Abstract
Poor monocular visual acuity and binocular vision, including stereopsis, are characteristic of amblyopia. Motion perception is also often disrupted in both amblyopic and fellow eyes. Occlusion therapy is the gold-standard treatment for amblyopia, but it is often not successful at restoring visual acuity, stereopsis or motion perception. In this study, we evaluated the effectiveness of a recently developed video game-based dichoptic treatment for restoring these aspects of vision in amblyopia. Participants with strabismic or anisometropic amblyopia (5-56 years) were assessed before and after 8 weeks of binocular treatment (Vivid Vision) through a local optometry clinic. Treatment comprised either in-clinic supervised 30-min sessions or at-home training for at least 4 hours. We conducted monocular assessments of visual acuity and coherence thresholds for discriminating motion-defined form orientation and global motion direction. We also conducted binocular assessments of stereoacuity, depth-order (near/far) discrimination for fine (fused) and coarse (diplopia) disparity ranges, and interocular suppression measured as a contrast balance index on a dichoptic eye chart. Amblyopic eye visual acuity improved by 0.12 logMAR (p<.01) following treatment, but did not reach normal levels for any participant. Motion-defined form and global motion thresholds were abnormal in 70% and 75%, respectively, of amblyopic and in 40% and 50%, respectively, of fellow eyes before treatment. Motion-defined form improved with treatment (p=.01), and reached normal levels in young (5-8 years), but not older, participants. This improvement was only partially explained by the improvement in visual acuity. Global motion improved to normal levels in 2 participants. Stereoacuity did not improve. There was a trend towards improved depth-order discrimination for coarse, but not fine, disparities. Interocular suppression decreased in young (p=.01), but not older participants. The dichoptic treatment was modestly successful at improving visual acuity and binocular vision. It did prove efficacious at reducing motion deficits, particularly in younger children.