Quantitative analysis of the inner retina microvascular and structural changes in Parkinson disease patients and their clinical significance

Objective To investigate the vessel density of the macular superficial capillary plexus (SCP) and the thicknesses of the inner retina in patients with Parkinson disease (PD) through optical coherence tomography angiography (OCTA) and optical coherence tomography (OCT).Methods A total of 50 patients with primary PD, who were admitted to Department of Neurology, the Affiliated Hospital of Xuzhou Medical University from January 2022 to December 2022 were selected as a PD group. Meanwhile, another 56 healthy subjects who underwent physical examination were enrolled as a control group. Both groups were compared for the changes in the vessel density of SCP and the thicknesses of the inner retina. For PD patients, the difference between the eye with severer motor symptoms and the other side was compared. A receiver operating characteristic curve (ROC) was plotted to evaluate the value of inner retina parameters for the diagnosis for PD.Results The PD group presented significant decreases in the density of SCP and the thickness of inner retina, compared with the control group (all P<0.05).No statistical difference was found as to the changes in the vessel density of SCP and the thicknesses of the inner retina in the eye with severer motor symptoms and the other side (all P>0.05). According to ROC analysis, the area under the curve (AUC) of the thickness of the inner retina in the parafoveal temporal quadrant was the largest, and the optimal cutoff value was 129.5 μm, with a sensitivity of 96.0% and a specificity of 82.1%.Conclusions Reduced vascular density of SCP and thinning of the inner retina can be observed in PD patients bilaterally, which provide certain reference value for PD diagnosis.