Purpose: To assess regression of visual acuity in children who previously participated in three longitudinal studies of therapy with levodopa-carbidopa (L-dopa) plus occlusion for amblyopia.
Subjects and methods: Thirty (91%) of 33 subjects contacted who participated in three similar 7-week, longitudinal dosing studies returned for follow-up. The three previous studies were undertaken approximately 27 (study 1), 21 (study 2), and 9 (study 3) months prior to this follow-up test session. All subjects received L-dopa for 7 weeks combined with part-time occlusion of the dominant eye after the termination of standard, occlusion only, therapy. Some subjects in study 2 received L-dopa without occlusion. Sixteen subjects with amblyopia who received occlusion only served as a control group.
Results: Subjects who received L-dopa plus occlusion demonstrated significant, but similar, amounts of regression of visual acuity from the end of their respective L-dopa studies to the follow-up test session. Subjects in study 1 regressed 1.3 lines, subjects in study 2 regressed 1.5 lines, and subjects in study 3 regressed 1.4 lines. The control group regressed, on average, 1.1 lines. This was similar to the overall regression found in the groups receiving L-dopa plus occlusion. Subjects in study 2 who received L-dopa without occlusion regressed 2.1 lines, significantly more than the occlusion only group or the L-dopa plus occlusion group.
Conclusions: Children with amblyopia show similar amounts of regression of visual acuity after therapy with L-dopa plus occlusion and after therapy with occlusion only. Given that therapy with L-dopa plus occlusion initially improved visual acuity by approximately 1.7 lines following the termination of standard therapy, L-dopa plus occlusion may reset baseline visual acuity and lead to long-term improvement in visual acuity after recidivism.