Altered Outer Retinal Structure, Electrophysiology and Visual Perception in Parkinson's Disease

Abstract

Background: Visual biomarkers of Parkinson's disease (PD) are attractive as the retina is an outpouching of the brain. Although inner retinal neurodegeneration in PD is well-established this has overlap with other neurodegenerative diseases and thus outer retinal (photoreceptor) measures warrant further investigation. Objective: To examine in a cross-sectional study whether clinically implementable measures targeting outer retinal function and structure can differentiate PD from healthy ageing and whether these are sensitive to intraday levodopa (L-DOPA) dosing. Methods: Centre-surround perceptual contrast suppression, macular visual field sensitivity, colour discrimination, light-adapted el..