Computerized method of visual acuity testing: adaptation of the amblyopia treatment study visual acuity testing protocol.

PURPOSE: To report a computerized method for determining visual acuity in children using the Amblyopia Treatment Study visual acuity testing protocol. METHODS: A computerized visual acuity tester was developed that uses a programmed handheld device that uses the Palm operating system (Palm, Inc, Santa Clara, California). The handheld device communicates with a personal computer running a Linux operating system and 17-inch monitor. At a test distance of 3 m, single letters can be displayed from 20/800 to 20/12. A C program on the handheld device runs the Amblyopia Treatment Study visual acuity testing protocol. Using this method, visual acuity was tested in both the right and left eyes, and then the testing was repeated in 156 children age 3 to 7 years at four clinical sites. RESULTS: Test-retest reliability was high (r =.92 and 0.95 for and right and left eyes, respectively), with 88% of right eye retests and 94% of left eye retests within 0.1 logarithm of minimal angle of resolution (logMAR) units of the initial test. The 95% confidence interval for an acuity score was calculated to be the score +/- 0.13 logMAR units. For a change between two acuity scores, the 95% confidence interval was the difference +/- 0.19 logMAR units. CONCLUSIONS: We have developed a computerized method for measurement of visual acuity. Automation of the Amblyopia Treatment Study visual acuity testing protocol is an effective method of testing visual acuity in children 3 to 7 years of age.

The amblyopia treatment study visual acuity testing protocol.

OBJECTIVE: To evaluate the reliability of a new visual acuity testing protocol for children using isolated surrounded HOTV optotypes. METHODS: After initial pilot testing and modification, the protocol was evaluated using the Baylor-Video Acuity Tester (BVAT) to present isolated surrounded HOTV optotypes. At 6 sites, the protocol was evaluated for testability in 178 children aged 2 to 7 years and for reliability in a subset of 88 children. Twenty-eight percent of the 178 children were classified as having amblyopia. RESULTS: Using the modified protocol, testability ranged from 24% in 2-year-olds to 96% in 5- to 7-year-olds. Test-retest reliability was high (r = 0.82), with 93% of retest scores within 0.1 logMAR unit of the initial test score. The 95% confidence interval for an acuity score was calculated to be the score +/-0.125 logMAR unit. For a change between 2 acuity scores, the 95% confidence interval was the difference +/-0.18 logMAR unit. CONCLUSIONS: The visual acuity protocol had a high level of testability in 3- to 7-year-olds and excellent test-retest reliability. The protocol has been incorporated into the multicenter Amblyopia Treatment Study and has wide potential application for standardizing visual acuity testing in children.

The Amblyopia Treatment Index.

OBJECTIVE: To develop a questionnaire to assess the acceptability of amblyopia treatment and its effect on the child and family. METHODS: A 20-item parental survey was developed and pilot tested on 64 subjects, aged 3 to 6 years, participating in the Amblyopia Treatment Study, a randomized trial comparing patching and atropine as treatments for moderate amblyopia. The survey was administered after 4 weeks of treatment. A descriptive item analysis and an internal consistency reliability analysis were performed. RESULTS: Nineteen of the 20 items demonstrated adequate variability as evidenced by the frequency distributions for item responses. Only 4 (<1%) of 1280 possible item responses were missing, one each by 4 different respondents. Factor analysis identified 3 treatment-related factors--"adverse effects," "compliance," and "social stigma"--among 11 of the 20 items. The internal-consistency reliability alpha for the 5-item adverse effects subscale was 0.82, the 4-item compliance subscale alpha was 0.81, and the 2-item social stigma subscale alpha was 0.84. CONCLUSIONS: The Amblyopia Treatment Index appears to be a useful instrument for assessing the impact of amblyopia treatment in 3- to 6-year-old children.

The SKILL Card test in optic neuritis: experience of the Optic Neuritis Treatment Trial. Smith-Kettlewell Institute Low Luminance. Optic Neuritis Study Group.

OBJECTIVES: To assess the value of the Smith-Kettlewell Institute Low Luminance (SKILL) Card test, designed to measure vision at reduced contrast and luminance, among patients with previous optic neuritis. MATERIALS AND METHODS: The SKILL Card test was administered to 295 patients participating in the Optic Neuritis Treatment Trial (ONTT) follow-up study, concurrent with measurement of visual acuity, visual field, contrast sensitivity, and color vision. Health-related quality of life (HRQL) was also assessed in a subset of patients using the National Eye Institute Visual Function Questionnaire and an ONTT-developed questionnaire. RESULTS: The SKILL Card difference score (high-contrast acuity score minus low-contrast acuity score) was only weakly associated with the other measures of vision function (rs absolute range, 0.05-0.31) and with the HRQL measures (rs absolute range, 0.02-0.15). In contrast, the light and dark component scores of the SKILL Card test had higher associations with the other vision measures (rs absolute range, 0.27-0.54) and with the HRQL measures (rs absolute range, 0.10-0.40). CONCLUSIONS: The SKILL Card difference score is not a meaningful measure for patients with optic neuritis; however, the test appears to have clinical usefulness as a method to measure high-contrast and low-contrast acuity.

Interaction between HLA-DR2 and abnormal brain MRI in optic neuritis and early MS. Optic Neuritis Study Group.

The association of the human leukocyte antigen (HLA)-DR2 allele with brain MRI signal abnormalities and with the development of MS was assessed in 178 patients enrolled in the Optic Neuritis Treatment Trial. HLA haplotype DR2 was present in 85 (48%) of the 178 patients. Its presence was associated with increased odds of probable or definite MS at 5 years (odds ratio, 1.92; 95% confidence interval, 1.01 to 3.67; p = 0.04). The association was most apparent among patients with signal abnormalities on baseline brain MRI.

The National Eye Institute Visual Function Questionnaire: experience of the ONTT. Optic Neuritis Treatment Trial.

PURPOSE: To describe the health-related quality of life, measured with the National Eye Institute Visual Function Questionnaire (NEI-VFQ), of patients several years after the onset of optic neuritis, according to their neurologic and visual status; to assess the relationship between the NEI-VFQ subscales and clinical measures of visual function; and to assess the internal consistency reliability of the NEI-VFQ subscales. METHODS: The NEI-VFQ was administered to 244 patients 5 to 8 years after treatment for an episode of acute optic neuritis as part of the Optic Neuritis Treatment Trial. Visual acuity, visual field, contrast sensitivity, and color vision were measured at the same time as questionnaire completion. RESULTS: The NEI-VFQ scores generally were lower than those reported for a disease-free group. Reported dysfunction was greater when multiple sclerosis was present and when visual acuity was abnormal, supporting the construct validity of the NEI-VFQ. Rank correlations between the NEI-VFQ subscales and clinical measures of visual function were moderate at best. Internal consistency reliability was generally high for most of the NEI-VFQ subscales. CONCLUSIONS: These findings add support to the use of the NEI-VFQ as a valuable measure of self-reported visual impairment.

The predictive value of CSF oligoclonal banding for MS 5 years after optic neuritis. Optic Neuritis Study Group.

The predictive value of CSF oligoclonal banding for the development of clinically definite MS (CDMS) within 5 years after optic neuritis was assessed in 76 patients enrolled in the Optic Neuritis Treatment Trial. The presence of oligoclonal bands was associated with the development of CDMS (p = 0.02). However, the results suggest that CSF analysis is only useful in the risk assessment of optic neuritis patients when brain MRI is normal and is not of predictive value when brain MRI lesions are present at the time of optic neuritis.

Aspirin therapy in nonarteritic anterior ischemic optic neuropathy.

PURPOSE: To determine the benefit of aspirin in reducing the risk of nonarteritic anterior ischemic optic neuropathy in the fellow eye following its occurrence in the first eye. METHODS: A retrospective cohort study was conducted on 431 patients, 153 of whom were and 278 of whom were not prescribed aspirin following the development of unilateral nonarteritic anterior ischemic optic neuropathy. RESULTS: The 2-year cumulative probability of nonarteritic anterior ischemic optic neuropathy in the fellow eye was 7% in the aspirin group and 15% in the no-aspirin group, and 5-year cumulative probabilities were 17% and 20%, respectively. Compared with the no-aspirin group, the rate ratio for nonarteritic anterior ischemic optic neuropathy in the fellow eye in the aspirin-user group was 0.43 (95% confidence interval, 0.19 to 0.92) over the first 2 years and 0.68 (95% confidence interval, 0.36 to 1.26) over the 5-year period. The overall calculated 5-year risk was 19%; however, if none of the patients with incomplete follow-up developed nonarteritic anterior ischemic optic neuropathy in the fellow eye, then the 5-year risk would be about 12%. CONCLUSIONS: The 5-year risk of nonarteritic anterior ischemic optic neuropathy occurring in the second eye is far lower than that reported by previous studies. Our results suggest a possible short-term but little or no long-term benefit to aspirin in reducing the risk of nonarteritic anterior ischemic optic neuropathy in the fellow eye. However, this finding must be viewed with caution because this study was not conducted prospectively with a controlled protocol.

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.