A to Z of MS Optic neuritis
Optic neuritis is the most common eye problem of MS. It is caused by inflammation or demyelination (damage to the nerve covering) of the optic nerve, which transmits the image from the retina to the brain. Optic neuritis is usually transient and associated with good recovery.
The effects of optic neuritis, eg visual disturbance and pain behind the eyeball, are the first symptoms experienced by 25% of people with MS. 70% of people with MS will have optic neuritis during the course of their MS. Like MS itself, optic neuritis normally affects people aged between 20 and 40 years, women more than men.
The visual loss associated with optic neuritis is often in one eye only. It occurs suddenly, is progressive and usually reaches its peak after about two weeks. Optic neuritis commonly causes blind spots or areas of depressed visual function surrounded by an area of normal vision. Colour vision can also be severely impaired. Frequently there is pain, particularly during eye movement. Recovery takes from four to six weeks. Optic neuritis is often treated with steroids.
Optic neuritis is also recognised as a condition in its own right. Not everyone who experiences optic neuritis goes on to develop further symptoms of MS, but a significant proportion do.