Levodopa/Carbidopa Treatment for Amblyopia in Older Children

ABSTRACT The purpose of the present study is to determine how long visual function improves during levodopa/ carbidopa with part-time occlusion treatment in older amblyopic children. A 7-week open clinical trial of levodopa (0.55 mg/kg, three times daily) with 25% carbidopa combined with part-time occlusion (3 hours/day), was undertaken in 15 older (mean age, 8.87 years) amblyopic children. Visual acuity, fusion, and stereo acuity were measured at baseline, at weeks 1, 3, 5, and 7 during treatment, and 6 weeks following the end of all treatment. Health status was assessed by physical examination, questionnaire, and standard laboratory tests (CHEM 20, complete blood cell count [CBC], and differential). The results revealed that visual acuity in the amblyopic eye improved for 5 weeks, from 20/170 at baseline to 20/107, then stabilized for the last 2 weeks. Visual acuity also improved in the dominant eye by 0.6 lines, from 20/19 to 20/16. At the 6-week follow up, visual acuity in the amblyopic eye remained at 20/107 (paired t=4.78, df= 14, P<.001), a 37% improvement. Thirty-three percent of the subjects demonstrated improved fusion from baseline to the 7-week trial that was maintained at follow up (χ p 2 = 3.97, P<.05). Stereo acuity did not significantly change. Physical exam (blood pressure, body temperature, respiration, heart rate) and standard laboratory tests remained normal and side effects were minimal. It is concluded that levodopa/carbidopa combined with part-time occlusion in older amblyopic children improves visual acuity for 5 weeks then stabilizes, and can lead to improvements in visual acuity and in fusion over a period of at least 6 weeks following cessation of treatment, with minimal side effects.