Abbreviations: GCIP: Combined ganglion cell and inner plexiform layer, HC: Healthy control, Eye ON-: MOG-IgG-seropositive eyes without a history of ON, ON: Optic neuritis, OCT: Optical coherence tomography, pRNFL: Peripapillary retinal nerve fiber layer, MV: Macular volume. This evidence concerns the gene MOG and optic neuritis.