Correlations between Optical Coherence Tomography Angiography Findings and Multifocal Electroretinogram Parameters in Retinitis Pigmentosa Patients

Abstract

Purpose: We investigated the correlations between macular function recorded with a multifocal electroretinogram (mfERG) and macular structure evaluated by optical coherence tomography angiography (OCT-A) in patients with retinitis pigmentosa (RP). Methods: In total, 30 eyes of 15 RP patients and 40 eyes of 20 healthy subjects were enrolled in this study. OCT-A and mfERG were performed for all patients. The area and circularity of the foveal avascular zone (FAZ) were measured, and the vessel density (VD) and perfusion density (PD) of the superficial capillary plexus and deep capillary plexus (SCP and DCP, respectively) were estimated. The average amplitude and implicit time of N1, P1, and N2 in rings 1 and 2 were obtained from the mfERG findings. Correlation between the OCT-A results and mfERG parameters were analyzed in RP patients and normal subjects. Results: The mean FAZ area in RP patients increased significantly compared with that in normal subjects (p < 0.001). Both the PD and VD in the SCP and DCP were significantly reduced in RP patients compared with normal subjects (p < 0.001 and p < 0.001, respectively). The mean amplitude of N1, P1, and N2 from rings 1 and 2 were significantly reduced in RP patients compared with normal subjects. The superficial FAZ and deep FAZ area were significantly correlated with P1 amplitude (r = -0.682, p = 0.000 and r = -0.612, p = 0.000, respectively). Both the VD and PD of the superficial plexus were correlated with P1 amplitude on mfERG (r = 0.188, p = 0.021; r = 0.215, p = 0.013; r = 0.323, p = 0.002; and r = 0.362, p = 0.001, respectively). Conclusions: The P1 amplitude from mfERG was significantly correlated with FAZ area and the PD and VD of the SCP and DCP in RP patients. Together, these results suggest that OCT-A together with mfERG is a useful modality for evaluating macular structure and function in RP patients.