Efficacy and tolerance of levodopa to treat amblyopia: a systematic review and meta-analysis

Purpose. Amblyopia is the leading cause of visual impairment in children, affecting up to 4% of the general population. Several clinical trials evaluated the efficacy of levodopa versus placebo in treating amblyopia. However, the results appeared contradictory, suggesting both beneficial and ineffective. The aim of this study was to address the efficacy and tolerance of levodopa on amblyopia. Methods. Randomized controlled trials were identified and extracted from PubMed, EMBASE, Web of Science, and the Cochrane library. The quality of included trials was assessed by using Jadad score and heterogeneity was analyzed using chi-square test. Both efficacy and tolerance endpoints were evaluated. Data were extracted and analyzed using standard meta-analysis. Results. A total of 6 trials were identified from the search strategy. The pooled mean difference of endpoint logMAR of levodopa versus placebo was -0.11 (95% confidence interval -0.19~-0.02, p=0.01). Amblyopic patients receiving levodopa did not show significantly higher frequent adverse events than those receiving placebo. Conclusions. The use of levodopa is an effective and safe option for the treatment of amblyopia, and levodopa can be considered as first-line treatment of amblyopia.