Dopamine and Myopia Control

Dopamine, a major metabolite of levodopa, releases in response to light. Past Treatments with Dopamine: L-Dopa has been used as the gold-standard drug in the treatment of Parkinson’s disease and low-dose administration of the drug has been the most effective treatment of Parkinson’s. Possible treatments involving dopamine in preventing a decrease in visual acuity have shown to be successful in the past. L-dopa treatment in children with amblyopia showed an improvement in visual acuity. (Leguire LE, Komaromy KL, Nairus TM, Rogers GL. Long-term follow-up of L-dopa treatment in children with amblyopia.

Studies in animal eyes suggest that dopamine participates in visually guided eye growth regulation (Pendrak K, Nguyen T, Lin T, Capehart C, Zhu X, Stone RA. Retinal dopamine in the recovery from experimental myopia. Curr Eye Res. 1997 Feb;16(2):152-7)

Possible Side Effects of Dopamine Treatment: Unfortunately, several side effects of L-Dopa have been experimentally determined. L-Dopa and some of its metabolites have been shown to have pro-oxidant properties, and oxidative stress has been shown to increase the pathogenesis of Parkinson’s disease. This promotion of free-radical formation by L-Dopa does seem to directly effect its possible future treatment of myopia due to the fact that free-radicals could further cause damage to those proteins responsible for controlling structural proteins in the eye. It has also been shown that levodopa and some of its metabolites such as dopa/dopamine quinone are toxic for nigral neurons. This toxic effect must be analyzed before treatment of levodopa for myopia to prevent damaging effects to these neurons.