Dichoptic Movie Treatment of Childhood Amblyopia

Abstract

Purpose: Contrast-balanced dichoptic experience with perceptual-learning tasks, games, or both has been shown to improve visual acuity in amblyopia. We previously demonstrated that repeated binocular experience via at-home binocular iPad game play with reduced fellow-eye contrast was effective in treating childhood amblyopia^1,2 and that visual acuity was maintained for ≥12 months³. However, these tasks are intensive and repetitive and up to 40% of patients are noncompliant.^1,2,4 Here we investigated the efficacy of a potentially more engaging movie method to provide contrast-balanced binocular experience via complementary dichoptic stimulation.

Methods: Seven amblyopic children (4-10y; 0.5-1.2 logMAR or 20/63-20/320) were enrolled in a prospective cohort study to watch 3 dichoptic movies per week for 2 weeks on a passive 3D display. Dichoptic versions of 18 popular animated feature films were created. A patterned image mask of irregularly shaped blobs was multiplied with the movie images seen by the amblyopic eye and an inverse pattern mask was multiplied with the images seen by the fellow eye. Fellow-eye contrast was initially set for each amblyopic child at a reduced level that allowed binocular vision and was incremented by 10% at each visit. At the baseline and 2-week outcome visits, BCVA, random dot stereoacuity, interocular suppression, and fixation stability were measured. None of the children had any concurrent amblyopia treatment during this study.

Results: After watching 6 dichoptic movies during a two-week period (9.3±0.8 hours), mean (±SE) amblyopic eye BCVA improved from 0.71±0.10 logMAR at baseline to 0.54±0.10 logMAR (p= 0.006); i.e. 1.7 lines. Three children with 0.5 logMAR baseline BCVA improved 0.1 logMAR (1 line); three children with 0.7-0.8 logMAR baseline BCVA improved 0.2-0.4 logMAR (2-4 lines), and one child with 1.2 logMAR baseline BCVA improved 0.1 logMAR (1 line). Fellow-eye BCVA did not change significantly during the study (p=0.19). No significant change in random dot stereoacuity, interocular suppression, or fixation stability was found.

Conclusions: Repeated contrast-balanced binocular visual experience significantly improved amblyopic-eye visual acuity. Contrast-balanced dichoptic feature films may result in better compliance than repetitive perceptual-learning tasks or games. 1. Li et al Eye 2014; 28:1246-53. 2. Birch et al J AAPOS in press. 3. Li et al JAMA Ophthal in press.<br /> 4. Levi et al JOV 2014; 14:959