LAUSR

Background: Differentiating Parkinson disease (PD) from progressive supranuclear palsy (PSP) can be challenging early in the clinical course. The aim of our study was to see if specific retinal changes could serve as a distinguishing feature. Methods: We used spectral domain optical coherence tomography (SD-OCT) with automatic segmentation to measure peripapillary nerve fiber layer thickness and the thickness and volume of retinal layers at the macula. Results: Thicknesses of superior peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer, inner plexiform layer, inner nuclear layer, and macular volume were more affected in PSP compared with PD (P < 0.05). Thicker inferotemporal pRNFL and lower macular volume were detected in levodopa users compared with nonusers in patients with PD. Conclusions: PD and PSP are associated with distinct changes in retinal morphology, which can be assessed with SD-OCT.