Treatment of anisometropic amblyopia with spectacles or in combination with translucent Bangerter filters.

Purpose: To compare spectacle correction alone with spectacle correction with Bangerter filters to treat anisometropic amblyopia in children.
Design: Prospective, randomized clinical trial.
Participants: Eighty children (mean age, 4.4 years) with untreated anisometropic amblyopia and a median best-corrected visual acuity (BCVA) in the amblyopic eye of 0.4 logarithm of the minimum angle of resolution (logMAR).
Methods: Optimal refractive correction was provided, and the children were assigned to treatment with either spectacles or spectacles in combination with a Bangerter filter worn on the spectacle lens of the better eye. The BCVA, binocular function, and refractive errors were measured repeatedly over the course of 1 year.
Main Outcome Measures: The time course to resolution of the amblyopia (interocular difference, < or =1 line).
Results: The difference in the mean time to the resolution of amblyopia was 3.9+/-3.2 months for the spectacles group versus 2.2+/-1.9 months for the filter group, and the difference reached significance (P<0.05). The BCVA in the amblyopic eye improved significantly (P<0.001 for both comparisons) in both groups. After 1 year, there was no significant difference in the BCVA between the groups. The binocular function improved in both groups; at 1 year there was no significant difference between the groups. The median spherical equivalent refractive error increased significantly during the study in the amblyopic eyes (P<0.05) and the fellow eyes (P<0.001). The median anisometropia decreased significantly from the first visit to the 1-year visit in both groups (P<0.001 for both comparisons).
Conclusions: We found a more rapid visual acuity recovery with the Bangerter filters than with spectacles alone in eyes with anisometropic amblyopia. However, the 1-year visual acuity outcome was not statistically significantly different between the 2 treatments.