Table 2.
Distribution of Amblyopic-eye Visual Acuity Outcomes by Treatment Group at Baseline and Outcome Visits.
| Baseline | 4 weeksa | 8 weeksa | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
||||||||||||
| Binocular Treatment | Continued Spectacles | Binocular Treatment | Continued Spectacles | Binocular Treatment | Continued Spectacles | |||||||
|
|
||||||||||||
| N | % | N | % | N | % | N | % | N | % | N | % | |
|
| ||||||||||||
| Per Group (N) | 92 | 90 | 85 | 84 | 85 | 84 | ||||||
|
| ||||||||||||
| Amblyopic-eye VA | ||||||||||||
| 20/320 | 0 | 0% | 0 | 0% | 0 | 0% | 1 | 1% | 0 | 0% | 1 | 1% |
| 20/250 | 0 | 0% | 0 | 0% | 0 | 0% | 0 | 0% | 0 | 0% | 0 | 0% |
| 20/200 | 1 | 1% | 2 | 2% | 1 | 1% | 2 | 2% | 0 | 0% | 0 | 0% |
| 20/160 | 2 | 2% | 3 | 3% | 0 | 0% | 0 | 0% | 1 | 1% | 4 | 5% |
| 20/125 | 7 | 8% | 3 | 3% | 3 | 4% | 4 | 5% | 5 | 6% | 0 | 0% |
| 20/100 | 3 | 3% | 4 | 4% | 5 | 6% | 1 | 1% | 4 | 5% | 1 | 1% |
| 20/80 | 9 | 10% | 9 | 10% | 9 | 11% | 6 | 7% | 8 | 9% | 8 | 10% |
| 20/63 | 24 | 26% | 24 | 27% | 15 | 18% | 20 | 24% | 9 | 11% | 13 | 15% |
| 20/50 | 27 | 29% | 26 | 29% | 9 | 11% | 18 | 21% | 11 | 13% | 18 | 21% |
| 20/40 | 19 | 21% | 19 | 21% | 18 | 21% | 15 | 18% | 19 | 22% | 17 | 20% |
| 20/32 | 0 | 0% | 0 | 0% | 15 | 18% | 10 | 12% | 14 | 16% | 12 | 14% |
| 20/25 | 0 | 0% | 0 | 0% | 6 | 7% | 5 | 6% | 12 | 14% | 7 | 8% |
| 20/20 | 0 | 0% | 0 | 0% | 2 | 2% | 2 | 2% | 1 | 1% | 1 | 1% |
| 20/16 | 0 | 0% | 0 | 0% | 1 | 1% | 0 | 0% | 0 | 0% | 1 | 1% |
| 20/12 | 0 | 0% | 0 | 0% | 1 | 1% | 0 | 0% | 1 | 1% | 1 | 1% |
| Mean (SD) logMAR | 0.48 (0.16) | 0.48 (0.17) | 0.38 (0.22) | 0.42 (0.21) | 0.36 (0.22) | 0.38 (0.22) | ||||||
|
| ||||||||||||
| Mean IOD (SD) Lines | 4.8 (1.7) | 4.9 (1.7) | 3.8 (2.3) | 4.4 (2.2) | 4.0 (2.2) | 4.0 (2.3) | ||||||
|
| ||||||||||||
| Change in amblyopic-eye VA from baseline | ||||||||||||
| ≥ 3 lines better | 12 | 14% | 6 | 7% | 12 | 14% | 9 | 11% | ||||
| 2 lines better | 19 | 22% | 10 | 12% | 23 | 27% | 16 | 19% | ||||
| 1 line better | 22 | 26% | 30 | 36% | 29 | 34% | 33 | 39% | ||||
| 0 line | 23 | 27% | 25 | 30% | 12 | 14% | 13 | 15% | ||||
| 1 line worse | 7 | 8% | 9 | 11% | 8 | 9% | 11 | 13% | ||||
| 2 lines worse | 2 | 2% | 3 | 4% | 1 | 1% | 2 | 2% | ||||
| ≥ 3 lines worse | 0 | 0% | 1 | 1% | 0 | 0% | 0 | 0% | ||||
| Mean (SD) Linesb | 1.1 (1.4) | 0.6 (1.3) | 1.3 (1.4) | 1.0 (1.4) | ||||||||
| Adjusted mean (95% CI) at 4 weeksc | 1.1 (0.8, 1.4) | 0.6 (0.3, 0.9) | ||||||||||
| Adjusted mean difference (95.1% CI) at 4 weeksc | 0.5 (0.1, 0.9) | |||||||||||
| Adjusted mean (95% CI) at 8 weeksc | 1.3 (1.0, 1.6) | 1.0 (0.7, 1.3) | ||||||||||
| Adjusted mean difference (98.4% CI) at 8 weeksc | 0.3 (−0.2, 0.8) | |||||||||||
|
| ||||||||||||
| Improvement of ≥2 lines from baseline | 31 | 36% | 16 | 19% | 35 | 41% | 25 | 30% | ||||
| Difference (98.4% CI)d | 18% (1%, 34%) | 12% (−6%, 29%) | ||||||||||
|
| ||||||||||||
| Unmasked VA testing | 0 | 0% | 1 | 1% | 2 | 2% | 0 | 0% | ||||
CI = confidence interval; IOD = interocular difference; logMAR = logarithm of minimum angle of resolution; SD = standard deviation; VA = visual acuity.
Limited to follow-up visits completed within the pre-specified analysis windows.
Positive values indicate improvement in amblyopic-eye visual acuity from baseline.
Analysis of covariance model adjusting for baseline amblyopic-eye visual acuity was used to estimate the mean change in amblyopic-eye visual acuity within each treatment group as well as the treatment group difference (positive values favor the binocular treatment group) in the mean change in amblyopic-eye visual acuity from baseline to 4 weeks (P = .03) and to 8 weeks (Bonferroni-adjusted P = .60).
Binomial regression adjusting for baseline amblyopic-eye visual acuity was used to compare the proportion of participants with improvement of ≥2 lines in amblyopic-eye visual acuity from baseline to 4 weeks (Bonferroni-adjusted P = .03) and to 8 weeks (Bonferroni-adjusted P = .34) between the treatment groups. For the 3 exploratory visual acuity outcomes (which included the 8-week treatment group comparison of mean change in amblyopic-eye visual acuity), a Bonferroni adjustment was used to control for multiple testing to preserve the overall type I error rate at 4.9% (2-sided alpha=0.016 per test).