Dichoptic and Monocular Visual Acuity in Amblyopia

center dot PURPOSE: Standard-of-care assessment for children with amblyopia includes measuring amblyopic eye best -corrected visual acuity (AE BCVA) with the fellow eye occluded. By definition, this abolishes the interocular suppression fundamental to amblyopia. Thus, measured AE BCVA may not accurately represent that eye's con-tribution to natural binocular viewing. We compared di-choptic and monocular AE BCVA and examined whether any differences were associated with eye-hand coordina-tion or reading speed.center dot DESIGN: Cross-sectional study.center dot METHODS: Dichoptic and monocular AE BCVA of children aged 6-12 years (42 with amblyopia, 24 with recovered normal AE BCVA, 30 control) were mea-sured. Stereoacuity, suppression, eye-hand coordination, and reading speed were also assessed. center dot RESULTS: Overall, 81% of amblyopic children had worse dichoptic than monocular AE BCVA (mean difference = 0.15 +/- 0.11 logMAR; P < .0001), and 71% of children with recovered normal AE BCVA had worse dichoptic than monocular AE BCVA (mean differ-ence = 0.20 +/- 0.17 logMAR, P < .0001). Controls had no significant difference. The difference between dichop-tic and monocular AE BCVA was correlated with perfor-mance in standardized aiming/catching ( r =-0.48, 95% CI-0.72,-0.14) and manual dexterity tasks ( r =-0.37, 95% CI-0.62,-0.06), and with reading speed ( r = -0.38, 95% CI-0.65,-0.03).center dot CONCLUSIONS: Dichoptic AE BCVA deficits were worse than monocular AE BCVA deficits and were asso-ciated with reduced stereoacuity and suppression, consis-tent with the hypothesis that binocular dysfunction plays a role. Further, impaired eye-hand coordination and slow reading were associated with dichoptic, but not monocu-lar, AE BCVA. Some children with amblyopia may ben-efit from extra time for school tasks requiring eye-hand coordination or reading. (Am J Ophthalmol 2022;242: 209-214. (c) 2022 Elsevier Inc. All rights reserved.)