Amblyopia in High Accommodative Convergence/Accommodation Ratio Accommodative Esotropia. Influence of Bifocals on Treatment Outcome

Abstract

To study the influence of bifocal use on amblyopia treatment outcome in high accommodative convergence/accommodation (AC/A) ratio accommodative esotropia with deviation only at near. Retrospective comparative case series. Setting: Tertiary referral center. Children with high AC/A ratio accommodative esotropia aged 3-8 years old, with deviation only at near with glasses, neutralized with bifocal lenses (follow-up 1 year). Amblyopia was treated with patching. We compared bifocal and single-vision glasses users at 6months and 1 year, with control of potential confounding variables (multiple regression). LogMAR lines of improvement in visual acuity of the amblyopic eye, and improvement in stereoacuity. Of 78 children, 61 were eligible. All patients wore single-vision glasses for 2months (baseline visit), 46 of them changed to bifocals. Of 27 initially amblyopic children, 21 remained amblyopic at 2-month baseline (13of them changed to bifocals). After adjustment for initial deviation, refraction, age, and amblyopia, improvement of visual acuity in the amblyopic eye was larger in the bifocal vs single-vision group at 6months (mean 2.6 [95% confidence interval (CI): 1.9-2.9] logMAR lines vs mean 1.9 [95% CI: 0.5-2.2] logMAR lines, respectively, P= .01), but not at 1 year (mean 2.7 [95% CI: 2.2-3.1] logMAR lines vs mean 2.3 [95% CI: 1.6-3.1] logMAR lines, respectively, P= .3). Improvement of stereoacuity was not significantly different between the 2 groups. Use of bifocals may provide a transient advantage, but improvement in visual acuity and stereopsis is equal with single-vision glasses over time.