Comparison of macular changes according to the etiology of optic neuritis: a cross-sectional study

AIM: To compare the macular structure including foveal thickness among patients with optic neuritis (ON) according to the etiology and to investigate the possible correlation between structural and visual outcomes METHODS: In this retrospective cross-sectional study, the clinical data of patients with aquaporin-4 immunoglobulin G-related ON (AQP4 group, 40 eyes), myelin oligodendrocyte glycoprotein IgG-related ON (MOG group, 31 eyes), and multiple sclerosis-related ON (MS group, 24 eyes) were obtained. The retinal thickness of the foveal, parafoveal and perifoveal regions were measured. Visual acuity (VA), visual field index and mean deviation were measured as visual outcomes. RESULTS: The AQP4 group showed a significantly thinner fovea (226.4±13.4 μm) relative to the MOG (236.8±14.0 μm, P=0.015) and MS (238.9±14.3 μm, P=0.007) groups. The thickness in the parafoveal area also was thinner in the AQP4 group, though the difference in perifoveal retinal thickness was not significant. Foveal thickness was correlated with VA in the AQP4 group (coefficient ρ=-0.418, P=0.014), but not in the MOG and MS groups (P=0.218 and P=0.138, respectively). There was no significant correlation between foveal thickness and visual field test in all three groups. CONCLUSION: The significant thinning in the fovea and parafoveal areas in the AQP4 group compared to the MOG and MS groups are found. Additionally, macular changes in AQP4-ON show a significant correlation with VA. The results provide the possibility that retinal structural damage could reflect functional damage in AQP4-ON, distinct from MOGON and MS-ON.