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At least 631 records · Page 35Linked to original sources
PubMed2006

Amblyopia in astigmatic children: patterns of deficits.

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

Amblyopia↗
PubMed1997

Taxi drivers' accidents: how binocular vision problems are related to their rate and severity in terms of the number of victims.

Recent studies do not agree on the possible relationship between medical conditions and traffic safety; most of them do not control for exposure factors. In this study, we estimate the effect of binocular vision problems on taxi drivers' distributions of crashes (frequency). Moreover, given a crash, we estimate the effect of binocular vision problems on the distributions of the number of victims per crash (dead or injured). Our data and models permit the simultaneous consideration of many variables: age, medical condition, exposure factors measured by distance driven and time behind the wheel, qualitative risk factors, other characteristics of the driver, and crash circumstances in the models for the number of victims. Results show that taxi drivers have a large average number of crashes per year, larger for those with binocular vision problems compared with healthy ones, but not more severe in terms of the number of victims. The driver's past record (number of crashes and demerit points in the previous year) is a significant predictor of the number of crashes. Age is associated significantly with the number and the severity of crashes with older drivers having a better record than the youngest group (30 years old or less).

Accidents, Traffic↗
PubMed2000

Visual risk factors for driving difficulty among older drivers.

This study sought to evaluate associations between visual function and self-reported difficulty with driving tasks. Drivers (N = 384) between the ages of 55 and 85 were selected from ophthalmology practices and optometry clinics; three out of four of the sample had cataracts and the remaining were cataract-free. Information on driving exposure and difficulty was obtained via self-report. Visual functional status of all participants was measured with respect to acuity, contrast sensitivity, disability glare and useful field of view. Cognitive impairment was evaluated using the Mattis Organic Mental Syndrome Screening Examination. The results show a pattern of difficulty in high-risk driving situations among those with decreased visual acuity and contrast sensitivity, even after adjustments for age, gender, weekly mileage, and cognitive impairment.

Age Factors↗
PubMed2000

A short questionnaire on visual function of older adults to supplement ophthalmic examination.

PURPOSE: To estimate frequency of self-reported visual dysfunction in specific life situations. METHODS: Performance-based measures of visual function were obtained during the 5-year follow-up examination of the Beaver Dam Eye Study cohort. During the subsequent yearly follow-up telephone call, four questions concerning visual abilities in specific situations were administered. RESULTS: Visual difficulties in everyday life situations were commonly reported by adults aged 48 to 91 years, with only 17% to 35% of persons reporting excellent or very good vision in the four specific situations related to visual function. Visual acuity, near vision, and contrast sensitivity measures do not reflect the visual difficulties encountered in common daily activities in our study population (Spearman correlation coefficients all less than 0.35). CONCLUSIONS: A few simple questions about visual function in common daily activities may give a clinician insights into patient complaints. It may be that environmental changes could improve self-reported visual function.

Activities of Daily Living↗
PubMed2002

Impact of visual function on computer task accuracy and reaction time in a cohort of patients with age-related macular degeneration.

PURPOSE: To investigate the impact of visual function parameters on computer task performance in patients with age-related macular degeneration (AMD). DESIGN: Interventional case series. METHODS: Eighteen patients with visual impairment due to age-related macular degeneration underwent evaluation of visual acuity using the Early Treatment Diabetic Retinopathy Study protocol, contrast sensitivity using a Pelli-Robson chart, binocular simultaneous visual field using the Esterman program on an automated perimeter, and color vision using Farnsworth D-15. Each subject then completed 125 computer icon identification tasks. Relationships between computer task performance (accuracy and speed) and visual function parameters (visual acuity, contrast sensitivity, visual field, and color vision) were analyzed. RESULTS: Visual acuity and contrast sensitivity in the better eye, weighted average contrast sensitivity, and color vision defects are significantly associated with computer task accuracy. Visual acuity in the better eye, weighted average visual acuity, and color vision defects are significantly associated with performance speed. Visual function parameters and clinical features significantly associated with computer task accuracy in a multiple regression model include weighted average contrast sensitivity (P = 0.001), protan color vision defect (P = 0.002), cataract severity in the better-seeing eye (P = 0.036), and geographic atrophy outside the central macula (P = 0.046). Visual function parameters and clinical features significantly associated with computer task speed in a multiple regression model include color vision defects (deutan, P < 0.001; protan, P < 0.001) and gender (P = 0.05). CONCLUSIONS: Among this cohort of patients with AMD, visual acuity, contrast sensitivity, and color vision defects are significant predictors of computer task performance. Visual function parameters of the better eye played a more significant role than parameters of the worse eye, and contrast sensitivity is the most significant predictor of computer task accuracy.

Activities of Daily Living↗
PubMed2002

Macular translocation with 360 degree retinotomy for management of age-related macular degeneration with subfoveal choroidal neovascularization.

PURPOSE: The aim of this study is to evaluate the functional outcome in a group of patients treated with full macular translocation (FMT) with 360-degree retinotomy for treatment of age-related macular degeneration (ARMD) with subfoveal choroidal neovascularization. DESIGN: Consecutive interventional case series. METHODS: Fifty consecutive eyes (50 patients) with ARMD and subfoveal neovascularization who underwent a FMT in our department from January 1999 to July 2000 are included in this study. Compensatory muscle surgery, as described by Eckardt and associates, was performed on all the eyes. The median follow-up is 21 months (range, 12 to 36; SD, 5.4). RESULTS: The best-corrected postoperative visual acuity (BCVA) was improved by 2 or more Snellen lines in 33 eyes (66%) and remained stable (+/-1 line) in 14 eyes (28%). Only 3 eyes (6%) experienced a deterioration of the BCVA of 2 or more lines. The final BCVA was 20/50 or better in 32% of the cases; only 8 eyes (16%) had a final BCVA < 20/200. Thirty-four (68%) patients are able to read newspaper print (3.3/10) with normal (+3 diopters to +4 diopters) or increased (+5 diopters to +8 diopters) reading ads. Other patients are able to read with magnifying systems. Complications included proliferative vitreoretinopathy (PVR) in 9 eyes (18%), recurrent choroidal neovascularization in 5 eyes (10%), diplopia in 3 eyes (6%), choroidal hemorrhage in 2 eyes (4%), macular hole in 1 eye, and temporary hypotony in 1 eye. CONCLUSIONS: As 68% of the patients in the study group regained reading vision with reading glasses, FMT can be considered an effective approach in cases of subfoveal choroidal neovascularization. Further investigations are necessary to determine which patients will have the most benefit from this complex therapeutic method.

Aged↗
PubMed2003

A computerized method of visual acuity testing: adaptation of the early treatment of diabetic retinopathy study testing protocol.

PURPOSE: To develop a computerized method of visual acuity testing for clinical research as an alternative to the standard Early Treatment for Diabetic Retinopathy Study (ETDRS) testing protocol, and to evaluate its test-retest reliability and concordance with standard ETDRS testing. DESIGN: Test-retest reliability study. METHODS: Multicenter setting of a study population of 265 patients at three clinical sites. Visual acuity was measured with both the electronic visual acuity testing algorithm (E-ETDRS) and standard ETDRS protocol (S-ETDRS) twice on one eye of each patient. E-ETDRS testing was conducted using the electronic visual acuity tester (EVA), which utilizes a programmed Palm (Palm, Inc, Santa Clara, California, USA) hand-held device communicating with a personal computer and 17-inch monitor at a test distance of 3 meters. RESULTS: For the E-ETDRS protocol, test-retest reliability was high (r = 0.99; with 89% and 98% of retests within 0.1 logMAR and 0.2 logMAR of initial tests, respectively) and comparable with that of S-ETDRS testing (r = 0.99; with 87% and 98% of retests within 0.1 logMAR and 0.2 logMAR of initial test, respectively). The E-ETDRS and S-ETDRS scores were highly correlated (r = 0.96 for initial tests and r = 0.97 for repeat tests). Based on estimates of 95% confidence intervals, a change in visual acuity of 0.2 logMAR (10 letters) from a baseline level is unlikely to be related to measurement variability using either the E-ETDRS or the S-ETDRS visual acuity testing protocol. CONCLUSIONS: The E-ETDRS protocol has high test-retest reliability and good concordance with S-ETDRS testing. The computerized method has advantages over the S-ETDRS testing in electronically capturing the data for each tested letter, requiring only a single distance for testing from 20/12 to 20/800, potentially reducing testing time, and potentially decreasing technician-related bias.

Adolescent↗
PubMed2004

The monocular vertical prism dissociation test.

PURPOSE: To determine if the monocular vertical prism dissociation test can differentiate between organic and nonorganic visual loss. DESIGN: A prospective, single-masked observational study. METHODS: Three institutional neuro-ophthalmology practices. Group 1 consisted of 30 normal controls. Group 2 included 30 patients with known organic visual loss. Group 3 contained 35 patients with suspected nonorganic monocular visual loss. Participants were asked to describe what they saw while viewing a single Snellen letter when a 4-prism diopter base-down prism was placed in front of their better eye. Outcome was measured by whether the participant sees one or two letters with the prism in place. RESULTS: Vision-appropriate results were given by all members of Group 1 (two images) and by all members of Group 2 (one image). Two images were seen by 31 of 35 members of Group 3, indicating nonorganic visual loss. The other 4 subjects in Group 3 saw one image; each was subsequently found to have occult pathology. CONCLUSION: The vertical prism test quickly differentiates organic from nonorganic monocular visual acuity loss.

Adolescent↗
PubMed1997

Retinal vein occlusion and transient monocular visual loss associated with hyperhomocystinemia.

PURPOSE: To report a 24-year-old man with bilateral central retinal vein occlusions who had preceding episodes of prolonged transient monocular visual loss during which ophthalmoscopic findings were not suggestive of vein occlusion. METHOD: Case report. RESULT: Extensive hematologic studies for causes of vein occlusion were unremarkable with the exception of increased plasma homocysteine in the patient and in his asymptomatic father. CONCLUSIONS: Impending vein occlusion should be considered in the differential diagnosis of transient monocular visual loss regardless of ophthalmoscopic appearance, and hyperhomocystinemia should be considered as a possible cause of retinal vein occlusion.

Adult↗
PubMed1997

Visual symptoms after optic neuritis. Results from the Optic Neuritis Treatment Trial.

As part of the Optic Neuritis Treatment Trial, vision-specific quality-of-life data were collected on the patients at their 6-month visits. The purpose of this study was to determine the types of visual tasks in day-to-day living in which patients have difficulty and to compare the patients' subjective assessment of visual impairment with measurements of visual acuity, contrast sensitivity, mean deviation, and color vision. The questionnaire was completed by 382 (87%) of the 438 patients who had 6-month study visits. Associations between ophthalmic test scores and self-reported vision were examined using both a summary problem index and selected individual items. Although a substantial percentage of the patients (63%) indicated that vision had not recovered to normal in the affected eye, the reported visual deficits generally were mild. For most of the visual tasks of daily living, patients reported little or no problem. Among the 215 patients who perceived their vision at 6 months to be somewhat or much worse than it was before optic neuritis, 20% had normal results on none of the four visual function tests, 14% had normal results on one of the four tests, 23% had two of four, 23% had three of four, and 20% had normal results on all four. Reported visual symptoms 6 months after optic neuritis generally were mild. When patients were symptomatic, the four visual function tests often did not detect abnormality. This finding supports previous reports that visual deficits are frequently perceived even when vision testing is normal.

Adult↗
PubMed1991

Visual recovery in patients with optic neuritis and visual loss to no light perception.

We reviewed the records of 151 patients with optic neuritis examined over an eight-year period. Of these patients, 12 developed visual acuity of no light perception during the first episode of optic neuritis in the affected eye. Eight of the 12 patients recovered visual acuity of 20/40 or better. Of these, five patients had visual acuity of 20/20 or better, one had visual acuity of 20/25, one had visual acuity of 20/30, and one had visual acuity of 20/40. Four of the 12 patients recovered peripheral visual fields but had dense central scotomas and visual acuity of less than 20/400. Dyschromatopsia persisted after visual recovery in 11 of 12 patients.

Adolescent↗
PubMed1995

Reversible loss of light perception after vitreoretinal surgery.

PURPOSE: We studied reversible loss of light perception after vitreoretinal surgery to show that functional vision can return in some patients. METHODS: We reviewed the medical records of seven patients who had postoperative reversible loss of light perception in the eye that underwent vitreoretinal surgery. Differences in the postoperative courses and interventions were studied. RESULTS: Five of the seven patients had diabetes mellitus but none had hypertension. The indications for vitreoretinal surgery were severe proliferative diabetic retinopathy in five patients and retinal detachment with advanced proliferative vitreoretinopathy in two patients. Seven patients had reversible loss of light perception within the first three postoperative days. Six of the seven patients had an intraocular pressure greater than 26 mm Hg at the time the eye had no light perception. Decreasing the intraocular pressure was associated with return of light perception in five of seven patients. Return of useful vision was gradual. Four of seven patients had a visual acuity of 20/400 or better one month after surgery, and all seven had a visual acuity of 20/400 or better three months after surgery. Visual acuity in four eyes improved further to 20/70 or better at six months or more after surgery. CONCLUSION: Reversible loss of light perception after vitreoretinal surgery does occur in some patients. Monitoring vision and intraocular pressure is important because prompt treatment may assist in the recovery of functional vision.

Adult↗
PubMed1994

Factors affecting visual outcome after surgery for bilateral congenital cataracts.

The medical records of 33 patients with dense bilateral congenital cataracts were analyzed for factors affecting visual outcome. The average postoperative follow-up was 6.3 years. Of the 23 patients tested with optotypes (verbal children), 14 had visual acuities of 20/80 or better. Eight patients had binocular vision. Preoperative nystagmus, age at surgery, microphthalmos, and postoperative strabismus were not prognostically significant in visual outcome. Postoperative nystagmus was common and was not indicative of a poor visual outcome. Ocular anomalies, systemic anomalies, and postoperative complications were associated with a lower percentage of good postoperative visual acuities.

Cataract↗
PubMed1980

Automated clinical visual acuity testing.

We developed a method for testing visual acuity using a general-purpose microcomputer which displays visual acuity targets on a television monitor, controls a staircase psychophysical testing procedure, and provides a printed record of mean visual acuity and standard deviation. This automated procedure can be used to increase the precision of clinical visual acuity testing and to determine if changes in a patient's visual acuity are statistically significant.

Adolescent↗
PubMed1996

Contrast sensitivity and other vision tests in the optic neuritis treatment trial.

PURPOSE: To determine the intercorrelation, prevalence of abnormality, and incremental detection value of vision tests in optic neuritis. METHODS: We calculated the linear correlation of paired vision tests and prevalence of abnormal test values from baseline and six-month measurements of Snellen visual acuity, Pelli-Robson contrast sensitivity, Humphrey Field Analyzer mean deviation, and Farnsworth-Munsell 100-hue color vision in 438 patients entered in the Optic Neuritis Treatment Trial from 1988 to 1991. The incremental detection value of nonvisual acuity tests was defined as their frequency of abnormality when visual acuity was 20/20 or better. RESULTS: All four vision-test results were highly intercorrelated at baseline and at six months. At baseline, contrast sensitivity had the highest prevalence of abnormality, but all vision tests were so often abnormal that differences were not clinically relevant. At six months, when visual recovery had occurred, contrast sensitivity was most often abnormal (2.2 X visual acuity; 1.8 X mean deviation; 1.5 X Farnsworth-Munsell 100-hue color vision test); when contrast sensitivity, mean deviation, or Farnsworth-Munsell 100-hue color vision was normal, visual acuity was 20/25 or better in 98% of patients. CONCLUSIONS: The high intercorrelation of four vision tests suggests that optic neuritis affects a broad range of visual functions. Among non-visual acuity tests, Pelli-Robson contrast sensitivity proved to be a particularly practical and sensitive indicator of visual dysfunction in optic neuritis.

Adolescent↗
PubMed1990

Reversible visual loss caused by fibrous dysplasia.

Fibrous dysplasia is a developmental anomaly of bone, often affecting the facial bones. We treated a patient who had fibrous dysplasia involving the right maxillary and sphenoid bones. The patient had a sudden loss of visual acuity to R.E.: counting fingers. Visual fields demonstrated a central scotoma, and retrobulbar neuritis was diagnosed. When vision failed to improve spontaneously, however, radiologic studies were performed. These showed compromise of the optic canal by bony proliferation and an apparent mucocele at the orbital apex. Surgical exploration disclosed fibrous dysplastic bone and a cystic structure overlying the optic nerve. Successful surgical excision of the cyst and debulking of the fibrous dysplasia resulted in visual acuity returning to R.E.: 20/25.

Adult↗