Visual symptoms are common amongst people with multiple sclerosis (MS).
There are three main visual symptoms in MS – optic neuritis, nystagmus and diplopia (double vision). Some people also experience temporary blurring of vision, temporary loss of vision, blind spots, pain with eye movement and blind spots.
Visual problems are often the first symptoms associated with MS (1).
Optic neuritis is a common symptom in MS. It is caused by inflammation or demyelination to the optic nerve at the back of the eye, which transmits the signals from the visual image from the eye to the brain (1). Optic neuritis causes a disturbance in vision – sometimes blurring, and often a reduction in colour vision, particularly for the colour red. Optic neuritis can also cause a headache, or a pain behind the eye when the eye moves.
Visual flashing sensations can be present and over half of those affected by optic neuritis will experience Uhthoff’s sign – in which symptoms worsen with heat or exhaustion.
Optic neuritis is a variable condition where vision can be moderately to severely affected. It usually occurs in one eye but can occur in both eyes at the same time.
Optic neuritis starts suddenly and progresses for a few weeks before recovery happens spontaneously. Treatment with steroids may be advised by your MS nurse to help reduce inflammation and hopefully help speed up recovery.
If the optic nerve is damaged by demyelination a permanent loss of visual acuity (acuteness or clearness of vision), may be experienced.
Nystagmus is a condition in which the eyes move involuntarily. The movement is usually horizontal, but it can also be vertical or rotary. In almost all cases, both eyes move together. There are two main types of nystagmus, one which appears in the first months of life which is called congenital nystagmus and another which develops later in life which is usually called acquired nystagmus.
Acquired nystagmus is most common in people with MS and although they may be initially unaware of these involuntary movements, they may notice movement themselves in a mirror or it could be observed by others. Nystagmus will be diagnosed by an ophthalmologist who will examine the inside of your eyes and test your vision. Diagnosing acquired nystagmus may also require a referral to a neurologist.
Although acquired nystagmus is quite a common symptom, treatment of this condition is limited at present. Drug therapy with gabapentin or memantine may help. Botulinum toxin injections have also been shown to help some people with the acquired form of nystagmus associated with MS.
Diplopia, or double vision, can be a very early symptom of MS. It is caused when the pair of muscles that control a particular eye movement are weakened. The muscles then become uncoordinated, and this disturbs the vision by producing images in double. It may also cause loss of balance because spatial orientation, that ability of a person to correctly determine his/her body position in space, is disturbed. Double vision is usually temporary. It can occur through fatigue or over-use of the eyes. For example, too much time spent on a computer or reading for a long time. Resting the eyes periodically throughout the day can be beneficial.
If you experience double vision, talk to your GP or MS nurse about a referral to an ophthalmologist.
The key vitamins for eye health are the antioxidants – vitamins A, C and E, lutein and zeaxanthin. These support eye health and are all found in fruits and vegetables. Lutein is found in mango, yellow peppers and green leafy vegetables such as kale, chard, broccoli and cavolo nero. Zeaxanthin is found in orange sweet peppers, citrus fruits such as oranges and tangerines, broccoli, corn, spinach and eggs. These types of food also provide vitamins A, C and E. If you have a healthy diet with a good balance of fruit and vegetables, then you will get all the vitamins you need from your food, although you can choose to supplement these vitamins.
Vitamin D is important for a healthy immune system, brain development and function and the cardiovascular system (heart and blood vessels). Vitamin D helps the body to absorb calcium and phosphorus – the building blocks for strong bones.
A study looking at the effect of vitamin D in recovery from acute episodes of optic neuritis in people with MS found a link between the severity of optic neuritis and vitamin D levels. People with higher levels of vitamin D had less severe episodes of optic neuritis. However, there was no association with high vitamin D levels and a faster recovery from optic neuritis (10).
In the UK the NHS recommends people should have their eyes tested approximately every two years. This ensures that your eye health is checked regularly and any issues that require attention can be addressed without delay. Some people may be eligible for free NHS eye and sight tests (11).
For more information on all of the above conditions please see the following links. If you would like to discuss anything mentioned in this booklet then please call our helpline on 0800 783 0518. If you would like a plain text version of this booklet please email firstname.lastname@example.org
MS-UK Choices leaflets – MS symptoms, Vitamin D
The Nystagmus Network
A website packed with information about nystagmus, including personal experiences.
Call 029 2045 4242 or 0845 634 2630 open most weekdays 9am-5pm.
RNIB – Royal National Institute of the Blind
105 Judd Street
Helpline: 0303 123 9999 – Monday to Friday 8.45am-5.30pm