What ophthalmologists need to know about neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, antibody (Ab)-mediated, inflammatory autoimmune disorder of the central nervous system (CNS). Historically, the core clinical features were myelitis and optic neuritis (ON), but a better understanding of the neuroimmunology and the target (aquaporin-4 [AQP4] water channel) in NMOSD have led to expanded diagnostic criteria for NMO as a spectrum disorder. Unlike relapsing and remitting multiple sclerosis (MS), attacks of NMOSD are more severe and sometimes irreversible, leading to acute neuronal loss, blindness, and paralysis.