Optic neuritis is the most common cause of vision loss in MS. The vision loss of optic neuritis is usually temporary, lasting one or two months, before it improves on its own or with treatment. It can happen in one eye or both eyes at the same time.
Optic neuritis almost always also causes eye pain, with pain on eye movement, which is usually only moderate in intensity, but is occasionally severe.
Some people, particularly with progressive forms of MS, can develop chronic, persistent optic nerve problems and poor vision, even without ever having attacks of optic neuritis.
How is it diagnosed?
The eye doctor will do an evaluation, which may include: include visual acuity, color vision, intraocular pressure, visual fields, contrast sensitivity, eye examination, visual evoked potential testing and optical coherence tomography. If the cause of a visual disturbance is unclear, MRI scans or other diagnostic testing may be ordered. These could include orbital ultrasonography, orbital CT scanning and electroretinography.
Optic neuritis is caused by inflammation from MS that affects one or both optic nerves.
Optic neuritis is the presenting symptom of MS in 25-40 % of people with MS. Up to 80% of people with MS will experience optic neuritis at some point during the course of MS. Over the course of a lifetime, up to 15% of people with MS can be expected to sustain a certain degree of permanent vision loss in either eye as a manifestation of MS due to permanent damage to either or both optic nerves. On the other hand, MS as a cause of permanent blindness is very rare.
Even optic neuritis in one eye can have a profound effect on work function In certain individuals whose lives demand good vision in both eyes (for example, police officers and visual artists). If they suffer with optic neuritis, they have to wait until their vision improves to get back to functioning fully again.
Those individuals who develop significant optic neuritis in both eyes at the same time, which is uncommon, are often markedly functionally impaired until their vision improves. A small minority of patients who develop optic neuritis do not recover completely, and there is persistent impairment of vision in affected eyes.
A patient with MS who experiences loss of vision in one or both eyes must be evaluated promptly by an optometrist, ophthalmologist, or neuro-ophthalmologist in order to determine the cause of the visual problem.
- Steroid medication. If an eye doctor finds the vision loss is due to optic neuritis, it can be treated with a course of high-dose steroid medication. Such treatment has been proven to decrease the duration of the vision loss and associated pain, but has not been shown to improve long-term visual outcome.2
- OTC medications. Pain from optic neuritis is generally manageable with over-the-counter (OTC) medications. The non-steroidal anti-inflammatories, such as ibuprofen and naproxen-sodium, are probably most effective.
Find a specialist. For a person living with MS who has persistent vision loss due to MS, evaluation by an ophthalmologist or neuro-ophthalmologist (or both) is necessary to characterize the visual disturbance and to determine how much of the visual problem is due to MS.
If persistent vision loss is severe, referral to an optometrist or ophthalmologist who specializes in Low Vision evaluation and treatment is imperative to their care. A specialist can help maximize the person’s activities of daily living and help them get assistive assist devices for reading and functioning around their home and community.
- Glasses generally do not help correct the vision loss of optic neuritis or chronic optic nerve problems of MS. However, people with MS with optic nerve problems should still wear the best pair of glasses possible to correct their vision.