Eye movement problems
In some people with MS, the nerve pathways that control the movement of their eyes can be affected. As a result their eyes may not move smoothly, or the two eyes may be out of alignment.
The two most common eye movement problems in MS are double vision (diplopia) and involuntary eye movements (nystagmus).
Types of eye movement problems
Double vision (Diplopia)
If your eyes aren’t working perfectly together, then you may see double – a single object may appear as two objects. They may be side by side or one on top of another. Sometimes one of the images may appear tilted.
You may notice that the double vision only occurs when you’re looking in certain directions, for example, all the way to the side, or straight ahead.
Some people with double vision can also have problems with nausea (feeling sick), vertigo (a spinning sensation) or a lack of coordination which can affect their balance.
As with optic neuritis, if your double vision is related to a relapse if often improves on its own. A course of steroids may help speed up recovery. These are taken either as an infusion (or 'drip') into the hand or arm, or as tablets.
If your double vision is particularly troubling, there are things you can do to reduce the impact of it. Patching one eye blocks out one of the two images and can provide some relief. If you wear glasses, you can get these fitted with special prisms to realign the two images. These help to ease the imbalance caused by double vision by making your brain think your eyes are working together.
Involuntary eye movements (nystagmus)
Nystagmus is the name for an uncontrolled movement of the eyes. They can move in any direction: side to side, around or up and down.
Many people with MS who have nystagmus don’t realise they have it, as the movement has little or no effect on their vision. It’s often something doctors will pick up on when they’re testing eye movements. However, some people do notice a significant effect on their vision. Objects may seem to move back and forth, to jerk or to wiggle. This is known as oscillopsia.
As with other MS-related eye problems, visual problems caused by nystagmus can vary. For example, some people notice their vision can get worse when they are stressed, tired or hot.
Drugs such as gabapentin, baclofen, memantine or clonazepam can help to reduce the jerky movements, and improve your vision. However, they don’t work for everyone.
Research is underway into other possible treatments. Information about the latest research into nystagmus, as well as support for living with the condition, is available from the Nystagmus Network website.