A clinical study of changes in retina and visual field in patients with early Parkinson's disease

Abstract

To characterize the changes of retinal structure and visual field mean defects (MD) in early Parkinson's disease (PD) and the related factors. Twenty-five patients with early stage PD and 33 normal controls were enrolled in this study. PD patients were evaluated by unified Parkinson's disease rating scale (UPDRS) and Hoehn-Yahr (H-Y) stage in "off" period. All subjects undertook retina of retinal nerve fiber layer (RNFL) and macular examinations by optical coherence tomography (OCT), and MD by automatic visual field analyzer. (1) The average thicknesses of RNFL and C11 quadrant RNFL were thinner in PD group [(96.2 ± 7.6)µm and (124.4 ± 18.4)µm] than in healthy controls [(102.6 ± 5.0)µm and (135.4 ± 21.8)µm, respectively, P=0.000 and P=0.047]. Moreover, PD patients had a thinner average thickness of macular [(277.2 ± 9.6) µm vs (285.8 ± 12.6) µm, P=0.006], and smaller macular volume compared with controls [(10.0 ± 0.3) mm³ vs (10.3 ± 0.4) mm³, P=0.006]. However, there was no significant difference in MD between PD and control subjects [(0.43 ± 2.75)dB vs (-0.18 ± 1.41) dB, P=0.322]. (2) Pearson's correlation analysis showed that H-Y stage was negative correlated with the average RNFL thickness (r=-0.569), average macular thickness and volume (r=-0.501 and r=-0.417) in PD patients (all P<0.05). PD patients have thinner average thicknesses of RNFL, C11 quadrant RNFL and macular, smaller macular volume than those in normal controls. There were no significant differences in MD between two groups.There were negative relationships between H-Y stage, and retinal thickness and volume of PD patients.