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Understanding neuromyelitis optica spectrum disorder

Published 28 August 2019 

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, lifelong and debilitating autoimmune disease of the central nervous system (CNS) that primarily damages the optic nerve and the spinal cord.1

In NMOSD, the immune system mistakes normal tissues of the CNS as being foreign and attacks the optic nerve, which transmits signals from the eye to the brain, and the spinal cord, which controls body function.1

The exact cause of NMOSD remains unknown.1

Global burden

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NMOSD is a rare condition affecting fewer than five in every 100,000 people worldwide.2

Risk factors3,5

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most common in people aged 30 to 40


women are at higher risk

Signs and symptoms

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Inflammation of the optic nerve can cause visual disturbances, such as blurred vision and problems seeing colours. It is also associated with pain around the eye and/or at the back of the eye.3

Additional symptoms of NMOSD are similar to those of other CNS conditions, including:5

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Muscle weakness

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Nerve pain, numbness and tingling

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Spasms and increased muscle tone

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Uncontrollable vomiting and hiccups

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Bladder, bowel and sexual problems

Impact of neuromyelitis optica spectrum disorder


Most patients have relapses or ‘attacks’ every few months or years.2

Severe relapses can lead to accumulating, permanent neurological damage, visual impairment and disability, and in some cases death.2

Because NMOSD is a progressive disease, symptoms continue to build with each relapse. Within five years 50% of people require a wheelchair and 62% are functionally blind, or don’t have useful vision.4

Annual eye test


Getting an annual eye test is the best way to detect any changes in vision. A dilated retinal examination will help to diagnose any problems. If you’d like more information on NMOSD or retinal diseases, talk to your optician or visit


  1. Mayo Clinic. Neuromyelitis-optica [Internet; cited May 2019]. Available from:
  2. Orphanet. Neuromyelitis optica [Internet; cited May 2019]. Available from:
  3. NMO UK. Neuromyelitis Optica [Internet; cited May 2019]. Available from:
  4. Roche. Understanding neuromyelitis optica spectrum disorder, a debilitating and rare autoimmune disease [Internet; cited May 2019]. Available from:
  5. Guthy Jackson Foundation. NMO FAQs [Internet; cited May 2019]. Available from:

Tags: Science, Ophthalmology