Levodopa improved visual acuity in patients with amblyopia

A drug commonly used to treat Parkinson’s disease was found to improve visual function in amblyopic eyes in a small study. The drug also reduced the total volume of activation in the occipital cortex of patients with amblyopia as measured by functional MRI, the study found.

Antonio Algaze, PhD, and colleagues studied the response of six patients with amblyopia and nine healthy subjects to a single dose of levodopa (L-dopa). All subjects had baseline functional MRIs, then received a single dose of L-dopa, and then had a second MRI session 90 minutes later. Visual stimuli were presented monocularly and binocularly.

After the L-dopa administration, the mean visual acuity in the eyes with amblyopia improved significantly, from 0.72 LogMAR to 0.64. Mean visual acuity remained the same in the dominant eyes of patients with amblyopia and in the control subjects.

A decrease in the amount of activation of the occipital cortex by the amblyopic eye was observed on functional MRI despite the improvement in visual acuity, the study authors said. No L-dopa-related changes in activation of the occipital cortex were detected for the dominant eyes of amblyopic patients or with binocular stimulation in the group with amblyopia, and no change was detected in control subjects.

The study is published in the June issue of Journal of American Association for Pediatric Ophthalmology and Strabismus.