitation counselors that investigated the methods by which an individual could retain competitive employment after the onset of a significant vision loss. The purpose of the study was to identify and describe strategies that contribute to successful job retention and identify best…

Childhood blindness and visual loss: an assessment at two institutions including a "new" cause.

PubMed Central

Mets, M B

1999-01-01

PURPOSE: This study was initiated to investigate the causes of childhood blindness and visual impairment in the United States. We also sought a particular etiology--congenital lymphocytic choriomeningitis virus (LCMV)--which has been considered exceedingly rare, in a fixed target population of children, the severely mentally retarded. METHODS: We undertook a library-based study of the world literature to shed light on the causes of childhood blindness internationally and to put our data in context. We prospectively examined all consented children (159) at 2 institutions in the United States to determine their ocular status and the etiology of any visual loss present. One of the institutions is a school for the visually impaired (hereafter referred to as Location V), in which most of the students have normal mentation. The other is a home for severely mentally retarded, nonambulatory children (hereafter referred to as Location M). This institution was selected specifically to provide a sample of visual loss associated with severe retardation because the handful of cases of LCMV in the literature have been associated with severe central nervous system insults. Histories were obtained from records on site, and all children received a complete cyclopleged ophthalmic examination at their institution performed by the author. Patients at Location M with chorioretinal scars consistent with intrauterine infection (a possible sign of LCMV) had separate consents for blood drawing. Sera was obtained and sent for standard TORCHS titers, toxoplasmosis titers (Jack S. Remington, MD, Palo Alto, Calif), and ELISA testing for LCMV (Centers for Disease Control and Prevention, Atlanta, Ga). RESULTS: The diagnoses at Location V were varied and included retinopathy of prematurity (19.4%), optic atrophy (19.4%), retinitis pigmentosa (14.5%), optic nerve hypoplasia (12.9%), cataracts (8.1%), foveal hypoplasia (8.1%), persistent hyperplastic primary vitreous (4.8%), and microphthalmos (3.2%). The most common diagnosis at Location M was bilateral optic atrophy, which was found in 65% of the patients examined who had visual loss. Of these, the insults were most often congenital (42.6%), with birth trauma, prematurity, and genetics each responsible for about 15% of the optic atrophy. The second most common diagnosis was cortical visual impairment (24%), followed by chorioretinal scars (5%), which are strongly suggestive of intrauterine infection. Of 95 patients examined at Location M, 4 had chorioretinal scars. Two of these had dramatically elevated titers for LCMV, as did one of their mothers. One of the other 2 children died before serum could be drawn, and the fourth had negative titers for both TORCHS and LCMV. CONCLUSIONS: At both locations studied, visual loss was most often due to congenital insults, whether genetic or simply prenatal. The visual loss at Location V was twice as likely as that at Location M to be caused by a genetic disorder. The genetic disorders at Location V were more often isolated eye diseases, while those among the severely retarded at Location M were more generalized genetic disorders. Our study identified optic atrophy as a common diagnosis among the severely mentally retarded with vision loss, a finding that is supported by previous studies in other countries. In our population of severely retarded children, the target etiology of lymphocytic choriomeningitis virus was responsible for half the visual loss secondary to chorioretinitis from intrauterine infection. This is more common than would be predicted by the few cases previously described in the literature, and strongly suggests that LCMV may be a more common cause of visual loss than previously appreciated. We believe that serology for LCMV should be part of the workup for congenital chorioretinitis, especially if the TORCHS titers are negative, and that perhaps the mnemonic should be revised to "TORCHS + L." Childhood blindness and visual impairment are tragic and co Images FIGURE 5 FIGURE 6 PMID:10703143

A comparison of semiautomated versus manual Goldmann kinetic perimetry in patients with visually significant glaucoma.

PubMed

Ramirez, Adriana M; Chaya, Craig J; Gordon, Lynn K; Giaconi, Joann A

2008-03-01

To determine if semiautomated kinetic perimetry (SKP) is reproducible and comparable to Goldmann manual kinetic perimetry (GVF). Glaucoma patients were recruited to perform visual field testing using GVF and SKP. Specific isopters were tested, quantified, and compared. Visual field patterns were analyzed for shape and defect. Ten patients (16 eyes) underwent visual field studies using SKP and GVF, and 8 patients completed a second SKP on a different day. Individual isopter areas were similar between GVF and SKP, although 60% of isopters were larger on SKP by an average of 15%. This was statistically significant for the smaller isopters, I4e (P=0.02) and I2e (P=0.05). Retesting with SKP on a separate day, showed similar isopter areas (P values=0.3 to 1.0), however, the exact location of isopters in degrees from central fixation tended to vary with the smaller test object sizes. Isopter position in degrees from the central axis agreed in at least 3 quadrants in approximately 65% of fields compared. SKP visual field defects and patterns were similar between test strategies. SKP and GVF testing produce similar visual field results in glaucoma patients, and SKP testing seems to be reliable and reproducible in this population. However, overlapping isopters, typically associated with nonorganic vision loss, and jagged isopters were sometimes observed in SKP visual fields. Further study of SKP is needed to explore these findings.

The role of the thalamus and hippocampus in episodic memory performance in patients with multiple sclerosis.

PubMed

Koenig, Katherine A; Rao, Stephen M; Lowe, Mark J; Lin, Jian; Sakaie, Ken E; Stone, Lael; Bermel, Robert A; Trapp, Bruce D; Phillips, Micheal D

2018-03-01

Episodic memory loss is one of the most common cognitive symptoms in patients with multiple sclerosis (MS), but the pathophysiology of this symptom remains unclear. Both the hippocampus and thalamus have been implicated in episodic memory and show regional atrophy in patients with MS. In this work, we used functional magnetic resonance imaging (fMRI) during a verbal episodic memory task, lesion load, and volumetric measures of the hippocampus and thalamus to assess the relative contributions to verbal and visual-spatial episodic memory. Functional activation, lesion load, and volumetric measures from 32 patients with MS and 16 healthy controls were used in a predictive analysis of episodic memory function. After adjusting for disease duration, immediate recall performance on a visual-spatial episodic memory task was significantly predicted by hippocampal volume ( p < 0.003). Delayed recall on the same task was significantly predicted by volume of the left thalamus ( p < 0.003). For both memory measures, functional activation of the thalamus during encoding was more predictive than that of volume measures ( p < 0.002). Our results suggest that functional activation may be useful as a predictive measure of episodic memory loss in patients with MS.

The relationship between better-eye and integrated visual field mean deviation and visual disability.

PubMed

Arora, Karun S; Boland, Michael V; Friedman, David S; Jefferys, Joan L; West, Sheila K; Ramulu, Pradeep Y

2013-12-01

To determine the extent of difference between better-eye visual field (VF) mean deviation (MD) and integrated VF (IVF) MD among Salisbury Eye Evaluation (SEE) subjects and a larger group of glaucoma clinic subjects and to assess how those measures relate to objective and subjective measures of ability/performance in SEE subjects. Retrospective analysis of population- and clinic-based samples of adults. A total of 490 SEE and 7053 glaucoma clinic subjects with VF loss (MD ≤-3 decibels [dB] in at least 1 eye). Visual field testing was performed in each eye, and IVF MD was calculated. Differences between better-eye and IVF MD were calculated for SEE and clinic-based subjects. In SEE subjects with VF loss, models were constructed to compare the relative impact of better-eye and IVF MD on driving habits, mobility, self-reported vision-related function, and reading speed. Difference between better-eye and IVF MD and relationship of better-eye and IVF MD with performance measures. The median difference between better-eye and IVF MD was 0.41 dB (interquartile range [IQR], -0.21 to 1.04 dB) and 0.72 dB (IQR, 0.04-1.45 dB) for SEE subjects and clinic-based patients with glaucoma, respectively, with differences of ≥ 2 dB between the 2 MDs observed in 9% and 18% of the groups, respectively. Among SEE subjects with VF loss, both MDs demonstrated similar associations with multiple ability and performance metrics as judged by the presence/absence of a statistically significant association between the MD and the metric, the magnitude of observed associations (odds ratios, rate ratios, or regression coefficients associated with 5-dB decrements in MD), and the extent of variability in the metric explained by the model (R(2)). Similar associations of similar magnitude also were noted for the subgroup of subjects with glaucoma and subjects in whom better-eye and IVF MD differed by ≥ 2 dB. The IVF MD rarely differs from better-eye MD, and similar associations between VF loss and visual disability are obtained using either MD. Unlike better-eye MD, IVF measurements require extra software/calculation. As such, information from studies using better-eye MD can be more easily integrated into clinical decision-making, making better-eye MD a robust and meaningful method for reporting VF loss severity. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Loss of Visual Working Memory within Seconds: The Combined Use of Refreshable and Non-Refreshable Features

ERIC Educational Resources Information Center

Ricker, Timothy J.; Cowan, Nelson

2010-01-01

We reexamine the role of time in the loss of information from working memory, the limited information accessible for cognitive tasks. The controversial issue of whether working memory deteriorates over time was investigated using arrays of unconventional visual characters. Each array was followed by a postperceptual mask, a variable retention…

Clinical Phenotypes and Prognostic Full-Field Electroretinographic Findings in Stargardt Disease

PubMed Central

ZAHID, SARWAR; JAYASUNDERA, THIRAN; RHOADES, WILLIAM; BRANHAM, KARI; KHAN, NAHEED; NIZIOL, LESLIE M.; MUSCH, DAVID C.; HECKENLIVELY, JOHN R.

2013-01-01

PURPOSE To investigate the relationships between clinical and full-field electroretinographic (ERG) findings and progressive loss of visual function in Stargardt disease. DESIGN Retrospective cohort study. METHODS We performed a retrospective review of data from 198 patients with Stargardt disease. Measures of visual function over time, including visual acuity, quantified Goldmann visual fields, and full-field ERG data were recorded. Data were analyzed using SAS statistical software. Subgroup analyses were performed on 148 patients with ERG phenotypic data, 46 patients with longitudinal visual field data, and 92 patients with identified ABCA4 mutations (46 with 1 mutation, and 47 with 2 or more mutations). RESULTS Of 46 patients with longitudinal visual field data, 8 patients with faster central scotoma progression rates had significantly worse scotopic B-wave amplitudes at their initial assessment than 20 patients with stable scotomata (P = .014) and were more likely to have atrophy beyond the arcades (P = .047). Overall, 47.3% of patients exhibited abnormal ERG results, with rod–cone dysfunction in 14.2% of patients, cone–rod dysfunction in 17.6% of patients, and isolated cone dysfunction in 15.5% of patients. Abnormal values in certain ERG parameters were associated significantly with (maximum-stimulation A- and B-wave amplitudes) or tended toward (photopic and scotopic B-wave amplitudes) a higher mean rate of central scotoma progression compared with those patients with normal ERG values. Scotoma size and ERG parameters differed significantly between those with a single mutation versus those with multiple mutations. CONCLUSIONS Full-field ERG examination provides clinically relevant information regarding the severity of Stargardt disease, likelihood of central scotoma expansion, and visual acuity deterioration. Patients also may exhibit an isolated cone dystrophy on ERG examination. PMID:23219216

Visual speech alters the discrimination and identification of non-intact auditory speech in children with hearing loss.

PubMed

Jerger, Susan; Damian, Markus F; McAlpine, Rachel P; Abdi, Hervé

2017-03-01

Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development. Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/-B/aa or/-B/az). The items started with an easy-to-speechread/B/or difficult-to-speechread/G/onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/-B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same-as opposed to different-responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g.,/-B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz-as opposed to az- responses in the audiovisual than auditory mode. Performance in the audiovisual mode showed more same responses for the intact vs. non-intact different pairs (e.g., Baa:/-B/aa) and more intact onset responses for nonword repetition (Baz for/-B/az). Thus visual speech altered both discrimination and identification in the CHL-to a large extent for the/B/onsets but only minimally for the/G/onsets. The CHL identified the stimuli similarly to the CNH but did not discriminate the stimuli similarly. A bias-free measure of the children's discrimination skills (i.e., d' analysis) revealed that the CHL had greater difficulty discriminating intact from non-intact speech in both modes. As the degree of HL worsened, the ability to discriminate the intact vs. non-intact onsets in the auditory mode worsened. Discrimination ability in CHL significantly predicted their identification of the onsets-even after variation due to the other variables was controlled. These results clearly established that visual speech can fill in non-intact auditory speech, and this effect, in turn, made the non-intact onsets more difficult to discriminate from intact speech and more likely to be perceived as intact. Such results 1) demonstrate the value of visual speech at multiple levels of linguistic processing and 2) support intervention programs that view visual speech as a powerful asset for developing spoken language in CHL. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Visual Speech Alters the Discrimination and Identification of Non-Intact Auditory Speech in Children with Hearing Loss

PubMed Central

Jerger, Susan; Damian, Markus F.; McAlpine, Rachel P.; Abdi, Hervé

2017-01-01

Objectives Understanding spoken language is an audiovisual event that depends critically on the ability to discriminate and identify phonemes yet we have little evidence about the role of early auditory experience and visual speech on the development of these fundamental perceptual skills. Objectives of this research were to determine 1) how visual speech influences phoneme discrimination and identification; 2) whether visual speech influences these two processes in a like manner, such that discrimination predicts identification; and 3) how the degree of hearing loss affects this relationship. Such evidence is crucial for developing effective intervention strategies to mitigate the effects of hearing loss on language development. Methods Participants were 58 children with early-onset sensorineural hearing loss (CHL, 53% girls, M = 9;4 yrs) and 58 children with normal hearing (CNH, 53% girls, M = 9;4 yrs). Test items were consonant-vowel (CV) syllables and nonwords with intact visual speech coupled to non-intact auditory speech (excised onsets) as, for example, an intact consonant/rhyme in the visual track (Baa or Baz) coupled to non-intact onset/rhyme in the auditory track (/–B/aa or /–B/az). The items started with an easy-to-speechread /B/ or difficult-to-speechread /G/ onset and were presented in the auditory (static face) vs. audiovisual (dynamic face) modes. We assessed discrimination for intact vs. non-intact different pairs (e.g., Baa:/–B/aa). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more same—as opposed to different—responses in the audiovisual than auditory mode. We assessed identification by repetition of nonwords with non-intact onsets (e.g., /–B/az). We predicted that visual speech would cause the non-intact onset to be perceived as intact and would therefore generate more Baz—as opposed to az— responses in the audiovisual than auditory mode. Results Performance in the audiovisual mode showed more same responses for the intact vs. non-intact different pairs (e.g., Baa:/–B/aa) and more intact onset responses for nonword repetition (Baz for/–B/az). Thus visual speech altered both discrimination and identification in the CHL—to a large extent for the /B/ onsets but only minimally for the /G/ onsets. The CHL identified the stimuli similarly to the CNH but did not discriminate the stimuli similarly. A bias-free measure of the children’s discrimination skills (i.e., d’ analysis) revealed that the CHL had greater difficulty discriminating intact from non-intact speech in both modes. As the degree of HL worsened, the ability to discriminate the intact vs. non-intact onsets in the auditory mode worsened. Discrimination ability in CHL significantly predicted their identification of the onsets—even after variation due to the other variables was controlled. Conclusions These results clearly established that visual speech can fill in non-intact auditory speech, and this effect, in turn, made the non-intact onsets more difficult to discriminate from intact speech and more likely to be perceived as intact. Such results 1) demonstrate the value of visual speech at multiple levels of linguistic processing and 2) support intervention programs that view visual speech as a powerful asset for developing spoken language in CHL. PMID:28167003

Is high myopia a risk factor for visual field progression or disk hemorrhage in primary open-angle glaucoma?

PubMed

Nitta, Koji; Sugiyama, Kazuhisa; Wajima, Ryotaro; Tachibana, Gaku

2017-01-01

The purpose of this study was to clarify differences between highly myopic and non-myopic primary open-angle glaucoma (POAG) patients, including normal-tension glaucoma patients. A total of 269 POAG patients were divided into two groups: patients with ≥26.5 mm of axial length (highly myopic group) and patients with <24.0 mm of axial length (non-myopic group). We analyzed 53 highly myopic and 93 non-myopic POAG patients. Age at first visit of the highly myopic group was significantly less than that of the non-myopic group ( P <0.0001). Baseline intraocular pressures (IOPs) showed no significant differences. Follow-up IOPs of the non-myopic group were significantly lower than those of the highly myopic group ( P =0.0009). According to the mean deviation definition of progression, the cumulative probability of non-progression of visual field (VF) loss was significantly greater in the highly myopic group (10-year survival rate, 73.7%±6.8%) than in the non-myopic group (10-year survival rate, 46.3%±5.8%; log-rank test, P =0.0142). The occurrence of disk hemorrhage (DH) in the non-myopic group (1.60±3.04) was significantly greater than that in the highly myopic group (0.93±2.13, P =0.0311). The cumulative probability of DH was significantly lower in the highly myopic group (10-year survival rate, 26.4%±5.4%) than in the non-myopic group (10-year survival rate, 47.2%±6.6%, P =0.0413). Highly myopic POAG is considered as a combination of myopic optic neuropathy and glaucomatous optic neuropathy (GON). If GON is predominant, it has frequent DH and more progressive VF loss. However, when the myopic optic neuropathy is predominant, it has less DH and less progressive VF loss.

Ganglion cell loss in relation to visual disability in multiple sclerosis.

PubMed

Walter, Scott D; Ishikawa, Hiroshi; Galetta, Kristin M; Sakai, Reiko E; Feller, Daniel J; Henderson, Sam B; Wilson, James A; Maguire, Maureen G; Galetta, Steven L; Frohman, Elliot; Calabresi, Peter A; Schuman, Joel S; Balcer, Laura J

2012-06-01

We used high-resolution spectral-domain optical coherence tomography (SD-OCT) with retinal segmentation to determine how ganglion cell loss relates to history of acute optic neuritis (ON), retinal nerve fiber layer (RNFL) thinning, visual function, and vision-related quality of life (QOL) in multiple sclerosis (MS). Cross-sectional study. A convenience sample of patients with MS (n = 122; 239 eyes) and disease-free controls (n = 31; 61 eyes). Among MS eyes, 87 had a history of ON before enrollment. The SD-OCT images were captured using Macular Cube (200×200 or 512×128) and ONH Cube 200×200 protocols. Retinal layer segmentation was performed using algorithms established for glaucoma studies. Thicknesses of the ganglion cell layer/inner plexiform layer (GCL+IPL), RNFL, outer plexiform/inner nuclear layers (OPL+INL), and outer nuclear/photoreceptor layers (ONL+PRL) were measured and compared in MS versus control eyes and MS ON versus non-ON eyes. The relation between changes in macular thickness and visual disability was also examined. The OCT measurements of GCL+IPL and RNFL thickness; high contrast visual acuity (VA); low-contrast letter acuity (LCLA) at 2.5% and 1.25% contrast; on the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and 10-Item Neuro-Ophthalmic Supplement composite score. Macular RNFL and GCL+IPL were significantly decreased in MS versus control eyes (P<0.001 and P = 0.001) and in MS ON versus non-ON eyes (P<0.001 for both measures). Peripapillary RNFL, macular RNFL, GCL+IPL, and the combination of macular RNFL+GCL+IPL were significantly correlated with VA (P≤0.001), 2.5% LCLA (P<0.001), and 1.25% LCLA (P≤0.001). Among OCT measurements, reductions in GCL+IPL (P<0.001), macular RNFL (P = 0.006), and the combination (macular RNFL+GCL+IPL; P<0.001) were most strongly associated with lower (worse) NEI-VFQ-25 and 10-Item Supplement QOL scores; GCL+IPL thinning was significant even accounting for macular RNFL thickness (P = 0.03 for GCL+IPL, P = 0.39 for macular RNFL). We demonstrated that GCL+IPL thinning is most significantly correlated with both visual function and vision-specific QOL in MS, and may serve as a useful structural marker of disease. Our findings parallel those of magnetic resonance imaging studies that show gray matter disease is a marker of neurologic disability in MS. Proprietary or commercial disclosure may be found after the references. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

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

PubMed Central

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

2010-01-01

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

Exploring energy loss by vector flow mapping in children with ventricular septal defect: Pathophysiologic significance.

PubMed

Honda, Takashi; Itatani, Keiichi; Takanashi, Manabu; Kitagawa, Atsushi; Ando, Hisashi; Kimura, Sumito; Oka, Norihiko; Miyaji, Kagami; Ishii, Masahiro

2017-10-01

Vector flow mapping is a novel echocardiographic flow visualization method, and it has enabled us to quantitatively evaluate the energy loss in the left ventricle (intraventricular energy loss). Although intraventricular energy loss is assumed to be a part of left ventricular workload itself, it is unclear what this parameter actually represents. The aim of the present study was to elucidate the characteristics of intraventricular energy loss. We enrolled 26 consecutive children with ventricular septal defect (VSD). On echocardiography vector flow mapping, intraventricular energy loss was measured in the apical 3-chamber view. We measured peak energy loss and averaged energy loss in the diastolic and systolic phases, and subsequently compared these parameters with catheterization parameters and serum brain natrium peptide (BNP) level. Diastolic, peak, and systolic energy loss were strongly and positively correlated with right ventricular systolic pressure (r=0.76, 0.68, and 0.56, p<0.0001, = 0.0001, and 0.0029, respectively) and right ventricular end diastolic pressure (r=0.55, 0.49, and 0.49, p=0.0038, 0.0120, and 0.0111, respectively). In addition, diastolic, peak, and systolic energy loss were significantly correlated with BNP (r=0.75, 0.69 and 0.49, p<0.0001, < 0.0001, and=0.0116, respectively). In children with VSD, elevated right ventricular pressure is one of the factors that increase energy loss in the left ventricle. The results of the present study encourage further studies in other study populations to elucidate the characteristics of intraventricular energy loss for its possible clinical application. Copyright © 2017 Elsevier B.V. All rights reserved.

Experience and information loss in auditory and visual memory.

PubMed

Gloede, Michele E; Paulauskas, Emily E; Gregg, Melissa K

2017-07-01

Recent studies show that recognition memory for sounds is inferior to memory for pictures. Four experiments were conducted to examine the nature of auditory and visual memory. Experiments 1-3 were conducted to evaluate the role of experience in auditory and visual memory. Participants received a study phase with pictures/sounds, followed by a recognition memory test. Participants then completed auditory training with each of the sounds, followed by a second memory test. Despite auditory training in Experiments 1 and 2, visual memory was superior to auditory memory. In Experiment 3, we found that it is possible to improve auditory memory, but only after 3 days of specific auditory training and 3 days of visual memory decay. We examined the time course of information loss in auditory and visual memory in Experiment 4 and found a trade-off between visual and auditory recognition memory: Visual memory appears to have a larger capacity, while auditory memory is more enduring. Our results indicate that visual and auditory memory are inherently different memory systems and that differences in visual and auditory recognition memory performance may be due to the different amounts of experience with visual and auditory information, as well as structurally different neural circuitry specialized for information retention.

Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease

PubMed Central

Kokona, Despina; Georgiou, Panagiota-Christina; Kounenidakis, Mihalis; Kiagiadaki, Foteini; Thermos, Kyriaki

2016-01-01

The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago. In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma. The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss. Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness. The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease. PMID:26881135

Fundus autofluorescence and optical coherence tomography in relation to visual function in Usher syndrome type 1 and 2.

PubMed

Fakin, Ana; Jarc-Vidmar, Martina; Glavač, Damjan; Bonnet, Crystel; Petit, Christine; Hawlina, Marko

2012-12-15

Purpose of this study was to characterize retinal disease in Usher syndrome using fundus autofluorescence and optical coherence tomography. Study included 54 patients (26 male, 28 female) aged 7-70 years. There were 18 (33%) USH1 and 36 (67%) USH2 patients. 49/52 (94%) patients were found to carry at least one mutation in Usher genes. Ophthalmological examination included assessment of Snellen visual acuity, color vision with Ishihara tables, Goldmann visual fields (targets II/1-4 and V/4), microperimetry, fundus autofluorescence imaging and optical coherence tomography. Average age at disease onset (nyctalopia) was significantly lower in USH1 than USH2 patients (average 9 vs. 17 years, respectively; p<0.01); however no significant differences were found regarding type of autofluorescence patterns, frequency of foveal lesions and CME, rate of disease progression and age at legal blindness. All representative eyes had abnormal fundus autofluorescence of either hyperautofluorescent ring (55%), hyperautofluorescent foveal patch (35%) or foveal atrophy (10%). Disease duration of more than 30 years was associated with a high incidence of abnormal central fundus autofluorescence (patch or atrophy) and visual acuity loss. Copyright © 2012 Elsevier Ltd. All rights reserved.

Left-right asymmetry is required for the habenulae to respond to both visual and olfactory stimuli.

PubMed

Dreosti, Elena; Vendrell Llopis, Nuria; Carl, Matthias; Yaksi, Emre; Wilson, Stephen W

2014-02-17

Left-right asymmetries are most likely a universal feature of bilaterian nervous systems and may serve to increase neural capacity by specializing equivalent structures on left and right sides for distinct roles. However, little is known about how asymmetries are encoded within vertebrate neural circuits and how lateralization influences processing of information in the brain. Consequently, it remains unclear the extent to which lateralization of the nervous system is important for normal cognitive and other brain functions and whether defects in lateralization contribute to neurological deficits. Here we show that sensory responses to light and odor are lateralized in larval zebrafish habenulae and that loss of brain asymmetry leads to concomitant loss of responsiveness to either visual or olfactory stimuli. We find that in wild-type zebrafish, most habenular neurons responding to light are present on the left, whereas neurons responding to odor are more frequent on the right. Manipulations that reverse the direction of brain asymmetry reverse the functional properties of habenular neurons, whereas manipulations that generate either double-left- or double-right-sided brains lead to loss of habenular responsiveness to either odor or light, respectively. Our results indicate that loss of brain lateralization has significant consequences upon sensory processing and circuit function. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Impact of the Alexander technique on well-being: a randomised controlled trial involving older adults with visual impairment.

PubMed

Gleeson, Michael; Sherrington, Catherine; Lo, Serigne; Auld, Robin; Keay, Lisa

2017-11-01

Older adults with visual loss have high rates of depression, restricted participation and reduced quality of life. We sought to measure the impact of lessons in the Alexander technique on vision-related emotional and social well-being, as secondary outcomes to a study on improving physical functioning in this population. This is a single-blind randomised controlled trial. One hundred and twenty community-dwelling adults aged 50 to 90 years with visual impairments were randomised to either 12 Alexander lessons over 12 weeks and usual care or usual care. The Perceived Visual Ability Scale, the Keele Assessment of Participation, the emotional subscale of the Impact of Vision Impairment Profile, the Positive and Negative Affect Scale and the five-item Geriatric Depression Scale were administered at baseline and three and 12 months. Participants were receiving services from Guide Dogs NSW/ACT. None of the validated questionnaires found statistically significant improvements after adjustment for baseline at three or 12 months, although the emotional subscale of the Impact of Vision Impairment approached significance in favour of the intervention group (4.54 points, 95 per cent CI: -0.14 to 9.21, p = 0.06). Depressive symptoms were prevalent and associated with greater impact of visual impairment on emotional well-being (odds ratio: 1.12, 95 per cent CI: 1.07 to 1.17, p < 0.0001). Faster gait, an indicator of general mobility, was associated with less depressive symptoms (odds ratio: 1.27, 95 per cent CI: 1.06 to 1.54, p = 0.01). On average, there was no significant impact of weekly lessons in the Alexander technique on social and emotional well-being, although the emotional impact of visual impairment showed a trend toward less distress in the intervention group. Our data found that emotional distress associated with visual impairment influences depressive symptoms but contrary to expectations, the level of social support received was not significant. Additionally, gait speed is a significant predictor of depressive symptoms, suggesting that general mobility is of importance to the well-being of older adults with visual impairments. © 2017 Optometry Australia.

Corneal Collagen Crosslinking Combined with Phototherapeutic Keratectomy and Photorefractive Keratectomy for Corneal Ectasia after Laser in situ Keratomileusis.

PubMed

Zhu, Wei; Han, Yunfei; Cui, Changxia; Xu, Wenwen; Wang, Xuan; Dou, Xiaoxiao; Xu, Linlin; Xu, Yanyun; Mu, Guoying

2018-01-01

The aim of this study was to analyze the effects of corneal crosslinking (CXL) combined with phototherapeutic keratectomy (PTK) and photorefractive keratectomy (PRK) in halting the progression and improving the visual function of corneal ectasia after laser in situ keratomileusis (LASIK). PTK-PRK-CXL was performed on 14 eyes of 14 patients who developed corneal ectasia after LASIK. The visual acuity, spherical refraction and cylinder, corneal topography indices, thinnest corneal thickness (TCT), and endothelial cell count were evaluated at baseline and at 1, 3, 6, and 12 months postoperatively. The mean uncorrected visual acuity improved significantly from 0.64 ± 0.36 logMAR preoperatively to 0.19 ± 0.12 logMAR at 12 months of follow-up (p < 0.001), while the mean best corrected visual acuity improved from 0.21 ± 0.14 logMAR at baseline to 0.04 ± 0.10 logMAR at 12 months postoperatively (p < 0.001). A significant decrease was observed in Kmax and Kmean values from 52.51 ± 6.74 and 43.55 ± 3.37 D at baseline to 45.72 ± 5.18 (p < 0.001) and 40.60 ± 3.05 D (p < 0.001) at the 1-year follow-up. The mean TCT decreased significantly from 419.07 ± 36.56 µm before treatment to 320.93 ± 39.78 µm at 12 months of follow-up (p < 0.001), and there was no significant endothelial cell loss (p > 0.05) beyond 6 months after treatment. PTK-PRK-CXL is a promising procedure to halt the progression of post-LASIK keratectasia with significant visual quality improvement. © 2018 S. Karger AG, Basel.

aCNViewer: Comprehensive genome-wide visualization of absolute copy number and copy neutral variations

PubMed Central

Wang-Renault, Shu-Fang; Letouzé, Eric; Imbeaud, Sandrine; Zucman-Rossi, Jessica; Deleuze, Jean-François; How-Kit, Alexandre

2017-01-01

Motivation Copy number variations (CNV) include net gains or losses of part or whole chromosomal regions. They differ from copy neutral loss of heterozygosity (cn-LOH) events which do not induce any net change in the copy number and are often associated with uniparental disomy. These phenomena have long been reported to be associated with diseases and particularly in cancer. Losses/gains of genomic regions are often correlated with lower/higher gene expression. On the other hand, loss of heterozygosity (LOH) and cn-LOH are common events in cancer and may be associated with the loss of a functional tumor suppressor gene. Therefore, identifying recurrent CNV and cn-LOH events can be important as they may highlight common biological components and give insights into the development or mechanisms of a disease. However, no currently available tools allow a comprehensive whole-genome visualization of recurrent CNVs and cn-LOH in groups of samples providing absolute quantification of the aberrations leading to the loss of potentially important information. Results To overcome these limitations, we developed aCNViewer (Absolute CNV Viewer), a visualization tool for absolute CNVs and cn-LOH across a group of samples. aCNViewer proposes three graphical representations: dendrograms, bi-dimensional heatmaps showing chromosomal regions sharing similar abnormality patterns, and quantitative stacked histograms facilitating the identification of recurrent absolute CNVs and cn-LOH. We illustrated aCNViewer using publically available hepatocellular carcinomas (HCCs) Affymetrix SNP Array data (Fig 1A). Regions 1q and 8q present a similar percentage of total gains but significantly different copy number gain categories (p-value of 0.0103 with a Fisher exact test), validated by another cohort of HCCs (p-value of 5.6e-7) (Fig 2B). Availability and implementation aCNViewer is implemented in python and R and is available with a GNU GPLv3 license on GitHub https://github.com/FJD-CEPH/aCNViewer and Docker https://hub.docker.com/r/fjdceph/acnviewer/. Contact aCNViewer@cephb.fr PMID:29261730

Alteration of travel patterns with vision loss from glaucoma and macular degeneration.

PubMed

Curriero, Frank C; Pinchoff, Jessie; van Landingham, Suzanne W; Ferrucci, Luigi; Friedman, David S; Ramulu, Pradeep Y

2013-11-01

The distance patients can travel outside the home influences how much of the world they can sample and to what extent they can live independently. Recent technological advances have allowed travel outside the home to be directly measured in patients' real-world routines. To determine whether decreased visual acuity (VA) from age-related macular degeneration (AMD) and visual field (VF) loss from glaucoma are associated with restricted travel patterns in older adults. Cross-sectional study. Patients were recruited from an eye clinic, while travel patterns were recorded during their real-world routines using a cellular tracking device. Sixty-one control subjects with normal vision, 84 subjects with glaucoma with bilateral VF loss, and 65 subjects with AMD with bilateral or severe unilateral loss of VA had their location tracked every 15 minutes between 7 am and 11 pm for 7 days using a tracking device. Average daily excursion size (defined as maximum distance away from home) and average daily excursion span (defined as maximum span of travel) were defined for each individual. The effects of vision loss on travel patterns were evaluated after controlling for individual and geographic factors. In multivariable models comparing subjects with AMD and control subjects, average excursion size and span decreased by approximately one-quarter mile for each line of better-eye VA loss (P ≤ .03 for both). Similar but not statistically significant associations were observed between average daily excursion size and span for severity of better-eye VF loss in subjects with glaucoma and control subjects. Being married or living with someone and younger age were associated with more distant travel, while less-distant travel was noted for older individuals, African Americans, and those living in more densely populated regions. Age-related macular degeneration-related loss of VA, but not glaucoma-related loss of VF, is associated with restriction of travel to more nearby locations. This constriction of life space may impact quality of life and restrict access to services.

The Functional Classification of Brain Damage-Related Vision Loss

ERIC Educational Resources Information Center

Colenbrander, August

2009-01-01

This article provides a terminological framework to show the relationships among different types of visual deficits. It distinguishes between visual functions, which describe how the eye and the lower visual system function, and functional vision, which describes how a person functions. When visual functions are disturbed, the term "visual…

Shifts in Selective Pressures on Snake Phototransduction Genes Associated with Photoreceptor Transmutation and Dim-Light Ancestry.

PubMed

Schott, Ryan K; Van Nynatten, Alexander; Card, Daren C; Castoe, Todd A; S W Chang, Belinda

2018-06-01

The visual systems of snakes are heavily modified relative to other squamates, a condition often thought to reflect their fossorial origins. Further modifications are seen in caenophidian snakes, where evolutionary transitions between rod and cone photoreceptors, termed photoreceptor transmutations, have occurred in many lineages. Little previous work, however, has focused on the molecular evolutionary underpinnings of these morphological changes. To address this, we sequenced seven snake eye transcriptomes and utilized new whole-genome and targeted capture sequencing data. We used these data to analyze gene loss and shifts in selection pressures in phototransduction genes that may be associated with snake evolutionary origins and photoreceptor transmutation. We identified the surprising loss of rhodopsin kinase (GRK1), despite a low degree of gene loss overall and a lack of relaxed selection early during snake evolution. These results provide some of the first evolutionary genomic corroboration for a dim-light ancestor that lacks strong fossorial adaptations. Our results also indicate that snakes with photoreceptor transmutation experienced significantly different selection pressures from other reptiles. Significant positive selection was found primarily in cone-specific genes, but not rod-specific genes, contrary to our expectations. These results reveal potential molecular adaptations associated with photoreceptor transmutation and also highlight unappreciated functional differences between rod- and cone-specific phototransduction proteins. This intriguing example of snake visual system evolution illustrates how the underlying molecular components of a complex system can be reshaped in response to changing selection pressures.

Local infiltration analgesia adds no clinical benefit in pain control to peripheral nerve blocks after total knee arthroplasty.

PubMed

Hinarejos, Pedro; Capurro, Bruno; Santiveri, Xavier; Ortiz, Pere; Leal, Joan; Pelfort, Xavier; Torres-Claramunt, Raul; Sánchez-Soler, Juan; Monllau, Joan C

2016-10-01

To evaluate the effect of the local infiltration of analgesics for pain after total knee arthroplasty in patients treated with femoral and sciatic peripheral nerve blocks. The secondary objective was to detect differences in analgesic consumption as well as blood loss after local infiltration of analgesics. Prospective randomized double-blinded study in patients who underwent a TKA for knee osteoarthritis under spinal anesthesia and treated with femoral and sciatic nerve blocks. This study compared 50 patients treated with local infiltration with ropivacaine, epinephrine, ketorolac and clonidine and 50 patients treated with a placebo with the same technique. The visual analogic score was registered postoperatively at 2, 6, 12, 24, 36, 48 and 72 h after surgery. Analgesic consumption was also registered. Both groups of patients were treated with the same surgical and rehabilitation protocols. A significant difference of one point was found in the visual analogic pain scores 12 h after surgery (0.6 ± 1.5 vs. 1.7 ± 2.3). There were no significant differences in the visual analogic pain scores evaluated at any other time between 2 and 72 h after surgery. No significant differences were found in the required doses of tramadol or morphine in the postoperative period. Postoperative hemoglobin and blood loss were also similar in both groups. Adding local infiltration of analgesics to peripheral nerve blocks after TKA surgery only provides minimal benefit for pain control. This benefit may be considered as non-clinically relevant. Moreover, the need for additional analgesics was the same in both groups. Therefore, the use of local infiltration of analgesics treatment in TKA surgery cannot be recommended if peripheral nerve blocks are used. I.

The effect of changing the secondary task in dual-task paradigms for measuring listening effort.

PubMed

Picou, Erin M; Ricketts, Todd A

2014-01-01

The purpose of this study was to evaluate the effect of changing the secondary task in dual-task paradigms that measure listening effort. Specifically, the effects of increasing the secondary task complexity or the depth of processing on a paradigm's sensitivity to changes in listening effort were quantified in a series of two experiments. Specific factors investigated within each experiment were background noise and visual cues. Participants in Experiment 1 were adults with normal hearing (mean age 23 years) and participants in Experiment 2 were adults with mild sloping to moderately severe sensorineural hearing loss (mean age 60.1 years). In both experiments, participants were tested using three dual-task paradigms. These paradigms had identical primary tasks, which were always monosyllable word recognition. The secondary tasks were all physical reaction time measures. The stimulus for the secondary task varied by paradigm and was a (1) simple visual probe, (2) a complex visual probe, or (3) the category of word presented. In this way, the secondary tasks mainly varied from the simple paradigm by either complexity or depth of speech processing. Using all three paradigms, participants were tested in four conditions, (1) auditory-only stimuli in quiet, (2) auditory-only stimuli in noise, (3) auditory-visual stimuli in quiet, and (4) auditory-visual stimuli in noise. During auditory-visual conditions, the talker's face was visible. Signal-to-noise ratios used during conditions with background noise were set individually so word recognition performance was matched in auditory-only and auditory-visual conditions. In noise, word recognition performance was approximately 80% and 65% for Experiments 1 and 2, respectively. For both experiments, word recognition performance was stable across the three paradigms, confirming that none of the secondary tasks interfered with the primary task. In Experiment 1 (listeners with normal hearing), analysis of median reaction times revealed a significant main effect of background noise on listening effort only with the paradigm that required deep processing. Visual cues did not change listening effort as measured with any of the three dual-task paradigms. In Experiment 2 (listeners with hearing loss), analysis of median reaction times revealed expected significant effects of background noise using all three paradigms, but no significant effects of visual cues. None of the dual-task paradigms were sensitive to the effects of visual cues. Furthermore, changing the complexity of the secondary task did not change dual-task paradigm sensitivity to the effects of background noise on listening effort for either group of listeners. However, the paradigm whose secondary task involved deeper processing was more sensitive to the effects of background noise for both groups of listeners. While this paradigm differed from the others in several respects, depth of processing may be partially responsible for the increased sensitivity. Therefore, this paradigm may be a valuable tool for evaluating other factors that affect listening effort.

A Simplified Method of Identifying the Trained Retinal Locus for Training in Eccentric Viewing

ERIC Educational Resources Information Center

Vukicevic, Meri; Le, Anh; Baglin, James

2012-01-01

In the typical human visual system, the macula allows for high visual resolution. Damage to this area from diseases, such as age-related macular degeneration (AMD), causes the loss of central vision in the form of a central scotoma. Since no treatment is available to reverse AMD, providing low vision rehabilitation to compensate for the loss of…

Gender Differences and the Risk of Falls in Individuals with Profound Vision Loss

ERIC Educational Resources Information Center

Ray, Christopher T.; Wolf, Steven L.

2010-01-01

Adults with visual impairments experience a loss of balance and mobility, which presents a barrier to independence and is associated with the fear of falling. The purpose of this study was to determine the extent to which visual status, age, gender, body mass index (BMI), and the strength of quadriceps and hamstrings contribute to compromised…

Contrasting the use of 2 vision-specific quality of life questionnaires in subjects with open-angle glaucoma.

PubMed

Wren, Patricia A; Musch, David C; Janz, Nancy K; Niziol, Leslie M; Guire, Kenneth E; Gillespie, Brenda W

2009-01-01

To compare 2 vision-specific functional status measures to each other and to clinical parameters in the Collaborative Initial Glaucoma Treatment Study (CIGTS). CIGTS participants completed the Visual Activities Questionnaire (VAQ) and the National Eye Institute-Visual Function Questionnaire (NEI-VFQ) and were tested for visual field (VF) and visual acuity (VA). In all, 426 subjects contributed the VAQ and NEI-VFQ scores at 54 months. Pearson correlations were used to assess associations. The VAQ subscales (range, 0 to 100) that assessed light-dark adaptation (mean=66.1), glare disability (66.4), and acuity/spatial vision (67.7) indicated vision-related functions that CIGTS participants found most difficult. On the NEI-VFQ, subjects reported high levels of visual functioning, with mean >/=90 (out of 100) on the total score and in 9 of 12 subscales. General vision (mean=82.6) received the lowest subscale score. Two subscales common to both questionnaires were highly correlated: VA (r=0.68) and peripheral vision (r=0.77) (both P<0.0001). Correlations between participants' perceptions and clinical measures of visual function were in the expected direction, but weaker. Stronger associations were found between clinical measures and the NEI-VFQ than the VAQ. Better eye VF and worse eye VA had the highest number of significant correlations with subjects' perceptions of their visual function. Increasing VF loss was associated with a significant decrease in the overall and peripheral vision subscale scores from both questionnaires, and also several other subscales. CIGTS patients reported excellent visual function on both the NEI-VFQ and VAQ. These findings will help researchers interested in assessing patients' perceptions of their visual function make an informed selection when choosing between the VAQ and the NEI-VFQ.

Driving with Binocular Visual Field Loss? A Study on a Supervised On-Road Parcours with Simultaneous Eye and Head Tracking

PubMed Central

Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the central area of the visual field than patients who failed the test. In addition, patients who passed the test performed more glances towards the area of their visual field defect. In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning. Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario. PMID:24523869

A GIS-based Upscaling Estimation of Nutrient Runoff Losses from Rice Paddy Fields to a Regional Level.

PubMed

Sun, Xiaoxiao; Liang, Xinqiang; Zhang, Feng; Fu, Chaodong

2016-11-01

Nutrient runoff losses from cropping fields can lead to nonpoint source pollution; however, the level of nutrient export is difficult to evaluate, particularly at the regional scale. This study aimed to establish a novel yet simple approach for estimating total nitrogen (TN) and total phosphorus (TP) runoff losses from regional paddy fields. In this approach, temporal changes of nutrient concentrations in floodwater were coupled with runoff-processing functions in rice ( L.) fields to calculate nutrient runoff losses for three site-specific field experiments. Validation experiments verified the accuracy of this method. The geographic information system technique was used to upscale and visualize the TN and TP runoff losses from field to regional scales. The results indicated that nutrient runoff losses had significant spatio-temporal variation characteristics during rice seasons, which were positively related to fertilizer rate and precipitation. The average runoff losses over five study seasons were 20.21 kg N ha for TN and 0.76 kg P ha for TP. Scenario analysis showed that TN and TP losses dropped by 7.64 and 3.0%, respectively, for each 10% reduction of fertilizer input. For alternate wetting and drying water management, the corresponding reduction ratio was 24.7 and 14.0% respectively. Our results suggest that, although both water and fertilizer management can mitigate nutrient runoff losses, the former is significantly more effective. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The role of visual deprivation and experience on the performance of sensory substitution devices.

PubMed

Stronks, H Christiaan; Nau, Amy C; Ibbotson, Michael R; Barnes, Nick

2015-10-22

It is commonly accepted that the blind can partially compensate for their loss of vision by developing enhanced abilities with their remaining senses. This visual compensation may be related to the fact that blind people rely on their other senses in everyday life. Many studies have indeed shown that experience plays an important role in visual compensation. Numerous neuroimaging studies have shown that the visual cortices of the blind are recruited by other functional brain areas and can become responsive to tactile or auditory input instead. These cross-modal plastic changes are more pronounced in the early blind compared to late blind individuals. The functional consequences of cross-modal plasticity on visual compensation in the blind are debated, as are the influences of various etiologies of vision loss (i.e., blindness acquired early or late in life). Distinguishing between the influences of experience and visual deprivation on compensation is especially relevant for rehabilitation of the blind with sensory substitution devices. The BrainPort artificial vision device and The vOICe are assistive devices for the blind that redirect visual information to another intact sensory system. Establishing how experience and different etiologies of vision loss affect the performance of these devices may help to improve existing rehabilitation strategies, formulate effective selection criteria and develop prognostic measures. In this review we will discuss studies that investigated the influence of training and visual deprivation on the performance of various sensory substitution approaches. Copyright © 2015 Elsevier B.V. All rights reserved.

Hearing loss in Usher syndrome type II is nonprogressive.

PubMed

Reisser, Christoph F V; Kimberling, William J; Otterstedde, Christian R

2002-12-01

Usher syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss and progressive visual loss secondary to retinitis pigmentosa. In the literature, a possible progression of the moderate to severe hearing loss in Usher syndrome type II (Usher II) is controversial. We studied the development of the hearing loss of 125 patients with a clinical diagnosis of Usher syndrome type II intraindividually and interindividually by repeatedly performing complete audiological and neuro-otologic examinations. Our data show a very characteristic slope of the hearing curve in all Usher II patients and no clinically relevant progression of the hearing loss over up to 17 years. The subjective impression of a deterioration of the communicative abilities of Usher II patients must therefore be attributed to the progressive visual loss. The patients should be reassured that changes in their hearing abilities are unlikely and should be provided with optimally fitted modern hearing aids.

Effect of a patient training video on visual field test reliability

PubMed Central

Sherafat, H; Spry, P G D; Waldock, A; Sparrow, J M; Diamond, J P

2003-01-01

Aims: To evaluate the effect of a visual field test educational video on the reliability of the first automated visual field test of new patients. Methods: A prospective, randomised, controlled trial of an educational video on visual field test reliability of patients referred to the hospital eye service for suspected glaucoma was undertaken. Patients were randomised to either watch an educational video or a control group with no video. The video group was shown a 4.5 minute audiovisual presentation to familiarise them with the various aspects of visual field examination with particular emphasis on sources of unreliability. Reliability was determined using standard criteria of fixation loss rate less than 20%, false positive responses less than 33%, and false negative responses less than 33%. Results: 244 patients were recruited; 112 in the video group and 132 in the control group with no significant between group difference in age, sex, and density of field defects. A significant improvement in reliability (p=0.015) was observed in the group exposed to the video with 85 (75.9%) patients having reliable results compared to 81 (61.4%) in the control group. The difference was not significant for the right (first tested) eye with 93 (83.0%) of the visual fields reliable in the video group compared to 106 (80.0%) in the control group (p = 0.583), but was significant for the left (second tested) eye with 97 (86.6 %) of the video group reliable versus 97 (73.5%) of the control group (p = 0.011). Conclusions: The use of a brief, audiovisual patient information guide on taking the visual field test produced an improvement in patient reliability for individuals tested for the first time. In this trial the use of the video had most of its impact by reducing the number of unreliable fields from the second tested eye. PMID:12543740

Effect of a patient training video on visual field test reliability.

PubMed

Sherafat, H; Spry, P G D; Waldock, A; Sparrow, J M; Diamond, J P

2003-02-01

To evaluate the effect of a visual field test educational video on the reliability of the first automated visual field test of new patients. A prospective, randomised, controlled trial of an educational video on visual field test reliability of patients referred to the hospital eye service for suspected glaucoma was undertaken. Patients were randomised to either watch an educational video or a control group with no video. The video group was shown a 4.5 minute audiovisual presentation to familiarize them with the various aspects of visual field examination with particular emphasis on sources of unreliability. Reliability was determined using standard criteria of fixation loss rate less than 20%, false positive responses less than 33%, and false negative responses less than 33%. 244 patients were recruited; 112 in the video group and 132 in the control group with no significant between group difference in age, sex, and density of field defects. A significant improvement in reliability (p=0.015) was observed in the group exposed to the video with 85 (75.9%) patients having reliable results compared to 81 (61.4%) in the control group. The difference was not significant for the right (first tested) eye with 93 (83.0%) of the visual fields reliable in the video group compared to 106 (80.0%) in the control group (p = 0.583), but was significant for the left (second tested) eye with 97 (86.6 %) of the video group reliable versus 97 (73.5%) of the control group (p = 0.011). The use of a brief, audiovisual patient information guide on taking the visual field test produced an improvement in patient reliability for individuals tested for the first time. In this trial the use of the video had most of its impact by reducing the number of unreliable fields from the second tested eye.

Blue-on-yellow perimetry to evaluate S cone sensitivity in diabetics.

PubMed

Nomura, R; Terasaki, H; Hirose, H; Miyake, Y

2000-01-01

Blue-on-yellow (B/Y) perimetry was performed on 31 patients with non-insulin-dependent diabetes mellitus to study the loss of sensitivity to short wavelengths. Of these patients, 21 were without retinopathy (NDR) and 10 had early background retinopathy (SDR). Eleven normal subjects served as controls. The results were compared to white-on-white (W/W) perimetry. Foveal sensitivity determined by B/Y and W/W perimetry showed no significant difference between NDR, SDR and normals. However, the mean sensitivity in the central 30-degree area and that in the upper half of the central 20- to 30-degree concentric circular field were significantly decreased in B/Y perimetry in SDR patients (p < 0.05, p < 0.01, respectively). No significant sensitivity loss was detected in the W/W test. We conclude that there is a blue cone system sensitivity loss in the central 30-degree area, particularly in the upper half of the visual field and the paracentral area in diabetic patients with early background retinopathy. Copyright 2000 S. Karger AG, Basel

Geographic Visualization of Power-Grid Dynamics

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

Sukumar, Sreenivas R.

2015-06-18

The visualization enables the simulation analyst to see changes in the frequency through time and space. With this technology, the analyst has a bird's eye view of the frequency at loads and generators as the simulated power system responds to the loss of a generator, spikes in load, and other contingencies. The significance of a contingency to the operation of an electrical power system depends critically on how the resulting tansients evolve in time and space. Consequently, these dynamic events can only be understood when seen in their proper geographic context. this understanding is indispensable to engineers working on themore » next generation of distributed sensing and control systems for the smart grid. By making possible a natural and intuitive presentation of dynamic behavior, our new visualization technology is a situational-awareness tool for power-system engineers.« less

Central and peripheral vision loss differentially affects contextual cueing in visual search.

PubMed

Geringswald, Franziska; Pollmann, Stefan

2015-09-01

Visual search for targets in repeated displays is more efficient than search for the same targets in random distractor layouts. Previous work has shown that this contextual cueing is severely impaired under central vision loss. Here, we investigated whether central vision loss, simulated with gaze-contingent displays, prevents the incidental learning of contextual cues or the expression of learning, that is, the guidance of search by learned target-distractor configurations. Visual search with a central scotoma reduced contextual cueing both with respect to search times and gaze parameters. However, when the scotoma was subsequently removed, contextual cueing was observed in a comparable magnitude as for controls who had searched without scotoma simulation throughout the experiment. This indicated that search with a central scotoma did not prevent incidental context learning, but interfered with search guidance by learned contexts. We discuss the role of visuospatial working memory load as source of this interference. In contrast to central vision loss, peripheral vision loss was expected to prevent spatial configuration learning itself, because the restricted search window did not allow the integration of invariant local configurations with the global display layout. This expectation was confirmed in that visual search with a simulated peripheral scotoma eliminated contextual cueing not only in the initial learning phase with scotoma, but also in the subsequent test phase without scotoma. (c) 2015 APA, all rights reserved).

Eye-Tracking as a Tool to Evaluate Functional Ability in Everyday Tasks in Glaucoma.

PubMed

Kasneci, Enkelejda; Black, Alex A; Wood, Joanne M

2017-01-01

To date, few studies have investigated the eye movement patterns of individuals with glaucoma while they undertake everyday tasks in real-world settings. While some of these studies have reported possible compensatory gaze patterns in those with glaucoma who demonstrated good task performance despite their visual field loss, little is known about the complex interaction between field loss and visual scanning strategies and the impact on task performance and, consequently, on quality of life. We review existing approaches that have quantified the effect of glaucomatous visual field defects on the ability to undertake everyday activities through the use of eye movement analysis. Furthermore, we discuss current developments in eye-tracking technology and the potential for combining eye-tracking with virtual reality and advanced analytical approaches. Recent technological developments suggest that systems based on eye-tracking have the potential to assist individuals with glaucomatous loss to maintain or even improve their performance on everyday tasks and hence enhance their long-term quality of life. We discuss novel approaches for studying the visual search behavior of individuals with glaucoma that have the potential to assist individuals with glaucoma, through the use of personalized programs that take into consideration the individual characteristics of their remaining visual field and visual search behavior.

Eye-Tracking as a Tool to Evaluate Functional Ability in Everyday Tasks in Glaucoma

PubMed Central

Black, Alex A.

2017-01-01

To date, few studies have investigated the eye movement patterns of individuals with glaucoma while they undertake everyday tasks in real-world settings. While some of these studies have reported possible compensatory gaze patterns in those with glaucoma who demonstrated good task performance despite their visual field loss, little is known about the complex interaction between field loss and visual scanning strategies and the impact on task performance and, consequently, on quality of life. We review existing approaches that have quantified the effect of glaucomatous visual field defects on the ability to undertake everyday activities through the use of eye movement analysis. Furthermore, we discuss current developments in eye-tracking technology and the potential for combining eye-tracking with virtual reality and advanced analytical approaches. Recent technological developments suggest that systems based on eye-tracking have the potential to assist individuals with glaucomatous loss to maintain or even improve their performance on everyday tasks and hence enhance their long-term quality of life. We discuss novel approaches for studying the visual search behavior of individuals with glaucoma that have the potential to assist individuals with glaucoma, through the use of personalized programs that take into consideration the individual characteristics of their remaining visual field and visual search behavior. PMID:28293433

Restoration of vision in blind individuals using bionic devices: a review with a focus on cortical visual prostheses.

PubMed

Lewis, Philip M; Ackland, Helen M; Lowery, Arthur J; Rosenfeld, Jeffrey V

2015-01-21

The field of neurobionics offers hope to patients with sensory and motor impairment. Blindness is a common cause of major sensory loss, with an estimated 39 million people worldwide suffering from total blindness in 2010. Potential treatment options include bionic devices employing electrical stimulation of the visual pathways. Retinal stimulation can restore limited visual perception to patients with retinitis pigmentosa, however loss of retinal ganglion cells precludes this approach. The optic nerve, lateral geniculate nucleus and visual cortex provide alternative stimulation targets, with several research groups actively pursuing a cortically-based device capable of driving several hundred stimulating electrodes. While great progress has been made since the earliest works of Brindley and Dobelle in the 1960s and 1970s, significant clinical, surgical, psychophysical, neurophysiological, and engineering challenges remain to be overcome before a commercially-available cortical implant will be realized. Selection of candidate implant recipients will require assessment of their general, psychological and mental health, and likely responses to visual cortex stimulation. Implant functionality, longevity and safety may be enhanced by careful electrode insertion, optimization of electrical stimulation parameters and modification of immune responses to minimize or prevent the host response to the implanted electrodes. Psychophysical assessment will include mapping the positions of potentially several hundred phosphenes, which may require repetition if electrode performance deteriorates over time. Therefore, techniques for rapid psychophysical assessment are required, as are methods for objectively assessing the quality of life improvements obtained from the implant. These measures must take into account individual differences in image processing, phosphene distribution and rehabilitation programs that may be required to optimize implant functionality. In this review, we detail these and other challenges facing developers of cortical visual prostheses in addition to briefly outlining the epidemiology of blindness, and the history of cortical electrical stimulation in the context of visual prosthetics. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Implications of Deafblindness on Visual Assessment Procedures: Considerations for Audiologists, Ophthalmologists, and Interpreters

PubMed Central

Hyvärinen, Lea

2007-01-01

Visual assessment of deaf persons presents a challenge to the ophthalmologist and the optometrist. At the time they want to measure visual function, the interpreter uses visual communication, competing for the patient's attention. Important rules of good assessment of visual functioning include taking turns and giving the interpreter sufficient time to convey the questions related to each test. This has implications for audiologists working with this population as well. Communication should be tailored to the varying needs of people who may have long-standing deafness and good sign language, may have lost their hearing at an advanced age and have limited or no sign language, or may be young persons or children who have congenital or progressive loss of hearing combined with congenital or progressive vision loss. Individuals with sudden hearing and vision loss, as well as those with intellectual disabilities and limited language, are particularly challenging groups for the assessment of vision and require special communication skills for ophthalmologists and audiologists. The ophthalmologist usually knows the nature of vision changes typical of disorders that the patient has. For the clinical follow-up of a condition, a few measurements are usually taken. For a comprehensive assessment of visual functioning for rehabilitation and education, many more measurements, observations, and questions are needed so that vision for communication, orientation in the environment, and performance of near-vision tasks can be reported and the effects of the environment can be evaluated. Testing should cover ocular disorders and vision loss caused by brain damage. PMID:18003866

Effect of EPI-743 on the clinical course of the mitochondrial disease Leber hereditary optic neuropathy.

PubMed

Sadun, Alfredo A; Chicani, Carlos Filipe; Ross-Cisneros, Fred N; Barboni, Piero; Thoolen, Martin; Shrader, William D; Kubis, Kenneth; Carelli, Valerio; Miller, Guy

2012-03-01

To evaluate the safety and efficacy of a new therapeutic agent, EPI-743, in Leber hereditary optic neuropathy (LHON) using standard clinical, anatomic, and functional visual outcome measures. Open-label clinical trial. University medical center. Patients  Five patients with genetically confirmed LHON with acute loss of vision were consecutively enrolled and treated with the experimental therapeutic agent EPI-743 within 90 days of conversion. Intervention  During the course of the study, 5 consecutive patients received EPI-743, by mouth, 3 times daily (100-400 mg per dose). Treatment effect was assessed by serial measurements of anatomic and functional visual indices over 6 to 18 months, including Snellen visual acuity, retinal nerve fiber layer thickness measured by optical coherence tomography, Humphrey visual fields (mean decibels and area with 1-log unit depression), and color vision. Treatment effect in this clinical proof of principle study was assessed by comparison of the prospective open-label treatment group with historical controls. Of 5 subjects treated with EPI-743, 4 demonstrated arrest of disease progression and reversal of visual loss. Two patients exhibited a total recovery of visual acuity. No drug-related adverse events were recorded. In a small open-label trial, EPI-743 arrested disease progression and reversed vision loss in all but 1 of the 5 consecutively treated patients with LHON. Given the known natural history of acute and rapid progression of LHON resulting in chronic and persistent bilateral blindness, these data suggest that the previously described irreversible priming to retinal ganglion cell loss may be reversed.

[Deficient prevention and late treatment of diabetic retinopathy in Mexico].

PubMed

Cervantes-Castañeda, René A; Menchaca-Díaz, Rufino; Alfaro-Trujillo, Beatriz; Guerrero-Gutiérrez, Manuel; Chayet-Berdowsky, Arturo S

2014-01-01

Retinopathy is a frequent complication of diabetes, causing visual impairment in 10% and blindness in 2% of diabetic patients. The aim of this study is to describe the clinical profile of diabetic patients in an ophthalmologic unit in Tijuana, México. Retrospective study of a random sample of 500 clinical charts of patients with diabetes who attended the Retina Service of "Fundación CODET para la Prevención de la Ceguera IBP" Ophthalmologic Center between 2006 and 2010. The main complaint of 58% of patients was decreased visual acuity in first evaluation. Only 6.2% of patients were referred by a health professional. Forty-six percent of the patients had a history of diabetes of at least 15 years. Thirty percent had clinically significant visual impairment at first visit, which was associated with a long history of diabetes and previous eye surgery. Twenty-five percent of these patients who were treated at our clinic experienced visual deterioration due to advanced retinopathy. Patients with diabetic retinopathy are referred to ophthalmological service tardily, when visual loss is usually severe and irreversible.

Baseline Fourier-Domain Optical Coherence Tomography Structural Risk Factors for Visual Field Progression in the Advanced Imaging for Glaucoma Study.

PubMed

Zhang, Xinbo; Dastiridou, Anna; Francis, Brian A; Tan, Ou; Varma, Rohit; Greenfield, David S; Schuman, Joel S; Sehi, Mitra; Chopra, Vikas; Huang, David

2016-12-01

To identify baseline structural parameters that predict the progression of visual field (VF) loss in patients with open-angle glaucoma. Multicenter cohort study. Participants from the Advanced Imaging for Glaucoma (AIG) study were enrolled and followed up. VF progression is defined as either a confirmed progression event on Humphrey Progression Analysis or a significant (P < .05) negative slope for VF index (VFI). Fourier-domain optical coherence tomography (FDOCT) was used to measure optic disc, peripapillary retinal nerve fiber layer (NFL), and macular ganglion cell complex (GCC) thickness parameters. A total of 277 eyes of 188 participants were followed up for 3.7 ± 2.1 years. VF progression was observed in 83 eyes (30%). Several baseline NFL and GCC parameters, but not disc parameters, were found to be significant predictors of progression on univariate Cox regression analysis. The most accurate single predictors were the GCC focal loss volume (FLV), followed closely by NFL-FLV. An abnormal GCC-FLV at baseline increased risk of progression by a hazard ratio of 3.1. Multivariate Cox analysis showed that combining age and central corneal thickness with GCC-FLV in a composite index called "Glaucoma Composite Progression Index" (GCPI) further improved the accuracy of progression prediction. GCC-FLV and GCPI were both found to be significantly correlated with the annual rate of change in VFI. Focal GCC and NFL loss as measured by FDOCT are the strongest predictors for VF progression among the measurements considered. Older age and thinner central corneal thickness can enhance the predictive power using the composite risk model. Copyright © 2016 Elsevier Inc. All rights reserved.

How does susceptibility to proactive interference relate to speech recognition in aided and unaided conditions?

PubMed

Ellis, Rachel J; Rönnberg, Jerker

2015-01-01

Proactive interference (PI) is the capacity to resist interference to the acquisition of new memories from information stored in the long-term memory. Previous research has shown that PI correlates significantly with the speech-in-noise recognition scores of younger adults with normal hearing. In this study, we report the results of an experiment designed to investigate the extent to which tests of visual PI relate to the speech-in-noise recognition scores of older adults with hearing loss, in aided and unaided conditions. The results suggest that measures of PI correlate significantly with speech-in-noise recognition only in the unaided condition. Furthermore the relation between PI and speech-in-noise recognition differs to that observed in younger listeners without hearing loss. The findings suggest that the relation between PI tests and the speech-in-noise recognition scores of older adults with hearing loss relates to capability of the test to index cognitive flexibility.

How does susceptibility to proactive interference relate to speech recognition in aided and unaided conditions?

PubMed Central

Ellis, Rachel J.; Rönnberg, Jerker

2015-01-01

Proactive interference (PI) is the capacity to resist interference to the acquisition of new memories from information stored in the long-term memory. Previous research has shown that PI correlates significantly with the speech-in-noise recognition scores of younger adults with normal hearing. In this study, we report the results of an experiment designed to investigate the extent to which tests of visual PI relate to the speech-in-noise recognition scores of older adults with hearing loss, in aided and unaided conditions. The results suggest that measures of PI correlate significantly with speech-in-noise recognition only in the unaided condition. Furthermore the relation between PI and speech-in-noise recognition differs to that observed in younger listeners without hearing loss. The findings suggest that the relation between PI tests and the speech-in-noise recognition scores of older adults with hearing loss relates to capability of the test to index cognitive flexibility. PMID:26283981

Visual rehabilitation: visual scanning, multisensory stimulation and vision restoration trainings

PubMed Central

Dundon, Neil M.; Bertini, Caterina; Làdavas, Elisabetta; Sabel, Bernhard A.; Gall, Carolin

2015-01-01

Neuropsychological training methods of visual rehabilitation for homonymous vision loss caused by postchiasmatic damage fall into two fundamental paradigms: “compensation” and “restoration”. Existing methods can be classified into three groups: Visual Scanning Training (VST), Audio-Visual Scanning Training (AViST) and Vision Restoration Training (VRT). VST and AViST aim at compensating vision loss by training eye scanning movements, whereas VRT aims at improving lost vision by activating residual visual functions by training light detection and discrimination of visual stimuli. This review discusses the rationale underlying these paradigms and summarizes the available evidence with respect to treatment efficacy. The issues raised in our review should help guide clinical care and stimulate new ideas for future research uncovering the underlying neural correlates of the different treatment paradigms. We propose that both local “within-system” interactions (i.e., relying on plasticity within peri-lesional spared tissue) and changes in more global “between-system” networks (i.e., recruiting alternative visual pathways) contribute to both vision restoration and compensatory rehabilitation, which ultimately have implications for the rehabilitation of cognitive functions. PMID:26283935

Anton-Babinski syndrome, case report.

PubMed

Martín Juan, A; Madrigal, R; Porta Etessam, J; Sáenz-Francés San Baldomero, F; Santos Bueso, E

2018-05-30

A 22 year-old woman complained about blurred vision after an episode of recovered cardiorespiratory arrest. She had bilateral low visual acuity («count fingers») and no ophthalmological or visual pathways changes. She also had an apparent lack of awareness of the deficit. The Magnetic Resonance Imaging (MRI) showed ischaemic changes in both occipital lobes. As a result, she was diagnosed with Anton-Babinski syndrome. This is a rare disease that should be suspected in strange or poorly congruent visual loss. It is usually due to an ischaemic injury in this region of brain, manifesting itself with low vision not perceived by the patient (visual confabulation). It can simulate a non-organic visual loss or psychiatric disease. Copyright © 2018 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Bone loss of vertebral bodies at the operative segment after cervical arthroplasty: a potential complication?

PubMed

Heo, Dong Hwa; Lee, Dong Chan; Oh, Jong Yang; Park, Choon Keun

2017-02-01

OBJECTIVE Bony overgrowth and spontaneous fusion are complications of cervical arthroplasty. In contrast, bone loss or bone remodeling of vertebral bodies at the operation segment after cervical arthroplasty has also been observed. The purpose of this study is to investigate a potential complication-bone loss of the anterior portion of the vertebral bodies at the surgically treated segment after cervical total disc replacement (TDR)-and discuss the clinical significance. METHODS All enrolled patients underwent follow-up for more than 24 months after cervical arthroplasty using the Baguera C disc. Clinical evaluations included recording demographic data and measuring the visual analog scale and Neck Disability Index scores. Radiographic evaluations included measurements of the functional spinal unit's range of motion and changes such as bone loss and bone remodeling. The grading of the bone loss of the operative segment was classified as follows: Grade 1, disappearance of the anterior osteophyte or small minor bone loss; Grade 2, bone loss of the anterior portion of the vertebral bodies at the operation segment without exposure of the artificial disc; or Grade 3, significant bone loss with exposure of the anterior portion of the artificial disc. RESULTS Forty-eight patients were enrolled in this study. Among them, bone loss developed in 29 patients (Grade 1 in 15 patients, Grade 2 in 6 patients, and Grade 3 in 8 patients). Grade 3 bone loss was significantly associated with postoperative neck pain (p < 0.05). Bone loss was related to the motion preservation effect of the operative segment after cervical arthroplasty in contrast to heterotopic ossification. CONCLUSIONS Bone loss may be a potential complication of cervical TDR and affect early postoperative neck pain. However, it did not affect mid- to long-term clinical outcomes or prosthetic failure at the last follow-up. Also, this phenomenon may result in the motion preservation effect in the operative segment after cervical TDR.

Hypoglycemia-occipital syndrome: a specific neurologic syndrome following neonatal hypoglycemia?

PubMed

Karimzadeh, Parvaneh; Tabarestani, Sepideh; Ghofrani, Mohammad

2011-02-01

This study attempted to elaborate the existence of a specific neurologic pattern observed in children who experienced neonatal hypoglycemia. Twenty-seven patients with seizure and history of neonatal hypoglycemia were compared with 28 children suffering from idiopathic occipital epilepsy. In both groups the most common type of seizure activities included eye movements and impaired consciousness responding well to treatment; however, ictal vomiting was more common in controls. Subjects were in epileptic and nonepileptic groups. Ninety percent of cases showed abnormal signal of the posterior head region on magnetic resonance imaging (MRI). A large number showed posterior abnormalities on electroencephalography (EEG). Visual loss with abnormal visual evoked potential was the most frequent visual finding. Fifty-five percent showed mild psychomotor retardation. This study demonstrates that neonatal hypoglycemia can induce a syndrome with a specific clinical spectrum consisting of epilepsy, visual disturbances, and psychomotor retardation. Hypoglycemia-occipital syndrome is an entity without statistically significant semiologic differences from the idiopathic type.

Cotinine improves visual recognition memory and decreases cortical Tau phosphorylation in the Tg6799 mice.

PubMed

Grizzell, J Alex; Patel, Sagar; Barreto, George E; Echeverria, Valentina

2017-08-01

Alzheimer's disease (AD) is associated with the progressive aggregation of hyperphosphorylated forms of the microtubule associated protein Tau in the central nervous system. Cotinine, the main metabolite of nicotine, reduced working memory deficits, synaptic loss, and amyloid β peptide aggregation into oligomers and plaques as well as inhibited the cerebral Tau kinase, glycogen synthase 3β (GSK3β) in the transgenic (Tg)6799 (5XFAD) mice. In this study, the effect of cotinine on visual recognition memory and cortical Tau phosphorylation at the GSK3β sites Serine (Ser)-396/Ser-404 and phospho-CREB were investigated in the Tg6799 and non-transgenic (NT) littermate mice. Tg mice showed short-term visual recognition memory impairment in the novel object recognition test, and higher levels of Tau phosphorylation when compared to NT mice. Cotinine significantly improved visual recognition memory performance increased CREB phosphorylation and reduced cortical Tau phosphorylation. Potential mechanisms underlying theses beneficial effects are discussed. Copyright © 2017. Published by Elsevier Inc.

The Role of Teleophthalmology in the Management of Diabetic Retinopathy.

PubMed

Salongcay, Recivall P; Silva, Paolo S

2018-01-01

The emergence of diabetes as a global epidemic is accompanied by the rise in diabetes‑related retinal complications. Diabetic retinopathy, if left undetected and untreated, can lead to severe visual impairment and affect an individual's productivity and quality of life. Globally, diabetic retinopathy remains one of the leading causes of visual loss in the working‑age population. Teleophthalmology for diabetic retinopathy is an innovative means of retinal evaluation that allows identification of eyes at risk for visual loss, thereby preserving vision and decreasing the overall burden to the health care system. Numerous studies worldwide have found teleophthalmology to be a reliable and cost‑efficient alternative to traditional clinical examinations. It has reduced barriers to access to specialized eye care in both rural and urban communities. In teleophthalmology applications for diabetic retinopathy, it is critical that standardized protocols in image acquisition and evaluation are used to ensure low image ungradable rates and maintain the quality of images taken. Innovative imaging technology such as ultrawide field imaging has the potential to provide significant benefit with integration into teleophthalmology programs. Teleophthalmology programs for diabetic retinopathy rely on a comprehensive and multidisciplinary approach with partnerships across specialties and health care professionals to attain wider acceptability and allow evidence‑based eye care to reach a much broader population. Copyright 2017 Asia-Pacific Academy of Ophthalmology.

Treatment strategies for inherited optic neuropathies: past, present and future

PubMed Central

Yu-Wai-Man, P; Votruba, M; Moore, A T; Chinnery, P F

2014-01-01

Bilateral visual loss secondary to inherited optic neuropathies is an important cause of registrable blindness among children and young adults. The two prototypal disorders seen in clinical practice are Leber hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (DOA). About 90% of LHON cases are due to one of three mitochondrial DNA (mtDNA) point mutations: m.3460G>A, m.11778G>A, and m.14484T>C, which affect critical complex I subunits of the mitochondrial respiratory chain. The majority of patients with DOA harbour pathogenic mutations within OPA1, a nuclear gene that codes for a multifunctional inner mitochondrial membrane protein. Despite their contrasting genetic basis, LHON and DOA share overlapping pathological and clinical features that serve to highlight the striking tissue-specific vulnerability of the retinal ganglion cell (RGC) layer to disturbed mitochondrial function. In addition to severe visual loss secondary to progressive optic nerve degeneration, a subgroup of patients will also develop a more aggressive syndromic phenotype marked by significant neurological deficits. The management of LHON and DOA remains largely supportive, but major advances in our understanding of the mechanisms underpinning RGC loss in these two disorders are paving the way for novel forms of treatment aimed at halting or reversing visual deterioration at different stages of the disease process. In addition to neuroprotective strategies for rescuing RGCs from irreversible cell death, innovative in vitro fertilisation techniques are providing the tantalising prospect of preventing the germline transmission of pathogenic mtDNA mutations, eradicating in so doing the risk of disease in future generations. PMID:24603424

The contribution of LM to the neuroscience of movement vision

PubMed Central

Zihl, Josef; Heywood, Charles A.

2015-01-01

The significance of early and sporadic reports in the 19th century of impairments of motion vision following brain damage was largely unrecognized. In the absence of satisfactory post-mortem evidence, impairments were interpreted as the consequence of a more general disturbance resulting from brain damage, the location and extent of which was unknown. Moreover, evidence that movement constituted a special visual perception and may be selectively spared was similarly dismissed. Such skepticism derived from a reluctance to acknowledge that the neural substrates of visual perception may not be confined to primary visual cortex. This view did not persist. First, it was realized that visual movement perception does not depend simply on the analysis of spatial displacements and temporal intervals, but represents a specific visual movement sensation. Second persuasive evidence for functional specialization in extrastriate cortex, and notably the discovery of cortical area V5/MT, suggested a separate region specialized for motion processing. Shortly thereafter the remarkable case of patient LM was published, providing compelling evidence for a selective and specific loss of movement vision. The case is reviewed here, along with an assessment of its contribution to visual neuroscience. PMID:25741251

Visual symptomatology and referral patterns for Operation Iraqi Freedom and Operation Enduring Freedom veterans with traumatic brain injury.

PubMed

Bulson, Ryan; Jun, Weon; Hayes, John

2012-01-01

Advances in protective armor technology and changes in the "patterns of war" have created a population of Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) veterans with traumatic brain injury (TBI) that provide a unique challenge to Department of Veterans Affairs (VA) healthcare practitioners. The purpose of the study was to determine the frequency of symptomatic ocular and visual sequelae of TBI in OIF/OEF veterans at the Portland VA Medical Center, a Polytrauma Support Clinic Team site. A retrospective analysis of 100 OIF/OEF veterans with TBI was conducted to determine the prevalence of ocular and visual complaints. Referral patterns were also investigated. Visual symptoms were reported in approximately 50% of veterans with TBI. Loss of consciousness, but not number of deployments or number of blast exposures, was found to have a statistically significant association with severity of reported visual symptoms. The most commonly reported symptoms included blurred vision (67%), photosensitivity (50%), and accommodative problems (40%). Visual symptoms of OIF/OEF veterans at the Portland VA Medical Center are reported at slightly lower rates than similar studies conducted at the Palo Alto and Edward Hines Jr VA facilities.

Experience-Dependent Synaptic Plasticity in V1 Occurs without Microglial CX3CR1

PubMed Central

Stevens, Beth

2017-01-01

Brief monocular deprivation (MD) shifts ocular dominance and reduces the density of thalamic synapses in layer 4 of the mouse primary visual cortex (V1). We found that microglial lysosome content is also increased as a result of MD. Previous studies have shown that the microglial fractalkine receptor CX3CR1 is involved in synaptic development and hippocampal plasticity. We therefore tested the hypothesis that neuron-to-microglial communication via CX3CR1 is an essential component of visual cortical development and plasticity in male mice. Our data show that CX3CR1 is not required for normal development of V1 responses to visual stimulation, multiple forms of experience-dependent plasticity, or the synapse loss that accompanies MD in layer 4. By ruling out an essential role for fractalkine signaling, our study narrows the search for understanding how microglia respond to active synapse modification in the visual cortex. SIGNIFICANCE STATEMENT Microglia in the visual cortex respond to monocular deprivation with increased lysosome content, but signaling through the fractalkine receptor CX3CR1 is not an essential component in the mechanisms of visual cortical development or experience-dependent synaptic plasticity. PMID:28951447

A systematic review on zinc for the prevention and treatment of age-related macular degeneration.

PubMed

Vishwanathan, Rohini; Chung, Mei; Johnson, Elizabeth J

2013-06-12

The objective of this systematic review was to examine the evidence on zinc intake from foods and supplements in the primary prevention and treatment of AMD. Randomized controlled trials (RCTs), prospective cohort, retrospective cohort, and case-control studies that investigated zinc intake from foods and/or supplements, and AMD in men and women with a mean age of 50 years or older were included. Medline and Cochrane Central were searched from inception to February 2012 and November 2012, respectively. Data extraction and quality appraisal were done on all eligible studies. TEN STUDIES WERE INCLUDED: four RCTs, four prospective cohort, and two retrospective cohort studies. Age-related Eye Disease Study (AREDS) showed zinc treatment to significantly reduce the risk of progression to advanced AMD. The risk of visual acuity loss was of similar magnitude, but not statistically significant. Two RCTs reported statistically significant increases in visual acuity in early AMD patients and one RCT showed no effect of zinc treatment on visual acuity in advanced AMD patients. Results from six cohort studies on associations between zinc intake and incidence of AMD were inconsistent. Current evidence on zinc intake for the prevention of AMD is inconclusive. Based on the strength of AREDS, we can conclude that zinc treatment may be effective in preventing progression to advanced AMD. Zinc supplementation alone may not be sufficient to produce clinically meaningful changes in visual acuity.

Archelosaurian Color Vision, Parietal Eye Loss, and the Crocodylian Nocturnal Bottleneck.

PubMed

Emerling, Christopher A

2017-03-01

Vertebrate color vision has evolved partly through the modification of five ancestral visual opsin proteins via gene duplication, loss, and shifts in spectral sensitivity. While many vertebrates, particularly mammals, birds, and fishes, have had their visual opsin repertoires studied in great detail, testudines (turtles) and crocodylians have largely been neglected. Here I examine the genomic basis for color vision in four species of turtles and four species of crocodylians, and demonstrate that while turtles appear to vary in their number of visual opsins, crocodylians experienced a reduction in their color discrimination capacity after their divergence from Aves. Based on the opsin sequences present in their genomes and previous measurements of crocodylian cones, I provide evidence that crocodylians have co-opted the rod opsin (RH1) for cone function. This suggests that some crocodylians might have reinvented trichromatic color vision in a novel way, analogous to several primate lineages. The loss of visual opsins in crocodylians paralleled the loss of various anatomical features associated with photoreception, attributed to a "nocturnal bottleneck" similar to that hypothesized for Mesozoic mammals. I further queried crocodylian genomes for nonvisual opsins and genes associated with protection from ultraviolet light, and found evidence for gene inactivation or loss for several of these genes. Two genes, encoding parietopsin and parapinopsin, were additionally inactivated in birds and turtles, likely co-occurring with the loss of the parietal eye in these lineages. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

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

PubMed

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

2018-06-01

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

Case Report: Use of Sports and Performance Vision Training to Benefit a Low-vision Patient's Function.

PubMed

Laby, Daniel M

2018-05-17

Despite our inability to attenuate the course of many ocular diseases that can ultimately lead to loss or significantly decreased visual function, this report describes a potential technique to aid such patients in maximizing the use of the vision that remains. The aim of this study was to demonstrate the applicability of utilizing sports vision training to improve objective and subjective visuomotor function in a low-vision patient. A 37-year-old woman with Usher syndrome presented with reduced central visual acuity and visual field. Although we were unable to reverse the damage resulting from her diagnosis, we were able to improve the use of the remaining vision. A 27 to 31% improvement in hand-eye coordination was achieved along with a 41% improvement in object tracking and visual concentration. Most importantly, following the 14-week training period, there was also a subjective improvement in the patient's appreciation of her visual ability. The sports vision literature cites many examples in which sports vision training is useful in improving visuomotor and on-field performance. We hypothesized that these techniques may be used to aid not only athletes but also patients with low vision. Despite suffering from reduced acuity and a limited visual field, these patients often still have a significant amount of vision ability that can be used to guide motor actions. Using techniques to increase the efficient use of this remaining vision may reduce the impact of the reduced visual function and aid in activities of daily living.

Physical activity among older people with sight loss: a qualitative research study to inform policy and practice.

PubMed

Phoenix, C; Griffin, M; Smith, B

2015-02-01

To investigate the ways in which participation in physical activity is prevented or facilitated among older people with acquired sight loss later in life. Qualitative research. Interviews were conducted with 48 visually impaired adults age 60+ years, recruited from a range of settings including local sight loss organisations and via talking newspaper advertisements. Visual impairment was defined by self-report. Data was analysed using a thematic analysis. This research represents a first step toward the development of empirically based practical suggestions for decision-makers and health professionals in terms of supporting - when required - visually impaired older adults participation in physical activity. Six themes were identified that captured why physical activity was prevented or facilitated: disabling environments; organisational opportunities; transport; lack of information; confidence, fear and personal safety; and exercise as medicine. Recommendations for policy change need to be focused at the societal level. This includes developing more accessible and inclusive environments and providing meaningful information about physical activity to older adults with a visual impairment, and visual impairment in older age to physical activity providers. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

The impact of macular surgery in different grades of epiretinal membrane.

PubMed

Batman, Cosar; Citirik, Mehmet

2017-01-01

To assess the impact of macular surgery on the functional and anatomic outcomes of the patients in different grades of epiretinal membrane (ERM). Seventy-one eyes of 71 patients who underwent 23-gauge transconjunctival sutureless pars plana vitrectomy for primary isolated ERM were evaluated in this study. There were 38 females (53.5%) and 33 males (46.5%). The average age of the patients was 68.1y (range 42-89y). Mean follow up period was 14mo (range 6-26mo). The cases were divided into two subgroups of cellophane maculopathy (CM) and macular pucker (MP). An improvement was observed in the postoperative best-corrected visual acuity (BCVA), as well as a decrement in central foveal thickness (CFT) in both groups (both of these being statistically significant; P =0.001). In comparison between two groups, it was found that there was a significant improvement on BCVA and CFT in CM group than MP group ( P =0.01). Furthermore, the postoperative fundus findings regarding RPE alterations and macular edema were significantly higher in MP group when compared to the CM group ( P =0.01). ERM and internal limiting membrane peeling surgery can lead to a significant reduction of CFT and visual improvements in idiopathic ERM. A long-term ERM persistence will cause unrecoverable retinal damage and visual loss.

Ube3a loss increases excitability and blunts orientation tuning in the visual cortex of Angelman syndrome model mice.

PubMed

Wallace, Michael L; van Woerden, Geeske M; Elgersma, Ype; Smith, Spencer L; Philpot, Benjamin D

2017-07-01

Angelman syndrome (AS) is a neurodevelopmental disorder caused by loss of the maternally inherited allele of UBE3A Ube3a STOP/p+ mice recapitulate major features of AS in humans and allow conditional reinstatement of maternal Ube3a with the expression of Cre recombinase. We have recently shown that AS model mice exhibit reduced inhibitory drive onto layer (L)2/3 pyramidal neurons of visual cortex, which contributes to a synaptic excitatory/inhibitory imbalance. However, it remains unclear how this loss of inhibitory drive affects neural circuits in vivo. Here we examined visual cortical response properties in individual neurons to explore the consequences of Ube3a loss on intact cortical circuits and processing. Using in vivo patch-clamp electrophysiology, we measured the visually evoked responses to square-wave drifting gratings in L2/3 regular-spiking (RS) neurons in control mice, Ube3a -deficient mice, and mice in which Ube3a was conditionally reinstated in GABAergic neurons. We found that Ube3a -deficient mice exhibited enhanced pyramidal neuron excitability in vivo as well as weaker orientation tuning. These observations are the first to show alterations in cortical computation in an AS model, and they suggest a basis for cortical dysfunction in AS. NEW & NOTEWORTHY Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by the loss of the gene UBE3A Using electrophysiological recording in vivo, we describe visual cortical dysfunctions in a mouse model of AS. Aberrant cellular properties in AS model mice could be improved by reinstating Ube3a in inhibitory neurons. These findings suggest that inhibitory neurons play a substantial role in the pathogenesis of AS. Copyright © 2017 the American Physiological Society.

The Effects of Hearing Aid Directional Microphone and Noise Reduction Processing on Listening Effort in Older Adults with Hearing Loss.

PubMed

Desjardins, Jamie L

2016-01-01

Older listeners with hearing loss may exert more cognitive resources to maintain a level of listening performance similar to that of younger listeners with normal hearing. Unfortunately, this increase in cognitive load, which is often conceptualized as increased listening effort, may come at the cost of cognitive processing resources that might otherwise be available for other tasks. The purpose of this study was to evaluate the independent and combined effects of a hearing aid directional microphone and a noise reduction (NR) algorithm on reducing the listening effort older listeners with hearing loss expend on a speech-in-noise task. Participants were fitted with study worn commercially available behind-the-ear hearing aids. Listening effort on a sentence recognition in noise task was measured using an objective auditory-visual dual-task paradigm. The primary task required participants to repeat sentences presented in quiet and in a four-talker babble. The secondary task was a digital visual pursuit rotor-tracking test, for which participants were instructed to use a computer mouse to track a moving target around an ellipse that was displayed on a computer screen. Each of the two tasks was presented separately and concurrently at a fixed overall speech recognition performance level of 50% correct with and without the directional microphone and/or the NR algorithm activated in the hearing aids. In addition, participants reported how effortful it was to listen to the sentences in quiet and in background noise in the different hearing aid listening conditions. Fifteen older listeners with mild sloping to severe sensorineural hearing loss participated in this study. Listening effort in background noise was significantly reduced with the directional microphones activated in the hearing aids. However, there was no significant change in listening effort with the hearing aid NR algorithm compared to no noise processing. Correlation analysis between objective and self-reported ratings of listening effort showed no significant relation. Directional microphone processing effectively reduced the cognitive load of listening to speech in background noise. This is significant because it is likely that listeners with hearing impairment will frequently encounter noisy speech in their everyday communications. American Academy of Audiology.

Real Time Intraoperative Monitoring of Blood Loss with a Novel Tablet Application.

PubMed

Sharareh, Behnam; Woolwine, Spencer; Satish, Siddarth; Abraham, Peter; Schwarzkopf, Ran

2015-01-01

Real-time monitoring of blood loss is critical in fluid management. Visual estimation remains the standard of care in estimating blood loss, yet is demonstrably inaccurate. Photometric analysis, which is the referenced "gold-standard" for measuring blood loss, is both time-consuming and costly. The purpose of this study was to evaluate the efficacy of a novel tablet-monitoring device for measurement of Hb loss during orthopaedic procedures. This is a prospective study of 50 patients in a consecutive series of joint arthroplasty cases. The novel System with Feature Extraction Technology was used to measure the amount of Hb contained within surgical sponges intra-operatively. The system's measures were then compared with those obtained via gravimetric method and photometric analysis. Accuracy was evaluated using linear regression and Bland-Altman analysis. Our results showed a significant positive correlation between Triton tablet system and photometric analysis with respect to intra-operative hemoglobin and blood loss at 0.92 and 0.91, respectively. This novel system can accurately determine Hb loss contained within surgical sponges. We believe that this user-friendly software can be used for measurement of total intraoperative blood loss and thus aid in a more accurate fluid management protocols during orthopaedic surgical procedures.

An improved cost-effective, reproducible method for evaluation of bone loss in a rodent model.

PubMed

Fine, Daniel H; Schreiner, Helen; Nasri-Heir, Cibele; Greenberg, Barbara; Jiang, Shuying; Markowitz, Kenneth; Furgang, David

2009-02-01

This study was designed to investigate the utility of two "new" definitions for assessment of bone loss in a rodent model of periodontitis. Eighteen rats were divided into three groups. Group 1 was infected by Aggregatibacter actinomycetemcomitans (Aa), group 2 was infected with an Aa leukotoxin knock-out, and group 3 received no Aa (controls). Microbial sampling and antibody titres were determined. Initially, two examiners measured the distance from the cemento-enamel-junction to alveolar bone crest using the three following methods; (1) total area of bone loss by radiograph, (2) linear bone loss by radiograph, (3) a direct visual measurement (DVM) of horizontal bone loss. Two "new" definitions were adopted; (1) any site in infected animals showing bone loss >2 standard deviations above the mean seen at that site in control animals was recorded as bone loss, (2) any animal with two or more sites in any quadrant affected by bone loss was considered as diseased. Using the "new" definitions both evaluators independently found that infected animals had significantly more disease than controls (DVM system; p<0.05). The DVM method provides a simple, cost effective, and reproducible method for studying periodontal disease in rodents.

Vision In Stroke cohort: Profile overview of visual impairment.

PubMed

Rowe, Fiona J

2017-11-01

To profile the full range of visual disorders from a large prospective observation study of stroke survivors referred by stroke multidisciplinary teams to orthoptic services with suspected visual problems. Multicenter prospective study undertaken in 20 acute Trust hospitals. Standardized screening/referral forms and investigation forms documented data on referral signs and symptoms plus type and extent of visual impairment. Of 1,345 patients referred with suspected visual impairment, 915 were recruited (59% men; mean age at stroke onset 69 years [SD 14]). Initial visual assessment was at median 22 days post stroke onset. Eight percent had normal visual assessment. Of 92% with confirmed visual impairment, 24% had reduced central visual acuity <0.3 logMAR and 13.5% <0.5 logMAR. Acquired strabismus was noted in 16% and acquired ocular motility disorders in 68%. Peripheral visual field loss was present in 52%, most commonly homonymous hemianopia. Fifteen percent had visual inattention and 4.6% had other visual perceptual disorders. Overall 84% were visually symptomatic with visual field loss the most common complaint followed by blurred vision, reading difficulty, and diplopia. Treatment options were provided to all with confirmed visual impairment. Targeted advice was most commonly provided along with refraction, prisms, and occlusion. There are a wide range of visual disorders that occur following stroke and, frequently, with visual symptoms. There are equally a wide variety of treatment options available for these individuals. All stroke survivors require screening for visual impairment and warrant referral for specialist assessment and targeted treatment specific to the type of visual impairment.

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

Dominant optic atrophy.

PubMed

Lenaers, Guy; Hamel, Christian; Delettre, Cécile; Amati-Bonneau, Patrizia; Procaccio, Vincent; Bonneau, Dominique; Reynier, Pascal; Milea, Dan

2012-07-09

DEFINITION OF THE DISEASE: Dominant Optic Atrophy (DOA) is a neuro-ophthalmic condition characterized by a bilateral degeneration of the optic nerves, causing insidious visual loss, typically starting during the first decade of life. The disease affects primary the retinal ganglion cells (RGC) and their axons forming the optic nerve, which transfer the visual information from the photoreceptors to the lateral geniculus in the brain. The prevalence of the disease varies from 1/10000 in Denmark due to a founder effect, to 1/30000 in the rest of the world. DOA patients usually suffer of moderate visual loss, associated with central or paracentral visual field deficits and color vision defects. The severity of the disease is highly variable, the visual acuity ranging from normal to legal blindness. The ophthalmic examination discloses on fundoscopy isolated optic disc pallor or atrophy, related to the RGC death. About 20% of DOA patients harbour extraocular multi-systemic features, including neurosensory hearing loss, or less commonly chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illness, spastic paraplegia or cataracts. Two genes (OPA1, OPA3) encoding inner mitochondrial membrane proteins and three loci (OPA4, OPA5, OPA8) are currently known for DOA. Additional loci and genes (OPA2, OPA6 and OPA7) are responsible for X-linked or recessive optic atrophy. All OPA genes yet identified encode mitochondrial proteins embedded in the inner membrane and ubiquitously expressed, as are the proteins mutated in the Leber Hereditary Optic Neuropathy. OPA1 mutations affect mitochondrial fusion, energy metabolism, control of apoptosis, calcium clearance and maintenance of mitochondrial genome integrity. OPA3 mutations only affect the energy metabolism and the control of apoptosis. Patients are usually diagnosed during their early childhood, because of bilateral, mild, otherwise unexplained visual loss related to optic discs pallor or atrophy, and typically occurring in the context of a family history of DOA. Optical Coherence Tomography further discloses non-specific thinning of retinal nerve fiber layer, but a normal morphology of the photoreceptors layers. Abnormal visual evoked potentials and pattern ERG may also reflect the dysfunction of the RGCs and their axons. Molecular diagnosis is provided by the identification of a mutation in the OPA1 gene (75% of DOA patients) or in the OPA3 gene (1% of patients). Visual loss in DOA may progress during puberty until adulthood, with very slow subsequent chronic progression in most of the cases. On the opposite, in DOA patients with associated extra-ocular features, the visual loss may be more severe over time. To date, there is no preventative or curative treatment in DOA; severely visually impaired patients may benefit from low vision aids. Genetic counseling is commonly offered and patients are advised to avoid alcohol and tobacco consumption, as well as the use of medications that may interfere with mitochondrial metabolism. Gene and pharmacological therapies for DOA are currently under investigation.

Dominant optic atrophy

PubMed Central

2012-01-01

Definition of the disease Dominant Optic Atrophy (DOA) is a neuro-ophthalmic condition characterized by a bilateral degeneration of the optic nerves, causing insidious visual loss, typically starting during the first decade of life. The disease affects primary the retinal ganglion cells (RGC) and their axons forming the optic nerve, which transfer the visual information from the photoreceptors to the lateral geniculus in the brain. Epidemiology The prevalence of the disease varies from 1/10000 in Denmark due to a founder effect, to 1/30000 in the rest of the world. Clinical description DOA patients usually suffer of moderate visual loss, associated with central or paracentral visual field deficits and color vision defects. The severity of the disease is highly variable, the visual acuity ranging from normal to legal blindness. The ophthalmic examination discloses on fundoscopy isolated optic disc pallor or atrophy, related to the RGC death. About 20% of DOA patients harbour extraocular multi-systemic features, including neurosensory hearing loss, or less commonly chronic progressive external ophthalmoplegia, myopathy, peripheral neuropathy, multiple sclerosis-like illness, spastic paraplegia or cataracts. Aetiology Two genes (OPA1, OPA3) encoding inner mitochondrial membrane proteins and three loci (OPA4, OPA5, OPA8) are currently known for DOA. Additional loci and genes (OPA2, OPA6 and OPA7) are responsible for X-linked or recessive optic atrophy. All OPA genes yet identified encode mitochondrial proteins embedded in the inner membrane and ubiquitously expressed, as are the proteins mutated in the Leber Hereditary Optic Neuropathy. OPA1 mutations affect mitochondrial fusion, energy metabolism, control of apoptosis, calcium clearance and maintenance of mitochondrial genome integrity. OPA3 mutations only affect the energy metabolism and the control of apoptosis. Diagnosis Patients are usually diagnosed during their early childhood, because of bilateral, mild, otherwise unexplained visual loss related to optic discs pallor or atrophy, and typically occurring in the context of a family history of DOA. Optical Coherence Tomography further discloses non-specific thinning of retinal nerve fiber layer, but a normal morphology of the photoreceptors layers. Abnormal visual evoked potentials and pattern ERG may also reflect the dysfunction of the RGCs and their axons. Molecular diagnosis is provided by the identification of a mutation in the OPA1 gene (75% of DOA patients) or in the OPA3 gene (1% of patients). Prognosis Visual loss in DOA may progress during puberty until adulthood, with very slow subsequent chronic progression in most of the cases. On the opposite, in DOA patients with associated extra-ocular features, the visual loss may be more severe over time. Management To date, there is no preventative or curative treatment in DOA; severely visually impaired patients may benefit from low vision aids. Genetic counseling is commonly offered and patients are advised to avoid alcohol and tobacco consumption, as well as the use of medications that may interfere with mitochondrial metabolism. Gene and pharmacological therapies for DOA are currently under investigation. PMID:22776096

Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss

PubMed Central

Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

2015-01-01

The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research. PMID:25972788

Normal Threshold Size of Stimuli in Children Using a Game-Based Visual Field Test.

PubMed

Wang, Yanfang; Ali, Zaria; Subramani, Siddharth; Biswas, Susmito; Fenerty, Cecilia; Henson, David B; Aslam, Tariq

2017-06-01

The aim of this study was to demonstrate and explore the ability of novel game-based perimetry to establish normal visual field thresholds in children. One hundred and eighteen children (aged 8.0 ± 2.8 years old) with no history of visual field loss or significant medical history were recruited. Each child had one eye tested using a game-based visual field test 'Caspar's Castle' at four retinal locations 12.7° (N = 118) from fixation. Thresholds were established repeatedly using up/down staircase algorithms with stimuli of varying diameter (luminance 20 cd/m 2 , duration 200 ms, background luminance 10 cd/m 2 ). Relationships between threshold and age were determined along with measures of intra- and intersubject variability. The Game-based visual field test was able to establish threshold estimates in the full range of children tested. Threshold size reduced with increasing age in children. Intrasubject variability and intersubject variability were inversely related to age in children. Normal visual field thresholds were established for specific locations in children using a novel game-based visual field test. These could be used as a foundation for developing a game-based perimetry screening test for children.

Relationship between slow visual processing and reading speed in people with macular degeneration

PubMed Central

Cheong, Allen MY; Legge, Gordon E; Lawrence, Mary G; Cheung, Sing-Hang; Ruff, Mary A

2007-01-01

Purpose People with macular degeneration (MD) often read slowly even with adequate magnification to compensate for acuity loss. Oculomotor deficits may affect reading in MD, but cannot fully explain the substantial reduction in reading speed. Central-field loss (CFL) is often a consequence of macular degeneration, necessitating the use of peripheral vision for reading. We hypothesized that slower temporal processing of visual patterns in peripheral vision is a factor contributing to slow reading performance in MD patients. Methods Fifteen subjects with MD, including 12 with CFL, and five age-matched control subjects were recruited. Maximum reading speed and critical print size were measured with RSVP (Rapid Serial Visual Presentation). Temporal processing speed was studied by measuring letter-recognition accuracy for strings of three randomly selected letters centered at fixation for a range of exposure times. Temporal threshold was defined as the exposure time yielding 80% recognition accuracy for the central letter. Results Temporal thresholds for the MD subjects ranged from 159 to 5881 ms, much longer than values for age-matched controls in central vision (13 ms, p<0.01). The mean temporal threshold for the 11 MD subjects who used eccentric fixation (1555.8 ± 1708.4 ms) was much longer than the mean temporal threshold (97.0 ms ± 34.2 ms, p<0.01) for the age-matched controls at 10° in the lower visual field. Individual temporal thresholds accounted for 30% of the variance in reading speed (p<0.05). Conclusion The significant association between increased temporal threshold for letter recognition and reduced reading speed is consistent with the hypothesis that slower visual processing of letter recognition is one of the factors limiting reading speed in MD subjects. PMID:17881032

Improving PAGER's real-time earthquake casualty and loss estimation toolkit: a challenge

USGS Publications Warehouse

Jaiswal, K.S.; Wald, D.J.

2012-01-01

We describe the on-going developments of PAGER’s loss estimation models, and discuss value-added web content that can be generated related to exposure, damage and loss outputs for a variety of PAGER users. These developments include identifying vulnerable building types in any given area, estimating earthquake-induced damage and loss statistics by building type, and developing visualization aids that help locate areas of concern for improving post-earthquake response efforts. While detailed exposure and damage information is highly useful and desirable, significant improvements are still necessary in order to improve underlying building stock and vulnerability data at a global scale. Existing efforts with the GEM’s GED4GEM and GVC consortia will help achieve some of these objectives. This will benefit PAGER especially in regions where PAGER’s empirical model is less-well constrained; there, the semi-empirical and analytical models will provide robust estimates of damage and losses. Finally, we outline some of the challenges associated with rapid casualty and loss estimation that we experienced while responding to recent large earthquakes worldwide.

Modification of visual function by early visual experience.

PubMed

Blakemore, C

1976-07-01

Physiological experiments, involving recording from the visual cortex in young kittens and monkeys, have given new insight into human developmental disorders. In the visual cortex of normal cats and monkeys most neurones are selectively sensitive to the orientation of moving edges and they receive very similar signals from both eyes. Even in very young kittens without visual experience, most neurones are binocularly driven and a small proportion of them are genuinely orientation selective. There is no passive maturation of the system in the absence of visual experience, but even very brief exposure to patterned images produces rapid emergence of the adult organization. These results are compared to observations on humans who have "recovered" from early blindness. Covering one eye in a kitten or a monkey, during a sensitive period early in life, produces a virtually complete loss of input from that eye in the cortex. These results can be correlated with the production of "stimulus deprivation amblyopia" in infants who have had one eye patched. Induction of a strabismus causes a loss of binocularity in the visual cortex, and in humans it leads to a loss of stereoscopic vision and binocular fusion. Exposing kittens to lines of one orientation modifies the preferred orientations of cortical cells and there is an analogous "meridional amblyopia" in astigmatic humans. The existence of a sensitive period in human vision is discussed, as well as the possibility of designing remedial and preventive treatments for human developmental disorders.

Biomarkers in primary open angle glaucoma.

PubMed

Kokotas, Haris; Kroupis, Christos; Chiras, Dimitrios; Grigoriadou, Maria; Lamnissou, Klea; Petersen, Michael B; Kitsos, George

2012-12-01

Glaucoma, a leading cause of blindness worldwide, is currently defined as a disturbance of the structural or functional integrity of the optic nerve that causes characteristic atrophic changes in the optic nerve, which may lead to specific visual field defects over time. This disturbance usually can be arrested or diminished by adequate lowering of intraocular pressure (IOP). Glaucoma can be divided roughly into two main categories, ‘ open angle ’ and ‘ closed angle ’ glaucoma.Open angle, chronic glaucoma tends to progress at a slower rate and patients may not notice loss of vision until the disease has progressed significantly. Primary open angle glaucoma(POAG) is described distinctly as a multifactorial optic neuropathy that is chronic and progressive with a characteristic acquired loss of optic nerve fibers. Such loss develops in the presence of open anterior chamber angles, characteristic visual field abnormalities, and IOP that is too high for the healthy eye. It manifests by cupping and atrophy of the optic disc, in the absence of other known causes of glaucomatous disease. Several biological markers have been implicated with the disease. The purpose of this study was to summarize the current knowledge regarding the non-genetic molecular markers which have been predicted to have an association with POAG but have not yet been validated.

[Treatment of difficult endocrine orbitopathy cases].

PubMed

Breuer, T; Ammann-Rauch, D; Tasman, A J

2007-05-01

There can be many differences between the clinical presentation and disease development of endocrine orbitopathy. Uncommon clinical expressions of the disease may lead to misinterpretations causing difficulties in treatment. Misdiagnosed forms of the disease can end with irreversible vision loss. A 79-year old female with severe bilateral thyroid eye disease, progressive almost blinding visual loss, with the absence of exophthalmos is described. Second, a 39 year old female with a unilateral thyroid eye disease and relapsing episodes of the disease is reported. Exophthalmos, as a symptom, occurs in about 60 % of the patients diagnosed with thyroid eye disease. The absence of exophthalmos may be due to a reduced volume (atrophy ) of retrobulbar fat tissue. Progressive visual loss can be related to direct compression of the optic nerve by thickened eye muscles in the orbital apex. Thyroid eye disease presents itself unilaterally in 5-11 % of all cases and involvement of the contra lateral orbit may occur years later. A relapse of the disease may be triggered by episodes of hypo- or hyperthyroidism. Smoking is a significant risk factor for orbitopathy relapse. Physicians treating thyroid eye disease should be aware of atypical clinical presentations in order for early satisfactory treatment. An interdisciplinary approach including ophthalmologists, endocrinologists and oto-rhino-laryngologists is necessary for optimal management.

An Exploration of the Associations among Hearing Loss, Physical Health, and Visual Memory in Adults from West Central Alabama

ERIC Educational Resources Information Center

Hay-McCutcheon, Marcia J.; Hyams, Adriana; Yang, Xin; Parton, Jason; Panasiuk, Brianna; Ondocsin, Sarah; James, Mary Margaret; Scogin, Forrest

2017-01-01

Purpose: The purpose of this preliminary study was to explore the associations among hearing loss, physical health, and visual memory in adults living in rural areas, urban clusters, and an urban city in west Central Alabama. Method: Two hundred ninety-seven adults (182 women, 115 men) from rural areas, urban clusters, and an urban city of west…

Tractional retinal detachment in Usher syndrome type II.

PubMed

Rani, Alka; Pal, Nikhil; Azad, Raj Vardhan; Sharma, Yog Raj; Chandra, Parijat; Vikram Singh, Deependra

2005-08-01

Retinal detachment is a rare complication in patients with retinitis pigmentosa. A case is reported of tractional retinal detachment in a patient with retinitis pigmentosa and sensorineural hearing loss, which was diagnosed as Usher syndrome type II. Because of the poor visual prognosis, the patient refused surgery in that eye. Tractional retinal detachment should be added to the differential diagnoses of visual loss in patients with retinitis pigmentosa.

Auditory, Visual, and Auditory-Visual Perceptions of Emotions by Young Children with Hearing Loss versus Children with Normal Hearing

ERIC Educational Resources Information Center

Most, Tova; Michaelis, Hilit

2012-01-01

Purpose: This study aimed to investigate the effect of hearing loss (HL) on emotion-perception ability among young children with and without HL. Method: A total of 26 children 4.0-6.6 years of age with prelingual sensory-neural HL ranging from moderate to profound and 14 children with normal hearing (NH) participated. They were asked to identify…

Working Memory and Speech Recognition in Noise under Ecologically Relevant Listening Conditions: Effects of Visual Cues and Noise Type among Adults with Hearing Loss

ERIC Educational Resources Information Center

Miller, Christi W.; Stewart, Erin K.; Wu, Yu-Hsiang; Bishop, Christopher; Bentler, Ruth A.; Tremblay, Kelly

2017-01-01

Purpose: This study evaluated the relationship between working memory (WM) and speech recognition in noise with different noise types as well as in the presence of visual cues. Method: Seventy-six adults with bilateral, mild to moderately severe sensorineural hearing loss (mean age: 69 years) participated. Using a cross-sectional design, 2…

45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... A child is visually impaired if: (1) The vision loss meets the definition of legal blindness in the... vision such that the widest diameter of the visual field subtends an angle no greater than 20 degrees. (b..., limited field of vision, cataracts, etc. ...

45 CFR 1308.13 - Eligibility criteria: Visual impairment including blindness.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... A child is visually impaired if: (1) The vision loss meets the definition of legal blindness in the... vision such that the widest diameter of the visual field subtends an angle no greater than 20 degrees. (b..., limited field of vision, cataracts, etc. ...

[Leber's hereditary optic neuropathy].

PubMed

Hilo, Wasseem; Jabaly-Habib, Haneen; Modi, Naftali; Briscoe, Daniel

2013-08-01

Lebers hereditary optic neuropathy (LHON) is a maternally inherited disease characterized by subacute severe visual loss in both eyes, which usually manifests in young adulthood. The disease has maternal inheritance due to mitochondrial DNA mutation. The final diagnosis is genetic. There is still no proven treatment, but there is significant progress in developments on the genetics of the disease to reach gene therapy. In this article we review the latest literature relevant to this disease.

Return of visual function after bilateral visual loss following flow diversion embolization of a giant ophthalmic aneurysm due to both reduction in mass effect and reduction in aneurysm pulsation.

PubMed

Patel, Saharsh; Fargen, Kyle M; Peters, Keith; Krall, Peter; Samy, Hazem; Hoh, Brian L

2014-01-10

Large and giant paraclinoid aneurysms are challenging to treat by either surgical or endovascular means. Visual dysfunction secondary to optic nerve compression and its relationship with aneurysm size, pulsation and thrombosis is poorly understood. We present a patient with a giant paraclinoid aneurysm resulting in bilateral visual loss that worsened following placement of a Pipeline Embolization Device and adjunctive coiling. Visual worsening occurred in conjunction with aneurysm thrombosis, increase in maximal aneurysm diameter and new adjacent edema. Her visual function spontaneously improved in a delayed fashion to better than pre-procedure, in conjunction with reduced aneurysmal mass effect, size and pulsation artifact on MRI. This report documents detailed ophthalmologic and MRI evidence for the role of thrombosis, aneurysm mass effect and aneurysm pulsation as causative etiologies for both cranial nerve dysfunction and delayed resolution following flow diversion treatment of large cerebral aneurysms.

Neuro-ophthalmic manifestations of cerebrovascular accidents.

PubMed

Ghannam, Alaa S Bou; Subramanian, Prem S

2017-11-01

Ocular functions can be affected in almost any type of cerebrovascular accident (CVA) creating a burden on the patient and family and limiting functionality. The present review summarizes the different ocular outcomes after stroke, divided into three categories: vision, ocular motility, and visual perception. We also discuss interventions that have been proposed to help restore vision and perception after CVA. Interventions that might help expand or compensate for visual field loss and visuospatial neglect include explorative saccade training, prisms, visual restoration therapy (VRT), and transcranial direct current stimulation (tDCS). VRT makes use of neuroplasticity, which has shown efficacy in animal models but remains controversial in human studies. CVAs can lead to decreased visual acuity, visual field loss, ocular motility abnormalities, and visuospatial perception deficits. Although ocular motility problems can be corrected with surgery, vision, and perception deficits are more difficult to overcome. Interventions to restore or compensate for visual field deficits are controversial despite theoretical underpinnings, animal model evidence, and case reports of their efficacies.

Gradient-based multiresolution image fusion.

PubMed

Petrović, Valdimir S; Xydeas, Costas S

2004-02-01

A novel approach to multiresolution signal-level image fusion is presented for accurately transferring visual information from any number of input image signals, into a single fused image without loss of information or the introduction of distortion. The proposed system uses a "fuse-then-decompose" technique realized through a novel, fusion/decomposition system architecture. In particular, information fusion is performed on a multiresolution gradient map representation domain of image signal information. At each resolution, input images are represented as gradient maps and combined to produce new, fused gradient maps. Fused gradient map signals are processed, using gradient filters derived from high-pass quadrature mirror filters to yield a fused multiresolution pyramid representation. The fused output image is obtained by applying, on the fused pyramid, a reconstruction process that is analogous to that of conventional discrete wavelet transform. This new gradient fusion significantly reduces the amount of distortion artefacts and the loss of contrast information usually observed in fused images obtained from conventional multiresolution fusion schemes. This is because fusion in the gradient map domain significantly improves the reliability of the feature selection and information fusion processes. Fusion performance is evaluated through informal visual inspection and subjective psychometric preference tests, as well as objective fusion performance measurements. Results clearly demonstrate the superiority of this new approach when compared to conventional fusion systems.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting.

PubMed

Ishii, Masashi; Hayashi, Morito; Yagi, Fumihiko; Sato, Kenichiro; Tomita, Goji; Iwabuchi, Satoshi

2016-01-01

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS ( P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow ( P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

Functional correlates of musical and visual ability in frontotemporal dementia.

PubMed

Miller, B L; Boone, K; Cummings, J L; Read, S L; Mishkin, F

2000-05-01

The emergence of new skills in the setting of dementia suggests that loss of function in one brain area can release new functions elsewhere. To characterise 12 patients with frontotemporal dementia (FTD) who acquired, or sustained, new musical or visual abilities despite progression of their dementia. Twelve patients with FTD who acquired or maintained musical or artistic ability were compared with 46 patients with FTD in whom new or sustained ability was absent. The group with musical or visual ability performed better on visual, but worse on verbal tasks than did the other patients with FTD. Nine had asymmetrical left anterior dysfunction. Nine showed the temporal lobe variant of FTD. Loss of function in the left anterior temporal lobe may lead to facilitation of artistic or musical skills. Patients with the left-sided temporal lobe variant of FTD offer an unexpected window into the neurological mediation of visual and musical talents.

Evolutionary Interactions Between Visual and Chemical Signals: Chemosignals Compensate for the Loss of a Visual Signal in Male Sceloporus Lizards.

PubMed

Pruett, Jake A; Zúñiga-Vega, J Jaime; Campos, Stephanie M; Soini, Helena A; Novotny, Milos V; Vital-García, Cuauhcihuatl; Martins, Emília P; Hews, Diana K

2016-11-01

Animals rely on multimodal signals to obtain information from conspecifics through alternative sensory systems, and the evolutionary loss of a signal in one modality may lead to compensation through increased use of signals in an alternative modality. We investigated associations between chemical signaling and evolutionary loss of abdominal color patches in males of four species (two plain-bellied and two colorful-bellied) of Sceloporus lizards. We conducted field trials to compare behavioral responses of male lizards to swabs with femoral gland (FG) secretions from conspecific males and control swabs (clean paper). We also analyzed the volatile organic compound (VOC) composition of male FG secretions by stir bar extraction and gas chromatography-mass spectrometry (GC-MS) to test the hypothesis that loss of the visual signal is associated with elaboration of the chemical signal. Males of plain-bellied, but not colorful-bellied species exhibited different rates of visual displays when exposed to swabs of conspecific FG secretions relative to control swabs. The VOC composition of male Sceloporus FG secretions was similar across all four species, and no clear association between relative abundances of VOCs and evolutionary loss of abdominal color patches was observed. The emerging pattern is that behavioral responses to conspecific chemical signals are species- and context-specific in male Sceloporus, and compensatory changes in receivers, but not signalers may be involved in mediating increased responsiveness to chemical signals in males of plain-bellied species.

Sensory factors limiting horizontal and vertical visual span for letter recognition

PubMed Central

Yu, Deyue; Legge, Gordon E.; Wagoner, Gunther; Chung, Susana T. L.

2014-01-01

Reading speed for English text is slower for text oriented vertically than horizontally. Yu, Park, Gerold, and Legge (2010) showed that slower reading of vertical text is associated with a smaller visual span (the number of letters recognized with high accuracy without moving the eyes). Three possible sensory determinants of the size of the visual span are: resolution (decreasing acuity at letter positions farther from the midline), mislocations (uncertainty about the relative position of letters in strings), and crowding (interference from flanking letters in recognizing the target letter). In the present study, we asked which of these factors is most important in determining the size of the visual span, and likely in turn in determining the horizontal/vertical difference in reading when letter size is above the critical print size for reading. We used a decomposition analysis to represent constraints due to resolution, mislocations, and crowding as losses in information transmitted (in bits) about letter recognition. Across vertical and horizontal conditions, crowding accounted for 75% of the loss in information, mislocations accounted for 19% of the loss, and declining acuity away from fixation accounted for only 6%. We conclude that crowding is the major factor limiting the size of the visual span, and that the horizontal/vertical difference in the size of the visual span is associated with stronger crowding along the vertical midline. PMID:25187253

Sensory factors limiting horizontal and vertical visual span for letter recognition

PubMed Central

Yu, Deyue; Legge, Gordon E.; Wagoner, Gunther; Chung, Susana T. L.

2014-01-01

Reading speed for English text is slower for text oriented vertically than horizontally. Yu, Park, Gerold, and Legge (2010) showed that slower reading of vertical text is associated with a smaller visual span (the number of letters recognized with high accuracy without moving the eyes). Three possible sensory determinants of the size of the visual span are: resolution (decreasing acuity at letter positions farther from the midline), mislocations (uncertainty about the relative position of letters in strings), and crowding (interference from flanking letters in recognizing the target letter). In the present study, we asked which of these factors is most important in determining the size of the visual span, and likely in turn in determining the horizontal/vertical difference in reading when letter size is above the critical print size for reading. We used a decomposition analysis to represent constraints due to resolution, mislocations, and crowding as losses in information transmitted (in bits) about letter recognition. Across vertical and horizontal conditions, crowding accounted for 75% of the loss in information, mislocations accounted for 19% of the loss, and declining acuity away from fixation accounted for only 6%. We conclude that crowding is the major factor limiting the size of the visual span, and that the horizontal/vertical difference in the size of the visual span is associated with stronger crowding along the vertical midline.

Oral-Fluid Thiol-Detection Test Identifies Underlying Active Periodontal Disease Not Detected by the Visual Awake Examination.

PubMed

Queck, Katherine E; Chapman, Angela; Herzog, Leslie J; Shell-Martin, Tamara; Burgess-Cassler, Anthony; McClure, George David

Periodontal disease in dogs is highly prevalent but can only be accurately diagnosed by performing an anesthetized oral examination with periodontal probing and dental radiography. In this study, 114 dogs had a visual awake examination of the oral cavity and were administered an oral-fluid thiol-detection test prior to undergoing a a full-mouth anesthetized oral examination and digital dental radiographs. The results show the visual awake examination underestimated the presence and severity of active periodontal disease. The thiol-detection test was superior to the visual awake examination at detecting the presence and severity of active periodontal disease and was an indicator of progression toward alveolar bone loss. The thiol-detection test detected active periodontal disease at early stages of development, before any visual cues were present, indicating the need for intervention to prevent periodontal bone loss. Early detection is important because without intervention, dogs with gingivitis (active periodontal disease) progress to irreversible periodontal bone loss (stage 2+). As suggested in the current AAHA guidelines, a thiol-detection test administered in conjunction with the visual awake examination during routine wellness examinations facilitates veterinarian-client communication and mitigates under-diagnosis of periodontal disease and underutilization of dental services. The thiol-detection test can be used to monitor the periodontal health status of the conscious patient during follow-up examinations based on disease severity.

Don’t Assume Deaf Students are Visual Learners

PubMed Central

Marschark, Marc; Paivio, Allan; Spencer, Linda J.; Durkin, Andreana; Borgna, Georgianna; Convertino, Carol; Machmer, Elizabeth

2016-01-01

In the education of deaf learners, from primary school to postsecondary settings, it frequently is suggested that deaf students are visual learners. That assumption appears to be based on the visual nature of signed languages—used by some but not all deaf individuals—and the fact that with greater hearing losses, deaf students will rely relatively more on vision than audition. However, the questions of whether individuals with hearing loss are more likely to be visual learners than verbal learners or more likely than hearing peers to be visual learners have not been empirically explored. Several recent studies, in fact, have indicated that hearing learners typically perform as well or better than deaf learners on a variety of visual-spatial tasks. The present study used two standardized instruments to examine learning styles among college deaf students who primarily rely on sign language or spoken language and their hearing peers. The visual-verbal dimension was of particular interest. Consistent with recent indirect findings, results indicated that deaf students are no more likely than hearing students to be visual learners and are no stronger in their visual skills and habits than their verbal skills and habits, nor are deaf students’ visual orientations associated with sign language skills. The results clearly have specific implications for the educating of deaf learners. PMID:28344430

Retinotopic memory is more precise than spatiotopic memory.

PubMed

Golomb, Julie D; Kanwisher, Nancy

2012-01-31

Successful visually guided behavior requires information about spatiotopic (i.e., world-centered) locations, but how accurately is this information actually derived from initial retinotopic (i.e., eye-centered) visual input? We conducted a spatial working memory task in which subjects remembered a cued location in spatiotopic or retinotopic coordinates while making guided eye movements during the memory delay. Surprisingly, after a saccade, subjects were significantly more accurate and precise at reporting retinotopic locations than spatiotopic locations. This difference grew with each eye movement, such that spatiotopic memory continued to deteriorate, whereas retinotopic memory did not accumulate error. The loss in spatiotopic fidelity is therefore not a generic consequence of eye movements, but a direct result of converting visual information from native retinotopic coordinates. Thus, despite our conscious experience of an effortlessly stable spatiotopic world and our lifetime of practice with spatiotopic tasks, memory is actually more reliable in raw retinotopic coordinates than in ecologically relevant spatiotopic coordinates.

Healing of cornea following an electric burn.

PubMed

Chaudhry, Tanveer Anjum; Shaikh, Farheen; Ahmad, Khabir

2012-08-01

Electrical injuries have become a significant health problem in developing countries because of increase in access to electricity in the last few decades and lack of adequate safety measures. Electrical injuries of eyes are relatively uncommon. A case report of a rapid and complete corneal healing accompanied by satisfactory visual recovery after an electric burn event in a 20-year-old male is reported. The patient had accidental exposure to high voltage live wire while he was repairing it, resulting in severe ocular and superficial body burn. He was not wearing any protective equipment at the time of injury. On examination, the best-corrected visual acuity was counting fingers in the left eye with severe corneal epithelial loss and diffuse corneal oedema. The patient was treated medically, with a rapid corneal healing and resolution of oedema over the next few days. Visual acuity in the worse eye (left) improved to 20/25 from counting fingers.

Adaptation, perceptual learning, and plasticity of brain functions.

PubMed

Horton, Jonathan C; Fahle, Manfred; Mulder, Theo; Trauzettel-Klosinski, Susanne

2017-03-01

The capacity for functional restitution after brain damage is quite different in the sensory and motor systems. This series of presentations highlights the potential for adaptation, plasticity, and perceptual learning from an interdisciplinary perspective. The chances for restitution in the primary visual cortex are limited. Some patterns of visual field loss and recovery after stroke are common, whereas others are impossible, which can be explained by the arrangement and plasticity of the cortical map. On the other hand, compensatory mechanisms are effective, can occur spontaneously, and can be enhanced by training. In contrast to the human visual system, the motor system is highly flexible. This is based on special relationships between perception and action and between cognition and action. In addition, the healthy adult brain can learn new functions, e.g. increasing resolution above the retinal one. The significance of these studies for rehabilitation after brain damage will be discussed.

Correcting intermittent central suppression improves binocular marksmanship.

PubMed

Hussey, Eric S

2007-04-01

Intermittent central suppression (ICS) is a defect in normal binocular (two-eyed) vision that causes confusion in visual detail. ICS is a repetitive intermittent loss of visual sensation in the central area of vision. As the central vision of either eye "turns on and off", aiming errors in sight can occur that must be corrected when both eyes are seeing again. Any aiming errors in sight might be expected to interfere with marksmanship during two-eyed seeing. We compared monocular (one-eyed, patched) and binocular (two-eyed) marksmanship with pistol shooting with an Army ROTC cadet before and after successful therapy for diagnosed ICS. Pretreatment, monocular marksmanship was significantly better than binocular marksmanship, suggesting defective binocularity reduced accuracy. After treatment for ICS, binocular and monocular marksmanship were essentially the same. Results confirmed predictions that with increased visual stability from correcting the suppression, binocular and monocular marksmanship accuracies should merge.

Central serous retinopathy with permanent visual deficit in a commercial air transport pilot: a case report.

PubMed

Newman, David G

2002-11-01

This report describes a case of central serous retinopathy (CSR) in the right eye of a commercial air transport pilot which resulted in a permanent reduction in visual acuity and the loss of his license. The previously fit and well pilot developed sudden loss of central vision, which resolved spontaneously. He then went on to experience recurrent episodes of fluctuating visual acuity (down to 6/60) and visual dysfunction in the right eye. His left eye remained unaffected. Eventually his condition stabilized, and he was left with a permanent reduction in right visual acuity (6/36) with intact peripheral visual fields and a completely normal left eye. After a period of grounding of 12 mo, he sought to have his license reinstated. He was considered to be a functionally monocular pilot, and as such was granted a conditional Class 1 medical category. The aeromedical disposition of this pilot and the issues involved in determining the fitness to fly of pilots with permanent visual defects arising from CSR are discussed.

Unilateral pigmentary retinopathy--a review of literature and case presentation.

PubMed

Stamate, Alina-Cristina; Burcea, Marian; Zemba, Mihail

2016-01-01

To report a rare case of unilateral pigmentary retinopathy and describe the clinical and visual field characteristics of this particular case. We present the case of a 30-year-old male patient with a gradual loss of the visual field on his left eye (LE) for the past 10 years, with further gradual painless loss of his central visual field in the last year, and no similar symptoms in his right eye. His past medical and ocular history were unremarkable. No family history of acquired or inherited diseases was determined. Based on the history, clinical findings, and visual field examination, the diagnosis of unilateral pigmentary retinopathy was established. Visual acuity and visual field in the left eye (LE) were severely affected, while in the right eye (RE), they were completely normal. In this case, distinct features of pigmentary retinopathy were observed only in one eye, with the fellow eye being unaffected. The diagnosis requires a long follow-up period, visual field and electrophysiological testing to rule out a delayed onset of a bilateral form of pigmentary retinopathy.

Differential functional magnetic resonance imaging response to food pictures in successful weight-loss maintainers relative to normal-weight and obese controls1234

PubMed Central

Haley, Andreana P; Sweet, Lawrence H; Phelan, Suzanne; Raynor, Hollie A; Del Parigi, Angelo; Cohen, Ron; Wing, Rena R

2009-01-01

Background: Prior research indicates that successful weight-loss maintainers (SWLs) work harder than people of normal weight to maintain their weight loss, including greater dietary restriction of fat and higher physical activity levels. However, little work to date has examined how SWLs differ biologically from normal-weight (NW) and obese controls. Objective: The objective was to compare the brain responses of SWLs to food pictures with those of NW and obese controls. Design: Blood oxygen level–dependent responses to high- and low-energy food pictures were measured in 18 NW controls, 16 obese controls, and 17 SWLs. Results: Group differences were identified in 4 regions, which indicated significant change in activation in response to the food pictures. SWLs showed greater activation in the left superior frontal region and right middle temporal region than did NW and obese controls—a pattern of results confirmed in exploratory voxel-wise analyses. Obese controls also showed greater activation in a bilateral precentral region. Conclusions: These results suggest that SWLs show greater activation in frontal regions and primary and secondary visual cortices—a pattern consistent with greater inhibitory control in response to food cues and greater visual attention to the food cues. A greater engagement of inhibitory control regions in response to food cues as well as a greater monitoring of foods may promote control of food intake and successful weight-loss maintenance. PMID:19675107

The effects of aging on hypoglossal motoneurons in rats.

PubMed

Schwarz, Emilie C; Thompson, Jodi M; Connor, Nadine P; Behan, Mary

2009-03-01

Aging can result in a loss of neuronal cell bodies and a decrease in neuronal size in some regions of the brain and spinal cord. Motoneuron loss in the spinal cord is thought to contribute to the progressive decline in muscle mass and strength that occurs with age (sarcopenia). Swallowing disorders represent a large clinical problem in elderly persons; however, age-related alterations in cranial motoneurons that innervate muscles involved in swallowing have been understudied. We aimed to determine if age-related alterations occurred in the hypoglossal nucleus in the brainstem. If present, these changes might help explain alterations at the neuromuscular junction and changes in the contractile properties of tongue muscle that have been reported in older rats. We hypothesized that with increasing age there would be a loss of motoneurons and a reduction in neuronal size and the number of primary dendrites associated with each hypoglossal motoneuron. Neurons in the hypoglossal nucleus were visualized with the neuronal marker NeuN in young (9-10 months), middle-aged (24-25 months), and old (32-33 months) male F344/BN rats. Hypoglossal motoneurons were retrograde-labeled with injections of Cholera Toxin beta into the genioglossus muscle of the tongue and visualized using immunocytochemistry. Results indicated that the number of primary dendrites of hypoglossal motoneurons decreased significantly with age, while no age-associated changes were found in the number or size of hypoglossal motoneurons. Loss of primary dendrites could reduce the number of synaptic inputs and thereby impair function.

The Effects of Aging on Hypoglossal Motoneurons in Rats

PubMed Central

Schwarz, Emilie C.; Thompson, Jodi M.; Connor, Nadine P.; Behan, Mary

2008-01-01

Aging can result in a loss of neuronal cell bodies and a decrease in neuronal size in some regions of the brain and spinal cord. Motoneuron loss in the spinal cord is thought to contribute to the progressive decline in muscle mass and strength that occurs with age (sarcopenia). Swallowing disorders represent a large clinical problem in elderly persons; however, age-related alterations in cranial motoneurons that innervate muscles involved in swallowing have been understudied. We aimed to determine if age-related alterations occurred in the hypoglossal nucleus in the brainstem. If present, these changes might help explain alterations at the neuromuscular junction and changes in the contractile properties of tongue muscle that have been reported in older rats. We hypothesized that with increasing age, there would be a loss of motoneurons and a reduction in neuronal size and the number of primary dendrites associated with each hypoglossal motoneuron. Neurons in the hypoglossal nucleus were visualized with the neuronal marker NeuN in young (9–10 months), middle-aged (24–25 months), and old (32–33 months) male F344/BN rats. Hypoglossal motoneurons were retrograde labeled with injections of Cholera Toxin β into the genioglossus muscle of the tongue and visualized using immunocytochemistry. Results indicated that the number of primary dendrites of hypoglossal motoneurons decreased significantly with age, while no age-associated changes were found in the number or size of hypoglossal motoneurons. Loss of primary dendrites could reduce the number of synaptic inputs and thereby impair function. PMID:18716837

The effect of vision and hearing loss on listeners' perception of referential meaning in music.

PubMed

Darrow, Alice-Ann; Novak, Julie

2007-01-01

The purpose of the present study was to examine the effect of vision and hearing loss on listeners' perception of referential meaning in music. Participants were students at a state school for the deaf and blind, and students with typical hearing and vision who attended neighboring public schools (N = 96). The music stimuli consisted of six 37-second randomly ordered excerpts from Saint Saëns, Carnival of the Animals. The excerpts were chosen because of their use in similar studies and the composer's clearly intended meaning conveyed in the titles of the excerpts. After allowing for appropriate procedural accommodations for participants with hearing or vision loss, all participants were asked to select the image portrayed by the music. A univariate ANOVA was computed to address the research question, "Do students with vision or hearing loss assign the same visual images to music as students without such sensory losses?" Data were analyzed to examine the effects of sensory condition as well as age and gender. A significant main effect was found for sensory condition, with follow up tests indicating that participants with typical hearing and vision agreed with the composer's intended meaning significantly more often than did participants with vision or hearing loss. No significant main effects were found for gender or age, and no significant interactions were found. Summary data indicated that selected images were more easily identified, or were more difficult to identify across conditions. The data also revealed an order of difficulty and patterns of confusion that were similar across sensory conditions and ages, indicating participant responses were not random, and that some referential meaning in music is conventional.

Stroke survivors' views and experiences on impact of visual impairment.

PubMed

Rowe, Fiona J

2017-09-01

We sought to determine stroke survivors' views on impact of stroke-related visual impairment to quality of life. Stroke survivors with visual impairment, more than 1 year post stroke onset, were recruited. Semistructured biographical narrative interviews were audio-recorded and transcribed verbatim. A thematic approach to analysis of the qualitative data was adopted. Transcripts were systematically coded using NVivo10 software. Thirty-five stroke survivors were interviewed across the UK: 16 females, 19 males; aged 20-75 years at stroke onset. Five qualitative themes emerged: "Formal care," "Symptoms and self," "Adaptations," "Daily life," and "Information." Where visual problems existed, they were often not immediately recognized as part of the stroke syndrome and attributed to other causes such as migraine. Many participants did not receive early vision assessment or treatment for their visual problems. Visual problems included visual field loss, double vision, and perceptual problems. Impact of visual problems included loss in confidence, being a burden to others, increased collisions/accidents, and fear of falling. They made many self-identified adaptations to compensate for visual problems: magnifiers, large print, increased lighting, use of white sticks. There was a consistent lack of support and provision of information about visual problems. Poststroke visual impairment causes considerable impact to daily life which could be substantially improved by simple measures including early formal visual assessment, management and advice on adaptive strategies and self-management options. Improved education about poststroke visual impairment for the public and clinicians could aid earlier diagnosis of visual impairments.

Stimulation of functional vision in children with perinatal brain damage.

PubMed

Alimović, Sonja; Mejaski-Bosnjak, Vlatka

2011-01-01

Cerebral visual impairment (CVI) is one of the most common causes of bilateral visual loss, which frequently occurs due to perinatal brain injury. Vision in early life has great impact on acquisition of basic comprehensions which are fundamental for further development. Therefore, early detection of visual problems and early intervention is necessary. The aim of the present study is to determine specific visual functioning of children with perinatal brain damage and the influence of visual stimulation on development of functional vision at early age of life. We initially assessed 30 children with perinatal brain damage up to 3 years of age, who were reffered to our pediatric low vision cabinet in "Little house" from child neurologists, ophthalmologists Type and degree of visual impairment was determined according to functional vision assessment of each child. On the bases of those assessments different kind of visual stimulations were carried out with children who have been identified to have a certain visual impairment. Through visual stimulation program some of the children were stimulated with light stimulus, some with different materials under the ultraviolet (UV) light, and some with bright color and high contrast materials. Children were also involved in program of early stimulation of overall sensory motor development. Goals and methods of therapy were determined individually, based on observation of child's possibilities and need. After one year of program, reassessment was done. Results for visual functions and functional vision were compared to evaluate the improvement of the vision development. These results have shown that there was significant improvement in functional vision, especially in visual attention and visual communication.

Causes of blindness and visual impairment in Pakistan. The Pakistan national blindness and visual impairment survey

PubMed Central

Dineen, B; Bourne, R R A; Jadoon, Z; Shah, S P; Khan, M A; Foster, A; Gilbert, C E; Khan, M D

2007-01-01

Objective To determine the causes of blindness and visual impairment in adults (⩾30 years old) in Pakistan, and to explore socio‐demographic variations in cause. Methods A multi‐stage, stratified, cluster random sampling survey was used to select a nationally representative sample of adults. Each subject was interviewed, had their visual acuity measured and underwent autorefraction and fundus/optic disc examination. Those with a visual acuity of <6/12 in either eye underwent a more detailed ophthalmic examination. Causes of visual impairment were classified according to the accepted World Health Organization (WHO) methodology. An exploration of demographic variables was conducted using regression modeling. Results A sample of 16 507 adults (95.5% of those enumerated) was examined. Cataract was the most common cause of blindness (51.5%; defined as <3/60 in the better eye on presentation) followed by corneal opacity (11.8%), uncorrected aphakia (8.6%) and glaucoma (7.1%). Posterior capsular opacification accounted for 3.6% of blindness. Among the moderately visually impaired (<6/18 to ⩾6/60), refractive error was the most common cause (43%), followed by cataract (42%). Refractive error as a cause of severe visual impairment/blindness was significantly higher in rural dwellers than in urban dwellers (odds ratio (OR) 3.5, 95% CI 1.1 to 11.7). Significant provincial differences were also identified. Overall we estimate that 85.5% of causes were avoidable and that 904 000 adults in Pakistan have cataract (<6/60) requiring surgical intervention. Conclusions This comprehensive survey provides reliable estimates of the causes of blindness and visual impairment in Pakistan. Despite expanded surgical services, cataract still accounts for over half of the cases of blindness in Pakistan. One in eight blind adults has visual loss from sequelae of cataract surgery. Services for refractive errors need to be further expanded and integrated into eye care services, particularly those serving rural populations. PMID:17229806

Correlation of a scanning laser derived oedema index and visual function following grid laser treatment for diabetic macular oedema.

PubMed

Hudson, C; Flanagan, J G; Turner, G S; Chen, H C; Young, L B; McLeod, D

2003-04-01

To correlate change of an oedema index derived by scanning laser tomography with change of visual function in patients undergoing grid laser photocoagulation for clinically significant diabetic macular oedema (DMO). The sample comprised 24 diabetic patients with retinal thickening within 500 micro m of the fovea. Inclusion criteria included a logMAR visual acuity of 0.25, or better. Patients were assessed twice before a single session of grid laser treatment and within 1 week of, and at 1, 2, 4, and 12 weeks after, treatment. At each visit, patients underwent logMAR visual acuity, conventional and short wavelength automated perimetry (SWAP), and scanning laser tomography. Each visual function parameter was correlated with the mean oedema index. The mean oedema index represented the z-profile signal width divided by the maximum reflectance intensity (arbitrary units). A Pearson correlation coefficient (Bonferroni corrected) was undertaken on the data set of each patient. 13 patients exhibited significant correlation of the mean oedema index and at least one measure of visual function for the 10 degrees x 10 degrees scan field while 10 patients correlated for the 20 degrees x 20 degrees scan field. Seven patients demonstrated correlation for both scan fields. Laser photocoagulation typically resulted in an immediate loss of perimetric sensitivity whereas the oedema index changed over a period of weeks. Localised oedema did not impact upon visual acuity or letter contrast sensitivity when situated extrafoveally. Correlation of change of the oedema index and of visual function following grid laser photocoagulation was not found in all patients. An absence of correlation can be explained by the localised distribution of DMO in this sample of patients, as well as by differences in the time course of change of the oedema index and visual function. The study has objectively documented change in the magnitude and distribution of DMO following grid laser treatment and has established the relation of this change to the change in visual function.

38 CFR 17.149 - Sensori-neural aids.

Code of Federal Regulations, 2010 CFR

2010-07-01

... attendance or by reason of being permanently housebound; (6) Those who have a visual or hearing impairment... normally occurring visual or hearing impairments; and (8) Those visually or hearing impaired so severely... frequency ranges which contribute to a loss of communication ability; however, hearing aids are to be...

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy.

PubMed

Miller, N R; Arnold, A C

2015-01-01

Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Patients typically present with acute, painless, unilateral loss of vision associated with a variable visual field defect, a relative afferent pupillary defect, a swollen, hyperaemic optic disc, and one or more flame-shaped peripapillary retinal haemorrhages. The pathogenesis of this condition is unknown, but it occurs primarily in patients with structurally small optic discs that have little or no cup and a variety of underlying vascular disorders that may or may not be known at the time of visual loss. There is no consistently beneficial medical or surgical treatment for the condition, but there are now animal models that allow testing of various potential therapies. About 40% of patients experience spontaneous improvement in visual acuity. Patients in whom NAION occurs in one eye have a 15-19% risk of developing a similar event in the opposite eye over the subsequent 5 years.

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy

PubMed Central

Miller, N R; Arnold, A C

2015-01-01

Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Patients typically present with acute, painless, unilateral loss of vision associated with a variable visual field defect, a relative afferent pupillary defect, a swollen, hyperaemic optic disc, and one or more flame-shaped peripapillary retinal haemorrhages. The pathogenesis of this condition is unknown, but it occurs primarily in patients with structurally small optic discs that have little or no cup and a variety of underlying vascular disorders that may or may not be known at the time of visual loss. There is no consistently beneficial medical or surgical treatment for the condition, but there are now animal models that allow testing of various potential therapies. About 40% of patients experience spontaneous improvement in visual acuity. Patients in whom NAION occurs in one eye have a 15–19% risk of developing a similar event in the opposite eye over the subsequent 5 years. PMID:24993324

Visual deficits in a mouse model of Batten disease are the result of optic nerve degeneration and loss of dorsal lateral geniculate thalamic neurons

PubMed Central

Weimer, Jill M.; Custer, Andrew W.; Benedict, Jared W.; Alexander, Noreen A.; Kingsley, Evan; Federoff, Howard J.; Cooper, Jonathan D.; Pearce, David A.

2013-01-01

Juvenile neuronal ceroid lipofuscinosis (JNCL) is an autosomal recessive disorder of childhood caused by mutations in CLN3. Although visual deterioration is typically the first clinical sign to manifest in affected children, loss of Cln3 in a mouse model of JNCL does not recapitulate this retinal deterioration. This suggests that either the loss of CLN3 does not directly affect retinal cell survival or that nuclei involved in visual processing are affected prior to retinal degeneration. Having previously demonstrated that Cln3−/− mice have decreased optic nerve axonal density, we now demonstrate a decrease in nerve conduction. Examination of retino-recipient regions revealed a decreased number of neurons within the dorsal lateral geniculate nucleus (LGNd). We demonstrate decreased transport of amino acids from the retina to the LGN, suggesting an impediment in communication between the retina and projection nuclei. This study defines a novel path of degeneration within the LGNd, providing a mechanism for causation of JNCL visual deficits. PMID:16412658

Visual impairment and blindness in Europe and their prevention.

PubMed

Kocur, I; Resnikoff, S

2002-07-01

The European region currently differs in many aspects, such as political, socioeconomic, and geographical. After substantial political changes at the beginning of the 1990s, the majority of central and eastern European countries started to rebuild their healthcare systems. It is apparent that eastern Europe represents a highly diverse region where the difference among countries broadens year after year. In highly industrialised countries of Europe, the leading causes of childhood serious visual loss are lesions of the central nervous system, congenital anomalies and retinal disorders. In the middle income countries of Europe, congenital cataract, glaucoma and, mainly, retinopathy of prematurity are highly expressed. The major cause of serious visual loss in adults in industrialised countries is age related macular degeneration. The other conditions comprise cataract, glaucoma, diabetic retinopathy, and uncorrected/uncorrectable refractive errors, along with low vision. In people of working age, diabetic retinopathy, retinopathy pigmentosa, and optic atrophy are the most frequently reported causes of serious visual loss. In the middle income countries of Europe, advanced cataract, glaucoma, and diabetic retinopathy are more frequently observed.

Visual impairment and blindness in Europe and their prevention

PubMed Central

Kocur, I; Resnikoff, S

2002-01-01

The European region currently differs in many aspects, such as political, socioeconomic, and geographical. After substantial political changes at the beginning of the 1990s, the majority of central and eastern European countries started to rebuild their healthcare systems. It is apparent that eastern Europe represents a highly diverse region where the difference among countries broadens year after year. In highly industrialised countries of Europe, the leading causes of childhood serious visual loss are lesions of the central nervous system, congenital anomalies and retinal disorders. In the middle income countries of Europe, congenital cataract, glaucoma and, mainly, retinopathy of prematurity are highly expressed. The major cause of serious visual loss in adults in industrialised countries is age related macular degeneration. The other conditions comprise cataract, glaucoma, diabetic retinopathy, and uncorrected/uncorrectable refractive errors, along with low vision. In people of working age, diabetic retinopathy, retinopathy pigmentosa, and optic atrophy are the most frequently reported causes of serious visual loss. In the middle income countries of Europe, advanced cataract, glaucoma, and diabetic retinopathy are more frequently observed. PMID:12084735

Localization of Usher syndrome type II to chromosome 1q.

PubMed

Kimberling, W J; Weston, M D; Möller, C; Davenport, S L; Shugart, Y Y; Priluck, I A; Martini, A; Milani, M; Smith, R J

1990-06-01

Usher syndrome is characterized by congenital hearing loss, progressive visual impairment due to retinitis pigmentosa, and variable vestibular problems. The two subtypes of Usher syndrome, types I and II, can be distinguished by the degree of hearing loss and by the presence or absence of vestibular dysfunction. Type I is characterized by a profound hearing loss and totally absent vestibular responses, while type II has a milder hearing loss and normal vestibular function. Fifty-five members of eight type II Usher syndrome families were typed for three DNA markers in the distal region of chromosome 1q: D1S65 (pEKH7.4), REN (pHRnES1.9), and D1S81 (pTHH33). Statistically significant linkage was observed for Usher syndrome type II with a maximum multipoint lod score of 6.37 at the position of the marker THH33, thus localizing the Usher type II (USH2) gene to 1q. Nine families with type I Usher syndrome failed to show linkage to the same three markers. The statistical test for heterogeneity of linkage between Usher syndrome types I and II was highly significant, thus demonstrating that they are due to mutations at different genetic loci.

The Health Of Patients' Eyes (HOPE) Glaucoma study. The effectiveness of a 'glaucoma personal record' for newly diagnosed glaucoma patients: study protocol for a randomised controlled trial.

PubMed

Forbes, Marina; Fairlamb, Helen; Jonker, Leon

2015-08-07

Glaucoma involves progressive optic nerve fibre loss, subsequently leading to irreversible and disabling visual field defects. In Europe, the prevalence of glaucoma is approximately 2.2 % of all people aged over 40 years; this equates to 12 million people. Glaucoma patients require regular lifelong follow-up, contributing to a large financial and resource burden for the National Health Service (NHS) in the UK. This study aims to determine whether providing newly diagnosed glaucoma patients with a personalised client-held eye health summary ('glaucoma personal record'), improves patients' knowledge of their glaucoma condition. A potential long-term benefit could be improved self-management and henceforth a slower rate of deterioration. HOPE Glaucoma is a 3-year, prospective, parallel-group, pragmatic, single-centred, randomised controlled trial. An anticipated 122 adults, newly diagnosed with glaucoma (including ocular hypertension, suspected glaucoma and/or chronic open-angle glaucoma) will be recruited from a nurse-led ophthalmology outpatient clinic at a medium-sized NHS Trust. Participants will be randomly allocated to receive standard clinical care (control arm) or standard care plus a glaucoma personal record, detailing the current state of their condition (interventional arm). Participant assessments are designed to test whether provision of a glaucoma personal record 1) improves patient knowledge of glaucoma and 2) contributes to improvements in clinical outcomes, i.e. delay of visual field loss. The primary outcome measure is better client knowledge of glaucoma at the 9-12 month follow-up visit. Secondary outcome measures include the rate of visual field loss and patient-reported outcome measures on visual function (National Eye Institute VFQ - 25) measured at baseline, 9-12 months, 24 months and 36 months. Estimating a 20 % drop-out rate, the study will have 90 % power to detect a mean two-point difference in glaucoma knowledge score between groups at 5 % significance - based on two-sided Mann-Whitney U test. If a glaucoma personal record is found to significantly improve glaucoma patients' knowledge of their condition, this intervention could potentially provide a low-cost, straightforward tool to educate and engage glaucoma patients. Subsequently, this could have the potential to increase patient self-management and therefore allow glaucoma patients to prolong their sight functionality for longer. ISRCTN41306818 , registered on 22 August 2013.

Cerebral venous hypertension and blindness: a reversible complication.

PubMed

Cuadra, Salvador A; Padberg, Frank T; Turbin, Roger E; Farkas, Jeffrey; Frohman, Larry P

2005-10-01

A 57-year-old woman developed blindness during treatment for sarcoidosis-induced end-stage renal disease. An initial renal transplantation failed, and hemoaccess was maintained with multiple central catheters and upper extremity prosthetic arteriovenous grafts. A successful second transplantation eliminated her need for hemodialysis, but a right brachial to internal jugular graft remained patent. Progressive visual loss 2 years after transplantation prompted ophthalmic evaluation which initially revealed unilateral left optic nerve edema and visual loss, ultimately worsening over several months to no light perception in the left eye, 20/60 vision in the right eye, and bilateral papilledema. Arteriography demonstrated cerebral venous hypertension attributed to the functioning hemoaccess graft. Permanent graft occlusion normalized the papilledema, and visual field defects in the right eye and visual acuity returned to 20/20 in the right eye.

A daily skincare regimen with a unique ceramide and filaggrin formulation rapidly improves chronic xerosis, pruritus, and quality of life in older adults.

PubMed

Chang, Anne Lynn S; Chen, Suephy C; Osterberg, Lars; Brandt, Staci; von Grote, Erika C; Meckfessel, Matthew H

A skin care regimen which significantly improved atopic dermatitis and pruritus was evaluated for its efficacy and acceptability in senior subjects diagnosed with xerosis who also suffer from pruritus. This was an open-label, single-center study, designed to evaluate the daily use of a skin care regimen for 15 days. Assessments were made at baseline, day 8 and day 15 for visual skin dryness, transepidermal water loss (TEWL), hydration, desquamation, subject-perceived itch and quality of life (QoL). Twenty-five subjects, ages 60-73 years, had significantly improved skin visual dryness, hydration, desquamation, itch and QoL at days 8 and 15, relative to baseline (P < .05). TEWL was improved, though not significantly. Subjects expressed a high degree of satisfaction with the results. This regimen provides geriatric patients with an easily incorporated skin routine to help improve a common symptom of aging skin which negatively affects QoL. Copyright © 2017 Elsevier Inc. All rights reserved.

[Visual and motor functions in schizophrenic patients].

PubMed

Del Vecchio, S; Gargiulo, P A

1992-12-01

In the present work, visual and motor functions have been explored in 26 chronic schizophrenic patients, and 7 acute schizophrenic patients, compared with 26 normal controls, by means of the Bender-Gestalt Test. Parameters under consideration were: Form distortion, rotation, integration, perseveration, use of space, subtle motricity, score (global parameter), and time employed. As regards distortion and rotation there have been highly significant differences between chronic patients and control group. Among acute patients, it was observed that perseveration was also highly significant. Conversely, integration and use of space did not differ significantly among the three groups involved. The global score, resulting from all the above mentioned parameters showed important differences between both patient groups on the one hand, and control group on the other hand. Taking into account that patients were being administered neuroleptic drugs, it can safely be said, however, that the Bender-Gestalt Test allows to recognize alteration in perceptual closure consistent with a loss of the objective structure of perceived phenomena, in both chronic and acute patients.

Development and evaluation of vision rehabilitation devices.

PubMed

Luo, Gang; Peli, Eli

2011-01-01

We have developed a range of vision rehabilitation devices and techniques for people with impaired vision due to either central vision loss or severely restricted peripheral visual field. We have conducted evaluation studies with patients to test the utilities of these techniques in an effort to document their advantages as well as their limitations. Here we describe our work on a visual field expander based on a head mounted display (HMD) for tunnel vision, a vision enhancement device for central vision loss, and a frequency domain JPEG/MPEG based image enhancement technique. All the evaluation studies included visual search paradigms that are suitable for conducting indoor controllable experiments.

The Rhetoric of Disfigurement in First World War Britain

PubMed Central

Biernoff, Suzannah

2011-01-01

Summary During the First World War, the horror of facial mutilation was evoked in journalism, poems, memoirs and fiction; but in Britain it was almost never represented visually outside the professional contexts of clinical medicine and medical history. This article asks why, and offers an account of British visual culture in which visual anxiety and aversion are of central importance. By comparing the rhetoric of disfigurement to the parallel treatment of amputees, an asymmetrical picture emerges in which the ‘worst loss of all’—the loss of one's face—is perceived as a loss of humanity. The only hope was surgery or, if that failed, prosthetic repair: innovations that were often wildly exaggerated in the popular press. Francis Derwent Wood was one of several sculptors whose technical skill and artistic ‘wizardry’ played a part in the improvised reconstruction of identity and humanity.

Quality of life in newly diagnosed glaucoma patients : The Collaborative Initial Glaucoma Treatment Study.

PubMed

Janz, N K; Wren, P A; Lichter, P R; Musch, D C; Gillespie, B W; Guire, K E

2001-05-01

The Collaborative Initial Glaucoma Treatment Study (CIGTS) was designed to determine whether patients with newly diagnosed open-angle glaucoma are better treated initially by medicine or immediate filtering surgery. This paper describes the quality-of-life (QOL) measurement approach, instruments included, and the CIGTS participants' QOL findings at the time of diagnosis. Baseline results from a randomized, controlled clinical trial. Six hundred seven patients from 14 clinical centers were enrolled. Patients randomized to initial medication received a stepped medical regimen (n = 307). Those randomized to initial surgery underwent a trabeculectomy (n = 300). The baseline interview was conducted before treatment initiation. All baseline and posttreatment QOL assessments were conducted by telephone from a centralized interviewing center. The primary outcome measure described in this paper was QOL. The QOL instrument is multidimensional and incorporates both disease-specific and generic measures, including the Visual Activities Questionnaire, Sickness Impact Profile, and a Symptom and Health Problem CHECKLIST: The correlations between QOL measures and clinical outcomes were in the expected direction, but relatively weak. At initial diagnosis, difficulty with bright lights and with light and dark adaptation were the most frequently reported symptoms related to visual function, whereas visual distortion was the most bothersome. Approximately half of the patients reported at least some worry or concern about the possibility of blindness. Within the Visual Activities Questionnaire, higher scores on the Peripheral Vision subscale were associated with more field loss (P < 0.01). In regression analyses controlling for sociodemographics and nonocular comorbidities, increased visual field loss was significantly associated with higher dysfunction among five disease-specific QOL measures (P < 0.05). Newly diagnosed glaucoma patients reported experiencing some visual function symptoms at the time of diagnosis that would not be intuitively expected based on clinical testing. Some discussion about the association between clinical presentation and worry about blindness may reduce unnecessary concern. These results provide the basis for long-term comparisons of the QOL effects of initial medical and surgical treatment for open-angle glaucoma.

The First Rapid Assessment of Avoidable Blindness (RAAB) in Thailand

PubMed Central

Isipradit, Saichin; Sirimaharaj, Maytinee; Charukamnoetkanok, Puwat; Thonginnetra, Oraorn; Wongsawad, Warapat; Sathornsumetee, Busaba; Somboonthanakij, Sudawadee; Soomsawasdi, Piriya; Jitawatanarat, Umapond; Taweebanjongsin, Wongsiri; Arayangkoon, Eakkachai; Arame, Punyawee; Kobkoonthon, Chinsuchee; Pangputhipong, Pannet

2014-01-01

Background The majority of vision loss is preventable or treatable. Population surveys are crucial for planning, implementation, and monitoring policies and interventions to eliminate avoidable blindness and visual impairments. This is the first rapid assessment of avoidable blindness (RAAB) study in Thailand. Methods A cross-sectional study of a population in Thailand age 50 years old or over aimed to assess the prevalence and causes of blindness and visual impairments. Using the Thailand National Census 2010 as the sampling frame, a stratified four-stage cluster sampling based on a probability proportional to size was conducted in 176 enumeration areas from 11 provinces. Participants received comprehensive eye examination by ophthalmologists. Results The age and sex adjusted prevalence of blindness (presenting visual acuity (VA) <20/400), severe visual impairment (VA <20/200 but ≥20/400), and moderate visual impairment (VA <20/70 but ≥20/200) were 0.6% (95% CI: 0.5–0.8), 1.3% (95% CI: 1.0–1.6), 12.6% (95% CI: 10.8–14.5). There was no significant difference among the four regions of Thailand. Cataract was the main cause of vision loss accounted for 69.7% of blindness. Cataract surgical coverage in persons was 95.1% for cut off VA of 20/400. Refractive errors, diabetic retinopathy, glaucoma, and corneal opacities were responsible for 6.0%, 5.1%, 4.0%, and 2.0% of blindness respectively. Conclusion Thailand is on track to achieve the goal of VISION 2020. However, there is still much room for improvement. Policy refinements and innovative interventions are recommended to alleviate blindness and visual impairments especially regarding the backlog of blinding cataract, management of non-communicative, chronic, age-related eye diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy, prevention of childhood blindness, and establishment of a robust eye health information system. PMID:25502762

The effect of drainage tube on bleeding and prognosis after total knee arthroplasty: a prospective cohort study.

PubMed

Liu, Xiao-Han; Fu, Pei-Liang; Wang, Shi-Ying; Yang, Ya-Juan; Lu, Gen-Di

2014-04-23

To evaluate the effect of drainage tube on prognosis after total knee arthroplasty (TKA) and explore an effective treatment with favorable prognosis. In a prospective study, 18 patients with TKA for the first time were included and randomly divided into three groups, group A (no placement of drainage tube), group B (negative pressure drainage), and group C (4 h clamping drainage). Intraoperative and postoperative blood loss, operation time, and the drainage volume were recorded and analyzed. Arthrocele, ecchymosis, and range of motion (ROM) were examined postoperatively. The degree of pain was scored by Visual Analog Scale (VAS) after 6, 12, and 24 h of operation. The complications were examined and HSS (hospital for special surgery) knee score was taken during the follow-up period. There was no significant difference in operation time, total blood loss, intraoperative blood loss, and VAS score among three groups. Meanwhile, the hidden blood loss in group B was significantly decreased compared with group A (P = 0.0015). The postoperative drainage volume of group B was significantly increased compared with group C (P = 0.0002). No drainage increased the rate of arthrocele and ecchymosis. Compared with group A, ROM after 3 days of operation in groups B and C was significantly increased (P = 0.0357, P = 0.0372, respectively). During follow-up study, no deep infection or deep venous thrombosis was found. After TKA, early clamping of the drainage tube reduced the bleeding loss without adverse effect on prognosis, which might be useful for clinical application in future.

A randomized controlled trial comparing 2 interventions for visual field loss with standard occupational therapy during inpatient stroke rehabilitation.

PubMed

Mödden, Claudia; Behrens, Marion; Damke, Iris; Eilers, Norbert; Kastrup, Andreas; Hildebrandt, Helmut

2012-06-01

Compensatory and restorative treatments have been developed to improve visual field defects after stroke. However, no controlled trials have compared these interventions with standard occupational therapy (OT). A total of 45 stroke participants with visual field defect admitted for inpatient rehabilitation were randomized to restorative computerized training (RT) using computer-based stimulation of border areas of their visual field defects or to a computer-based compensatory therapy (CT) teaching a visual search strategy. OT, in which different compensation strategies were used to train for activities of daily living, served as standard treatment for the active control group. Each treatment group received 15 single sessions of 30 minutes distributed over 3 weeks. The primary outcome measures were visual field expansion for RT, visual search performance for CT, and reading performance for both treatments. Visual conjunction search, alertness, and the Barthel Index were secondary outcomes. Compared with OT, CT resulted in a better visual search performance, and RT did not result in a larger expansion of the visual field. Intragroup pre-post comparisons demonstrated that CT improved all defined outcome parameters and RT several, whereas OT only improved one. CT improved functional deficits after visual field loss compared with standard OT and may be the intervention of choice during inpatient rehabilitation. A larger trial that includes lesion location in the analysis is recommended.

Visual Behaviors and Adaptations Associated with Cortical and Ocular Impairment in Children.

ERIC Educational Resources Information Center

Jan, J. E.; Groenveld, M.

1993-01-01

This article shows the usefulness of understanding visual behaviors in the diagnosis of various types of visual impairments that are due to ocular and cortical disorders. Behaviors discussed include nystagmus, ocular motor dyspraxia, head position, close viewing, field loss adaptations, mannerisms, photophobia, and abnormal color perception. (JDD)

Frida Kahlo: Visual Articulations of Suffering and Loss.

ERIC Educational Resources Information Center

Nixon, Lois LaCivita

1996-01-01

Illustrates the value of interdisciplinary approaches to patient care by exploring visual articulations of suffering as rendered by one artist. Makes general observations about the nature of humanities courses offered to medical students and depicts a visual portrayal of an illness story representing personal perspectives about patient suffering…

Are Deaf Students Visual Learners?

ERIC Educational Resources Information Center

Marschark, Marc; Morrison, Carolyn; Lukomski, Jennifer; Borgna, Georgianna; Convertino, Carol

2013-01-01

It is frequently assumed that by virtue of their hearing losses, deaf students are visual learners. Deaf individuals have some visual-spatial advantages relative to hearing individuals, but most have been linked to use of sign language rather than auditory deprivation. How such cognitive differences might affect academic performance has been…

Ocular Complications Following Autologous Fat Injections into Facial Area: Case Report of a Recovery from Visual Loss After Ophthalmic Artery Occlusion and a Review of the Literature.

PubMed

Szantyr, Aleksandra; Orski, Michał; Marchewka, Ida; Szuta, Mariusz; Orska, Małgorzata; Zapała, Jan

2017-06-01

With the increase in popularity of the use of cosmetic fillers in plastic and esthetic surgery, the possibility of severe ocular complications should not be neglected. Of the fillers used, autologous fat is the most common to cause permanent visual deterioration, one of the most severe complications associated with the use of cosmetic fillers. Here we present the first report of a complete recovery of visual acuity from an instance of visual loss with no light perception caused by ophthalmic artery occlusion of the right eye following autologous fat injection in the facial area. Immediate ophthalmological intervention and comprehensive therapy with prostaglandins and vinpocetine made it possible to restore retinal perfusion and achieve complete recovery of visual acuity. Awareness of the iatrogenic artery occlusions associated with facial fillers and the need for immediate treatment should be popularized among injectors to prevent devastating consequences, such as permanent vision loss. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Severe visual loss and cerebral infarction after injection of hyaluronic acid gel.

PubMed

Kim, Eung Gyu; Eom, Tae Kyung; Kang, Seok Joo

2014-01-01

We report a case of a 23-year-old man with cerebral infarction and permanent visual loss after injection of a hyaluronic acid gel filler for augmentation rhinoplasty. The patient was admitted to the hospital with complaints of loss of vision in the right eye, facial paralysis on the right side, and paralysis of the left limbs with severe pain during augmentation rhinoplasty with filler injection. Brain magnetic resonance imaging and computed tomography showed ophthalmic artery obstruction and right middle cerebral artery infarction. Acute thrombolysis was performed to treat the infarction; however, the patient's condition did not improve. Intracerebral hemorrhage in the right temporal/frontal/occipital/parietal lobe, subarachnoid hemorrhage, and midline shifting were observed on brain computed tomography after 24 hours after thrombolysis. Emergency decompressive craniectomy was performed. After the surgery, the patient continued to experience drowsiness, with no improvement in visual loss and motor weakness. Three months later, he could walk with cane. This case indicates that surgeons who administer filler injections should be familiar with the possibility of accidental intravascular injection and should explain the adverse effects of fillers to patients before surgery.

Gene mapping of the Usher syndromes.

PubMed

Kimberling, W; Smith, R J

1992-10-01

USH is an autosomal recessive group of diseases characterized by auditory impairment and visual loss owing to RP. Two common types of USH are known, types I and II. USH type I is characterized by a congenital severe to profound hearing impairment, absent vestibular function, and a progressive pigmentary retinopathy. Persons with type I do not find hearing aids useful, have delayed motor development, and experience progressive night blindness and peripheral visual loss, which usually begins in their second decade. USH type II is characterized by a congenital moderate to severe hearing loss with a down-sloping audiogram, normal vestibular function, and a progressive pigmentary retinopathy. Persons with USH2 find hearing aids beneficial, have normal psychomotor development, and experience progressive night blindness and peripheral visual loss, which usually begins in their third decade. Vestibular dysfunction is the best distinguishing hallmark to differentiate USH type I from type II. One USH type II gene (called USH2) has been assigned to chromosome 1q. One USH type I gene has been tentatively assigned to chromosome 14q. There are other USH genes that have not yet been localized.

Vascular endothelial growth factor inhibitor use and treatment approach for choroidal neovascularization secondary to pathologic myopia.

PubMed

Pakzad-Vaezi, Kaivon; Mehta, Hemal; Mammo, Zaid; Tufail, Adnan

2016-07-01

Myopic choroidal neovascularization (CNV) is the most common cause of CNV in those under 50 years of age. It is a significant cause of visual loss in those with pathologic myopia. The current standard of care involves therapy with intravitreal inhibitors of vascular endothelial growth factor (VEGF). The epidemiology of myopia, high myopia, pathologic myopia, and myopic CNV is reviewed, along with a brief discussion of historical treatments. The pharmacology of the three most commonly used anti-VEGF agents is discussed, with an emphasis on the licensed drugs, ranibizumab and aflibercept. A comprehensive clinical approach to diagnosis and treatment of myopic CNV is presented. The current standard of care for myopic CNV is intravitreal inhibition of VEGF, with ranibizumab and aflibercept licensed for intraocular use. The diagnosis, OCT features of disease activity and retreatment algorithm for myopic CNV is different from wet age-related macular degeneration. In the long-term, myopic CNV may be associated with gradual, irreversible visual loss due to progressive chorioretinal atrophy, for which there is currently no treatment.

Presentation of suspected pediatric uveitis.

PubMed

Saeed, Muhammad Usman; Raza, Syed Hamid; Goyal, Sudeshna; Cleary, Gavin; Newman, William David; Chandna, Arvind

2014-01-01

Presentation of suspected pediatric uveitis: Pediatric uveitis is usually managed in specialized ophthalmic centers in the UK. Meaningful data acquisition in these clinics may be helpful in clinical governance, and healthcare planning in a specialty that is gradually changing due to changes in treatment choices. Retrospective analysis of prospectively acquired data in the Liverpool pediatric uveitis database was performed. Analysis of our data, based on 147 patients, with a mean age of 10 years, indicated a female to male ratio of 2:1. 99% of patients were Caucasian. Our data indicates 86% of all patients attending the uveitis clinic were diagnosed with juvenile idiopathic arthritis, followed by intermediate uveitis 5% and idiopathic uveitis 4%. 46% of patients required treatment. Systemic treatment included methotrexate (34%), prednisolone (14%), etanercept (6%), ciclosporin (6%), mycophenolate (3%), and infliximab (1%). Severe visual loss (defined by counting fingers or below vision) was seen in 10 eyes despite appropriately treated chronic uveitis. Our data shows uveitis-related ocular morbidity in a predominantly pediatric Caucasian population. Patients with severe and chronic uveitis may experience significant uveitis-related complications and subsequent visual loss despite aggressive treatment.

Ocular dynamics and visual tracking performance after Q-switched laser exposure

NASA Astrophysics Data System (ADS)

Zwick, Harry; Stuck, Bruce E.; Lund, David J.; Nawim, Maqsood

2001-05-01

In previous investigations of q-switched laser retinal exposure in awake task oriented non-human primates (NHPs), the threshold for retinal damage occurred well below that of the threshold for permanent visual function loss. Visual function measures used in these studies involved measures of visual acuity and contrast sensitivity. In the present study, we examine the same relationship for q-switched laser exposure using a visual performance task, where task dependency involves more parafoveal than foveal retina. NHPs were trained on a visual pursuit motor tracking performance task that required maintaining a small HeNe laser spot (0.3 degrees) centered in a slowly moving (0.5deg/sec) annulus. When NHPs reliably produced visual target tracking efficiencies > 80%, single q-switched laser exposures (7 nsec) were made coaxially with the line of sight of the moving target. An infrared camera imaged the pupil during exposure to obtain the pupillary response to the laser flash. Retinal images were obtained with a scanning laser ophthalmoscope 3 days post exposure under ketamine and nembutol anesthesia. Q-switched visible laser exposures at twice the damage threshold produced small (about 50mm) retinal lesions temporal to the fovea; deficits in NHP visual pursuit tracking were transient, demonstrating full recovery to baseline within a single tracking session. Post exposure analysis of the pupillary response demonstrated that the exposure flash entered the pupil, followed by 90 msec refractory period and than a 12 % pupillary contraction within 1.5 sec from the onset of laser exposure. At 6 times the morphological threshold damage level for 532 nm q-switched exposure, longer term losses in NHP pursuit tracking performance were observed. In summary, q-switched laser exposure appears to have a higher threshold for permanent visual performance loss than the corresponding threshold to produce retinal threshold injury. Mechanisms of neural plasticity within the retina and at higher visual brain centers may mediat

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

The effects of 72 hours of sleep loss on psychological variables.

PubMed

Mikulincer, M; Babkoff, H; Caspy, T; Sing, H

1989-05-01

A study was conducted on the effects of 72 hours of sleep loss and modified continuous operations on performance and psychological variables. This paper presents the results of self-report data of 12 subjects for the following psychological variables: sleepiness, affect, motivation, cognitive difficulties, and waking dreams. The relationship between the self-report measures and performance in a visual search and memory task is also examined. Most of the psychological variables are significantly affected by the number of days of sleep deprivation, all are significantly affected by hour of day; but only sleepiness, affect and motivation are also significantly affected by the interaction between these variables. The peak hours for self-reported psychological complaints are generally between 0400 and 0800, while the lowest number of complaints are usually reported in the afternoon/early evening, between 1600 and 2000. In addition, the results showed that (a) the amplitude of the circadian component of the psychological data increased over the period of sleep loss, and (b) psychological data were more highly correlated with a measure of general performance than with accuracy. The mechanisms of sleep deprivation underlying its effects on psychological and performance measures are discussed.

Visual adaptation and the amplitude spectra of radiological images.

PubMed

Kompaniez-Dunigan, Elysse; Abbey, Craig K; Boone, John M; Webster, Michael A

2018-01-01

We examined how visual sensitivity and perception are affected by adaptation to the characteristic amplitude spectra of X-ray mammography images. Because of the transmissive nature of X-ray photons, these images have relatively more low-frequency variability than natural images, a difference that is captured by a steeper slope of the amplitude spectrum (~ - 1.5) compared to the ~ 1/f (slope of - 1) spectra common to natural scenes. Radiologists inspecting these images are therefore exposed to a different balance of spectral components, and we measured how this exposure might alter spatial vision. Observers (who were not radiologists) were adapted to images of normal mammograms or the same images sharpened by filtering the amplitude spectra to shallower slopes. Prior adaptation to the original mammograms significantly biased judgments of image focus relative to the sharpened images, demonstrating that the images are sufficient to induce substantial after-effects. The adaptation also induced strong losses in threshold contrast sensitivity that were selective for lower spatial frequencies, though these losses were very similar to the threshold changes induced by the sharpened images. Visual search for targets (Gaussian blobs) added to the images was also not differentially affected by adaptation to the original or sharper images. These results complement our previous studies examining how observers adapt to the textural properties or phase spectra of mammograms. Like the phase spectrum, adaptation to the amplitude spectrum of mammograms alters spatial sensitivity and visual judgments about the images. However, unlike the phase spectrum, adaptation to the amplitude spectra did not confer a selective performance advantage relative to more natural spectra.

Health services experiences of parents of recently diagnosed visually impaired children

PubMed Central

Rahi, J S; Manaras, I; Tuomainen, H; Lewando Hundt, G

2005-01-01

Aim: To investigate the health service experiences and needs of parents in the period around diagnosis of ophthalmic disorders in their children. Methods: Parents of children newly diagnosed with visual impairment and/or ophthalmic disorders at a tertiary level hospital in London participated in a questionnaire survey, using standard instruments, followed by in-depth individual interviews, to elicit their views about the processes of care, their overall level of satisfaction, and their unmet needs. Results: 67% (147) of eligible families (135 mothers, 76 fathers) participated. Overall satisfaction with care was high, being greater among parents of children with milder visual loss or isolated ophthalmic disorders than those with more severe visual loss or multiple impairments. Nevertheless, parents’ reported greatest need was the provision of general information, including about their child’s ophthalmic disorder and educational and social services and support. Mothers reported greater information needs than fathers, as did white parents compared to those from ethnic minorities. White parents also regarded the processes of care to be less comprehensive and coordinated, as well as less enabling, than did parents from ethnic minorities. Conclusions: Although parents reported high overall satisfaction with services, improving the medium, content, and scope of general information provided by professionals to parents of visually impaired children emerges as a priority. Equitable planning and provision of health services for families of children with visual impairment needs to take into account that informational and other needs vary by whether the parent is the primary carer or not and their ethnicity, as well as by the severity and complexity of their child’s visual loss. PMID:15665355

A Portable Platform for Evaluation of Visual Performance in Glaucoma Patients

PubMed Central

Rosen, Peter N.; Boer, Erwin R.; Gracitelli, Carolina P. B.; Abe, Ricardo Y.; Diniz-Filho, Alberto; Marvasti, Amir H.; Medeiros, Felipe A.

2015-01-01

Purpose To propose a new tablet-enabled test for evaluation of visual performance in glaucoma, the PERformance CEntered Portable Test (PERCEPT), and to evaluate its ability to predict history of falls and motor vehicle crashes. Design Cross-sectional study. Methods The study involved 71 patients with glaucomatous visual field defects on standard automated perimetry (SAP) and 59 control subjects. The PERCEPT was based on the concept of increasing visual task difficulty to improve detection of central visual field losses in glaucoma patients. Subjects had to perform a foveal 8-alternative-forced-choice orientation discrimination task, while detecting a simultaneously presented peripheral stimulus within a limited presentation time. Subjects also underwent testing with the Useful Field of View (UFOV) divided attention test. The ability to predict history of motor vehicle crashes and falls was investigated by odds ratios and incident-rate ratios, respectively. Results When adjusted for age, only the PERCEPT processing speed parameter showed significantly larger values in glaucoma compared to controls (difference: 243ms; P<0.001). PERCEPT results had a stronger association with history of motor vehicle crashes and falls than UFOV. Each 1 standard deviation increase in PERCEPT processing speed was associated with an odds ratio of 2.69 (P = 0.003) for predicting history of motor vehicle crashes and with an incident-rate ratio of 1.95 (P = 0.003) for predicting history of falls. Conclusion A portable platform for testing visual function was able to detect functional deficits in glaucoma, and its results were significantly associated with history of involvement in motor vehicle crashes and history of falls. PMID:26445501

The Economic Impact of Blindness in Europe.

PubMed

Chakravarthy, Usha; Biundo, Eliana; Saka, Rasit Omer; Fasser, Christina; Bourne, Rupert; Little, Julie-Anne

2017-08-01

To estimate the annual loss of productivity from blindness and moderate to severe visual impairment (MSVI) in the population aged >50 years in the European Union (EU). We estimated the cost of lost productivity using three simple models reported in the literature based on (1) minimum wage (MW), (2) gross national income (GNI), and (3) purchasing power parity-adjusted gross domestic product (GDP-PPP) losses. In the first two models, assumptions included that all individuals worked until 65 years of age, and that half of all visual impairment cases in the >50-year age group would be in those aged between 50 and 65 years. Loss of productivity was estimated to be 100% for blind individuals and 30% for those with MSVI. None of these models included direct medical costs related to visual impairment. The estimated number of blind people in the EU population aged >50 years is ~1.28 million, with a further 9.99 million living with MSVI. Based on the three models, the estimated cost of blindness is €7.81 billion, €6.29 billion and €17.29 billion and that of MSVI €18.02 billion, €24.80 billion and €39.23 billion, with their combined costs €25.83 billion, €31.09 billion and €56.52 billion, respectively. The estimates from the MW and adjusted GDP-PPP models were generally comparable, whereas the GNI model estimates were higher, probably reflecting the lack of adjustment for unemployment. The cost of blindness and MSVI in the EU is substantial. Wider use of available cost-effective treatment and prevention strategies may reduce the burden significantly.

Vestibular ataxia following shuttle flights: effects of microgravity on otolith-mediated sensorimotor control of posture.

PubMed

Paloski, W H; Black, F O; Reschke, M F; Calkins, D S; Shupert, C

1993-01-01

Orbital spaceflight exposes astronauts to an environment in which gravity is reduced to negligible magnitudes of 10(-3) to 10(-6) G. Upon insertion into earth orbit, the abrupt loss of the constant linear acceleration provided by gravity removes the otolith stimulus for vestibular sensation of vertical orientation constantly present on Earth. Since the central nervous system (CNS) assesses spatial orientation by simultaneously interpreting sensory inputs from the vestibular, visual, and proprioceptive systems, loss of the otolith-mediated vertical reference input results in an incorrect estimation of spatial orientation, which, in turn, causes a degradation in movement control. Over time, however, the CNS adapts to the loss of gravitational signals. Upon return to Earth, the vertical reference provided by gravitational stimulation of the otolith organ reappears. As a result, a period of CNS readaptation must occur upon return to terrestrial environment. Among the physiological changes observed during the postflight CNS readaptation period is a disruption of postural equilibrium control. Using a dynamic posturography system (modified NeuroCom EquiTest), 16 astronauts were tested at 60, 30, and 10 days preflight and retested at 1 to 5 hours, and 8 days postflight. All astronauts tested demonstrated decreased postural stability immediately upon return to Earth. The most dramatic increases in postural sway occurred during those sensory conditions in which both the visual and proprioceptive feedback information used for postural control were altered by the dynamic posturography system, requiring reliance primarily upon vestibular function for control of upright stance. Less marked but statistically significant increases in sway were observed under those conditions in which visual and foot support surface inputs alone were altered.(ABSTRACT TRUNCATED AT 250 WORDS)

Undertreatment of Vascular Risk Factors in Patients with Monocular Ischaemic Visual Loss.

PubMed

Zarkali, Angeliki; Cheng, Suk Fun; Dados, Agnes; Simister, Robert; Chandratheva, Arvind

2018-05-17

Ischaemic visual loss is often considered a lower risk factor than other transient ischaemic attacks (TIA). We aimed to determine the recurrence risk, prevalence and management of vascular risk factors in these patients. The study took place in the University College Hospital London daily TIA clinic, main referral centre for North-Central London and Moorfields Eye Hospital. Consecutive records for patients with transient (< 24 h) or permanent (> 24 h) ischaemic visual loss were reviewed during the period January 2014-October 2016. Patients diagnosed with temporal arteritis were excluded. Of 400 patients, 224 (56%) were male with mean age 64.5 years (SD 15.1); 263 patients (65.8%) presented with transient and 137 patients (34.2%) with permanent ischaemic visual loss; 51.3% had hypertension (HTN), 35.3% hypercholesterolaemia, 14.5% diabetes, 11.8% ischaemic ocular events, 10.0% ischaemic heart disease, 7.3% atrial fibrillation (AF), 6.3% TIA, 5.3% stroke, and 12.3% were smokers. Median vascular risk factors were 2 (range 1-6), but 122 (30.5%) had ≥3. Those with diabetes (p < 0.001), HTN (p = 0.008), previous myocardial infarction (p = 0.005), or ≥3 vascular risk factors (p = 0.012) were more likely to present with permanent visual loss, while patients with history of transient events, TIA (p = 0.002), or ocular (p = 0.002) presented with transient visual loss. Ninety-day recurrence was 10.5%; this was higher in patients with ≥3 risk factors (hazard ratio 1.42, 95% CI 0.95-2.11, p = 0.111). Patients with past TIA were more likely to be on secondary prevention than those with ocular ischaemia; 60.0 vs. 34.1% received antiplatelets and 76.0 vs. 43.9% statins. At presentation, only 55.2% (16 patients) with known AF were anticoagulated, despite all of them having CHADSVASC ≥1. Approximately one-third of patients with ocular ischaemia had ≥3 vascular risk factors with recurrences higher in these patients. Yet only half of those with previous ischaemic ocular events were on antiplatelets or statins. These patients should be investigated and treated as aggressively as other forms of TIA or stroke. © 2018 S. Karger AG, Basel.

A rare ocular complication after a heart transplant: toxoplasma retinitis.

PubMed

Kervan, Umit; Ozdamar, Yasemin; Yurdakok, Okan; Kucuker, Seref Alp; Pac, Mustafa

2014-02-01

Ocular infections after a heart transplant are rare; but when present, they generally appear during the first year after surgery. Ocular infections may cause significant loss of vision and morbidity if not diagnosed early. For that reason, heart transplant patients should undergo a routine visual examination during follow-up. We report our experience regarding the followup and treatment of a case of toxoplasma retinitis diagnosed in one of our heart transplant recipients.

Brain function predictors and outcome of weight loss and weight loss maintenance.

PubMed

Szabo-Reed, Amanda N; Breslin, Florence J; Lynch, Anthony M; Patrician, Trisha M; Martin, Laura E; Lepping, Rebecca J; Powell, Joshua N; Yeh, Hung-Wen Henry; Befort, Christie A; Sullivan, Debra; Gibson, Cheryl; Washburn, Richard; Donnelly, Joseph E; Savage, Cary R

2015-01-01

Obesity rates are associated with public health consequences and rising health care costs. Weight loss interventions, while effective, do not work for everyone, and weight regain is a significant problem. Eating behavior is influenced by a convergence of processes in the brain, including homeostatic factors and motivational processing that are important contributors to overeating. Initial neuroimaging studies have identified brain regions that respond differently to visual food cues in obese and healthy weight individuals that are positively correlated with reports of hunger in obese participants. While these findings provide mechanisms of overeating, many important questions remain. It is not known whether brain activation patterns change after weight loss, or if they change differentially based on amount of weight lost. Also, little is understood regarding biological processes that contribute to long-term weight maintenance. This study will use neuroimaging in participants while viewing food and non-food images. Functional Magnetic Resonance Imaging will take place before and after completion of a twelve-week weight loss intervention. Obese participants will be followed though a 6-month maintenance period. The study will address three aims: 1. Characterize brain activation underlying food motivation and impulsive behaviors in obese individuals. 2. Identify brain activation changes and predictors of weight loss. 3. Identify brain activation predictors of weight loss maintenance. Findings from this study will have implications for understanding mechanisms of obesity, weight loss, and weight maintenance. Results will be significant to public health and could lead to a better understanding of how differences in brain activation relate to obesity. Copyright © 2014 Elsevier Inc. All rights reserved.

Brain function predictors and outcome of weight loss and weight loss maintenance

PubMed Central

Szabo-Reed, Amanda N.; Breslin, Florence J.; Lynch, Anthony M.; Patrician, Trisha M.; Martin, Laura E.; Lepping, Rebecca J.; Powell, Joshua N.; Yeh, Hung-Wen (Henry); Befort, Christie A.; Sullivan, Debra; Gibson, Cheryl; Washburn, Richard; Donnelly, Joseph E.; Savage, Cary R.

2015-01-01

Obesity rates are associated with public health consequences and rising health care costs. Weight loss interventions, while effective, do not work for everyone, and weight regain is a significant problem. Eating behavior is influenced by a convergence of processes in the brain, including homeostatic factors and motivational processing that are important contributors to overeating. Initial neuroimaging studies have identified brain regions that respond differently to visual food cues in obese and healthy weight individuals that are positively correlated with reports of hunger in obese participants. While these findings provide mechanisms of overeating, many important questions remain. It is not known whether brain activation patterns change after weight loss, or if they change differentially based on amount of weight lost. Also, little is understood regarding biological processes that contribute to long-term weight maintenance. This study will use neuroimaging in participants while viewing food and non-food images. Functional Magnetic Resonance Imaging will take place before and after completion of a twelve-week weight loss intervention. Obese participants will be followed though a 6-month maintenance period. The study will address three aims: 1. Characterize brain activation underlying food motivation and impulsive behaviors in obese individuals. 2. Identify brain activation changes and predictors of weight loss. 3. Identify brain activation predictors of weight loss maintenance. Findings from this study will have implications for understanding mechanisms of obesity, weight loss, and weight maintenance. Results will be significant to public health and could lead to a better understanding of how differences in brain activation relate to obesity. PMID:25533729

Bilateral uveitis and Usher syndrome: a case report.

PubMed

Benson, Matthew D; MacDonald, Ian M

2015-03-15

Usher syndrome is a genetically heterogeneous condition and represents the most common cause of inherited combined vision and hearing loss. Deficits manifest as sensorineural hearing loss that typically develops at a young age and retinitis pigmentosa that can lead to peripheral vision loss and night blindness. As a result, this syndrome can have a significant impact on a patient's quality of life. Previous studies have described an association between Usher syndrome and Fuchs' heterochromic iridocyclitis, a form of non-granulomatous uveitis that generally presents in a unilateral manner. We present a rare finding of bilateral uveitis and, to the best of our knowledge, the first report of granulomatous uveitis as a feature in a patient with Usher syndrome. A 45-year-old Caucasian woman with a known history of retinitis pigmentosa presented to our clinic with suspected Usher syndrome, given her report of long-standing hearing loss. Aside from a mild loss in visual acuity, our patient was otherwise asymptomatic. Visual field testing, audiology and electroretinography findings supported the diagnosis of Usher syndrome. With slit lamp examination she was found to have bilateral keratic precipitates, with large, greasy-white, mutton-fat keratic precipitates on the endothelial surface of her left eye. A thorough work-up that included blood tests and imaging was negative for an alternative cause of her uveitis. We present a rare finding of bilateral uveitis and what we believe to be the first reported instance of mutton-fat keratic precipitates and granulomatous uveitis as a feature in a patient with Usher syndrome. By identifying atypical presentations of the disease, we hope to contribute to the range of ophthalmic conditions that may be seen in association with Usher syndrome.

Fast neuromimetic object recognition using FPGA outperforms GPU implementations.

PubMed

Orchard, Garrick; Martin, Jacob G; Vogelstein, R Jacob; Etienne-Cummings, Ralph

2013-08-01

Recognition of objects in still images has traditionally been regarded as a difficult computational problem. Although modern automated methods for visual object recognition have achieved steadily increasing recognition accuracy, even the most advanced computational vision approaches are unable to obtain performance equal to that of humans. This has led to the creation of many biologically inspired models of visual object recognition, among them the hierarchical model and X (HMAX) model. HMAX is traditionally known to achieve high accuracy in visual object recognition tasks at the expense of significant computational complexity. Increasing complexity, in turn, increases computation time, reducing the number of images that can be processed per unit time. In this paper we describe how the computationally intensive and biologically inspired HMAX model for visual object recognition can be modified for implementation on a commercial field-programmable aate Array, specifically the Xilinx Virtex 6 ML605 evaluation board with XC6VLX240T FPGA. We show that with minor modifications to the traditional HMAX model we can perform recognition on images of size 128 × 128 pixels at a rate of 190 images per second with a less than 1% loss in recognition accuracy in both binary and multiclass visual object recognition tasks.

A Comparative Study of Emotional Stability of Visually Impaired Students Studying at Secondary Level in Inclusive Setup and Special Schools

ERIC Educational Resources Information Center

Pant, Pankaj; Joshi, P. K.

2016-01-01

Visual impairment as an umbrella term includes all levels of vision loss. Researches in the field of visual disability are far from satisfactory in India. Some attempts have been made to study different aspects of the lives of visually disabled children. Such attempts help, revealing the facts of their life, characteristics, activities,…

Functional assessment of the visual pathway with multifocal visual evoked potentials, and their relationship with disability in patients with multiple sclerosis.

PubMed

Blanco, Román; Pérez-Rico, Consuelo; Puertas-Muñoz, Inmaculada; Ayuso-Peralta, Lucía; Boquete, Luciano; Arévalo-Serrano, Juan

2014-02-01

To objectively evaluate the visual function, and the relationship between disability and optic nerve dysfunction, in patients with multiple sclerosis (MS) and optic neuritis (ON), using multifocal visual evoked potentials (mfVEP). This observational, cross-sectional study assessed 28 consecutive patients with clinically definite MS, according to the McDonald criteria, and 19 age-matched healthy subjects. Disability was recorded using the Expanded Disability Status Scale (EDSS) score. The patients' mfVEP were compared to their clinical, psychophysical (Humphrey perimetry) and structural (optic coherence tomography (OCT)) diagnostic test data. We observed a significant agreement between mfVEP amplitude and Humphrey perimetry/OCT in MS-ON eyes, and between mfVEP amplitude and OCT in MS but non-ON eyes. We found significant differences in EDSS score between patients with abnormal and normal mfVEP amplitudes. Abnormal mfVEP amplitude defects (from interocular and monocular probability analysis) were found in 67.9% and 73.7% of the MS-ON and MS-non-ON group eyes, respectively. Delayed mfVEP latencies (interocular and monocular probability analysis) were seen in 70.3% and 73.7% of the MS-ON and MS-non-ON groups, respectively. We found a significant relationship between mfVEP amplitude and disease severity, as measured by EDSS score, that suggested there is a role for mfVEP amplitude as a functional biomarker of axonal loss in MS.

Audiovisual plasticity following early abnormal visual experience: Reduced McGurk effect in people with one eye.

PubMed

Moro, Stefania S; Steeves, Jennifer K E

2018-04-13

Previously, we have shown that people who have had one eye surgically removed early in life during visual development have enhanced sound localization [1] and lack visual dominance, commonly observed in binocular and monocular (eye-patched) viewing controls [2]. Despite these changes, people with one eye integrate auditory and visual components of multisensory events optimally [3]. The current study investigates how people with one eye perceive the McGurk effect, an audiovisual illusion where a new syllable is perceived when visual lip movements do not match the corresponding sound [4]. We compared individuals with one eye to binocular and monocular viewing controls and found that they have a significantly smaller McGurk effect compared to binocular controls. Additionally, monocular controls tended to perceive the McGurk effect less often than binocular controls suggesting a small transient modulation of the McGurk effect. These results suggest altered weighting of the auditory and visual modalities with both short and long-term monocular viewing. These results indicate the presence of permanent adaptive perceptual accommodations in people who have lost one eye early in life that may serve to mitigate the loss of binocularity during early brain development. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

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

Structural and functional changes associated with normal and abnormal fundus autofluorescence in patients with retinitis pigmentosa.

PubMed

Greenstein, Vivienne C; Duncker, Tobias; Holopigian, Karen; Carr, Ronald E; Greenberg, Jonathan P; Tsang, Stephen H; Hood, Donald C

2012-02-01

To analyze the structure and visual function of regions bordering the hyperautofluorescent ring/arcs in retinitis pigmentosa. Twenty-one retinitis pigmentosa patients (21 eyes) with rings/arcs and 21 normal individuals (21 eyes) were studied. Visual sensitivity in the central 10° was measured with microperimetry. Retinal structure was evaluated with spectral-domain optical coherence tomography. The distance from the fovea to disruption/loss of the inner outer segment (IS/OS) junction and thicknesses of the total receptor plus retinal pigment epithelial complex and outer segment plus retinal pigment epithelial complex layers were measured. Results were compared with measurements of the distance from the fovea to the inner and outer borders of the ring/arc seen on fundus autofluorescence. Disruption/loss of the inner outer segment junction occurred closer to the inner border of the ring/arc and it was closer to the fovea in eight eyes. For 19 eyes, outer segment plus and receptor plus RPE complex thicknesses were significantly decreased at locations closer to the fovea than the appearance of the inner border of hyperautofluorescence. Mean visual sensitivity was decreased inside, across, and outside the ring/arc by 3.5 ± 3.8, 8.9 ± 4.8, and 17.0 ± 2.4 dB, respectively. Structural and functional changes can occur inside the hyperfluorescent ring/arc in retinitis pigmentosa.

Structural and Functional Changes Associated with Normal and Abnormal Fundus Autofluorescence in Patients with Retinitis Pigmentosa

PubMed Central

Greenstein, Vivienne C.; Duncker, Tobias; Holopigian, Karen; Carr, Ronald E.; Greenberg, Jonathan; Tsang, Stephen H.; Hood, Donald C.

2013-01-01

Purpose To analyze the structure and visual function of regions bordering the hyperautofluorescent ring/arcs in retinitis pigmentosa (RP). Methods Twenty -one RP patients (21 eyes) with rings/arcs and 21 normals (21 eyes) were studied. Visual sensitivity in the central 10° was measured with microperimetry. Retinal structure was evaluated with spectral domain optical coherence tomography (SD-OCT). The distance from the fovea to disruption/loss of the inner outer segment (IS/OS) junction and thicknesses of the total receptor plus retinal pigment epithelial (RPE) complex (R+), and outer segment plus RPE complex (OS+) layers were measured. Results were compared to measurements of the distance from the fovea to the inner and outer borders of the ring/arc seen on fundus autofluorescence (FAF). Results Disruption/loss of the IS/OS junction occurred closer to the inner border of the ring/arc and it was closer to the fovea in 8 eyes. For 19 eyes, OS+ and R+ thicknesses were significantly decreased at locations closer to the fovea than the appearance of the inner border of hyperautofluorescence. Mean visual sensitivity was decreased inside, across and outside the ring/arc by 3.5 ± 3.8, 8.9 ± 4.8 and 17.0±2.4 dB respectively. Conclusions Structural and functional changes can occur inside the hyperfluorescent ring/arc in RP. PMID:21909055

Prediction of functional loss in glaucoma from progressive optic disc damage.

PubMed

Medeiros, Felipe A; Alencar, Luciana M; Zangwill, Linda M; Bowd, Christopher; Sample, Pamela A; Weinreb, Robert N

2009-10-01

To evaluate the ability of progressive optic disc damage detected by assessment of longitudinal stereophotographs to predict future development of functional loss in those with suspected glaucoma. The study included 639 eyes of 407 patients with suspected glaucoma followed up for an average of 8.0 years with annual standard automated perimetry visual field and optic disc stereophotographs. All patients had normal and reliable standard automated perimetry results at baseline. Conversion to glaucoma was defined as development of 3 consecutive abnormal visual fields during follow-up. Presence of progressive optic disc damage was evaluated by grading longitudinally acquired simultaneous stereophotographs. Other predictive factors included age, intraocular pressure, central corneal thickness, pattern standard deviation, and baseline stereophotograph grading. Hazard ratios for predicting visual field loss were obtained by extended Cox models, with optic disc progression as a time-dependent covariate. Predictive accuracy was evaluated using a modified R(2) index. Progressive optic disc damage had a hazard ratio of 25.8 (95% confidence interval, 16.0-41.7) and was the most important risk factor for development of visual field loss with an R(2) of 79%. The R(2)s for other predictive factors ranged from 6% to 26%. Presence of progressive optic disc damage on stereophotographs was a highly predictive factor for future development of functional loss in glaucoma. These findings suggest the importance of careful monitoring of the optic disc appearance and a potential role for longitudinal assessment of the optic disc as an end point in clinical trials and as a reference for evaluation of diagnostic tests in glaucoma.

Vision loss and hearing loss in painting and musical composition.

PubMed

Marmor, Michael F

2014-07-01

This article considers the impact of vision and hearing loss on great painters and musical composers. The visual work of Mary Cassatt, Georgia O'Keeffe, Edgar Degas, and Claude Monet all showed alterations as their vision failed. In contrast, Gabriel Fauré, Bedřich Smetana, and Ludwig von Beethoven wrote many of their best compositions while totally deaf, and Georg Friedrich Handel and Frederick Delius struggled to compose late in life when they lost their vision (although their hearing remained excellent). There are 2 major distinctions between the role of vision and hearing for these artistic disciplines. First, there is a surrogate means of "hearing" music, through the musical score, which allows composers to write and edit music while totally deaf. The greatest problem with deafness for a skilled composer is interference from internal noise (tinnitus). There is no surrogate for vision to allow a painter to work when the subject is a blur or the colors on the canvas cannot be distinguished. Second, although the appreciation of art is visual and that of music is auditory, the transcription of both art and musical composition is visual. Thus, visual loss does pose a problem for a composer accustomed to working with good sight, because it disrupts habitual methods of writing and editing music. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Effect of disease stage on progression of hydroxychloroquine retinopathy.

PubMed

Marmor, Michael F; Hu, Julia

2014-09-01

Hydroxychloroquine sulfate retinopathy can progress after the drug is stopped. It is not clear how this relates to the stage of retinopathy or whether early screening with modern imaging technology can prevent progression and visual loss. To determine the relationship between progression of retinopathy and the severity of disease using objective data from optical coherence tomography and assess the value of early screening for the toxic effects of hydroxychloroquine. Clinical findings in patients with hydroxychloroquine retinopathy were monitored with repeated anatomical and functional examinations for 13 to 40 months after the drug was stopped in a referral practice in a university medical center. Eleven patients participated, with the severity of toxic effects categorized as early (patchy parafoveal damage shown on field or objective testing), moderate (a 50%-100% parafoveal ring of optical coherence tomography thinning but intact retinal pigment epithelium), and severe (visible bull's-eye damage). Visual acuity, white 10-2 visual field pattern density plots, fundus autofluorescence, spectral-density optical coherence tomography cross sections, thickness (from cube diagrams), and ellipsoid zone length. Visual acuity and visual fields showed no consistent change. Fundus autofluorescence showed little or no change except in severe cases in which the bull's-eye damage expanded progressively. Optical coherence tomography cross sections showed little visible change in early and moderate cases but progressive foveal thinning (approximately 7 μm/y) and loss of ellipsoid zone (in the range of 100 μm/y) in severe cases, which was confirmed by quantitative measurements. The measurements also showed some foveal thinning (approximately 4 μm/y) and deepening of parafoveal loss in moderate cases, but the breadth of the ellipsoid zone remained constant in both early and moderate cases. A few cases showed a suggestion of ellipsoid zone improvement. Patients with hydroxychloroquine retinopathy involving the retinal pigment epithelium demonstrated progressive damage on optical coherence tomography for at least 3 years after the drug was discontinued, including loss of foveal thickness and cone structure. Cases recognized before retinal pigment epithelium damage retained foveal architecture with little retinal thinning. Early recognition of hydroxychloroquine toxic effects before any fundus changes are visible, using visual fields and optical coherence tomography (along with fundus autofluorescence and multifocal electroretinography as indicated), will greatly minimize late progression and the risk of visual loss.

New approach to estimating variability in visual field data using an image processing technique.

PubMed Central

Crabb, D P; Edgar, D F; Fitzke, F W; McNaught, A I; Wynn, H P

1995-01-01

AIMS--A new framework for evaluating pointwise sensitivity variation in computerised visual field data is demonstrated. METHODS--A measure of local spatial variability (LSV) is generated using an image processing technique. Fifty five eyes from a sample of normal and glaucomatous subjects, examined on the Humphrey field analyser (HFA), were used to illustrate the method. RESULTS--Significant correlation between LSV and conventional estimates--namely, HFA pattern standard deviation and short term fluctuation, were found. CONCLUSION--LSV is not dependent on normals' reference data or repeated threshold determinations, thus potentially reducing test time. Also, the illustrated pointwise maps of LSV could provide a method for identifying areas of fluctuation commonly found in early glaucomatous field loss. PMID:7703196

Internal limiting membrane peeling and gas tamponade for myopic foveoschisis: a systematic review and meta-analysis.

PubMed

Meng, Bo; Zhao, Lu; Yin, Yi; Li, Hongyang; Wang, Xiaolei; Yang, Xiufen; You, Ran; Wang, Jialin; Zhang, Youjing; Wang, Hui; Du, Ran; Wang, Ningli; Zhan, Siyan; Wang, Yanling

2017-09-08

Myopic foveoschisis (MF) is among the leading causes of visual loss in high myopia. However, it remains controversial whether internal limiting membrane (ILM) peeling or gas tamponade is necessary treatment option for MF. PubMed, EMBASE, CBM, CNKI, WANFANG DATA and VIP databases were systematically reviewed. Outcome indicators were myopic foveoschisis resolution rate, visual acuity improvement and postoperative complications. Nine studies that included 239 eyes were selected. The proportion of resolution of foveoschisis was higher in ILM peeling group than non-ILM peeling group (OR = 2.15, 95% CI: 1.06-4.35; P = 0.03). The proportion of postoperative complications was higher in Tamponade group than non-Tamponade group (OR = 10.81, 95% CI: 1.26-93.02; P = 0.03). However, the proportion of visual acuity improvement (OR = 1.63, 95% CI: 0.56-4.80; P = 0.37) between ILM peeling group and non-ILM peeling group and the proportion of resolution of foveoschisis (OR = 1.80, 95% CI: 0.76-4.28; P = 0.18) between Tamponade group and non-Tamponade group were similar. Vitrectomy with internal limiting membrane peeling could contribute to better resolution of myopic foveoschisis than non-peeling, however it does not significantly influence the proportion of visual acuity improvement and postoperative complications. Vitrectomy with gas tamponade is associated with more complications than non-tamponade and does not significantly influence the proportion of visual acuity improvement and resolution of myopic foveoschisis.

Dual Sensory Loss: Overview of Problems, Visual Assessment, and Rehabilitation

PubMed Central

Brabyn, John A.; Schneck, Marilyn E.; Haegerstrom-Portnoy, Gunilla; Lott, Lori A.

2007-01-01

This article provides an overview of some of the problems and possible solutions surrounding the neglected issue of combined vision and hearing deficits. The subject is treated by considering each subpopulation, ranging from those who have no residual vision or hearing to those with mild coexisting vision and hearing losses. An attempt is made to relate the different types of visual deficit to the likely problems encountered in real-life activities, such as communication and travel, among individuals who also have a hearing impairment. The assessment and appropriate referral of patients with these combined deficits is discussed, including the interpretation of visual test results and the importance of factors other than standard visual acuity. Speculation is offered on potential strategies and solutions for rehabilitation as well as the need for future research and improvements in service delivery. PMID:18003865

Gun trauma and ophthalmic outcomes.

PubMed

Chopra, N; Gervasio, K A; Kalosza, B; Wu, A Y

2018-04-01

PurposeThis retrospective cohort study assesses the visual outcomes of patients who survive gunshot wounds to the head.MethodsThe Elmhurst City Hospital Trauma Registry and Mount Sinai Data Warehouse were queried for gun trauma resulting in ocular injury over a 16-year period. Thirty-one patients over 16 years of age were found who suffered a gunshot wound to the head and resultant ocular trauma: orbital fracture, ruptured globe, foreign body, or optic nerve injury. Gun types included all firearms and air guns. Nine patients were excluded due to incorrect coding or unavailable charts. Statistical analysis was performed using a simple bivariate analysis (χ 2 ).ResultsOf the 915 victims of gun trauma to the head, 27 (3.0%) sustained ocular injuries. Of the 22 patients whose records were accessible, 18 survived. Eight of the 18 surviving patients (44%) suffered long-term visual damage, defined as permanent loss of vision in at least one eye to the level of counting fingers or worse. Neither location of injury (P=0.243), nor type of gun used (P=0.296), nor cause of gun trauma (P=0.348) predicted visual loss outcome. The Glasgow Coma Scale eye response score on arrival to the hospital also did not predict visual loss outcome (P=0.793).ConclusionThere has been a dearth of research into gun trauma and even less research on the visual outcomes following gun trauma. Our study finds that survivors of gun trauma to the head suffer long-term visual damage 44% of the time after injury.

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.

Plasticity Beyond V1: Reinforcement of Motion Perception upon Binocular Central Retinal Lesions in Adulthood.

PubMed

Burnat, Kalina; Hu, Tjing-Tjing; Kossut, Małgorzata; Eysel, Ulf T; Arckens, Lutgarde

2017-09-13

Induction of a central retinal lesion in both eyes of adult mammals is a model for macular degeneration and leads to retinotopic map reorganization in the primary visual cortex (V1). Here we characterized the spatiotemporal dynamics of molecular activity levels in the central and peripheral representation of five higher-order visual areas, V2/18, V3/19, V4/21a,V5/PMLS, area 7, and V1/17, in adult cats with central 10° retinal lesions (both sexes), by means of real-time PCR for the neuronal activity reporter gene zif268. The lesions elicited a similar, permanent reduction in activity in the center of the lesion projection zone of area V1/17, V2/18, V3/19, and V4/21a, but not in the motion-driven V5/PMLS, which instead displayed an increase in molecular activity at 3 months postlesion, independent of visual field coordinates. Also area 7 only displayed decreased activity in its LPZ in the first weeks postlesion and increased activities in its periphery from 1 month onward. Therefore we examined the impact of central vision loss on motion perception using random dot kinematograms to test the capacity for form from motion detection based on direction and velocity cues. We revealed that the central retinal lesions either do not impair motion detection or even result in better performance, specifically when motion discrimination was based on velocity discrimination. In conclusion, we propose that central retinal damage leads to enhanced peripheral vision by sensitizing the visual system for motion processing relying on feedback from V5/PMLS and area 7. SIGNIFICANCE STATEMENT Central retinal lesions, a model for macular degeneration, result in functional reorganization of the primary visual cortex. Examining the level of cortical reactivation with the molecular activity marker zif268 revealed reorganization in visual areas outside V1. Retinotopic lesion projection zones typically display an initial depression in zif268 expression, followed by partial recovery with postlesion time. Only the motion-sensitive area V5/PMLS shows no decrease, and even a significant activity increase at 3 months post-retinal lesion. Behavioral tests of motion perception found no impairment and even better sensitivity to higher random dot stimulus velocities. We demonstrate that the loss of central vision induces functional mobilization of motion-sensitive visual cortex, resulting in enhanced perception of moving stimuli. Copyright © 2017 the authors 0270-6474/17/378989-11$15.00/0.

Real Time Intraoperative Monitoring of Blood Loss with a Novel Tablet Application

PubMed Central

Sharareh, Behnam; Woolwine, Spencer; Satish, Siddarth; Abraham, Peter; Schwarzkopf, Ran

2015-01-01

Introduction : Real-time monitoring of blood loss is critical in fluid management. Visual estimation remains the standard of care in estimating blood loss, yet is demonstrably inaccurate. Photometric analysis, which is the referenced “gold-standard” for measuring blood loss, is both time-consuming and costly. The purpose of this study was to evaluate the efficacy of a novel tablet-monitoring device for measurement of Hb loss during orthopaedic procedures. Methods : This is a prospective study of 50 patients in a consecutive series of joint arthroplasty cases. The novel System with Feature Extraction Technology was used to measure the amount of Hb contained within surgical sponges intra-operatively. The system’s measures were then compared with those obtained via gravimetric method and photometric analysis. Accuracy was evaluated using linear regression and Bland-Altman analysis. Results : Our results showed a significant positive correlation between Triton tablet system and photometric analysis with respect to intra-operative hemoglobin and blood loss at 0.92 and 0.91, respectively. Discussion : This novel system can accurately determine Hb loss contained within surgical sponges. We believe that this user-friendly software can be used for measurement of total intraoperative blood loss and thus aid in a more accurate fluid management protocols during orthopaedic surgical procedures. PMID:26401167

The impact of macular surgery in different grades of epiretinal membrane

PubMed Central

Batman, Cosar; Citirik, Mehmet

2017-01-01

AIM To assess the impact of macular surgery on the functional and anatomic outcomes of the patients in different grades of epiretinal membrane (ERM). METHODS Seventy-one eyes of 71 patients who underwent 23-gauge transconjunctival sutureless pars plana vitrectomy for primary isolated ERM were evaluated in this study. RESULTS There were 38 females (53.5%) and 33 males (46.5%). The average age of the patients was 68.1y (range 42-89y). Mean follow up period was 14mo (range 6-26mo). The cases were divided into two subgroups of cellophane maculopathy (CM) and macular pucker (MP). An improvement was observed in the postoperative best-corrected visual acuity (BCVA), as well as a decrement in central foveal thickness (CFT) in both groups (both of these being statistically significant; P=0.001). In comparison between two groups, it was found that there was a significant improvement on BCVA and CFT in CM group than MP group (P=0.01). Furthermore, the postoperative fundus findings regarding RPE alterations and macular edema were significantly higher in MP group when compared to the CM group (P=0.01). CONCLUSION ERM and internal limiting membrane peeling surgery can lead to a significant reduction of CFT and visual improvements in idiopathic ERM. A long-term ERM persistence will cause unrecoverable retinal damage and visual loss. PMID:29259907

Unilateral Hearing Loss Is Associated With Impaired Balance in Children: A Pilot Study.

PubMed

Wolter, Nikolaus E; Cushing, Sharon L; Vilchez-Madrigal, Luis D; James, Adrian L; Campos, Jennifer; Papsin, Blake C; Gordon, Karen A

2016-12-01

To determine if children with unilateral sensorineural hearing loss (UHL) demonstrate impaired balance compared with their normal hearing (NH) peers. Prospective, case-control study. Balance was assessed in14 UHL and 14 NH children using the Bruininks-Oseretsky Test-2 (BOT-2) and time to fall (TTF) in an immersive, virtual-reality laboratory. Postural control was quantified by center of pressure (COP) using force plates. The effect of vision on balance was assessed by comparing scores and COP characteristics on BOT-2 tasks performed with eyes open and closed. Balance ability as measured by the BOT-2 score was significantly worse in children with UHL compared with NH children (p = 0.004). TTF was shorter in children with UHL compared with NH children in the most difficult tasks when visual and somatosensory inputs were limited (p < 0.01). Visual input improved postural control (reduced COP variability) in both groups in all tasks (p < 0.05) but postural control as measured by COP variability was more affected in children with UHL when visual input was removed while performing moderately difficult tasks (i.e., standing on one foot) (p = 0.02). In this pilot study, children with UHL show poorer balance skills than NH children. Significant differences in TTF between the two groups were only seen in the most difficult tasks and therefore may be missed on routine clinical assessment. Children with UHL appear to rely more on vision for maintaining postural control than their NH peers. These findings may point to deficits not only in the hearing but also the vestibular portion of the inner ear.

Finger force changes in the absence of visual feedback in patients with Parkinson’s disease

PubMed Central

Jo, Hang Jin; Ambike, Satyajit; Lewis, Mechelle M.; Huang, Xuemei; Latash, Mark L.

2015-01-01

Objectives We investigated the unintentional drift in total force and in sharing of the force between fingers in two-finger accurate force production tasks performed without visual feedback by patients with Parkinson’s disease (PD) and healthy controls. In particular, we were testing a hypothesis that adaptation to the documented loss of action stability could lead to faster force drop in PD. Methods PD patients and healthy controls performed accurate constant force production tasks without visual feedback by different finger pairs, starting with different force levels and different sharing patterns of force between the two fingers. Results Both groups showed an exponential force drop with time and a drift of the sharing pattern towards 50:50. The PD group showed a significantly faster force drop without a change in speed of the sharing drift. These results were consistent across initial force levels, sharing patterns, and finger pairs. A pilot test of four subjects, two PD and two controls, showed no consistent effects of memory on the force drop. Conclusions We interpret the force drop as a consequence of back-coupling between the actual and referent finger coordinates that draws the referent coordinate towards the actual one. The faster force drop in the PD group is interpreted as adaptive to the loss of action stability in PD. The lack of group differences in the sharing drift suggests two potentially independent physiological mechanisms contributing to the force and sharing drifts. Significance The hypothesis on adaptive changes in PD with the purpose to ensure stability of steady states may have important implications for treatment of PD. The speed of force drop may turn into a useful tool to quantify such adaptive changes. PMID:26072437

Projected impact of travoprost versus both timolol and latanoprost on visual field deficit progression and costs among black glaucoma subjects.

PubMed Central

Halpern, Michael T; Covert, David W; Robin, Alan L

2002-01-01

PURPOSE: We compared differences associated with use of travoprost and latanoprost on both progression of perimetric loss over time and associated costs among black patients. METHODS: Patients with primary open-angle glaucome or ocular hypertension were randomly assigned to one of four arms in a 12-month, double-masked study: travoprost (0.004% or 0.0015%), latanoprost (0.005%), or timolol (0.5%). Forty-nine patients received 0.004% travoprost, 43 received latanoprost, and 40 received timolol. We applied algorithms found in published studies that link intraocular pressure (IOP) control to visual field progression and calculated the likelihood of visual field deterioration based on IOP data. This was used to estimate differences in medical care costs. RESULTS: The average IOP was lower for patients receiving travoprost than for patients receiving latanoprost or timolol (17.3 versus 18.7 versus 20.5 mm Hg respectively, P < .05). Travoprost-treated patients had a smaller predicted change in visual field defect score (VFDS) than latanoprost-treated patients and timolol-treated patients, and significantly fewer were expected to demonstrate visual field progression. Medical care costs would be higher for latanoprost-treated and timolol-treated patients. CONCLUSIONS: Recent studies have provided algorithms linking IOP control to changes in visual fields. We found that treatment with travoprost was associated with less visual field progression and potential cost savings. PMID:12545683

THE VISUALLY HANDICAPPED CHILD IN SCHOOL.

ERIC Educational Resources Information Center

FIELDS, HELEN W.

THE EMPHASIS UPON VISION RATHER THAN THE SAVING OF VISION HAS BROUGHT ABOUT A CHANGE IN DETERMINATION OF CLASS PLACEMENT. IN PUBLIC SCHOOL, CHILDREN WITH VISUAL LIMITATIONS ARE AIDED BY FOUR KINDS OF PROGRAMS--(1) RESOURCE CLASSES FOR CHILDREN WITH VISUAL LIMITATIONS, (2) BRAILLE RESOURCE CLASSES FOR CHILDREN WHOSE LOSS OF VISION WARRANTS BRAILLE…

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.

Phakic Intraocular Lens Implantation: Refractive Outcome and Safety in Patients with Anterior Chamber Depth between 2.8 and 3.0 versus ≥3.0 mm.

PubMed

Guerra, Marta G; Silva, Andreia M M; Marques, Sara H M; Melo, Sofia H; Póvoa, João A; Lobo, Conceição; Murta, Joaquim Neto

2017-01-01

To compare endothelial cell (EC) variation after anterior chamber phakic intraocular lens (AC-pIOL) implantation in highly myopic patients with a preoperative anterior chamber depth (ACD) between 2.8 and 3.0 versus ≥3.0 mm. A total of 280 eyes submitted to primary AC-pIOL implantation were analyzed. Pre- and postoperative values for uncorrected distance visual acuity, corrected distance visual acuity, spherical equivalent, ACD (endothelial surface), and EC count were collected. The eyes were divided into 2 groups: group A - ACD between 2.8 and 3.0 mm; group B - ACD ≥3.0 mm. Mean global EC loss (ECL) and loss for each ACD group, according to pIOL type, were analyzed. Significant improvement of the spherical equivalent (-11.38 ± 4.57 vs. -0.49 ± 0.79; p = 0.000) and a significant decrease in EC density (2,810.95 ± 343.88 vs. 2,584.09 ± 374.88 cells/mm2; p = 0.000) were noted. The mean annual ECL was -2.19 ± 3.97%. Regarding group A (n = 80), a mean annual ECL of -2.06 ± 3.88% was registered, higher for the Acrysof Cachet® subtype, while group B (n = 200) showed -2.25 ± 4.01% ECL, higher for the Verisyse® subtype. There was no significant difference between the groups (p = 0.96). AC-pIOL implantation significantly improves the spherical equivalent in myopic patients. The mean annual ECL after pIOL implantation was higher in the larger ACD group, but this value was not statistically significant. A 2.8-mm ACD value seems to be a safe cutoff for AC-pIOL implantation. © 2017 S. Karger AG, Basel.

Excessive radiofrequency application: effects on capsular tissue in an animal model.

PubMed

Wolf, Brian R; Heiner, Anneliese D; Albright, John P; Nepola, James V

2005-01-01

Capsular attenuation has been seen after thermal capsulorrhaphy surgery. The purpose of this study was to evaluate the mechanical, histologic, and morphologic effects on capsular tissue after cumulative applications of radiofrequency energy. Ovine patellofemoral capsular tissue was treated with 1, 2, 4, or 8 applications of bipolar radiofrequency energy and then analyzed. No acute capsular ablation or destruction was seen grossly, even in the 8-application group. No definitive visual clues that excessive radiofrequency energy had been applied were seen. There was significant shrinkage and loss of tensile stiffness for all thermal application groups. Given the small sample sizes, post-application failure load, percent relaxation, and stiffness were not observed to be significantly different among the groups. Cumulative applications produced minimal further tissue shrinkage but were accompanied by larger, though not statistically significant, mechanical property losses and increased depth of tissue penetration. These findings suggest that there is no benefit to repeated applications of radiofrequency energy to capsular tissue.

Damage Patterns at the Head-Stem Taper Junction Helps Understand the Mechanisms of Material Loss.

PubMed

Hothi, Harry S; Panagiotopoulos, Andreas C; Whittaker, Robert K; Bills, Paul J; McMillan, Rebecca A; Skinner, John A; Hart, Alister J

2017-01-01

Material loss at the taper junction of metal-on-metal total hip arthroplasties has been implicated in their early failure. The mechanisms of material loss are not fully understood; analysis of the patterns of damage at the taper can help us better understand why material loss occurs at this junction. We mapped the patterns of material loss in a series of 155 metal-on-metal total hip arthroplasties received at our center by scanning the taper surface using a roundness-measuring machine. We examined these material loss maps to develop a 5-tier classification system based on visual differences between different patterns. We correlated these patterns to surgical, implant, and patient factors known to be important for head-stem taper damage. We found that 63 implants had "minimal damage" at the taper (material loss <1 mm 3 ), and the remaining 92 implants could be categorized by 4 distinct patterns of taper material loss. We found that (1) head diameter and (2) time to revision were key significant variables separating the groups. These material loss maps allow us to suggest different mechanisms that dominate the cause of the material loss in each pattern: (1) corrosion, (2) mechanically assisted corrosion, or (3) intraoperative damage or poor size tolerances leading to toggling of trunnion in taper. Copyright © 2016 Elsevier Inc. All rights reserved.

Fragile X Mental Retardation Protein Is Required to Maintain Visual Conditioning-Induced Behavioral Plasticity by Limiting Local Protein Synthesis

PubMed Central

Liu, Han-Hsuan

2016-01-01

Fragile X mental retardation protein (FMRP) is thought to regulate neuronal plasticity by limiting dendritic protein synthesis, but direct demonstration of a requirement for FMRP control of local protein synthesis during behavioral plasticity is lacking. Here we tested whether FMRP knockdown in Xenopus optic tectum affects local protein synthesis in vivo and whether FMRP knockdown affects protein synthesis-dependent visual avoidance behavioral plasticity. We tagged newly synthesized proteins by incorporation of the noncanonical amino acid azidohomoalanine and visualized them with fluorescent noncanonical amino acid tagging (FUNCAT). Visual conditioning and FMRP knockdown produce similar increases in FUNCAT in tectal neuropil. Induction of visual conditioning-dependent behavioral plasticity occurs normally in FMRP knockdown animals, but plasticity degrades over 24 h. These results indicate that FMRP affects visual conditioning-induced local protein synthesis and is required to maintain the visual conditioning-induced behavioral plasticity. SIGNIFICANCE STATEMENT Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. Exaggerated dendritic protein synthesis resulting from loss of fragile X mental retardation protein (FMRP) is thought to underlie cognitive deficits in FXS, but no direct evidence has demonstrated that FMRP-regulated dendritic protein synthesis affects behavioral plasticity in intact animals. Xenopus tadpoles exhibit a visual avoidance behavior that improves with visual conditioning in a protein synthesis-dependent manner. We showed that FMRP knockdown and visual conditioning dramatically increase protein synthesis in neuronal processes. Furthermore, induction of visual conditioning-dependent behavioral plasticity occurs normally after FMRP knockdown, but performance rapidly deteriorated in the absence of FMRP. These studies show that FMRP negatively regulates local protein synthesis and is required to maintain visual conditioning-induced behavioral plasticity in vivo. PMID:27383604

A study of initial therapy for glaucoma in southern India: India Glaucoma Outcomes and Treatment (INGOT) Study.

PubMed

Congdon, Nathan G; Krishnadas, R; Friedman, David S; Goggins, William; Ramakrishnan, R; Kader, M A; Gilbert, Donna; Tielsch, James; Quigley, Harry A

2012-06-01

To compare initial glaucoma therapy with medications and trabeculectomy in southern India. Patients aged ≥ 30 years newly diagnosed with glaucoma were randomized to trabeculectomy with 5-fluorouracil or medical therapy. Subjects with best-corrected vision <6/18 due to cataract underwent phacoemulsification (phaco/intraocular lens, IOL). Intraocular pressure (IOP), vision and visual function were assessed at 12 months. Patients assigned to medications and surgery received the expected therapy in 86% (172/199) and 64% (126/199) of cases, respectively. Forty patients (20%) assigned to surgery refused any treatment and 33 (17%) received medications. Among 199 patients randomized to medications, 52 (26.1%) underwent phaco/IOL, as did 89/199 (43.7%) of patients randomized to trabeculectomy. Baseline parameters of the two groups did not differ, nor did 1-year follow-up rates (medication 65%, trabeculectomy 58%, P = 0.15). Final IOP was lower with randomization to trabeculectomy (16.3 ± 5.1 mmHg) than medication (18.8 ± 6.7 mmHg, P < 0.0001). In regression models, randomization to trabeculectomy (P < 0.0001) was associated with lower IOP, and simultaneous trabeculectomy and cataract surgery was associated with higher IOP (P = 0.008) than trabeculectomy alone. Subjects receiving Phaco/IOL had significantly better final acuity (P < 0.0001) and visual function (P = 0.035), despite concurrent glaucoma treatment. Final visual acuity was worse in those receiving trabeculectomy in addition to cataract surgery, but this was of borderline significance (P = 0.06). Trabeculectomy lowered IOP significantly more than medical treatment, but with slightly greater loss of visual acuity. Combined phaco/IOL and trabeculectomy improved visual acuity with substantial IOP lowering.

Individual memory change after anterior temporal lobectomy: a base rate analysis using regression-based outcome methodology.

PubMed

Martin, R C; Sawrie, S M; Roth, D L; Gilliam, F G; Faught, E; Morawetz, R B; Kuzniecky, R

1998-10-01

To characterize patterns of base rate change on measures of verbal and visual memory after anterior temporal lobectomy (ATL) using a newly developed regression-based outcome methodology that accounts for effects of practice and regression towards the mean, and to comment on the predictive utility of baseline memory measures on postoperative memory outcome. Memory change was operationalized using regression-based change norms in a group of left (n = 53) and right (n = 48) ATL patients. All patients were administered tests of episodic verbal (prose recall, list learning) and visual (figure reproduction) memory, and semantic memory before and after ATL. ATL patients displayed a wide range of memory outcome across verbal and visual memory domains. Significant performance declines were noted for 25-50% of left ATL patients on verbal semantic and episodic memory tasks, while one-third of right ATL patients displayed significant declines in immediate and delayed episodic prose recall. Significant performance improvement was noted in an additional one-third of right ATL patients on delayed prose recall. Base rate change was similar between the two ATL groups across immediate and delayed visual memory. Approximately one-fourth of all patients displayed clinically meaningful losses on the visual memory task following surgery. Robust relationships between preoperative memory measures and nonstandardized change scores were attenuated or reversed using standardized memory outcome techniques. Our results demonstrated substantial group variability in memory outcome for ATL patients. These results extend previous research by incorporating known effects of practice and regression to the mean when addressing meaningful neuropsychological change following epilepsy surgery. Our findings also suggest that future neuropsychological outcome studies should take steps towards controlling for regression-to-the-mean before drawing predictive conclusions.

The Neuronal Ceroid-Lipofuscinoses

ERIC Educational Resources Information Center

Bennett, Michael J.; Rakheja, Dinesh

2013-01-01

The neuronal ceroid-lipofuscinoses (NCL's, Batten disease) represent a group of severe neurodegenerative diseases, which mostly present in childhood. The phenotypes are similar and include visual loss, seizures, loss of motor and cognitive function, and early death. At autopsy, there is massive neuronal loss with characteristic storage in…

Prevalence of vision loss among hospital in-patients; a risk factor for falls?

PubMed

Leat, Susan J; Zecevic, Aleksandra A; Keeling, Alexis; Hileeto, Denise; Labreche, Tammy; Brymer, Christopher

2018-01-01

Despite poor vision being a risk factor for falls, current hospital policies and practices often do not include a vision assessment at patient admission or in the hospital's incident reporting system when a fall occurs. Our purpose was to document the prevalence of vision loss in hospital general medicine units to increase awareness of poor vision as a potential risk factor for falls that occur within the hospital, and inform future preventative practice. This cross-sectional study took place in medicine units of an acute care hospital. Participants were adult in-patients. Visual acuity (VA), contrast sensitivity and stereoacuity were measured, and patients were screened for field loss, extinction and neglect. 115 participants took part (average age 67 ± 17, 48% female). Overall, 89% had a visual impairment defined as being outside the age-norms for one or more vision measure, 62% had low vision, and 36% had vision loss equivalent to legal blindness [VA equal to or poorer than 1.0 logMAR (6/60, 20/200) or ≥10x below age-norms]. There was a considerable discrepancy between the prevalence of low vision and the percentage of patients who reported an ocular diagnosis that would result in visual loss (30%). Ten patients fell during the study period, and of these 100% had visual impairment, 90% had low vision and 60% had vision loss equivalent to legal blindness, which compares to 58%, 22% and 9% for non-fallers. Similar high prevalences were found in those whose reason for admission to the hospital was a fall (92%, 63% and 33% respectively). Vision loss has a high prevalence among patients in hospital medicine units, and is higher still among those who fall. Since vision loss may be a contributing factor to falls that occur in hospitals, implementing an assessment of vision at hospital admission would be useful to alert staff to those patients who are at risk for falls due to poor vision, so that preventative measures can be applied. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

[Impact of hypoglycemic episodes on nerves conduction and auditory and visual evoked potentials in children with type 1 diabetes].

PubMed

Wysocka-Mincewicz, Marta; Trippenbach-Dulska, Hanna; Emeryk-Szajewska, Barbara; Zakrzewska-Pniewska, Beata; Kochanek, Krzysztof; Pańkowska, Ewa

2007-01-01

Hypoglycemia is an acute disturbance of energy, especially impacting the central nervous system, but direct influence on peripheral nervous function is not detected. The aim of the study was to establish the influence of hypoglycemic moderate and severe episodes on the function of peripheral nerves, hearing and visual pathway. 97 children with type 1 diabetes (mean age 15.4+/-2.16 years, mean duration of diabetes 8.11+/-2.9 years, mean HbA1c 8,58+/-1.06%), at least 10 years old and with at least 3 years duration of diabetes, were included to study. Nerve conduction studies, visual (VEP) and auditory (ABR) evoked potentials were performed with standard surface stimulating and recording techniques. Moderate hypoglycemic episodes were defined as events of low glycemia requiring help of another person but without loss of consciousness and/or convulsions but recurrent frequently in at least one year. Severe hypoglycemia was defined as events with loss of consciousness and/or convulsions. Univariate ANOVA tests of significance or H Kruskal-Wallis test were used, depending on normality of distribution. The subgroups with a history of hypoglycemic episodes had significant delay in all conduction parameters in the sural nerve (amplitude p<0.05, sensory latency p<0.05, and velocity p<0.005) and in motor potential amplitude of tibial nerve (p<0.005). In ABR wave III latency and interval I-III in subgroups with episodes of hypoglycemia (p<0,05) were significantly prolonged. In analyses of VEP parameters no differences were detected. The study showed influence of hypoglycemic episodes on function of all sural nerve parameters and tibial motor amplitude, and in ABR on wave III and interval I-III. Frequent moderate hypoglycemic episodes were strong risk factors for damage of the peripheral and central nervous systems, comparable with impact of several severe hypoglycemias.

Predicting the Texas Windstorm Insurance Association claim payout of commercial buildings from Hurricane Ike

NASA Astrophysics Data System (ADS)

Kim, J. M.; Woods, P. K.; Park, Y. J.; Son, K.

2013-08-01

Following growing public awareness of the danger from hurricanes and tremendous demands for analysis of loss, many researchers have conducted studies to develop hurricane damage analysis methods. Although researchers have identified the significant indicators, there currently is no comprehensive research for identifying the relationship among the vulnerabilities, natural disasters, and economic losses associated with individual buildings. To address this lack of research, this study will identify vulnerabilities and hurricane indicators, develop metrics to measure the influence of economic losses from hurricanes, and visualize the spatial distribution of vulnerability to evaluate overall hurricane damage. This paper has utilized the Geographic Information System to facilitate collecting and managing data, and has combined vulnerability factors to assess the financial losses suffered by Texas coastal counties. A multiple linear regression method has been applied to develop hurricane economic damage predicting models. To reflect the pecuniary loss, insured loss payment was used as the dependent variable to predict the actual financial damage. Geographical vulnerability indicators, built environment vulnerability indicators, and hurricane indicators were all used as independent variables. Accordingly, the models and findings may possibly provide vital references for government agencies, emergency planners, and insurance companies hoping to predict hurricane damage.

Adaptive psychological structure in childhood hearing impairment: audiological correlations.

PubMed

Serra, A; Spinato, G; Cocuzza, S; Licciardello, L; Pavone, P; Maiolino, L

2017-06-01

The present research deals with the clinical and social problems present during linguistic and cognitive development of deaf children. Currently, the development of Theory of Mind represents an important research field in deafness studies. These international studies highlighted a significant alteration in the development of Theory of Mind in deaf children compared to normal hearing children, especially in cases of congenital or preverbal hearing loss. In particular, the research focuses on the skills of deaf children in recognising emotions and desires, through both perceptive and cognitive methods, by evaluation of psycho-cognitive skills of children with severe hearing loss using a set of questions to be administered to hearing loss patients. The experiment was performed on a group composed of 10 children (5 males and 5 females) aged 4 to 9 years and 54 to 108 months, affected by bilateral congenital hearing loss (severe to total), or hearing loss that developed in preverbal children the year before entering elementary school, or during the fourth year of elementary school. The selection criteria were based on: audiologic evaluation, neuro-psychological tests administered to assess general, cognitive as well as praxis and perceptive abilities, and clinical observations performed to assess psychopathology using tests that assess development of both visual perceptive (Coloured Progressive Matrices) and graphic representational abilities (Test of Human Figure Drawings and the Family Drawing Test). The instrument "cognitive" was the "Deaf Children Series", arranged by us, that consists of a mental status examination (MSE) that evaluates: level of cognitive (knowledge-related) ability, emotional mood, and speech and thought patterns at the time of evaluation. Deaf children show a reduced responsiveness to the expressions of sadness on the perceptive side. Through the test, we observed a psychodynamic defense mechanism considering perceptive understanding performance. On the contrary, in normal hearing children, the emotion 'fear' is the most difficult to identify. Deaf children seem to be more susceptible to recognition of visual emotions. Furthermore, deaf children present significant problem-solving skills and emotional recognition skills, possibly as a result of their hearing impairment. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

Disease activity, quality of life and indirect costs of reduced productivity at work, generated by Polish patients with ankylosing spondylitis.

PubMed

Kawalec, Paweł; Malinowski, Krzysztof

2015-01-01

The aim of the study was to investigate the association between activity of ankylosing spondylitis (AS) and decrease in quality of life as well as productivity loss of affected patients in a specified group of patients in the Polish setting. An questionnaire survey was conducted using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) to assess disease activity, as well as the Work Productivity and Activity Impairment Questionnaires to assess productivity loss; quality of life was presented as utility calculated using the EuroQol 5 questionnaire and also measured on a visual analogue scale (VAS). Indirect costs were assessed with the human capital approach implying gross domestic product per capita or gross value added per worker in Poland in 2014 and were expressed in Polish zlotys (PLN) as well as in euros. Correlation was presented using Spearman's rank correlation coefficient. We performed our analysis based on 78 full questionnaires collected. A mean BASDAI score of 5.91 in the analysed group of patients was detected and mean utility of 0.5135 was observed. Average quality of life measured on the visual analogue scale was 46.55. Mean number of days off work was 45.26 days per year and mean on-the-job productivity loss was 49.29%. Average annual indirect costs per patient were €4241 (17 686 PLN) calculated using gross domestic product and €10 172 (42 417 PLN) estimated using gross value added. Total productivity loss was significantly correlated with disease activity (strong correlation of 0.6005) and utility (moderate correlation of -0.3698). Ankylosing spondylitis causes a great decrease in quality of life as well as patients' productivity loss associated with both absenteeism and presenteeism. The greater the disease activity is, the lower is the utility, the lower is the quality of life measured on the VAS, and the greater are the total annual indirect costs. Total indirect costs were negatively correlated with utility; although the association was moderate, it was significant.

Effects of a new mild shampoo for preventing hair loss in Asian by a simple hand-held phototrichogram technique.

PubMed

Baek, J H; Lee, S Y; Yoo, M; Park, W-S; Lee, S J; Boo, Y C; Koh, J-S

2011-12-01

This study was conducted to evaluate the effects of a commercially available shampoo in Korean subjects with alopecia using a simple hand-held phototrichogram technique. Forty-four subjects with alopecia were enrolled and forty subjects continued for 16 weeks. In the test group, total hair counts increased significantly at weeks 8 and 16, and the number of shedding hair significantly decreased at week 16. Terminal hair counts significantly increased at week 8. In the control group, hair thickness and the number of vellus hairs significantly decreased at week 16. The number of total hairs significantly increased in the test group than in the control group at weeks 8 and 16. The number of shedding hairs significantly decreased in the test group than in the control group at week 16. Visual assessment using clinical digital images showed that the number of total hairs appeared to increase although there was no statistical significance. In this study, it was found that the test shampoo could prevent hair loss. © 2011 DERMAPRO Co Ltd. ICS © 2011 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

A Simple Method for Estimating the Economic Cost of Productivity Loss Due to Blindness and Moderate to Severe Visual Impairment.

PubMed

Eckert, Kristen A; Carter, Marissa J; Lansingh, Van C; Wilson, David A; Furtado, João M; Frick, Kevin D; Resnikoff, Serge

2015-01-01

To estimate the annual loss of productivity from blindness and moderate to severe visual impairment (MSVI) using simple models (analogous to how a rapid assessment model relates to a comprehensive model) based on minimum wage (MW) and gross national income (GNI) per capita (US$, 2011). Cost of blindness (COB) was calculated for the age group ≥50 years in nine sample countries by assuming the loss of current MW and loss of GNI per capita. It was assumed that all individuals work until 65 years old and that half of visual impairment prevalent in the ≥50 years age group is prevalent in the 50-64 years age group. For cost of MSVI (COMSVI), individual wage and GNI loss of 30% was assumed. Results were compared with the values of the uncorrected refractive error (URE) model of productivity loss. COB (MW method) ranged from $0.1 billion in Honduras to $2.5 billion in the United States, and COMSVI ranged from $0.1 billion in Honduras to $5.3 billion in the US. COB (GNI method) ranged from $0.1 million in Honduras to $7.8 billion in the US, and COMSVI ranged from $0.1 billion in Honduras to $16.5 billion in the US. Most GNI method values were near equivalent to those of the URE model. Although most people with blindness and MSVI live in developing countries, the highest productivity losses are in high income countries. The global economy could improve if eye care were made more accessible and more affordable to all.

[Phacoemulsification versus manual small incision cataract surgery: Anatomic and functional results].

PubMed

Ammous, I; Bouayed, E; Mabrouk, S; Boukari, M; Erraies, K; Zhioua, R

2017-06-01

Prospective randomised study to compare the impact of phacoemusification (PHACO) and small incision cataract surgery (SICS) on endothelial structure (cell density and morphology) and refractive results (visual acuity, induced astigmatism). Prospective study of 57 patients (63 eyes) over 20 months (May 2012-January 2014) undergoing surgery by 2 experienced surgeons. We included patients with senile or presenile cataracts, LOCS III class 2, 3 and 4. Patients were randomized into 2 groups based on their birth month (group 1: PHACO [33]; group 2: SICS [30]). All pre- intra- and postoperative data were collected prospectively. The minimum follow-up was 6 months. We used the SPSS 18.0 for statistical analysis. Statistical tests used included the test-t Student, the Anova test, the Mann-Witney non-parametric test and the Khi 2 test. A threshold of significance was set at 0.05. The mean preoperative endothelial cell density was 2447.5±225 c/mm 2 with no significant difference between the two groups (P=0.207). The mean percentage of hexagonality was 55.5±8.2% in groups 1 and 2. The most significant cell loss was during the first immediate postoperative period for both groups. At Day 15 postoperative, the decrease in cell loss was significant (P<0.001) with a mean loss of 312.9±208.9 c/mm 2 (P<10 -2 ). Postoperatively, the mean best-corrected visual acuity was 0.057 log MAR for all of our patients (P=0.170); no patient had an acuity ≤1/10. The mean astigmatism at the conclusion of follow-up was 1.08±0.42 D in group 1 and 1.51±0.55 D in group 2, with a significant difference (P=0.001). Both SICS and PHACO give excellent results, both anatomical and refractive. However, SICS appears to be more advantageous than PHACO in terms of speed, cost, and independence from technology, and appears to be better suited to dense cataracts and mass surgery. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

How Adolescent Girls Interpret Weight-Loss Advertising

ERIC Educational Resources Information Center

Hobbs, Renee; Broder, Sharon; Pope, Holly; Rowe, Jonelle

2006-01-01

While they demonstrate some ability to critically analyze the more obvious forms of deceptive weight-loss advertising, many girls do not recognize how advertising evokes emotional responses or how visual and narrative techniques are used to increase identification in weight-loss advertising. This study examined how girls aged 9-17 years…

Traumatic optic neuropathy—Clinical features and management issues

PubMed Central

Yu-Wai-Man, Patrick

2015-01-01

Traumatic optic neuropathy (TON) is an uncommon cause of visual loss following blunt or penetrating head trauma, but the consequences can be devastating, especially in cases with bilateral optic nerve involvement. Although the majority of patients are young adult males, about 20% of cases occur during childhood. A diagnosis of TON is usually straightforward based on the clinical history and examination findings indicative of an optic neuropathy. However, the assessment can be difficult when the patient's mental status is impaired owing to severe trauma. TON frequently results in profound loss of central vision, and the final visual outcome is largely dictated by the patient's baseline visual acuities. Other poor prognostic factors include loss of consciousness, no improvement in vision after 48 hours, the absence of visual evoked responses, and evidence of optic canal fractures on neuroimaging. The management of TON remains controversial. Some clinicians favor observation alone, whereas others opt to intervene with systemic steroids, surgical decompression of the optic canal, or both. The evidence base for these various treatment options is weak, and the routine use of high-dose steroids or surgery in TON is not without any attendant risks. There is a relatively high rate of spontaneous visual recovery among patients managed conservatively, and the possible adverse effects of intervention therefore need to be even more carefully considered in the balance. PMID:26052483

Cone Photoreceptor Abnormalities Correlate with Vision Loss in Patients with Stargardt Disease

PubMed Central

Chen, Yingming; Ratnam, Kavitha; Sundquist, Sanna M.; Lujan, Brandon; Ayyagari, Radha; Gudiseva, V. Harini; Roorda, Austin

2011-01-01

Purpose. To study the relationship between macular cone structure, fundus autofluorescence (AF), and visual function in patients with Stargardt disease (STGD). Methods. High-resolution images of the macula were obtained with adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography in 12 patients with STGD and 27 age-matched healthy subjects. Measures of retinal structure and AF were correlated with visual function, including best-corrected visual acuity, color vision, kinetic and static perimetry, fundus-guided microperimetry, and full-field electroretinography. Mutation analysis of the ABCA4 gene was completed in all patients. Results. Patients were 15 to 55 years old, and visual acuity ranged from 20/25–20/320. Central scotomas were present in all patients, although the fovea was spared in three patients. The earliest cone spacing abnormalities were observed in regions of homogeneous AF, normal visual function, and normal outer retinal structure. Outer retinal structure and AF were most normal near the optic disc. Longitudinal studies showed progressive increases in AF followed by reduced AF associated with losses of visual sensitivity, outer retinal layers, and cones. At least one disease-causing mutation in the ABCA4 gene was identified in 11 of 12 patients studied; 1 of 12 patients showed no disease-causing ABCA4 mutations. Conclusions. AOSLO imaging demonstrated abnormal cone spacing in regions of abnormal fundus AF and reduced visual function. These findings provide support for a model of disease progression in which lipofuscin accumulation results in homogeneously increased AF with cone spacing abnormalities, followed by heterogeneously increased AF with cone loss, then reduced AF with cone and RPE cell death. (ClinicalTrials.gov number, NCT00254605.) PMID:21296825

Treatment of Stargardt disease with dobesilate

PubMed Central

Cuevas, Pedro; Outeiriño, Luis A; Angulo, Javier; Giménez-Gallego, Guillermo

2012-01-01

Stargardt disease is a common inherited macular degeneration characterised by a significant loss in the central vision during the first or second decade of the life. Bilateral atrophic changes in the central retina are associated with degeneration of photoreceptors and underlying retinal pigment epithelium, and yellow flecks are extending from the macula. We present a patient with Stargardt disease treated with an intravitreal injection of dobesilate, showing an improvement of visual acuity 4 weeks after treatment PMID:23076703

Proprioceptive loss and the perception, control and learning of arm movements in humans: evidence from sensory neuronopathy.

PubMed

Miall, R Chris; Kitchen, Nick M; Nam, Se-Ho; Lefumat, Hannah; Renault, Alix G; Ørstavik, Kristin; Cole, Jonathan D; Sarlegna, Fabrice R

2018-05-19

It is uncertain how vision and proprioception contribute to adaptation of voluntary arm movements. In normal participants, adaptation to imposed forces is possible with or without vision, suggesting that proprioception is sufficient; in participants with proprioceptive loss (PL), adaptation is possible with visual feedback, suggesting that proprioception is unnecessary. In experiment 1 adaptation to, and retention of, perturbing forces were evaluated in three chronically deafferented participants. They made rapid reaching movements to move a cursor toward a visual target, and a planar robot arm applied orthogonal velocity-dependent forces. Trial-by-trial error correction was observed in all participants. Such adaptation has been characterized with a dual-rate model: a fast process that learns quickly, but retains poorly and a slow process that learns slowly and retains well. Experiment 2 showed that the PL participants had large individual differences in learning and retention rates compared to normal controls. Experiment 3 tested participants' perception of applied forces. With visual feedback, the PL participants could report the perturbation's direction as well as controls; without visual feedback, thresholds were elevated. Experiment 4 showed, in healthy participants, that force direction could be estimated from head motion, at levels close to the no-vision threshold for the PL participants. Our results show that proprioceptive loss influences perception, motor control and adaptation but that proprioception from the moving limb is not essential for adaptation to, or detection of, force fields. The differences in learning and retention seen between the three deafferented participants suggest that they achieve these tasks in idiosyncratic ways after proprioceptive loss, possibly integrating visual and vestibular information with individual cognitive strategies.

Causes of blindness in children attending four schools for the blind in Thailand and the Philippines. A comparison between urban and rural blind school populations.

PubMed

Gilbert, C; Foster, A

1993-08-01

Using WHO definitions of visual loss and a standardised methodology, 256 children were examined in schools for the blind in Thailand (1 school) and the Philippines (3 schools). 244 (95%) were blind (BL) or severely visually impaired (SVI). Causes of SVI and blindness were classified anatomically and aetiologically, and avoidable causes identified. Causes of visual loss in Khon Kaen, Thailand (n = 65) and Manila, Philippines, (n = 113) were similar, with conditions of the whole globe accounting for 27.7 and 27.4% of SVI/BL; retinal disease 29.2 and 23.0%; cataract 16.9 and 16.8%; corneal disease 12.3 and 13.4%; and optic nerve disease and glaucoma 6.2 and 8.8%. Perinatal factors accounted for 20.0 and 23.0% of SVI/BL; hereditary disease 13.8 and 17.7%; and 12.3 and 15.0% was due to events occurring during childhood. The underlying aetiology could not be determined in 50.8 and 41.6% of cases, respectively. In the two schools together twenty six children (15%) were blind from retinopathy of prematurity (ROP) and 16 (9%) from corneal scarring attributed to Vitamin A deficiency. 103 of 178 (58%) children had avoidable causes of visual loss. In the Filipino towns of Baguio and Davao (n = 66), the causes of visual loss were different from those in Khon Kaen and Manila, with 54.8 and 42.9% of SVI/BL being due to corneal disease, and only 3.2 and 8.5% to retinal disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Keeping Older Adults with Vision Loss Safe: Chronic Conditions and Comorbidities that Influence Functional Mobility

ERIC Educational Resources Information Center

Riddering, Anne T.

2008-01-01

Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans aged 60 and older. The loss of central vision from AMD can decrease visual acuity, contrast sensitivity, glare sensitivity, color discrimination, and the ability to adapt to changes in lighting conditions. Older adults with vision loss often have other chronic,…

The Greatest Generation Meets Its Greatest Challenge: Vision Loss and Depression in Older Adults

ERIC Educational Resources Information Center

O'Donnell, Coleen

2005-01-01

Having lived through the Great Depression and World War II, older adults now face the challenge of vision loss in record numbers. Depression is closely associated with functional loss and social isolation in late-life vision loss. The principles of assisting those who are aging will also benefit those who are aging with a visual impairment. They…

Factors associated with vision-related quality of life among the adult population living in Nagorno Karabagh.

PubMed

Harutyunyan, T; Giloyan, A; Petrosyan, V

2017-12-01

Visual impairment and blindness are major public health problems causing significant suffering, disability, loss of productivity, and diminishing quality of life for millions of people. This study explored the factors associated with the overall vision-related quality of life (VRQoL) and its different domains in the adult population of Nagorno Karabakh and assessed the independent contribution of specific eye diseases to VRQoL. A cross-sectional study. We conducted interviewer-administered survey along with free eye screenings among adult residents of Hadrut and Martuni regions of Nagorno Karabakh (Artsakh) in 2014-2015. The study questionnaire included questions about sociodemographic characteristics, non-communicable diseases, use of eye care services, visual acuity, eye diseases, and VRQoL. National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) was used to assess VRQoL. In total, 531 adults participated in the study. The mean age of participants was 60.1 years (standard deviation [SD] = 13.7), ranging from 18 to 90 years. The majority of participants were female (71.4%). The most frequently diagnosed eye disorder was cataract (33.8%). The prevalence of moderate and severe visual impairment was 7.0% and 0.8%, respectively. Almost 2.8% (15) of participants were blind. The mean global score of VFQ-25 in all study participants was 71.1 ± 19.28 (SD), whereas the mean global scores of VFQ-25 among not visually impaired, visually impaired, and blind participants were 74.0 ± 16.47 (SD), 51.7 ± 21.77 (SD), and 30.9 ± 20.2 (SD), respectively. In the adjusted linear regression model having moderate/severe visual impairment or blindness, age, socio-economic status, and having eye diseases such as glaucoma and cataract were significantly associated with VFQ-25 global score. The subscales of near vision, distance vision, peripheral vision, role difficulties, and mental health had significant associations with severe/moderate visual impairment in the adjusted analysis. After adjusting for visual impairment and demographic variables, participants with cataract and glaucoma were found to have statistically significant lower subscale scores than those without eye disease. Our data suggest that visual impairment was associated with lower scores of VRQoL. The strength of that association correlated with the increase in the level of visual impairment (from moderate/severe impairment to blindness). VRQoL was also shown to be affected by age, socio-economic status, and having eye diseases such as glaucoma and cataract. Further actions of remediation of visual impairment in this population are warranted. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

The effect of drainage tube on bleeding and prognosis after total knee arthroplasty: a prospective cohort study

PubMed Central

2014-01-01

Background To evaluate the effect of drainage tube on prognosis after total knee arthroplasty (TKA) and explore an effective treatment with favorable prognosis. Methods In a prospective study, 18 patients with TKA for the first time were included and randomly divided into three groups, group A (no placement of drainage tube), group B (negative pressure drainage), and group C (4 h clamping drainage). Intraoperative and postoperative blood loss, operation time, and the drainage volume were recorded and analyzed. Arthrocele, ecchymosis, and range of motion (ROM) were examined postoperatively. The degree of pain was scored by Visual Analog Scale (VAS) after 6, 12, and 24 h of operation. The complications were examined and HSS (hospital for special surgery) knee score was taken during the follow-up period. Results There was no significant difference in operation time, total blood loss, intraoperative blood loss, and VAS score among three groups. Meanwhile, the hidden blood loss in group B was significantly decreased compared with group A (P = 0.0015). The postoperative drainage volume of group B was significantly increased compared with group C (P = 0.0002). No drainage increased the rate of arthrocele and ecchymosis. Compared with group A, ROM after 3 days of operation in groups B and C was significantly increased (P = 0.0357, P = 0.0372, respectively). During follow-up study, no deep infection or deep venous thrombosis was found. Conclusion After TKA, early clamping of the drainage tube reduced the bleeding loss without adverse effect on prognosis, which might be useful for clinical application in future. PMID:24755244

78 FR 48941 - Advisory Committee on Prosthetics and Special-Disabilities Programs, Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-12

...- art prosthetics and the associated rehabilitation research, development, and evaluation of such..., blindness or visual impairments, loss of extremities or loss of function, deafness or hearing impairment...

Move with Me: A Parents' Guide to Movement Development for Visually Impaired Babies.

ERIC Educational Resources Information Center

Blind Childrens Center, Los Angeles, CA.

This booklet presents suggestions for parents to promote their visually impaired infant's motor development. It is pointed out that babies with serious visual loss often prefer their world to be constant and familiar and may resist change (including change in position); therefore, it is important that a wide range of movement activities be…

The Visual Uncertainty Paradigm for Controlling Screen-Space Information in Visualization

ERIC Educational Resources Information Center

Dasgupta, Aritra

2012-01-01

The information visualization pipeline serves as a lossy communication channel for presentation of data on a screen-space of limited resolution. The lossy communication is not just a machine-only phenomenon due to information loss caused by translation of data, but also a reflection of the degree to which the human user can comprehend visual…

Bullying in German Adolescents: Attending Special School for Students with Visual Impairment

ERIC Educational Resources Information Center

Pinquart, Martin; Pfeiffer, Jens P.

2011-01-01

The present study analysed bullying in German adolescents with and without visual impairment. Ninety-eight adolescents with vision loss from schools for students with visual impairment, of whom 31 were blind and 67 had low vision, were compared with 98 sighted peers using a matched-pair design. Students with low vision reported higher levels of…

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...

Psychophysical Evaluation of Achromatic and Chromatic Vision of Workers Chronically Exposed to Organic Solvents

PubMed Central

Lacerda, Eliza Maria da Costa Brito; Lima, Monica Gomes; Rodrigues, Anderson Raiol; Teixeira, Cláudio Eduardo Correa; de Lima, Lauro José Barata; Ventura, Dora Fix; Silveira, Luiz Carlos de Lima

2012-01-01

The purpose of this paper was to evaluate achromatic and chromatic vision of workers chronically exposed to organic solvents through psychophysical methods. Thirty-one gas station workers (31.5 ± 8.4 years old) were evaluated. Psychophysical tests were achromatic tests (Snellen chart, spatial and temporal contrast sensitivity, and visual perimetry) and chromatic tests (Ishihara's test, color discrimination ellipses, and Farnsworth-Munsell 100 hue test—FM100). Spatial contrast sensitivities of exposed workers were lower than the control at spatial frequencies of 20 and 30 cpd whilst the temporal contrast sensitivity was preserved. Visual field losses were found in 10–30 degrees of eccentricity in the solvent exposed workers. The exposed workers group had higher error values of FM100 and wider color discrimination ellipses area compared to the controls. Workers occupationally exposed to organic solvents had abnormal visual functions, mainly color vision losses and visual field constriction. PMID:22220188

Visual perception system and method for a humanoid robot

NASA Technical Reports Server (NTRS)

Chelian, Suhas E. (Inventor); Linn, Douglas Martin (Inventor); Wampler, II, Charles W. (Inventor); Bridgwater, Lyndon (Inventor); Wells, James W. (Inventor); Mc Kay, Neil David (Inventor)

2012-01-01

A robotic system includes a humanoid robot with robotic joints each moveable using an actuator(s), and a distributed controller for controlling the movement of each of the robotic joints. The controller includes a visual perception module (VPM) for visually identifying and tracking an object in the field of view of the robot under threshold lighting conditions. The VPM includes optical devices for collecting an image of the object, a positional extraction device, and a host machine having an algorithm for processing the image and positional information. The algorithm visually identifies and tracks the object, and automatically adapts an exposure time of the optical devices to prevent feature data loss of the image under the threshold lighting conditions. A method of identifying and tracking the object includes collecting the image, extracting positional information of the object, and automatically adapting the exposure time to thereby prevent feature data loss of the image.

Objective perimetry using a four-channel multifocal VEP system: correlation with conventional perimetry and thickness of the retinal nerve fibre layer.

PubMed

Horn, Folkert K; Kaltwasser, Christoph; Jünemann, Anselm G; Kremers, Jan; Tornow, Ralf P

2012-04-01

There is evidence that multifocal visual evoked potentials (VEPs) can be used as an objective tool to detect visual field loss. The aim of this study was to correlate multifocal VEP amplitudes with standard perimetry data and retinal nerve fibre layer (RNFL) thickness. Multifocal VEP recordings were performed with a four-channel electrode array using 58 stimulus fields (pattern reversal dartboard). For each field, the recording from the channel with maximal signal-to-noise ratio (SNR) was retained, resulting in an SNR optimised virtual recording. Correlation with RNFL thickness, measured with spectral domain optical coherence tomography and with standard perimetry, was performed for nerve fibre bundle related areas. The mean amplitudes in nerve fibre related areas were smaller in glaucoma patients than in normal subjects. The differences between both groups were most significant in mid-peripheral areas. Amplitudes in these areas were significantly correlated with corresponding RNFL thickness (Spearman R=0.76) and with standard perimetry (R=0.71). The multifocal VEP amplitude was correlated with perimetric visual field data and the RNFL thickness of the corresponding regions. This method of SNR optimisation is useful for extracting data from recordings and may be appropriate for objective assessment of visual function at different locations. This study has been registered at http://www.clinicaltrials.gov (NCT00494923).

Ocular consequences of bottle rocket injuries in children and adolescents.

PubMed

Khan, Mehnaz; Reichstein, David; M Recchia, Franco

2011-05-01

To describe the spectrum of ocular injuries and associated visual morbidity in the pediatric and adolescent population caused by bottle rockets. Retrospective review of consecutive medical records of patients 18 years or younger seen during a recent 4-year period. Outcome measures were ocular injuries at time of visit, interventions required, visual acuity at most recent follow-up, and most recent anatomic findings. Eleven eyes from 10 patients (8 boys and 2 girls aged 5-17 years) were identified. Significant ocular injuries included corneal epithelial defect (7 eyes), hyphema (6 eyes), traumatic iritis (2 eyes), iridodialysis (4 eyes), cataract (4 eyes), retinal dialysis (1 eye), and vitreous hemorrhage (2 eyes). Eight eyes required primary intervention (lensectomy in 4 eyes, corneal debridement in 2 eyes, globe exploration in 1 eye, and retinal laser photocoagulation in 1 eye). Three patients required additional procedures. These secondary interventions included pars plana vitrectomy (1 eye), muscle surgery for sensory strabismus (1 eye), corneal debridement (1 eye), and intraocular lens placement (1 eye). Most recent visual acuity (10 eyes with follow-up) was 20/30 or better in 4 eyes and 20/200 or worse in 6 eyes (for 1 eye, the patient was unavailable for follow-up). Permanent visual impairment was typically due to traumatic maculopathy. Bottle rockets can cause significant ocular injury in children, often with permanent loss of vision.

Obstacle Avoidance, Visual Detection Performance, and Eye-Scanning Behavior of Glaucoma Patients in a Driving Simulator: A Preliminary Study

PubMed Central

Prado Vega, Rocío; van Leeuwen, Peter M.; Rendón Vélez, Elizabeth; Lemij, Hans G.; de Winter, Joost C. F.

2013-01-01

The objective of this study was to evaluate differences in driving performance, visual detection performance, and eye-scanning behavior between glaucoma patients and control participants without glaucoma. Glaucoma patients (n = 23) and control participants (n = 12) completed four 5-min driving sessions in a simulator. The participants were instructed to maintain the car in the right lane of a two-lane highway while their speed was automatically maintained at 100 km/h. Additional tasks per session were: Session 1: none, Session 2: verbalization of projected letters, Session 3: avoidance of static obstacles, and Session 4: combined letter verbalization and avoidance of static obstacles. Eye-scanning behavior was recorded with an eye-tracker. Results showed no statistically significant differences between patients and control participants for lane keeping, obstacle avoidance, and eye-scanning behavior. Steering activity, number of missed letters, and letter reaction time were significantly higher for glaucoma patients than for control participants. In conclusion, glaucoma patients were able to avoid objects and maintain a nominal lane keeping performance, but applied more steering input than control participants, and were more likely than control participants to miss peripherally projected stimuli. The eye-tracking results suggest that glaucoma patients did not use extra visual search to compensate for their visual field loss. Limitations of the study, such as small sample size, are discussed. PMID:24146975

Randomized, sham-controlled trial of dexamethasone intravitreal implant in patients with macular edema due to retinal vein occlusion.

PubMed

Haller, Julia A; Bandello, Francesco; Belfort, Rubens; Blumenkranz, Mark S; Gillies, Mark; Heier, Jeffrey; Loewenstein, Anat; Yoon, Young-Hee; Jacques, Marie-Louise; Jiao, Jenny; Li, Xiao-Yan; Whitcup, Scott M

2010-06-01

To evaluate the safety and efficacy of dexamethasone intravitreal implant (DEX implant; OZURDEX, Allergan, Inc., Irvine, CA) compared with sham in eyes with vision loss due to macular edema (ME) associated with branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO). Two identical, multicenter, masked, randomized, 6-month, sham-controlled clinical trials (each of which included patients with BRVO and patients with CRVO). A total of 1267 patients with vision loss due to ME associated with BRVO or CRVO. A single treatment with DEX implant 0.7 mg (n = 427), DEX implant 0.35 mg (n = 414), or sham (n = 426). The primary outcome measure for the pooled data from the 2 studies was time to achieve a > or =15-letter improvement in best-corrected visual acuity (BCVA). Secondary end points included BCVA, central retinal thickness, and safety. After a single administration, the time to achieve a > or =15-letter improvement in BCVA was significantly less in both DEX implant groups compared with sham (P<0.001). The percentage of eyes with a > or =15-letter improvement in BCVA was significantly higher in both DEX implant groups compared with sham at days 30 to 90 (P<0.001). The percentage of eyes with a > or =15-letter loss in BCVA was significantly lower in the DEX implant 0.7-mg group compared with sham at all follow-up visits (P< or =0.036). Improvement in mean BCVA was greater in both DEX implant groups compared with sham at all follow-up visits (P< or =0.006). Improvements in BCVA with DEX implant were seen in patients with BRVO and patients with CRVO, although the patterns of response differed. The percentage of DEX implant-treated eyes with intraocular pressure (IOP) of > or =25 mmHg peaked at 16% at day 60 (both doses) and was not different from sham by day 180. There was no significant between-group difference in the occurrence of cataract or cataract surgery. Dexamethasone intravitreal implant can both reduce the risk of vision loss and improve the speed and incidence of visual improvement in eyes with ME secondary to BRVO or CRVO and may be a useful therapeutic option for eyes with these conditions. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Impact of high power and angle of incidence on prism corrections for visual field loss.

PubMed

Jung, Jae-Hyun; Peli, Eli

2014-01-17

Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice.

Impact of high power and angle of incidence on prism corrections for visual field loss

PubMed Central

Jung, Jae-Hyun; Peli, Eli

2014-01-01

Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice. PMID:24497649

Neuroretinitis associated with melanocytoma of the optic disk.

PubMed

García-Arumí, J; Salvador, F; Corcostegui, B; Mateo, C

1994-01-01

Melanocytomas of the optic disk are heavily pigmented benign tumors that are most often discovered during routine examination, as they are classically asymptomatic. Although a slight impairment of visual acuity attributable to the tumor may occur in large tumors, acute profound visual loss is extremely unusual. A case involving a 24-year-old woman with melanocytoma of the optic nervehead in the right eye, who experienced acute severe visual loss, an afferent pupillary defect, and optic nervehead edema, is discussed. Laboratory tests and serology for Toxoplasmosis, Syphilis, Borrelia, and Leptospira were performed. The severe loss of vision, optic disc swelling, exudative detachment of the peripapillary retina, macular star, and spontaneous resolution in an otherwise healthy patient were all consistent with Leber's stellate idiopathic neuroretinitis. Results of serologic testing were not contributory. This is the first report of Leber's neuroretinitis associated with melanocytoma of the optic nervehead, and should be included in the differential diagnosis of neuroretinitis. The possible mechanisms responsible for this association are discussed.

The idiopathic intracranial hypertension treatment trial: clinical profile at baseline.

PubMed

Wall, Michael; Kupersmith, Mark J; Kieburtz, Karl D; Corbett, James J; Feldon, Steven E; Friedman, Deborah I; Katz, David M; Keltner, John L; Schron, Eleanor B; McDermott, Michael P

2014-06-01

To our knowledge, there are no large prospective cohorts of untreated patients with idiopathic intracranial hypertension (IIH) to characterize the disease. To report the baseline clinical and laboratory features of patients enrolled in the Idiopathic Intracranial Hypertension Treatment Trial. We collected data at baseline from questionnaires, examinations, automated perimetry, and fundus photography grading. Patients (n = 165) were enrolled from March 17, 2010, to November 27, 2012, at 38 academic and private practice sites in North America. All participants met the modified Dandy criteria for IIH and had a perimetric mean deviation between -2 dB and -7 dB. All but 4 participants were women. Baseline and laboratory characteristics. The mean (SD) age of our patients was 29.0 (7.4) years and 4 (2.4%) were men. The average (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 39.9 (8.3). Headache was the most common symptom (84%). Transient visual obscurations occurred in 68% of patients, back pain in 53%, and pulse synchronous tinnitus in 52%. Only 32% reported visual loss. The average (SD) perimetric mean deviation in the worst eye was -3.5 (1.1) dB, (range, -2.0 to -6.4 dB) and in the best eye was -2.3 (1.1) dB (range, -5.2 to 0.8 dB). A partial arcuate visual field defect with an enlarged blind spot was the most common perimetric finding. Visual acuity was 85 letters or better (20/20) in 71% of the worst eyes and 77% of the best eyes. Quality of life measures, including the National Eye Institute Visual Function Questionnaire-25 and the Short Form-36 physical and mental health summary scales, were lower compared with population norms. The Idiopathic Intracranial Hypertension Treatment Trial represents the largest prospectively analyzed cohort of untreated patients with IIH. Our data show that IIH is almost exclusively a disease of obese young women. Patients with IIH with mild visual loss have typical symptoms, may have mild acuity loss, and have visual field defects, with predominantly arcuate loss and enlarged blind spots that require formal perimetry for detection. clinicaltrials.gov Identifier: NCT01003639.

3D Shape Perception in Posterior Cortical Atrophy: A Visual Neuroscience Perspective

PubMed Central

Gillebert, Céline R.; Schaeverbeke, Jolien; Bastin, Christine; Neyens, Veerle; Bruffaerts, Rose; De Weer, An-Sofie; Seghers, Alexandra; Sunaert, Stefan; Van Laere, Koen; Versijpt, Jan; Vandenbulcke, Mathieu; Salmon, Eric; Todd, James T.; Orban, Guy A.

2015-01-01

Posterior cortical atrophy (PCA) is a rare focal neurodegenerative syndrome characterized by progressive visuoperceptual and visuospatial deficits, most often due to atypical Alzheimer's disease (AD). We applied insights from basic visual neuroscience to analyze 3D shape perception in humans affected by PCA. Thirteen PCA patients and 30 matched healthy controls participated, together with two patient control groups with diffuse Lewy body dementia (DLBD) and an amnestic-dominant phenotype of AD, respectively. The hierarchical study design consisted of 3D shape processing for 4 cues (shading, motion, texture, and binocular disparity) with corresponding 2D and elementary feature extraction control conditions. PCA and DLBD exhibited severe 3D shape-processing deficits and AD to a lesser degree. In PCA, deficient 3D shape-from-shading was associated with volume loss in the right posterior inferior temporal cortex. This region coincided with a region of functional activation during 3D shape-from-shading in healthy controls. In PCA patients who performed the same fMRI paradigm, response amplitude during 3D shape-from-shading was reduced in this region. Gray matter volume in this region also correlated with 3D shape-from-shading in AD. 3D shape-from-disparity in PCA was associated with volume loss slightly more anteriorly in posterior inferior temporal cortex as well as in ventral premotor cortex. The findings in right posterior inferior temporal cortex and right premotor cortex are consistent with neurophysiologically based models of the functional anatomy of 3D shape processing. However, in DLBD, 3D shape deficits rely on mechanisms distinct from inferior temporal structural integrity. SIGNIFICANCE STATEMENT Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterized by progressive visuoperceptual dysfunction and most often an atypical presentation of Alzheimer's disease (AD) affecting the ventral and dorsal visual streams rather than the medial temporal system. We applied insights from fundamental visual neuroscience to analyze 3D shape perception in PCA. 3D shape-processing deficits were affected beyond what could be accounted for by lower-order processing deficits. For shading and disparity, this was related to volume loss in regions previously implicated in 3D shape processing in the intact human and nonhuman primate brain. Typical amnestic-dominant AD patients also exhibited 3D shape deficits. Advanced visual neuroscience provides insight into the pathogenesis of PCA that also bears relevance for vision in typical AD. PMID:26377458

Framing and visual type: Effect on future Zika vaccine uptake intent.

PubMed

Guidry, Jeanine P D; Carlyle, Kellie E; LaRose, Jessica G; Perrin, Paul; Ryan, Mark; Messner, Marcus; Adams, Jay

2018-02-05

The Zika virus is associated with the birth defect microcephaly, and while a vaccine was not available in early- 2017, several were under development. This study's purpose was to identify effective communication strategies to promote uptake of a new vaccine, particularly among women of reproductive age. In order to study the effects of Zika message framing (gain vs . loss) and visual type (photo vs . infographic) on future Zika vaccine uptake intent, a 2×2 between-subjects experiment was performed via an online survey in 2017 among 339 U.S. women of reproductive age (18-49 years). Participants were exposed to one of four messages, all resembling Instagram posts: gain-framed vs. loss-framed infographic, and gain-framed vs . loss-framed photo. These messages were followed by questions about Zika vaccine uptake intent as well as intermediate psychosocial variables that could lead to intent. There was no interaction between framing and visual type (P=0.116), and there was no effect for framing (P=0.185) or visual type (P=0.724) on future Zika vaccine uptake intent, which is likely indicative of insufficient dosage of the intervention. However, when focusing on intermediate psychosocial constructs that are known to influence behavior and intent, gain-framed messages were more effective in increasing subjective norms (P=0.005) as related to a future Zika vaccine, as well as perceived benefits (P=0.016) and self-efficacy (P=0.032). Gain-framed messages seem to be more effective than loss-framed messages to increase several constructs that could, in turn, affect future Zika vaccine uptake intent. This is a novel finding since, traditionally, loss-framed messages are considered more beneficial in promoting vaccine-related health behaviors.

Quantitative assessment of the long-term effect of photodynamic therapy in patients with pathologic myopia.

PubMed

Schnurrbusch, Ute E K; Jochmann, Claudia; Wiedemann, Peter; Wolf, Sebastian

2005-08-01

In patients with classic subfoveal choroidal neovascularization (CNV) secondary to pathologic myopia (PM), photodynamic therapy (PDT) has been shown to stabilize the visual acuity. We have analyzed the long-term visual prognosis after PDT in patients with CNV secondary to PM. In a retrospective study we reviewed the clinical charts of 102 patients. PDT was performed following the procedures described in the VIP and TAP study protocols. Follow-up examinations and PDT treatment were scheduled in 3-month intervals. Indications for retreatment were an active leaking CNV in combination with visual disturbances or visual loss. To assess treatment effects we analyzed the number of letters read on the ETDRS charts. The primary efficacy outcome was the proportion of eyes that had fewer than eight letters loss or gain at 24 months. Secondary efficacy outcomes included the proportion of eyes that had fewer than 15 letters loss or gain and the proportion of eyes that had fewer than 30 letters loss or gain at month 24. One hundred and two patients were included into the study. Mean follow-up was 32.5+/-5.7 months. Patients received an average of 2.2 treatments from study entry through the last follow-up, resulting in a total of 221 PDT sessions throughout the study. At 24 months 46% lost at least eight letters. A loss of at least 15 (30) letters was observed in 25% (8%). Improvement of at least eight letters was noted in 8%. Larger improvements of at least 15 letters occurred only in 4% of study eyes. Our study suggests that PDT can increase the chance of stabilizing or improving vision compared with the placebo arm of VIP trial.

Concentric retinitis pigmentosa: clinicopathologic correlations.

PubMed

Milam, A H; De Castro, E B; Smith, J E; Tang, W X; John, S K; Gorin, M B; Stone, E M; Aguirre, G D; Jacobson, S G

2001-10-01

Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitis pigmentosa. This study provides the first clinicopathologic correlations for this form of retinitis pigmentosa. A family with autosomal dominant concentric retinitis pigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitis pigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitis pigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective or modify photoreceptor degeneration in concentric retinitis pigmentosa.

The strengths and weaknesses in verbal short-term memory and visual working memory in children with hearing impairment and additional language learning difficulties.

PubMed

Willis, Suzi; Goldbart, Juliet; Stansfield, Jois

2014-07-01

To compare verbal short-term memory and visual working memory abilities of six children with congenital hearing-impairment identified as having significant language learning difficulties with normative data from typically hearing children using standardized memory assessments. Six children with hearing loss aged 8-15 years were assessed on measures of verbal short-term memory (Non-word and word recall) and visual working memory annually over a two year period. All children had cognitive abilities within normal limits and used spoken language as the primary mode of communication. The language assessment scores at the beginning of the study revealed that all six participants exhibited delays of two years or more on standardized assessments of receptive and expressive vocabulary and spoken language. The children with hearing-impairment scores were significantly higher on the non-word recall task than the "real" word recall task. They also exhibited significantly higher scores on visual working memory than those of the age-matched sample from the standardized memory assessment. Each of the six participants in this study displayed the same pattern of strengths and weaknesses in verbal short-term memory and visual working memory despite their very different chronological ages. The children's poor ability to recall single syllable words in relation to non-words is a clinical indicator of their difficulties in verbal short-term memory. However, the children with hearing-impairment do not display generalized processing difficulties and indeed demonstrate strengths in visual working memory. The poor ability to recall words, in combination with difficulties with early word learning may be indicators of children with hearing-impairment who will struggle to develop spoken language equal to that of their normally hearing peers. This early identification has the potential to allow for target specific intervention that may remediate their difficulties. Copyright © 2014. Published by Elsevier Ireland Ltd.

A case of dissociative fugue and general amnesia with an 11-year follow-up.

PubMed

Helmes, Edward; Brown, Julie-May; Elliott, Linda

2015-01-01

Dissociative fugue refers to loss of personal identity, often with the associated loss of memories of events (general amnesia). Here we report on the psychological assessment of a 54-year-old woman with loss of identity and memories of 33 years of her life attributed to dissociative fugue, along with a follow-up 11 years later. Significant levels of personal injury and stress preceded the onset of the amnesia. A detailed neuropsychological assessment was completed at a university psychology clinic, with a follow-up assessment there about 11 years later with an intent to determine whether changes in her cognitive status were associated with better recall of her life and with her emotional state. Psychomotor slowing and low scores on measures of attention and both verbal and visual memory were present initially, along with significant psychological distress associated with the diagnosis of posttraumatic stress disorder. Although memories of her life had not returned by follow-up, distress had abated and memory test scores had improved. The passage of time and a better emotional state did not lead to recovery of lost memories. Contrary to expectations, performance on tests of executive functions was good on both occasions. Multiple stressful events are attributed as having a role in maintaining the loss of memories.

A potential risk of overestimating apparent diffusion coefficient in parotid glands.

PubMed

Liu, Yi-Jui; Lee, Yi-Hsiung; Chang, Hing-Chiu; Huang, Teng-Yi; Chiu, Hui-Chu; Wang, Chih-Wei; Chiou, Ta-Wei; Hsu, Kang; Juan, Chun-Jung; Huang, Guo-Shu; Hsu, Hsian-He

2015-01-01

To investigate transient signal loss on diffusion weighted images (DWI) and overestimation of apparent diffusion coefficient (ADC) in parotid glands using single shot echoplanar DWI (EPDWI). This study enrolled 6 healthy subjects and 7 patients receiving radiotherapy. All participants received dynamic EPDWI with a total of 8 repetitions. Imaging quality of DWI was evaluated. Probability of severe overestimation of ADC (soADC), defined by an ADC ratio more than 1.2, was calculated. Error on T2WI, DWI, and ADC was computed. Statistical analysis included paired Student t testing and Mann-Whitney U test. A P value less than 0.05 was considered statistically significant. Transient signal loss was visually detected on some excitations of DWI but not on T2WI or mean DWI. soADC occurred randomly among 8 excitations and 3 directions of diffusion encoding gradients. Probability of soADC was significantly higher in radiotherapy group (42.86%) than in healthy group (24.39%). The mean error percentage decreased as the number of excitations increased on all images, and, it was smallest on T2WI, followed by DWI and ADC in an increasing order. Transient signal loss on DWI was successfully detected by dynamic EPDWI. The signal loss on DWI and overestimation of ADC could be partially remedied by increasing the number of excitations.

ERPs associated with monitoring and evaluation of monetary reward and punishment in children with ADHD.

PubMed

van Meel, Catharina S; Heslenfeld, Dirk J; Oosterlaan, Jaap; Luman, Marjolein; Sergeant, Joseph A

2011-09-01

Several models of attention-deficit hyperactivity disorder (ADHD) propose abnormalities in the response to behavioural contingencies. Using event-related potentials (ERPs), the present study investigated the monitoring and subsequent evaluation of performance feedback resulting in either reward or punishment in children with ADHD (N = 18) and normal controls (N = 18) aged 8 to 12 years. Children performed a time production task, in which visual performance feedback was given after each response. To manipulate its motivational salience, feedback was coupled with monetary gains, losses or no incentives. Performance feedback signalling omitted gains as well as omitted losses evoked a feedback-related negativity (FRN) in control children. The FRN, however, was entirely absent in children with ADHD in all conditions. Moreover, while losses elicited enhanced amplitudes of the late positive potential (LPP) in controls, omitted rewards had this effect in ADHD. The lack of modulation of the FRN by contingencies in ADHD suggests deficient detection of environmental cues as a function of their motivational significance. LPP findings suggest diminished response to punishment, but oversensitivity to the loss of desired rewards. These findings suggest that children with ADHD have problems assigning relative motivational significance to outcomes of their actions. © 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.

Differentiation of involved and uninvolved psoriatic skin from healthy skin using noninvasive visual, colorimeter and evaporimeter methods.

PubMed

Pershing, L K; Bakhtian, S; Wright, E D; Rallis, T M

1995-08-01

Uninvolved skin of psoriasis may not be entirely normal. The object was to characterize healthy, uninvolved psoriatic skin and lesional skin by biophysical methods. Involved and uninvolved psoriatic and age-gender matched healthy skin was measured objectively with a colorimeter and evaporimeter and subjectively with visual assessment in 14 subjects. Visual assessment of erythema (E), scaling (S) and induration (I) as well as the target lesion score at the involved psoriatic skin sites were significantly elevated (p<0.05) above uninvolved psoriatic or healthy skin sites. No difference between uninvolved psoriatic and healthy skin was measured visually. Transepidermal water loss at involved psoriatic skin >uninvolved psoriatic skin >healthy skin (p<0.05). Objective assessment of skin color in 3 color scales, L*, a*, and b*, differentiated involved and uninvolved psoriatic skin from healthy skin sites. Involved psoriatic skin demonstrated higher (p<0.01) a-scale values and lower (p<0.01) L* and b* scale values than uninvolved psoriatic skin. Further, colorimeter L* and a* scale values at uninvolved psoriatic skin sites were lower and higher (p<0.05), respectively, than healthy skin. The individual chromameter parameters (L*, a*, b*) correlated well with the visual parameters (E, S and I). Composite colorimeter description (L*× b*)/a* significantly differentiated healthy skin from both involved and uninvolved psoriatic skin. These collective data highlight that even visually appearing uninvolved psoriatic skin is compromised compared with healthy skin. These objective, noninvasive but differential capabilities of the colorimeter and evaporimeter will aid in the mechanistic quantification of new psoriatic drug therapies and in conjuction with biochemical studies, add to understanding of the multifactorial pathogenesis of psoriasis.

Relationship Between Rates of Binocular Visual Field Loss and Vision-Related Quality of Life in Glaucoma

PubMed Central

Lisboa, Renato; Chun, Yeoun Sook; Zangwill, Linda M.; Weinreb, Robert N.; Rosen, Peter N.; Liebmann, Jeffrey M.; Girkin, Christopher A.; Medeiros, Felipe A.

2013-01-01

Objective To evaluate the relationship between binocular rates of visual field change and vision-related quality of life (VRQOL) in glaucoma. Methods The study included 796 eyes of 398 participants that had diagnosed or suspected glaucoma followed for an average of 7.3 ± 2.0 years. Subjects were recruited from the Diagnostic Innovations in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). VRQOL was evaluated using the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) at the last follow-up visit. Integrated binocular visual fields (BVF) were calculated from the monocular fields of each patient. Linear regression of mean deviation (MD) values was used to evaluate rates of visual field change during the follow-up period. Logistic regression models were used to investigate the relationship between abnormal VRQOL and rates of visual field change, while adjusting for potentially confounding socio-economic and demographic variables. Results Thirty-two patients (8.0%) had abnormal VRQOL as determined by the results of the NEI VFQ-25 questionnaire. Subjects with abnormal VRQOL had significantly faster rates of BVF change than those with normal VRQOL (−0.18 db/year vs. −0.06 dB/year, respectively; P < 0.001). Rates of BVF change were significantly associated with abnormality in VRQOL (OR = 1.31 per 0.1dB/year faster; P = 0.038), after adjustment for confounding variables. Conclusions Patients with faster rates of BVF change were at higher risk of reporting abnormal VRQOL. Assessment of rates of BVF change may provide useful information in determining risk of functional impairment in glaucoma. PMID:23450425

Comparison of Threshold Saccadic Vector Optokinetic Perimetry (SVOP) and Standard Automated Perimetry (SAP) in Glaucoma. Part II: Patterns of Visual Field Loss and Acceptability.

PubMed

McTrusty, Alice D; Cameron, Lorraine A; Perperidis, Antonios; Brash, Harry M; Tatham, Andrew J; Agarwal, Pankaj K; Murray, Ian C; Fleck, Brian W; Minns, Robert A

2017-09-01

We compared patterns of visual field loss detected by standard automated perimetry (SAP) to saccadic vector optokinetic perimetry (SVOP) and examined patient perceptions of each test. A cross-sectional study was done of 58 healthy subjects and 103 with glaucoma who were tested using SAP and two versions of SVOP (v1 and v2). Visual fields from both devices were categorized by masked graders as: 0, normal; 1, paracentral defect; 2, nasal step; 3, arcuate defect; 4, altitudinal; 5, biarcuate; and 6, end-stage field loss. SVOP and SAP classifications were cross-tabulated. Subjects completed a questionnaire on their opinions of each test. We analyzed 142 (v1) and 111 (v2) SVOP and SAP test pairs. SVOP v2 had a sensitivity of 97.7% and specificity of 77.9% for identifying normal versus abnormal visual fields. SAP and SVOP v2 classifications showed complete agreement in 54% of glaucoma patients, with a further 23% disagreeing by one category. On repeat testing, 86% of SVOP v2 classifications agreed with the previous test, compared to 91% of SAP classifications; 71% of subjects preferred SVOP compared to 20% who preferred SAP. Eye-tracking perimetry can be used to obtain threshold visual field sensitivity values in patients with glaucoma and produce maps of visual field defects, with patterns exhibiting close agreement to SAP. Patients preferred eye-tracking perimetry compared to SAP. This first report of threshold eye tracking perimetry shows good agreement with conventional automated perimetry and provides a benchmark for future iterations.

Mechanisms of Docosahexaenoic and Eicosapentaenoic Acid Loss from Pacific Saury and Comparison of Their Retention Rates after Various Cooking Methods.

PubMed

Cheung, Lennie K Y; Tomita, Haruo; Takemori, Toshikazu

2016-08-01

The docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents of Pacific saury (Cololabis saira), a fatty fish and staple of the Japanese diet, have been reported to decrease after cooking. This study compared the DHA and EPA contents remaining in saury after grilling, pan-frying or deep-frying to center temperatures of 75, 85, or 95 °C, and examined physical loss, lipid oxidation, and thermal degradation as mechanisms of DHA and EPA loss. Temperature changes inside the saury were monitored using thermocouples, while DHA and EPA contents, oxygen radical absorbance capacity, and measurements of lipid oxidation (that is, carbonyl value and thiobarbituric acid value) were determined chemically. Visualization of temperature distribution inside fish samples during cooking revealed large differences in heat transfer among cooking methods. True retention rates in grilled (DHA: 84 ± 15%; EPA: 87 ± 14%) and pan-fried samples (DHA: 85 ± 16%; EPA: 77 ± 17%) were significantly higher than deep-fried samples (DHA: 58 ± 17%; EPA: 51 ± 18%), but were not affected by final center temperatures despite differences in cooking times. Physical loss via cooking losses (grilling and pan-frying) or migration into frying oil (deep-frying) accounted for large quantities of DHA and EPA loss, while lipid oxidation and thermal degradation did not appear to be major mechanisms of loss. The antioxidant capacity of saury was not significantly affected by cooking treatments. The results of this study suggest that minimization of physical losses during cooking may increase DHA and EPA contents retained in cooked Pacific saury. © 2016 Institute of Food Technologists®

Intravitreal Aflibercept Injection in Eyes With Substantial Vision Loss After Laser Photocoagulation for Diabetic Macular Edema: Subanalysis of the VISTA and VIVID Randomized Clinical Trials.

PubMed

Wykoff, Charles C; Marcus, Dennis M; Midena, Edoardo; Korobelnik, Jean-François; Saroj, Namrata; Gibson, Andrea; Vitti, Robert; Berliner, Alyson J; Williams Liu, Zinaria; Zeitz, Oliver; Metzig, Carola; Schmelter, Thomas; Heier, Jeffrey S

2016-12-22

Information on the effect of anti-vascular endothelial growth factor therapy in eyes with diabetic macular edema (DME) with vision loss after macular laser photocoagulation is clinically valuable. To evaluate visual and anatomic outcomes in a subgroup of macular laser photocoagulation treatment control (hereafter laser control) eyes with substantial vision loss receiving treatment with intravitreal aflibercept injection. This investigation was a post hoc analysis of a subgroup of laser control eyes in 2 phase 3 trials-VISTA (Study of Intravitreal Aflibercept Injection in Patients With Diabetic Macular Edema) and VIVID (Intravitreal Aflibercept Injection in Vision Impairment Due to DME)-in a multicenter setting. One hundred nine laser control eyes with center-involving DME were included. Treatment with intravitreal aflibercept injection (2 mg) every 8 weeks after 5 monthly doses with sham injections on nontreatment visits starting at week 24 was initiated on meeting prespecified criteria of at least a 10-letter visual acuity loss at 2 consecutive visits or at least a 15-letter visual acuity loss from the best previous measurement at 1 visit and vision not better than at baseline. Visual and anatomic outcomes in a subgroup of laser control eyes receiving treatment with intravitreal aflibercept injection. Through week 100, a total of 63 of 154 eyes (40.9%) in VISTA and 46 of 133 eyes (34.6%) in VIVID initially randomized to laser control received treatment with intravitreal aflibercept injection. The median time from week 24 to the first intravitreal aflibercept injection treatment was 34.0 (VISTA) and 83.5 (VIVID) days. In this subgroup, the mean (SD) visual gain from baseline to week 100 was 2.2 (12.5) (VISTA) and 3.8 (10.1) (VIVID) letters. At the time of intravitreal aflibercept injection initiation, these eyes had a mean (SD) loss of 11.0 (10.1) (VISTA) and 10.0 (6.5) (VIVID) letters from baseline, and they subsequently gained a mean (SD) of 17.4 (9.7) (VISTA) and 13.6 (8.6) (VIVID) letters from the initiation of treatment with intravitreal aflibercept injection through week 100. There was a minimal mean change in central subfield thickness from baseline in these eyes at the time of intravitreal aflibercept injection initiation (an increase of 3.9 μm in VISTA and a decrease of 3.0 μm in VIVID), after which further mean (SD) reductions of 285.6 (202.6) μm (VISTA) and 313.4 (181.9) μm (VIVID) occurred through week 100. Intravitreal aflibercept injection improves visual and anatomic outcomes in eyes experiencing substantial vision loss after macular laser photocoagulation treatment for DME. clinicaltrials.gov Identifiers: NCT01363440 and NCT01331681.

Visual Odometry for Autonomous Deep-Space Navigation

NASA Technical Reports Server (NTRS)

Robinson, Shane; Pedrotty, Sam

2016-01-01

Visual Odometry fills two critical needs shared by all future exploration architectures considered by NASA: Autonomous Rendezvous and Docking (AR&D), and autonomous navigation during loss of comm. To do this, a camera is combined with cutting-edge algorithms (called Visual Odometry) into a unit that provides accurate relative pose between the camera and the object in the imagery. Recent simulation analyses have demonstrated the ability of this new technology to reliably, accurately, and quickly compute a relative pose. This project advances this technology by both preparing the system to process flight imagery and creating an activity to capture said imagery. This technology can provide a pioneering optical navigation platform capable of supporting a wide variety of future missions scenarios: deep space rendezvous, asteroid exploration, loss-of-comm.

Selective loss of orientation column maps in visual cortex during brief elevation of intraocular pressure.

PubMed

Chen, Xin; Sun, Chao; Huang, Luoxiu; Shou, Tiande

2003-01-01

To compare the orientation column maps elicited by different spatial frequency gratings in cortical area 17 of cats before and during brief elevation of intraocular pressure (IOP). IOP was elevated by injecting saline into the anterior chamber of a cat's eye through a syringe needle. The IOP was elevated enough to cause a retinal perfusion pressure (arterial pressure minus IOP) of approximately 30 mm Hg during a brief elevation of IOP. The visual stimulus gratings were varied in spatial frequency, whereas other parameters were kept constant. The orientation column maps of the cortical area 17 were monocularly elicited by drifting gratings of different spatial frequencies and revealed by a brain intrinsic signal optical imaging system. These maps were compared before and during short-term elevation of IOP. The response amplitude of the orientation maps in area 17 decreased during a brief elevation of IOP. This decrease was dependent on the retinal perfusion pressure but not on the absolute IOP. The location of the most visible maps was spatial-frequency dependent. The blurring or loss of the pattern of the orientation maps was most severe when high-spatial-frequency gratings were used and appeared most significantly on the posterior part of the exposed cortex while IOP was elevated. However, the basic patterns of the maps remained unchanged. Changes in cortical signal were not due to changes in the optics of the eye with elevation of IOP. A stable normal IOP is essential for maintaining normal visual cortical functions. During a brief and high elevation of IOP, the cortical processing of high-spatial-frequency visual information was diminished because of a selectively functional decline of the retinogeniculocortical X pathway by a mechanism of retinal circulation origin.

SPECTRAL DOMAIN VERSUS SWEPT SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF THE RETINAL CAPILLARY PLEXUSES IN SICKLE CELL MACULOPATHY.

PubMed

Jung, Jesse J; Chen, Michael H; Frambach, Caroline R; Rofagha, Soraya; Lee, Scott S

2018-01-01

To compare the spectral domain and swept source optical coherence tomography angiography findings in two cases of sickle cell maculopathy. A 53-year-old man and a 24-year-old man both with sickle cell disease (hemoglobin SS) presented with no visual complaints; Humphrey visual field testing demonstrated asymptomatic paracentral scotomas that extended nasally in the involved eyes. Clinical examination and multimodal imaging including spectral domain and swept source optical coherence tomography, and spectral domain optical coherence tomography angiography and swept source optical coherence tomography angiography (Carl Zeiss Meditec Inc, Dublin, CA) were performed. Fundus examination of both patients revealed subtle thinning of the macula. En-face swept source optical coherence tomography confirmed the extent of the thinning correlating with the functional paracentral scotomas on Humphrey visual field. Swept source optical coherence tomography B-scan revealed multiple confluent areas of inner nuclear thinning and significant temporal retinal atrophy. En-face 6 × 6-mm spectral domain optical coherence tomography angiography of the macula demonstrated greater loss of the deep capillary plexus compared with the superficial capillary plexus. Swept source optical coherence tomography angiography 12 × 12-mm imaging captured the same macular findings and loss of both plexuses temporally outside the macula. In these two cases of sickle cell maculopathy, deep capillary plexus ischemia is more extensive within the macula, whereas both the superficial capillary plexus and deep capillary plexus are involved outside the macula likely due to the greater oxygen demands and watershed nature of these areas. Swept source optical coherence tomography angiography clearly demonstrates the angiographic extent of the disease correlating with the Humphrey visual field scotomas and confluent areas of inner nuclear atrophy.

Find Services for People Who Are Blind or Visually Impaired

MedlinePlus

... Vision Loss Eye Conditions Losing Your Sight? Using Technology For Parents of Blind Children For Job Seekers For Seniors Braille Video Description Programs & Services Technology Evaluation Center on Vision Loss Learning Center Professional ...

75 FR 65060 - Advisory Committee on Prosthetics and Special-Disabilities Programs; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-21

...-of-the- art prosthetics and the associated rehabilitation research, development, and evaluation of... injuries, blindness or visual impairments, loss of extremities or loss of function, deafness or hearing...

[Endothelial keratoplasty: Descemet stripping (DSEK) using TAN EndoGlide™ device: case series].

PubMed

Pazos, Henrique Santiago Baltar; Pazos, Paula Fernanda Morais Ramalho Baltar; Nogueira Filho, Pedro Antônio; Grisolia, Ana Beatriz Diniz; Silva, André Berger Emiliano; Gomes, José Álvaro Pereira

2011-01-01

To report the results of Descemet stripping endothelial keratoplasty (DSEK) using the TAN EndoGlideTM device to facilitate the insertion of the endothelial membrane. Prospective clinical study that included nine patients presenting corneal edema secondary to endothelial dysfunction. Best corrected visual acuity, refraction, central corneal thickness, endothelial cell density and complications were analyzed after a six-month follow-up. There was a significant improvement in the corneal edema and visual acuity in 7 patients (77.78%). The best corrected visual acuity ranged between 20/40 and 20/200. The average density of endothelial cells in six months varied between 1,305 cells/mm² and 2,346 cells/mm² with an average loss of 33.14% cells. Detachment of part of the graft was observed in one eye (11.11%) and primary failure of the endothelial transplantation occurred in 2 eyes (22.22%). The device TAN EndoGlideTM facilitates the introduction of the graft in Descemet stripping endothelial keratoplasty.

Active-duty military service members’ visual representations of PTSD and TBI in masks

PubMed Central

Walker, Melissa S.; Kaimal, Girija; Gonzaga, Adele M. L.; Myers-Coffman, Katherine A.; DeGraba, Thomas J.

2017-01-01

ABSTRACT Active-duty military service members have a significant risk of sustaining physical and psychological trauma resulting in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Within an interdisciplinary treatment approach at the National Intrepid Center of Excellence, service members participated in mask making during art therapy sessions. This study presents an analysis of the mask-making experiences of service members (n = 370) with persistent symptoms from combat- and mission-related TBI, PTSD, and other concurrent mood issues. Data sources included mask images and therapist notes collected over a five-year period. The data were coded and analyzed using grounded theory methods. Findings indicated that mask making offered visual representations of the self related to individual personhood, relationships, community, and society. Imagery themes referenced the injury, relational supports/losses, identity transitions/questions, cultural metaphors, existential reflections, and conflicted sense of self. These visual insights provided an increased understanding of the experiences of service members, facilitating their recovery. PMID:28452610

Topographic steep central islands following excimer laser photorefractive keratectomy

NASA Astrophysics Data System (ADS)

Krueger, Ronald R.; McDonnell, Peter J.

1994-06-01

The purpose of this study is to demonstrate that topographic irregularities in the form of central islands of higher refractive power can be seen following excimer laser refractive surgery. We reviewed the computerized corneal topographic maps of 35 patients undergoing excimer laser PRK for compound myopic astigmatism or anisometropia from 8/91 to 8/93 at the USC/Doheny Eye Institute. The topographic maps were generated by the Computed Anatomy Corneal Modeling System, and central islands were defined as topographic areas of steepening of at least 3 diopters and 3 mm in diameter. A grading system was developed based on the presence of central islands during the postoperative period. Visually significant topographic steep central islands may be seen in over 50% of patients at 1 month following excimer laser PRK, and persist at 3 months in up to 24% of patients without nitrogen gas blowing. Loss of best corrected visual acuity or ghosting is associated with island formation, and may prolong visual rehabilitation after excimer laser PRK.

Aging: A Predisposition to Dry Eyes

PubMed Central

Hindman, Holly B.

2014-01-01

Dry eye syndrome is a disease of the ocular surface and tear film that is prevalent in older adults. Even though the degree of visual acuity loss in dry eye patients is commonly mild-to-moderate, in the aging population, this minimal change in visual status can lead to a significant decrease in visual function and quality of life. A healthy ocular surface is maintained by appropriate tear production and tear drainage, and deficiencies in this delicate balance can lead to dryness. In the aging eye, risk factors such as polypharmacy, androgen deficiency, decreased blink rates, and oxidative stress can predispose the patient to developing dry eye that is frequently more severe, has higher economic costs, and leads to worse consequences to the well-being of the patient. Understanding why elderly patients are at higher risk for developing dry eyes can provide insights into the diagnosis and management of the growing number of older adults struggling with dry eye and minimize the burden of disease on our aging population. PMID:25197560

Neuropsychiatry of complex visual hallucinations.

PubMed

Mocellin, Ramon; Walterfang, Mark; Velakoulis, Dennis

2006-09-01

To describe the phenomenology and pathophysiology of complex visual hallucinations (CVH) in various organic states, in particular Charles Bonnet syndrome and peduncular hallucinosis. Three cases of CVH in the setting of pontine infarction, thalamic infarction and temporoparietal epileptiform activity are presented and the available psychiatric, neurological and biological literature on the structures of the central nervous system involved in producing hallucinatory states is reviewed. Complex visual hallucinations can arise from a variety of processes involving the retinogeniculocalcarine tract, or ascending brainstem modulatory structures. The cortical activity responsible for hallucinations results from altered or reduced input into these regions, or a loss of ascending inhibition of their afferent pathways. A significant degree of overlaps exists between the concepts of Charles Bonnet syndrome and peduncular hallucinosis. The fluidity of these eponymous syndromes reduces their validity and meaning, and may result in an inappropriate attribution of the underlying pathology. An understanding of how differing pathologies may produce CVH allows for the appropriate tailoring of treatment, depending on the site and nature of the lesion and content of perceptual disturbance.

Active-duty military service members' visual representations of PTSD and TBI in masks.

PubMed

Walker, Melissa S; Kaimal, Girija; Gonzaga, Adele M L; Myers-Coffman, Katherine A; DeGraba, Thomas J

2017-12-01

Active-duty military service members have a significant risk of sustaining physical and psychological trauma resulting in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Within an interdisciplinary treatment approach at the National Intrepid Center of Excellence, service members participated in mask making during art therapy sessions. This study presents an analysis of the mask-making experiences of service members (n = 370) with persistent symptoms from combat- and mission-related TBI, PTSD, and other concurrent mood issues. Data sources included mask images and therapist notes collected over a five-year period. The data were coded and analyzed using grounded theory methods. Findings indicated that mask making offered visual representations of the self related to individual personhood, relationships, community, and society. Imagery themes referenced the injury, relational supports/losses, identity transitions/questions, cultural metaphors, existential reflections, and conflicted sense of self. These visual insights provided an increased understanding of the experiences of service members, facilitating their recovery.