Full-time Bangerter Filters Versus Part-time Daily Patching for Moderate Amblyopia in Children

This study is a randomized clinical trial designed to evaluate the non-inferiority of Bangerter filters compared to 2 hours of daily patching as a primary treatment for moderate amblyopia (20/40 to 20/80) in children ages 3 to \< 10 years. Secondary objectives of this study are (1) to determine the time course of visual improvement with Bangerter filter treatment, (2) to compare patient quality of life, measured by a modified Amblyopia Treatment Index, between patients treated with patching vs. Bangerter filters, (3) to determine whether blurring the sound eye to a visual acuity worse than the amblyopic eye predicts improvement in acuity, and (4) to determine whether a change in fixation to the amblyopic eye is predictive of improvement in visual acuity. The primary outcome assessment is visual acuity at 24 weeks for both the amblyopic and sound eyes. The primary analytic approach for the amblyopic eye acuity will involve construction of a one-sided 95% confidence interval to assess non-inferiority based on a treatment group comparison of logMAR visual acuity scores adjusted for baseline visual acuity scores in an analysis of covariance (ANCOVA) model. Sound eye acuity data will be reported for each treatment regimen at the 24-week visit as mean change (logMAR lines) from baseline and as the distribution of the number of lines of change from baseline.