04/14/2026
This week is Parkinson's Disease Awareness Week, and for anyone working in eye care, it's worth pausing on.
Most people associate Parkinson's with tremors and movement problems. But visual symptoms are among the most common features of the disease, affecting the majority of patients and significantly impacting their ability to read, drive, and navigate daily life. These symptoms are frequently attributed to aging and go unaddressed for years.
The connection between Parkinson's and the eye runs deeper than most realize. The disease affects the retina directly, not just the brain's visual processing centers. The same underlying disease process that depletes dopamine in the brain also disrupts dopamine-producing cells within the retina itself, resulting in reduced contrast sensitivity, convergence problems that cause double vision, irregular eye movements, and a dramatically reduced blink rate that leads to chronic dry eye.
What's gaining real momentum in research is the potential for retinal imaging to serve as an early detection tool. A 2024 longitudinal study published in npj Parkinson's Disease followed 156 PD patients and found that the rate of ganglion cell layer thinning was roughly twice as high in Parkinson's patients compared to age-matched controls, and that this thinning correlated with cognitive decline over time.
Separately, a 2024 study in Frontiers in Neuroimaging found statistically significant retinal nerve fiber layer thinning that tracked directly with disease severity. A 2025 systematic review drawing on PubMed, Embase, and Cochrane databases concluded that the retina holds genuine promise as a non-invasive biomarker for both early detection and disease progression monitoring in Parkinson's. We are not yet at standardized clinical protocols, but the direction is clear.
The practical takeaway for eye care practices: Parkinson's patients benefit enormously from regular comprehensive eye exams. Identifying visual symptoms early, managing them appropriately, and coordinating with neurology leads to meaningfully better outcomes. Tools already in most of our practices, including OCT, may prove to be more relevant to this patient population than we previously understood.
The eye has always been a window into systemic health. In Parkinson's disease, the research is making that more true by the year.
