Visual problems are common among those with MS and are often a first sign of the disease.
Optic neuritis is often the first symptom of MS. This occurs when inflammation and demyelination are present along the optic nerve (the nerve that connects the brain to the eye). A diagnosis of optic neuritis may suggest MS, but does not necessarily indicate that a person has or will develop MS. Symptoms of optic neuritis include the acute onset of any of the following:
- Decreased vision/blindness in one eye
- Blurred vision
- Graying of vision
Rarely are both eyes affected simultaneously with optic neuritis in MS. Pain with eye movement usually accompanies or precedes visual loss, and visual loss tends to worsen over the course of a few days before improving. Almost 55 percent of people with MS will have an episode of optic neuritis (according to WebMD).
Many functions are involved in seeing an object. Two major components needed for effective vision are (1) the ability to correctly image what is seen and (2) the proper coordination of the muscles that surround the eye and control its movements. Either or both of these functions can be affected by MS.
The most common problems are decreased or blurred vision (caused by optic neuritis), double vision (diplopia), and shaking, involuntary movements of the eyes (nystagmus). While optic neuritis results from inflammation and demyelination along the optic nerve, double vision and involuntary eye movements are the result of lesions in the brain stem, a part of the nervous system between the brain and cervical spinal cord.
Types of Visual Disorders
Full loss of vision, decreased vision, or blurred vision frequently affects only one eye of a person with MS who is experiencing optic neuritis. Colors may appear washed out, and night vision may be particularly difficult. Sensitivity to contrasts in light or the presence of holes (scotomas or “blind spots”) may also occur. Occasionally, optic neuritis will cause pain upon movement of the affected eye.
Diplopia, also known as “double vision,” occurs when the muscles that control a particular eye movement are weakened and not coordinated. Although annoying, double vision usually resolves on its own without medical treatment. When diplopia comes on suddenly, it could indicate an acute attack.
Less common than diplopia, another disorder stemming from muscle weakness and loss of coordination around the eye is nystagmus. This is the uncontrolled side-to-side (horizontal) or up-and-down (vertical) movements of the eye. It can be asymptomatic (causing no visual problems) or severe enough to disturb vision. Objects may appear to jump or move unpredictably as the two eyes no longer coordinate well with each other. Nystagmus can be more of a nuisance than a major problem and is usually temporary.
Some individuals with MS may experience a scotoma, a disorder that causes a blind spot to appear in the center of vision. A different disorder, homonymous hemianopsia, occurs rarely, causing vision to be lost on the right or left visual fields of both eyes.
Treatment of Visual Disorders
Whenever a visual problem arises, an ophthalmologist or neuro-ophthalmologist should be consulted. At times, the doctor may decide that the best treatment is to wait for the inflammation to go down and to see if the visual symptoms disappear on their own, reserving steroid treatment for more severe attacks.
If the symptoms are severe, intravenous steroid treatment may be used to reduce the inflammation and accelerate the recovery process. The same steroid treatment used to treat other types of MS relapses is often effective in shortening the duration of visual problems. These are usually given via intravenous injection (IV) for a few days, but steroids may also be given orally. An example of high dose steroids would be 1,000 mg of Solu-Medrol® (IV methylprednisolone).
Steroids may be administered two ways. As mentioned, a high dose of Solu-Medrol may be given through intravenous injection (IV), and this is often given daily for three to five days during an attack. Deltasone® (oral prednisone), Decadron® (oral dexamethasone), or Medrol® (oral methylprednisone) in a pill form may also be administered orally for several days after IV treatment, or they may be taken alone without an earlier IV treatment. While these corticosteroids may shorten MS attacks and help one to recover more quickly, no convincing evidence has been shown that corticosteroids can affect the long-term course of MS. Acthar® Gel (ACTH given via injection) is another option for treating MS relapses.
Several non-pharmaceutical options are also available to help cope with visual changes. For instance, an eye patch is sometimes used to treat diplopia (double vision) when necessary, such as when driving or reading. An ophthalmologist may also offer additional ideas or treatments for specific visual symptoms. Examples include using yellow lenses to tone down light for those experiencing a light sensitivity, or prisms in eye glasses to redirect the image. In other instances, a patient may find ways to simply adjust – as by turning the head to allow better alignment of the eyes.
Individuals with MS experiencing visual problems are often comforted by the fact that these symptoms are usually temporary. As with other MS symptoms, as noted earlier, please keep in mind that visual problems in MS may also be worsened by stress, fatigue, infection, certain medications, or an increase in temperature. When possible, avoiding situations that could worsen the symptoms of MS will also help to minimize the occurrence of visual issues