Although the optic neuritis treatment trial study (ONTT study) found no convincing evidence of any benefit of prompt IVMP treatment in improving visual acuity at 6 months and 1 year [1], the results of that study may not be suitable for generalization to NMOSD because, as Chen et al. revealed, none of the patients in the ONTT study had NMOSD-ON, and only three cases were diagnosed as MOG-ON [14]. This evidence concerns the gene MOG and optic neuritis.