Association between a relative afferent pupillary defect using pupillography and inner retinal atrophy in optic nerve disease

PURPOSE The aim of this study was to compare the asymmetrical light reflex of the control subjects and patients with optic nerve disease and to evaluate the relationships among the relative afferent pupillary defect (RAPD), visual acuity (VA), central critical fusion frequency (CFF), ganglion cell complex thickness (GCCT), and circumpapillary retinal nerve fiber layer thickness (cpRNFLT) using spectral-domain optical coherence tomography. MATERIALS AND METHODS Using a pupillography device, the RAPD scores from 15 patients with unilateral optic nerve disease and 35 control subjects were compared. The diagnostic accuracy of the RAPD amplitude and latency scores was compared using the area under the receiver operating characteristic curve. Thereafter, we assessed the relationships among the RAPD scores, VA, central CFF, GCCT, and cpRNFLT. RESULTS The average RAPD amplitude score in patients with optic nerve disease was significantly higher than that of the control subjects (P<0.001). The average RAPD latency score in patients with optic nerve disease was significantly higher than that of the control subjects (P=0.001). The area under the receiver operating characteristic curve for the RAPD amplitude score was significantly higher than that for the latency score (P=0.010). The correlation coefficients for the RAPD amplitude and latency scores were 0.847 (P<0.001) and 0.874 (P<0.001) for VA, -0.868 (P<0.001) and -0.896 (P<0.001) for central CFF, -0.593 (P=0.020) and -0.540 (P=0.038) for GCCT, and -0.267 (P=0.337) and -0.228 (P=0.413) for cpRNFLT, respectively. CONCLUSION Our results suggest that pupillography is useful for detecting optic nerve disease.