Two‐year follow‐up of a randomized trial of spectacles alone or combined with Bangerter filters for treating anisometropic amblyopia

Abstract

To compare spectacle correction alone to spectacle correction with Bangerter filters as treatments for anisometropic amblyopia in children 1 year after completion of a 1-year randomized trial. In a randomized clinical trial, 80 children (mean age, 4.4 years) with anisometropic amblyopia and a best median visual acuity (VA) in the amblyopic eye of 0.4 logarithm of the minimum angle of resolution (logMAR) were assigned to treatment with either spectacles or spectacles in combination with a Bangerter filter for 1 year. After 1 year, treatment with spectacles continued. If the VA differed by ≥ 2 lines, treatment with Bangerter filters was continued if originally prescribed. The main outcome measure was the median change in VA of the amblyopic eye after 2 years. The median change in VA of the amblyopic eye did not differ significantly between the groups (0.4 log unit for both groups) at the 2-year visit. At that time, the VA in the amblyopic eyes and the fellow eyes was 0.0 median logMAR in both groups. Between years 1 and 2, the median VA improved in the amblyopic eyes; in the spectacles group (p = 0.0181) and in the Bangerter filter group (p = 0.0342). The median anisometropia decreased in both groups (p < 0.0001 for both comparisons). We found stability in the VA improvement in both groups. The magnitude of the VA change 2 years after treatment with spectacles alone did not differ significantly from that after treatment with spectacles and a Bangerter filter for anisometropic amblyopia.