Raymond T. Kraker

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.

The treatment of traumatic optic neuropathy: the International Optic Nerve Trauma Study.

OBJECTIVE To compare the visual outcome of traumatic optic neuropathy treated with corticosteroids, treated with optic canal decompression surgery, or observed without treatment. DESIGN Comparative nonrandomized interventional study with concurrent treatment groups. PARTICIPANTS A total of 133 patients with traumatic optic neuropathy (127 unilateral and 6 bilateral) who had an initial visual assessment within 3 days of injury. At least 1 month of follow-up was required for inclusion in the primary analysis. INTERVENTIONS On the basis of treatment received within 7 days of injury, patients with unilateral injuries were categorized as being in one of three treatment groups: untreated (n = 9), corticosteroid (n = 85), or optic canal decompression surgery (n = 33). MAIN OUTCOME MEASURE Visual acuity. RESULTS Visual acuity increased by > or = 3 lines in 32% of the surgery group, 57% of the untreated group, and 52% of the steroid group (P = 0.22). The surgery group had more patients whose initial vision was no light perception. After adjustment for the baseline visual acuity, there were no significant differences between any of the treatment groups. There was no indication that the dosage or timing of corticosteroid treatment or the timing of surgery was associated with an increased probability of visual improvement. CONCLUSIONS No clear benefit was found for either corticosteroid therapy or optic canal decompression surgery. The number of patients studied was sufficient to rule out major effects in the treatment groups, although clinically relevant effects in specific subgroups could have been missed. These results and the existing literature provide sufficient evidence to conclude that neither corticosteroids nor optic canal surgery should be considered the standard of care for patients with traumatic optic neuropathy. It is therefore clinically reasonable to decide to treat or not treat on an individual patient basis.

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.

Patching vs atropine to treat amblyopia in children aged 7 to 12 years: A randomized trial

OBJECTIVE To compare patching with atropine eyedrops in the treatment of moderate amblyopia (visual acuity, 20/40-20/100) in children aged 7 to 12 years. METHODS In a randomized, multicenter clinical trial, 193 children with amblyopia were assigned to receive weekend atropine or patching of the sound eye 2 hours per day. Main Outcome Measure Masked assessment of visual acuity in the amblyopic eye using the electronic Early Treatment Diabetic Retinopathy Study testing protocol at 17 weeks. RESULTS At 17 weeks, visual acuity had improved from baseline by an average of 7.6 letters in the atropine group and 8.6 letters in the patching group. The mean difference between groups (patching - atropine) adjusted for baseline acuity was 1.2 letters (ends of complementary 1-sided 95% confidence intervals for noninferiority, -0.7, 3.1 letters). This difference met the prespecified definition for equivalence (confidence interval <5 letters). Visual acuity in the amblyopic eye was 20/25 or better in 15 participants in the atropine group (17%) and 20 in the patching group (24%; difference, 7%; 95% confidence interval, -3% to 17%). CONCLUSIONS Treatment with atropine or patching led to similar degrees of improvement among 7- to 12-year-olds with moderate amblyopia. About 1 in 5 achieved visual acuity of 20/25 or better in the amblyopic eye. CLINICAL RELEVANCE Atropine and patching achieve similar results among older children with unilateral amblyopia. TRIAL REGISTRATION (clinicaltrials.gov) Identifier: NCT00315328.

Risk of amblyopia recurrence after cessation of treatment.

BACKGROUND Although amblyopia can be successfully treated with patching or atropine, there have been few prospective studies of amblyopia recurrence once treatment is discontinued. METHODS We enrolled 156 children with successfully treated anisometropic or strabismic amblyopia (145 completed follow-up), who were younger than 8 years of age and who received continuous amblyopia treatment for the previous 3 months (prescribed at least 2 hours of daily patching or prescribed at least one drop of atropine per week) and who had improved at least 3 logMAR levels during the period of continuous treatment. Patients were followed off treatment for 52 weeks to assess recurrence of amblyopia, defined as a 2 or more logMAR level reduction of visual acuity from enrollment, confirmed by a second examination. Recurrence was also considered to have occurred if treatment was restarted because of a nonreplicated 2 or more logMAR level reduction of visual acuity. RESULTS Recurrence occurred in 35 (24%) of 145 cases (95% confidence interval 17% to 32%) and was similar in patients who stopped patching (25%) and in patients who stopped atropine (21%). In patients treated with moderately intense patching (6 to 8 hours per day), recurrence was more common (11 of 26; 42%) when treatment was not reduced prior to cessation than when treatment was reduced to 2 hours per day prior to cessation (3 of 22; 14%, odds ratio 4.4, 95% confidence interval 1.0 to 18.7). CONCLUSIONS Approximately one fourth of successfully treated amblyopic children experience a recurrence within the first year off treatment. For patients treated with 6 or more hours of daily patching, our data suggest that the risk of recurrence is greater when patching is stopped abruptly rather than when it is reduced to 2 hours per day prior to cessation. A randomized clinical trial of no weaning versus weaning in successfully-treated amblyopia is warranted to confirm these observational findings.

Retinal Nerve Fiber Layer Thickness in Amblyopic Eyes

PURPOSE To compare the peripapillary retinal nerve fiber layer (RNFL) thickness of amblyopic and fellow eyes. We hypothesized that the RNFL of the amblyopic eye may be thinner. DESIGN Prospective, cross-sectional, observational case series. METHODS Optical coherence tomography of the peripapillary RNFL thickness of amblyopic and fellow eyes was performed in 37 patients 7 to 12 years of age (mean age +/- standard deviation, 9.2 +/- 1.5 years) with unilateral strabismic, anisometropic, or combined-mechanism amblyopia enrolled in a randomized treatment trial. RESULTS Mean global RNFL thickness of the amblyopic and fellow eyes was 111.4 and 109.6 microm, respectively (mean difference, 1.8 microm thicker in the amblyopic eyes; 95% confidence interval, -0.6 to 4.3 microm). The amblyopic eye was 8 microm or more thicker than the fellow eye in 9 patients (24%); the fellow eye was 8 microm or more thicker than the amblyopic eye in 2 patients (5%); and the difference was within test-retest variability (7 microm) in 26 patients (70%). CONCLUSIONS Our findings do not indicate that peripapillary RNFL thickness is thinner in eyes with moderate amblyopia compared with their fellow eyes.

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

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

Treatment of severe amblyopia with weekend atropine: Results from 2 randomized clinical trials

PURPOSE To determine the effectiveness of weekend atropine for severe amblyopia from strabismus, anisometropia, or both combined among children 3 to 12 years of age. METHODS We enrolled children into 2 prospective, randomized multicenter clinical trials of amblyopia therapy. Herein we report the results for severe amblyopia, 20/125 to 20/400. In Trial 1, 60 children 3 to 6 years of age (mean, 4.4 years) were randomized to weekend atropine plus a plano lens or weekend atropine plus full spectacle correction for the sound eye. In Trial 2, 40 children 7 to 12 years of age (mean, 9.3 years) were randomized to weekend atropine or 2 hours of daily patching. The visual acuity outcome was assessed at 18 weeks in Trial 1 and 17 weeks in Trial 2. RESULTS In Trial 1, visual acuity improved by an average of 4.5 lines in the atropine plus correction group (95% CI, 3.2-5.8 lines) and 5.1 lines in the atropine plus plano lens group (95% CI, 3.7-6.4 lines). In Trial 2, visual acuity improved by an average of 1.5 lines in the atropine group (95% CI, 0.5-2.5 lines) and 1.8 lines in the patching group (95% CI, 1.1-2.6 lines). CONCLUSIONS Weekend atropine can improve visual acuity in children 3 to 12 years of age with severe amblyopia. Improvement may be greater in younger children.

Stereoacuity in children with anisometropic amblyopia

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

Optical treatment of strabismic and combined strabismic-anisometropic amblyopia.

OBJECTIVE To determine visual acuity improvement in children with strabismic and combined strabismic-anisometropic (combined-mechanism) amblyopia treated with optical correction alone and to explore factors associated with improvement. DESIGN Prospective, multicenter, cohort study. PARTICIPANTS We included 146 children 3 to <7 years old with previously untreated strabismic amblyopia (n = 52) or combined-mechanism amblyopia (n = 94). METHODS Optical treatment was provided as spectacles (prescription based on a cycloplegic refraction) that were worn for the first time at the baseline visit. Visual acuity with spectacles was measured using the Amblyopia Treatment Study HOTV visual acuity protocol at baseline and every 9 weeks thereafter until no further improvement in visual acuity. Ocular alignment was assessed at each visit. MAIN OUTCOME MEASURES Visual acuity 18 weeks after baseline. RESULTS Overall, amblyopic eye visual acuity improved a mean of 2.6 lines (95% confidence interval [CI], 2.3-3.0), with 75% of children improving ≥ 2 lines and 54% improving ≥ 3 lines. Resolution of amblyopia occurred in 32% (95% CI, 24%-41%) of the children. The treatment effect was greater for strabismic amblyopia than for combined-mechanism amblyopia (3.2 vs 2.3 lines; adjusted P = 0.003). Visual acuity improved regardless of whether eye alignment improved. CONCLUSIONS Optical treatment alone of strabismic and combined-mechanism amblyopia results in clinically meaningful improvement in amblyopic eye visual acuity for most 3- to <7-year-old children, resolving in at least one quarter without the need for additional treatment. Consideration should be given to prescribing refractive correction as the sole initial treatment for children with strabismic or combined-mechanism amblyopia before initiating other therapies. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any of the materials discussed in this article.