Retinal vascular changes in Parkinson’s disease on ultra-widefield retinal imaging

Abstract

Purpose : Previous study of Parkinson’s disease (PD) using optical coherence tomography angiography has described retinal vascular changes at the capillary level. Our cross-sectional analysis aimed to assess the larger retinal vessels in a wider field of view using ultra-widefield imaging (UWF) for retinal vascular manifestations of PD.

Methods : UWF imaging with a scanning laser ophthalmoscope (California, Optos, Marlborough, MA) was performed on 22 patients (31 eyes; mean age=68, SD=7; 64% male) with a clinical diagnosis of PD and 33 controls (51 eyes; mean age=80, SD=6; 61% male). Patients with confounding medical or ocular comorbidities were excluded. The retinal vasculature was analyzed with specialized software (Vasculature Assessment Platform for Images of the REtina; Univs. of Edinburgh and Dundee, UK) measuring vascular network complexity [fractal dimension (D₀)], tortuosity, and average rate of change of vessel width from posterior to anterior (Figure 1). D₀ was measured in a consistent region of interest (Standard ROI) in each image and further subdivided into 2 other ROI (Figure 2).

Results : Comparison of PD and control patients showed no evidence of significant differences in age or sex. No evidence of significant differences in retinal vascular network complexity in any ROI was observed in PD compared to controls. Venular tortuosity was greater in the inferonasal (p= 0.046) and superonasal quadrants (p= 0.039) in PD compared to controls. No evidence of statistically significant differences in tortuosity of the retinal venous system was found in any temporal quadrant, or of the arteriolar system in any quadrant. There was no evidence of changes in the average rate of change of vessel width, stratifying by arterioles and venules and by quadrant.

Conclusions : Persons with PD may have more tortuous retinal venules compared to controls. Further analyses of the retinal vasculature using UWF imaging may offer additional insight as well as the potential identification of PD by retinal vascular phenotyping.

This is a 2021 ARVO Annual Meeting abstract.

 

Figure 1: Manual notation of main arteriole/venule in the retinal quadrants (white dash) for measurement of average rate of change in vessel width and tortuosity in the ROI (pink).

 

Figure 2: Measurement of vessel network complexity (D₀) of auto-segmented vessels (green) in the Standard ROI (1, blue), Zone C (2, black) and between Zone C and Standard ROI (3).