Retinal Structure Abnormalities in Parkinson's Disease and Atypical Parkinsonism.

We investigated retinal structure changes in patients with Parkinson's disease (PD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and controls, and explored the value of this method in differential diagnosis. Spectral domain optical coherence tomography (SD-OCT) was used to measure peripapillary retinal nerve fiber layer (pRNFL) thickness, and macular thickness and volume. PSP patients showed higher temporal pRNFL thickness than PD and MSA patients. Peripapillary RNFL thickness could be used for discriminating PSP from MSA and PD. PD and MSA patients showed retinal thinning in the foveal center circle and nasal inner sectors compared to controls. Macular thickness and volume could be used for discriminating MSA from PD. There were negative correlations between disease duration and OCT parameters in PD, MSA, and PSP, independent of age, sex ratio, and the side of the eye. PD and atypical parkinsonism correlate with specific patterns of retina alterations. OCT could be a biomarker for differential diagnosis and progression evaluation of parkinsonian syndrome.