Current understanding of the epidemiologic and clinical characteristics of optic neuritis.

Optic neuritis is an ocular disorder whose pathogenesis has not been fully determined, although autoimmune mechanisms have been suggested to be involved in its development. In recent years, anti-aquaporin-4 antibody (AQP4-Ab) and anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab) have been shown to play major roles in the development of optic neuritis. Because these two antibodies target different tissues, optic neuritis can be classified by the type of antibody. AQP4-Ab-positive optic neuritis responds poorly to steroid therapy and has a poor prognosis in terms of visual acuity. On the other hand, MOG-Ab-positive optic neuritis responds favorably to steroid therapy but is likely to recur when the dosage of steroids is reduced or discontinued. We first present the high incidence of idiopathic optic neuritis and discuss these relatively newer disease concepts of AQP4-Ab-positive optic neuritis and MOG-Ab-positive optic neuritis.