Evaluation of Retinal Nerve Fibre Layer Thickness and Choroidal Thickness in Parkinson Disease Patients

To evaluate the retinal nerve fibre layer (RNFL) thickness and choroidal thickness (CT) in Parkinson disease (PD) patients. A comparative cross-sectional, hospital-based study. 39 PD and 39 controls were recruited, who were gender and age matched. Subjects that fulfilled the inclusion criteria underwent optical coherence tomography for evaluation of RNFL thickness and choroidal thickness (CT). There was significant reduction of RNFL thickness in average (adjusted mean 88.87 µm vs. 94.82 µm, P=0.001), superior (adjusted mean 110.08 µm vs. 119.10 µm, P=0.002) and temporal (adjusted mean 63.77 µm vs. 70.36 µm, P=0.004) in PD compared to controls. The central subfoveal CT was significantly thinner in PD compared to controls (adjusted mean 271.13 µm vs. 285.10 µm, P=0.003). In PD group, there was significant weak negative correlation between the duration of PD with average RNFL thickness (r=–0.354, P=0.027), moderate negative correlation between the duration of PD with central subfoveal CT (r=–0.493, P=0.001), and weak negative correlation between the stage of PD with central subfoveal CT (r=–0.380, P=0.017). PD group had significant thinner average, superior and temporal RNFL thickness and CT compared to controls.