Optic neuritis is a common eye problem where inflammation or demyelination affects the optic nerve. It is a condition in its own right, but is also strongly associated with multiple sclerosis. Not everyone who experiences optic neuritis goes on to develop further symptoms of MS, but a significant proportion do.
For 1 in 4 people with MS, optic neuritis was the first MS symptom that they noticed.
What is optic neuritis?
Optic neuritis usually comes on suddenly and causes blind spots or areas of poor vision in one eye. Colour vision or visual field can be severely affected. You might also have pain, particularly when you move your eyes.
Optic neuritis generally gets worse over a few days and reaches a peak about two weeks from onset. After that, symptoms generally improve and you will usually have recovered within 4-6 weeks. However, you may find that problems with your vision persist longer than this.
Helena explains what it was like:
One day I noticed a fuzzy patch at the bottom of one eye. I thought my glasses were dirty and kept taking them off to clean them. It got worse and started feeling uncomfortable to move my eyes. I already had an MS diagnosis, so it soon dawned on me what was likely to be happening. I went for a few tests with an ophthalmologist and conferred with my MS team to confirm that it was optic neuritis. As I was breastfeeding, I opted not to take steroids. Luckily the pain wasn't too bad and it all cleared up within four weeks.
How many people get optic neuritis?
Optic neuritis is common in the general population, affecting between one and five people in 1000. Like multiple sclerosis itself, optic neuritis normally affects people aged between 20 and 40 and women more than men. Seven out of ten of people with MS will experience optic neuritis at some point.
How is optic neuritis treated?
Optic neuritis is usually temporary and associated with good recovery. You may be offered steroids as a treatment, which is intended to reduce the inflammation quickly and prevent permanent damage to the nerve. There is no long-term difference in progression and recovery between those that do take steroids and who choose not to.
Given the connection with MS, if you have optic neuritis you are likely to be asked to undergo a range of tests. These could include blood tests, an MRI scan and visual evoked potential tests, to see whether your doctor can diagnose MS. Getting treatment early can reduce the severity and progression of MS.
Bear in mind that the symptoms experienced with optic neuritis could be due to other eye conditions or headaches. Optic neuritis is also associated with a rare condition called neuromyelitis optica. The treatments for this and MS are different, and so a doctor needs to confirm exactly what is going on for you.
- International MS Journal 2009;16(3):82-89. Summary Optic neuritis: a review.
- Cochrane Database of Systematic Reviews 2015, Issue 8. Art. No.: CD001430. Full article Corticosteroids for treating optic neuritis.
- Eye and Brain 2016 28(8) 195-202 Summary Optic neuritis as an early sign of multiple sclerosis
- Multiple Sclerosis and Related Disorders 2017 20: 30-36 Summary Magnetic resonance imaging findings at the first episode of acute optic neuritis
- JAMA Opthamology 2018 136(1) 76-81 Summary Incidence and causes of overdiagnosis of optic neuritis