A recent study suggests that levodopa, a common Parkinson’s disease medication, may reduce the risk of progression from early-stage age-related macular degeneration (AMD) to its more severe neovascular form (wet AMD).
However, dopamine agonists (DAs), including those targeting dopamine receptor D2 (DRD2), do not appear to have the same protective effect.
Published in Ophthalmology Retina, the retrospective cohort study analysed data from the Sight Outcomes Research Collaborative (SOURCE) registry, which includes patient information from multiple academic health centres. Researchers from Northwestern University used propensity score matching to control for variables such as age, race, sex, smoking, and use of AREDS 2 vitamins.
The analysis compared three groups over five years: eyes exposed to dopamine agonists, those exposed to DRD2 agonists, and those treated with levodopa.
While neither dopamine agonists nor DRD2 agonists affected the likelihood of developing wet AMD, eyes treated with levodopa showed a 47% lower risk of progression compared to controls.
The authors propose that levodopa’s protective role may stem from its interaction with a G-protein coupled receptor (GPR143) in retinal pigment epithelial cells, which increases anti-angiogenic factors like PEDF and decreases pro-angiogenic VEGF. This mechanism may inhibit abnormal blood vessel growth characteristic of wet AMD.
They also note that levodopa is often given with a decarboxylase inhibitor (such as carbidopa), which might enhance local dopamine conversion in the retina – a process not replicated by dopamine agonists alone.
While promising, the study’s limitations include lack of OCT and fundus autofluorescence imaging data, and exclusion of patients with early AMD in both eyes. The researchers advocate for rigorous clinical trials to further explore levodopa’s potential in slowing AMD progression.
For full study details and author disclosures, see Chan et al., Ophthalmology Retina, published online December 8, 2025. DOI: 10.1016/j.oret.2025.12.004
