BACKGROUND:Dopamine is an intermediate product in the biosynthesis of melanin pigment, which is absent or reduced in albinism. Animal research has shown that supplying a precursor to dopamine, levodopa, may improve visual acuity in albinism by enhancing neural networks. This study examines the safety and effectiveness of levodopa on best-corrected visual acuity in human subjects with albinism. DESIGN: Prospective, randomized, placebo-controlled, double-masked clinical trial conducted at the University of Minnesota. PARTICIPANTS: Forty-five subjects with albinism. METHODS:Subjects with albinism were randomly assigned to one of three treatment arms: levodopa 0.76 mg/kg with 25% carbidopa, levodopa 0.51 mg/kg with 25% carbidopa, or placebo and followed for 20 weeks, with best-corrected visual acuity measured at enrollment, and at weeks 5, 10, 15, and 20 after enrollment. Side-effects were recorded with a symptom survey. Blood was drawn for genotyping. MAIN OUTCOME MEASURES: Side-effects and best-corrected visual acuity 20 weeks after enrolment. RESULTS: All subjects had at least one mutation found in a gene known to cause albinism. Mean age was 14.5 years (range: 3.5 to 57.8 years). Follow up was 100% and compliance was good. Minor side-effects were reported; there were no serious adverse events. There was no statistically significant improvement in best-corrected visual acuity after 20 weeks with either dose of levodopa. CONCLUSIONS:Levodopa, in the doses used in this trial and for the time course of administration, did not improve visual acuity in subjects with albinism.
RCT Entities:
BACKGROUND:Dopamine is an intermediate product in the biosynthesis of melanin pigment, which is absent or reduced in albinism. Animal research has shown that supplying a precursor to dopamine, levodopa, may improve visual acuity in albinism by enhancing neural networks. This study examines the safety and effectiveness of levodopa on best-corrected visual acuity in human subjects with albinism. DESIGN: Prospective, randomized, placebo-controlled, double-masked clinical trial conducted at the University of Minnesota. PARTICIPANTS: Forty-five subjects with albinism. METHODS: Subjects with albinism were randomly assigned to one of three treatment arms: levodopa 0.76 mg/kg with 25% carbidopa, levodopa 0.51 mg/kg with 25% carbidopa, or placebo and followed for 20 weeks, with best-corrected visual acuity measured at enrollment, and at weeks 5, 10, 15, and 20 after enrollment. Side-effects were recorded with a symptom survey. Blood was drawn for genotyping. MAIN OUTCOME MEASURES: Side-effects and best-corrected visual acuity 20 weeks after enrolment. RESULTS: All subjects had at least one mutation found in a gene known to cause albinism. Mean age was 14.5 years (range: 3.5 to 57.8 years). Follow up was 100% and compliance was good. Minor side-effects were reported; there were no serious adverse events. There was no statistically significant improvement in best-corrected visual acuity after 20 weeks with either dose of levodopa. CONCLUSIONS:Levodopa, in the doses used in this trial and for the time course of administration, did not improve visual acuity in subjects with albinism.
Authors: Susan A Cotter; Raymond H Chu; Danielle L Chandler; Roy W Beck; Jonathan M Holmes; Melissa L Rice; Richard W Hertle; Eileen E Birch; Pamela S Moke Journal: Am J Ophthalmol Date: 2003-10 Impact factor: 5.258
Authors: K C Yeh; T F August; D F Bush; K C Lasseter; D G Musson; S Schwartz; M E Smith; D C Titus Journal: Neurology Date: 1989-11 Impact factor: 9.910