Correlation analysis of retinal characteristics and disease severity in Parkinson's disease

Abstract

Objective To investigate the changes of retinal nerve fiber layer (RNFL) thickness and superficial vascular density in patients with Parkinson's disease (PD), and analyze the correlation between the changes and disease severity. Methods Total 43 patients (76 eyes) with PD admitted to the Affiliated Hospital of North Sichuan Medical College from June 2021 to March 2022, and 45 patients (90 eyes) with normal neurological and visual functions from their family members were recruited as the control group. Optical coherence tomography angiography (OCTA) was used to measure RNFL thickness, retinal blood vessel length density and perfusion density, and the area and circumference of foveal avascular zone (FAZ). Disease severity was evaluated by modified Hoehn - Yahr staging, and motor function was evaluated by Unified Parkinson's Disease Rating Scale Ⅲ (UPDRS Ⅲ) in PD group. Pearson and partial correlation analyses were used to investigate the correlation between retinal parameters and PD severity. Results Comparison of OCTA related parameters between the 2 groups: RNFL thickness (t = - 6.424, P = 0.000), central length density (t = - 3.629, P = 0.000), inner ring length density (Z = - 2.846, P = 0.004) and central perfusion density (Z = - 2.703, P = 0.007) in the PD group were lower than those in the control group. Correlation analysis showed that RNFL thickness was negatively correlated with UPDRSⅢ score (r = - 0.625, P = 0.000). Conclusions RNFL thickness may be a potential indicator for early diagnosis and evaluation of the severity of PD.

Keywords

• parkinson disease
• retina
• tomography, optical coherence