Characteristics of change on retinal nerve fiber layer thickness in mild Parkinson's disease

AIM:To study the thickness changes of retinal nerve fiber layer(RNFL)in Parkinson's disease(PD). <p>METHODS: Fifteen eyes of 15 PD patients in early stage and 18 eyes of 18 controls were chosen to take RNFL examination by optical coherence tomography(OCT). Circular scans were taken around the optic nerve head(diameter=3.46mm)to record the features of RNFL. Scanning areas included eight quadrants of the temporal, superior, nasal, inferior, inferior-temporal, superior-temporal, inferior-nasal and superior-nasal quadrant. RNFL thickness was comparatively analyzed in eight quadrants and the average level in two groups.<p>RESULTS: RNFL thickness in two groups in temporal, superior, nasal, inferior, temporal- inferior, temporal- superior, nasal-inferior, nasal-superior were:(control/PD)83.2±17.5μm/68.7±13.5μm, 132.7±17.4μm/128.1±25.3μm, 83.7±22.3μm/76.5±17.8μm, 141.5±15.3μm/128.6±13.2μm, 117.9±24.5μm/103.3±14.1μm, 120.8±21.2μm /102.6±23.7μm, 110.2±27.7μm/96.6±15.0μm, 109.6±20.6μm/101.2±20.9μm. The average RNFL thickness in controls was 109.9±8.5μm while it showed 102.3±11.9μm in PD group. RNFL thickness in inferior, temporal, inferior-temporal, superior-temporal and the average RNFL thickness were statistically different in two groups(<i>t</i>=2.595,2.700,2.153,2.330,2.131; <i>P</i>=0.014,0.011,0.040,0.026,0.041).<p>CONCLUSION: RNFL thickness in inferior, temporal, inferior temporal, superior temporal and the average RNFL thickness are significantly thinner in mild PD than those in the controls