Effect of levodopa therapy on visual-evoked potentials and visual acuity in amblyopia

Amblyopia represents the most common form of visual impairment in children, affecting approximately 2% of the population. To determine the efficacy of the dopa mine agonist levodopa for childhood amblyopia, a double-masked, p lacebo-controlled randomised study was performed on 32 amblyopic children w ith central fixation between 4 and 17 years. Subjects received 2 mg/kg levo dopa benzeraside or placebo 3 times per day over a 1 week period. Estimates of visual acuity for each eye (Snellen visual acuity) were obtained, and p attern-shift visually evoked potentials (VEP) were examined by an opthalmol ogist and a neurologist. At the end of the dosing regimens, the levodopa gr oup was significantly improved in visual acuity by 1.4 lines and pattern VE P amplitudes. No changes could be detected after placebo administration. On e week after the termination of the treatment, Snellen line acuity and patt ern VEP amplitude were decreased to pretreatment levels. The transient effe ct of levodopa points to a long-term treatment with the substance. Our resu lts should therefore encourage further long-term clinical trials investigat ing the therapeutic potential of levodopa in amblyopia.