The effect of increasing doses of levodopa on children with strabismic amblyopia

Purpose: The purpose of this study was to determine the efficacy and tolera nce of a levodopa/carbidopa combination and to test its dose-effect respons e when combined with occlusion therapy for children with amblyopia. Methods : A I-week randomized, double-blind, parallel, and placebo-controlled study was performed with 78 children with amblyopia aged between 7 and 17 years. Children who weighed less than 40 kg were randomly assigned to receive 5, 10, or 20 mg of levodopa or placebo (3 times a day), and those who weighed 40 kg or more were randomly assigned to receive 10, 20, or 40 mg of levodop a or placebo. Subjects were instructed to occlude the dominant eye (3 h/d). Snellen visual acuity was measured at baseline and at 2 hours after ingest ion of the last capsule. Compliance with occlusion and capsule consumption was verified by a questionnaire and counting capsules. Adverse effects were checked with a physical examination and a questionnaire. Results: From bas eline to the follow-up test trial, the improvement in the logarithm of the Snellen fraction was 0.05 +/- 0.11 in the placebo group, 0.18 +/- 0.21 in g roup I, 0.08 +/- 0.11 in group II, and 0.16 +/- 0.15 in group III (P = .031 ). Visual acuity improved from 0.59 to 0.45 in the levodopa/carbidopa group and from 0.69 to 0.63 in the control group (P = .023). The compliance with occlusion was similar in all groups. No one complained of adverse side eff ects. Conclusion: Levodopa, at an average dose of 0.51 mg/kg per day, is we ll tolerated and produces a clinical and statistically significant short-te rm improvement of visual acuity in children with amblyopia.