Visual symptoms which are common in MS include optic neuritis, uncontrolled eye movements (nystagmus), blurred vision, and double vision (diplopia). Although common, these symptoms seldom result in permanent blindness.
What is optic neuritis and how is it treated?
Optic neuritis is an inflammation of the optic nerve. Nerve damage caused by optic neuritis can result in changes in color vision (eg. color red becomes dull), blurring or graying of vision, appearance of a dark spot (scotoma) in the central visual field, or temporary blindness (typically in only one eye). Damage from optic neuritis is self-limiting and in most cases, vision returns to normal or near normal. Becoming overheated, whether through exercise, during hot humid weather, or from fever, can cause a flare-up of visual symptoms (Uhthoff’s phenomenon) until the body temperature returns to normal.
Optic neuritis sometimes responds to treatment with intravenous steroid infusions (IV methylprednisolone, or IVSM) followed by a course of oral corticosteroids. Very important - if optic neuritis is your first MS-like neurological attack, a 3-day or 5-day course of IV corticosteroids is recommended because IVSM treatment may delay the occurrence of a second demyelinating event or onset of MS. Non-drug management options to deal with vision changes include marking doorways and steps, eliminating glare by wearing polarized lenses, and increasing or improving lighting in your home.
What types of uncontrolled eye movements are common in MS and how are they treated?
Rapid, uncontrolled horizontal or vertical eye movements (nystagmus) can occur in MS. These jumping eye movements, which are rapid and unpredictable, may be triggered by certain visual stimuli and can cause disorientation.
Nystagmus can range in severity from mild to severe. Mild disorders may pose only an inconvenience and occur only when looking to the side. Severe disorders may result in significantly impaired vision.
Treatment options for eye movement disorders include medications, such as high-dose IV or oral corticosteroids, baclofen, Klonopin (cloazepam), Neurontin (gabapentin), and transdermal scopolamine, and the use of special optical devices to stabilize eye movements.
What causes double vision and how can it be treated?
Double vision (diplopia) is caused by a lack of coordination between the pairs of muscles that control eye movement. When one or both pairs of these muscles become weak, eyes no longer work together to produce a single or fused image and the person sees a false double image.
A short course of corticosteroids is often used to resolve double vision. However, double vision does not respond to corticosteroid treatment as well as optic neuritis does. Double vision will eventually resolve without treatment or without the need for special eye correction as the brain adjusts to the weakness or lack of muscle coordination which causes it. Using a patch over one eye while driving or reading helps to eliminate double vision caused by muscle incoordination. Disagreement exists regarding how often or how long an eye patch should be used.