Status: Funded - Open
Binocular iPad treatment for amblyopia
Krista Kelly, PhD
Purpose: Childhood amblyopia can be treated with binocular games or movies that rebalance contrast between the eyes, which is thought to reduce depth of interocular suppression so the child can experience binocular vision (Birch et al., 2015; Li et al., 2015). We recently found that two weeks of binocular games improved visual acuity more than patching (Kelly et al, 2016). Yet, stereoacuity improvement did not accompany the visual acuity improvement. Here we evaluate additional binocular outcomes.
Methods: 47 amblyopic children (4-12y; ≤4pd) assigned to binocular treatment [movies (n=29) or game (n=18)] were compared to 19 amblyopic children assigned to 2 h/d patching. Amblyopic eye best-corrected visual acuity (BCVA) and binocular outcomes were assessed at baseline and 2 weeks, after 9-10 h binocular or 28 h patching treatment. Binocular outcomes: dichoptic contrast ratio balance point (CR; depth of suppression), Worth-4-Dot (W4D at 7 distances; extent of suppression scotoma), Randot Preschool stereoacuity (RPS).
Results: Mean±SD BCVA improved by 1.4 lines with binocular treatment (0.56±0.29 vs 0.42±0.28 logMAR;t=10.04,p<0.001) and 0.7 lines with patching (0.50±0.15 vs 0.43±0.17 logMAR;t=3.64,p=0.002); i.e., binocular treatment was more successful than patching (t=2.71, p=0.009). Depth of suppression (CR) improved with binocular treatment (baseline: 4.63±3.41 vs 2 week: 3.41±2.66;t=3.81,p<0.001) and patching (4.71±3.08 vs 3.04±.2.07; t=2.85,p=0.012). For binocular treatment, CR improved more for children <7 years than children ≥7 years old (t=2.38, p=0.029). BCVA was correlated with CR at baseline (r=0.39, p=0.007) and at 2 weeks (r=0.38, p=0.008). Extent of suppression improved with binocular treatment (baseline: 0.53±0.41 vs 2 week: 0.41±0.44 log deg;t=2.98,p=0.005), but not with patching (0.36±0.33 vs 0.23±0.45 log deg;t=1.54,p=0.14). Stereoacuity improved with binocular treatment (baseline: 3.56±0.76 vs 2 week: 3.47±0.77 log arcsec;Z=2.00,p=0.045), but not with patching (3.21±0.88 vs 3.30±0.79 log arcsec;Z=1.35,p=0.18).
Conclusions: Contrast-rebalanced binocular treatment was not only successful in ameliorating the visual acuity deficit in childhood amblyopia, but also improved binocular outcomes more than patching, reducing the extent and depth of suppression and improving stereoacuity.
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