Quantitative analysis of related parameters of retinal nerve fiber layer and ganglion cell complex thickness in patients with different degrees of Parkinson's disease

Objective A quantitative analysis was performed to evaluate the morphologic changes of the retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) in patients with Parkinson’s disease (PD). Methods Thirty PD patients were enrolled, and they were allocated to the mild-to-moderate PD group ( n = 15) or severe PD group ( n = 15) according to the severity of PD. Twenty healthy volunteers (20 eyes) were included as controls. Optical coherence tomography (OCT) was used to measure the thickness of mean RNFL and each of the sectors: temporal-upper (TU), superior-temporal (ST), superior-nasal (SN), nasal-upper (NU), nasal-lower (NL), inferior-nasal (IN), inferior-temporal (IT), temporal-lower (TL). The thickness of macular GCC, superior GCC, and inferior GCC was also measured. Results No difference was found between the three groups with respect to age, sex and disease course ( p > 0.05). The mean RNFL thickness was 118.15 ± 10.25 µm in the control group, 96.12 ± 9.45 µm in the mild-to-moderate PD group, and 80.48 ± 10.35 µm in the severe PD group. Significant differences were found in the mean RNFL thickness and thickness of TU, IN, IT and TL sectors among the three groups ( p