Investigation of the Pathophysiology of the Retina and Choroid in Parkinson's Disease by Optical Coherence Tomography

Abstract PurposeThe pathology of Parkinson's disease (PD) is suspected to affect the retina and choroid. We investigated changes in the retina and choroid of patients with PD using optical coherence tomography (OCT).MethodsWe examined 14 patients with PD and 22 patients without PD. Patients without PD had no ophthalmic pathology other than cataracts and neurodegenerative disorders. The retinal nerve fiber layer, ganglion cell layer + inner plexiform layer, and choroidal thickness were compared between both groups. Additionally, the choroidal image was divided into the choroid area, luminal area, and interstitial area using the binarization method, and the area of each region and the percentage of luminal area in the choroid area was analyzed. ResultsPatients with PD had a significantly thinner ganglion cell layer + inner plexiform layer compared to those without PD. The choroid area, luminal area, and interstitial area were significantly decreased in patients with PD compared to those without PD. Seven patients with PD who were successfully followed-up for 3 years showed decreased retinal nerve fiber layer and interstitial area after 3 years.ConclusionAutonomic nervous disorders and neurodegeneration in PD can cause thinning of the retina and choroid, as well as a reduction of the choroid area.