Abstract
Purpose:
Amblyopia has been classically treated through patching the fellow eye (FE) to force use of the amblyopic eye (AE). However, patching does not always result in 20/20 vision and amblyopia often recurs. Furthermore, patching does not promote binocular cooperation, the absence of which may underlie residual and recurrent amblyopia. In this study, we examined the effectiveness of a binocular amblyopia treatment.
Methods:
We developed dichoptic (anaglyphic) iPad video games. Initially, FE contrast is reduced to allow AE to “kick in”. As the child experiences binocular vision (by achieving a criterion game score), FE contrast is gradually incremented. Thirty-nine amblyopic children (4-12y) were enrolled. Four hours per week of iPad play was assigned for each 4-week round of treatment; 26 children completed one round and 13 completed two rounds. In addition to iPad, most children (N=30) were also prescribed patching. Visual acuity (VA), stereoacuity, fusion and interocular suppression were measured.
Results:
After one round, iPad binocular treatment yielded a mean VA improvement of 0.10±0.02 logMAR (1.0 line; p<0.0001). For the 31 children who were compliant with iPad treatment, mean improvement was 0.12±0.02 logMAR (1.2 lines; p<0.0001). No significant change in VA was found for noncompliant children (p= 0.39; N=8). Among compliant children, significantly greater VA improvement was found for younger (<7y;~ 1.5 lines) compared with older children (≥7y;~ 3 letters) (p=0.02). Even among the 9 older children who had discontinued patching due to lack of response, 6 had 0.1 or 0.2 logMAR of improvement in VA (1.0 or 2.0 lines) with iPad treatment. No significant difference in VA improvement was found with vs. without concurrent patching, with vs. without prior treatment, for baseline VA≤0.6 vs. >0.6 logMAR, for nil vs. non-nil baseline stereoacuity or among different etiologies (anisometropia, strabismus or combined). After 4 weeks of treatment, only a few had improved stereoacuity (19%) and/or fusion (26%) but 75% had reduced suppression. Only 3 of the 12 children with a second round of iPad treatment had additional VA improvement.
Conclusions:
Binocular iPad treatment for amblyopia yields a significant improvement in VA after 4 weeks of treatment and younger children improve more than older children. Whether this treatment confers a prolonged and durable benefit in amblyopia treatment is currently under investigation.
Keywords: 417 amblyopia •
434 binocular vision/stereopsis