Neuromyelitis optica (NMO) is a central nervous system disorder that primarily affects the eye nerves (optic neuritis) and the spinal cord (myelitis). NMO is also known as neuromyelitis optica spectrum disorder or Devic’s disease, is a heterogeneous condition consisting of the inflammation and demyelination of the optic nerve (optic neuritis) and the spinal cord (myelitis). It can be monophasic or recurrent. Screening test for detection of antibodies against aquaporin-4(AQP4)/NMO-IgG.