ObjectiveTo shed light on the clinical characteristics, magnet resonance imaging(MRI) changes, and prognosis of myelin oligodendrocyte glycoprotein antibody (MOG-IgG) positive OPN in Han Chinese.MethodsWe observed 39 MOG-IgG positive patients in our ward from January 1, 2017 , to December 31, 2019. Twenty patients met OPN inclusion criteria included contrast enhancement surrounding the optic nerve, and at least one of the following clinical symptoms: 1) reduction of visual acuity, 2) impairment of visual field, and 3) eye pain. Single course group(n=11) and recurrence group(n=9) were used for comparison. Outcome variables included Wingerchuk visual acuity classification.Results Of the 20 patients with MOG-IgG positive OPN, 12(60%) were women. Ten cases (50%) presented with bilateral and 17 eyes (56.67%) with severe visual loss (SVL,≤ 0.1). Twenty-one(70.00%) eyes showed edema of optic disc. Twenty-five eyes (83.3%) had longitudinally extensive perineural enhancement. At follow-up, 4 (13%) eyes still had SVL, while 26 (87%) eyes had no SVL, and of the 19 ON patients, 3 (9%) eyes still had SVL. Seven patients (35.00%) experienced at least a relapse(median interval 13.5 months ), and of the 19 ON cases, 4 (21%) patients experienced relapse. The relapse occurred more often in younger patients than the older (mean year: 38.00 vs. 45.54 years; P = 0.025). There were no optic chiasm and brainstem lesions.ConclusionsMOG-IgG positive OPN in Han Chinese often causes severe bilateral visual loss and longitudinally extensive perineural lesion. Younger patients are more likely to relapse. Optic chiasm and brainstem lesions were relatively rare.