A randomized trial comparing Bangerter filters and patching for the treatment of moderate amblyopia in children.

Abstract

To determine whether visual acuity improvement with Bangerter filters is similar to improvement with patching as initial therapy for children with moderate amblyopia. Randomized, clinical trial. We enrolled 186 children, 3 to <10 years old, with moderate amblyopia (20/40-20/80). Children were randomly assigned to receive either daily patching or to use a Bangerter filter on the spectacle lens in front of the fellow eye. Study visits were scheduled at 6, 12, 18, and 24 weeks. Visual acuity in amblyopic eyes at 24 weeks. At 24 weeks, amblyopic eye improvement averaged 1.9 lines in the Bangerter group and 2.3 lines in the patching group (difference in mean visual acuities between groups adjusted for baseline acuity = 0.38 line). The upper limit of a 1-sided 95% confidence interval was 0.76 line, which slightly exceeded a prespecified noninferiority limit of <0.75 line. Similar percentages of subjects in each group improved > or =3 lines (Bangerter group 38% vs patching group 35%; P = 0.61) or had > or =20/25 amblyopic eye acuity (36% vs 31%, respectively; P = 0.86). There was a lower treatment burden in the Bangerter group as measured with the Amblyopia Treatment Index. With Bangerter filters, neither a fixation switch to the amblyopic eye nor induced blurring in the fellow eye to worse than that of the amblyopic eye was required for visual acuity improvement. Because the average difference in visual acuity improvement between Bangerter filters and patching was less than half a line, and there was lower burden of treatment on the child and family, Bangerter filter treatment is a reasonable option to consider for initial treatment of moderate amblyopia.