Macular Retinal Layer Thickness in Mild-to-Moderate Parkinson’s Disease

Background/Objectives: Characterization of individual retinal layer thicknesses in mild-to-moderate Parkinson’s disease (PD) remains limited. This study compares retinal layer thicknesses between patients with mild-to-moderate PD and controls.

Methods

In this cross-sectional study, patients with PD of Hoehn and Yahr (HY) stage 1 to stage 3 and age- and sex-matched cognitively normal controls without PD underwent spectral-domain optical coherence tomography (OCT) imaging. Seven retinal layers were segmented: nerve fiber layer, ganglion cell–inner plexiform layer (GC-IPL), inner nuclear layer (INL), outer plexiform layer, outer nuclear layer (ONL), photoreceptor layer (PRL), and retinal pigment epithelium (RPE). Mean thickness for each layer and the total retina were measured within the 3 mm and 6 mm Early Treatment Diabetic Retinopathy Study rings.