Binocular amblyopia treatment with contrast-rebalanced movies

Abstract

Background: Binocular amblyopia treatments promote visual acuity recovery and binocularity by rebalancing the signal strength of dichoptic images. Most require active participation by the amblyopic child to play a game or perform a repetitive visual task. The purpose of this study was to investigate a passive form of binocular treatment with contrast-rebalanced dichoptic movies.

Methods: A total of 27 amblyopic children, 4-10 years of age, wore polarized glasses to watch 6 contrast-rebalanced dichoptic movies on a passive 3D display during a 2-week period. Amblyopic eye contrast was 100%; fellow eye contrast was initially set to a lower level (20%-60%), which allowed the child to overcome suppression and use binocular vision. Fellow eye contrast was incremented by 10% for each subsequent movie. Best-corrected visual acuity, random dot stereoacuity, and interocular suppression were measured at baseline and at 2 weeks.

Results: Amblyopic eye best-corrected visual acuity improved from 0.57 ± 0.22 at baseline to 0.42 ± 0.23 logMAR (t26 = 8.09; P < 0.0001; 95% CI for improvement, 0.11-0.19 logMAR). Children aged 3-6 years had more improvement (0.21 ± 0.11 logMAR) than children aged 7-10 years (0.11 ± 0.06 logMAR; t25 = 3.05; P = 0.005). Children with severe amblyopia (≥0.7 logMAR) at baseline experienced greater improvement (0.24 ± 0.12 logMAR) than children with moderate amblyopia at baseline (0.12 ± 0.06 logMAR; t25 = 3.49; P = 0.002).

Conclusions: In this cohort, passive viewing of contrast-rebalanced dichoptic movies effectively improved visual acuity in amblyopic subjects. The degree of improvement observed was similar to that previously reported for 2 weeks of binocular games treatment and with 3-4 months of occlusion therapy.

Copyright © 2019 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Figures

FIG 1

A, Best-corrected visual acuity (mean with standard deviation) of the amblyopic and fellow eyes for the baseline and 2-week primary outcome visits. Also shown are retrospective data at 6 months, 3 months, and 1 month prior to baseline, obtained from medical records for 20, 23, and 27 of the 27 participants, respectively. B, Percentages of children with severe (≥0.7 logMAR), moderate (0.3–0.6 logMAR), and mild or no (≤0.2 logMAR) amblyopia at baseline and after treatment. C, Number of lines of best-corrected visual acuity improvement from baseline at the outcome examination.

FIG 2

Improvement in amblyopic eye best-corrected visual acuity in the younger (3–6 years) and the older (7–10 years) age subgroups and in subgroups with moderate (0.3–0.6 logMAR) or severe (≥0.7 logMAR) amblyopia at baseline.