Randomized Evaluation of Spectacles Plus Alternate-Day Occlusion to Treat Amblyopia

Purpose: To compare spectacles plus patching >= 8 hours daily 6 days a week with spectacles plus patching >= 8 hours on alternate days to treat amblyopia in children 4 to 5 years of age. Design: Prospective, randomized clinical trial. Participants: Forty children (median age, 4.3 years) with untreated amblyopia and a median best-corrected visual acuity (BCVA) in the amblyopic eye of 0.9 (range, 0.3-1.5) logarithm of the minimum angle of resolution. Methods: Refractive correction was provided, and the children were randomized to patching >= 8 hours daily 6 days a week or patching >= 8 hours on alternate days. The BCVA, binocular function, and refractive errors were measured repeatedly during the study. Main Outcome Measure: Median change in BCVA of the amblyopic eye after 1 year. Results: The median change in BCVA of the amblyopic eye did not differ significantly between the 2 groups (0.6 log units for daily occlusion; 0.8 log unit for alternate-day occlusion). The final median BCVA in the amblyopic eyes was 0.1 logarithm of the minimum angle of resolution in both groups. Binocular function improved in both groups with no significant differences between the groups at 1 year. The median spherical equivalent refractive error did not change significantly during the study period in the amblyopic eyes in either group; however, a significant increase was found in the fellow eyes in both groups (daily occlusion, P<0.05; alternate-day occlusion, P<0.001). Conclusions: The magnitude of change in the BCVA 1 year after spectacles plus prescribed alternate-day patching was not significantly different than that after spectacles plus prescribed daily patching to treat amblyopia in children 4 to 5 years old. The effect of patching was not separate from that of optical correction with a period of refractive adaptation. Thus, the improvement in visual acuity is a combined effect of spectacle wear and occlusion therapy.