Keeping an eye on Parkinson’s disease: color vision and outer retinal thickness as simple and non-invasive biomarkers

Abstract

Over the last two decades, visual symptoms and retinal changes in Parkinson’s disease (PD) have emerged as important biomarkers. Color vision deficiency, which begins in the outer retina, has been increasingly investigated, but a focused review of these papers has not recently been conducted. Similarly, thinning of the outer retina as measured using optical coherence tomography (OCT) holds potential as a screening marker for PD, particularly as these devices are already commonplace in community and hospital settings. Moreover, outer retinal thinning may be more specific for Parkinson’s disease as inner retinal changes also occur in more common neurodegenerative diseases like glaucoma and Alz..