Neuromyelitis optica (NMO), also known as Devic’s disease, is a rare autoimmune disorder primarily affecting the optic nerves and spinal cord. Think of it like your body’s immune system mistakenly attacking these vital parts of your central nervous system. The hallmark of NMO is inflammation of the optic nerve (optic neuritis), which can cause eye pain and vision loss in one or both eyes. People with NMO also experience inflammation of the spinal cord (myelitis), leading to symptoms like muscle weakness, numbness, pain, and problems with bladder and bowel control. What makes NMO distinct from multiple sclerosis (MS), another autoimmune disease of the central nervous system, is the presence of a specific antibody called anti-aquaporin-4 (AQP4) antibody in most individuals with NMO. Aquaporin-4 is a protein found in high concentrations in the optic nerves and spinal cord, and this antibody targets and damages cells expressing this protein. NMO attacks can be severe and can lead to permanent disability if not treated promptly. While there’s no cure for NMO, treatments focus on managing acute attacks, preventing relapses, and alleviating symptoms. These treatments often involve immunosuppressive therapies to reduce the abnormal immune response. Early diagnosis and appropriate management are crucial for improving the long-term outcomes for individuals living with NMO.