Vision Problems: The Basic Facts
A vision problem is the first symptom of MS for many people. The sudden onset of double vision, poor contrast, eye pain, or heavy blurring is frankly terrifying-and the knowledge that vision may be compromised makes people with MS anxious about the future. Fortunately, the prognosis for recovery from many vision problems associated with MS is good.
If vision problems do persist, resulting in permanent low vision, there are resources and tools to help people adapt. Complete blindness can occur, but it is very rare. More people are faced with the need to accommodate. Some have even turned vision problems into advantages. Flo Fox, a photographer with MS in New York City , says that her adaptations helped her to become a better photographer, and she has taught other people with vision problems how to use various types of cameras adjusted to their abilities.
This fact sheet discusses the main MS-related eye problems, but people with MS may have poor vision from many other causes, just like anyone else. Regular eye care and periodic examinations are recommended for all.
MS-Related Vision Problems
The three disorders are not linked to each other and usually occur separately.
Symptoms of optic neuritis include blurred vision, dimming of colors, pain when the eye is moved, blind spots, and loss of contrast sensitivity. These symptoms may worsen over the first few days to two weeks. Then the condition usually starts improving. Some people recover within a month; others need up to a year. Most people regain normal or close-to-normal sight. However, the quality of their vision, including color or depth perception and contrast sensitivity, may be reduced after an episode of optic neuritis.
Temporary flare-ups of optic neuritis symptoms may also occur. Hot showers or baths, exercise, a bout of flu, or a fever may all trigger dimmed color, blurred vision, and other problems. Nerve fibers that are demyelinated (they have lost their myelin insulation) or remyelinating (they are under repair) are very sensitive to higher temperatures. These heat-related symptoms resolve when the person cools off, be it from ice packs, over-the-counter fever reducers, cool drinks, air conditioning, or a soak in a cool tub of water.
"The symptoms mean the optic nerve is not conducting information as well as it should," said Dr. Gregory P. Van Stavern, a neuro-ophthalmologist at Wayne State University in Michigan . "This doesn't mean a person is having a new attack of MS. If symptoms persist for a couple of days, then contact a physician."
Nystagmus reduces vision in a number of ways, including oscillopsia-an experience of the world "wiggling." The wiggling may be horizontal or vertical, and may occur in one eye, or both. It typically causes general poor vision and, often, loss of balance.
Diplopia disturbs vision by producing images in doubles. This may also cause loss of balance as spatial orientation is disturbed.
In a controlled trial, the Optic Neuritis Treatment Trial (or ONTT), high-dose intravenous steroids were shown to accelerate recovery from visual symptoms and to delay development of MS. Dr. Roy W. Beck, executive director of the Jaeb Center for Health Research in Tampa, Florida, who was principal investigator, summed up the trial this way: "Intravenous corticosteroids at the time of a first episode of acute optic neuritis appear to have a short-term beneficial effect . delaying the time to the development of a second demyelinating event. However, there did not appear to be a long-term benefit from a single course of IV steroid treatment."
The ONTT also found that people treated with oral steroids did not do as well as the people who were not treated at all. Oral steroids apparently increased the risk of recurrence.
If the symptoms of optic neuritis are mild and an MRI does not show any lesions, a doctor may decide to allow the disorder to resolve on its own.
A newer, more experimental (and more expensive) therapy for MS-associated vision problems is intravenous immunoglobulin (IVIG). A study at the Mayo Clinic had inconclusive results as to the efficacy of IVIG as a treatment, and some neurologists would never prescribe it. Others feel it has a place. For example, Dr. Elliot Frohman, associate professor of Neurology and director of the MS Program at University of Texas , Southwestern Medical Center in Dallas , recommends IVIG for people with MS who have diabetes, are manic-depressive, or for other reasons cannot tolerate steroids.
There is little information on the effectiveness of complementary therapies for vision problems, but some people report relief from vitamin B-12 shots during an optic neuritis episode. "We know optic nerve function depends on vitamin B-12 and folate," said Dr. Thomas R. Hedges, III, professor of Ophthalmology and Neurology at Tufts University School of Medicine and the director of Neuro-ophthalmology at the New England Medical Center . "I encourage people to take multivitamins." According to Dr. Frohman, anyone coming in for a vision problem should be screened for vitamin B-12 levels as a deficiency can mimic symptoms of MS.
Diplopia and Nystagmus
"Patching an eye will not affect the vision in any way and will not delay recovery to any significant degree. The brain always tells both eyes to move at once," he said. In addition, it doesn't matter which eye is patched. "Patch whichever eye helps you to see better," he advises.
Nystagmus is more difficult to resolve. Dr. Van Stavern and Dr. Hedges agree that the existing medications for nystagmus, such as anticonvulsants and muscle relaxants, may not work well. Dr. Frohman says that gabapentin (Neurontin), a drug also used for seizures, may be helpful. Surgery is not usually recommended for nystagmus. According to Dr. Hedges, there is work being done on optical devices to stabilize the jiggling visual environment of people with nystagmus.
As difficult as these two disorders are initially, both diplopia and nystagmus may go away spontaneously. Moreover, the brain eventually learns to ignore wiggling and black spots, restoring more normal vision.
Low-vision specialists are licensed doctors of ophthalmology or optometry. The specialist will assess how your eyesight functions in day-to-day living-not just how well you do on an eye chart exam. He or she may ask questions about glare, contrast, sensitivity to light, and color perception. In addition, special charts may be used to measure other aspects of your vision. A typical session with a low-vision specialist lasts two to three times longer than a standard eye exam.
The low-vision specialist will want as much information as possible-not only about your medical and vision history, but your individual needs. If you have an occupational need, a hobby, or a favorite activity, explain it during your examination. Your low-vision specialist may be able to prescribe or recommend an optical device, such as microscopic or telescopic eyewear, a magnifier, a filter, or a closed circuit television system, that fits your specific needs.
Living with Low-Vision
According to Dr. Frohman, both you and your doctor should be aware that diplopia or nystagmus affects your navigation and balance. "Added to a little bit of leg weakness or gait imbalance, and these vision problems can increase one's safety risk," Dr. Frohman said. He notes that patching one eye leads to losing depth perception. A cane or other mobility aid may be essential to prevent accidents.
One of the more popular visual aids is the closed circuit television (CCTV) which can magnify a number of things-including photographs, letters, book pages, even the labels on medicine bottles-onto a television screen. Some CCTVs are freestanding, with a monitor that sits on a platform. Others are plugged into your television and use its screen.
Your computer can also be modified in dozens of ways. There are programs that translate text into voice and vice versa, and there are excellent text magnifiers. The Low Vision Gateway (www.lowvision.org) has an extensive list of computer programs for people with low vision.
Photographer Flo Fox recommends that people with visual problems register at their local post office for free mailing. As she puts it, "You might as well take advantage of the government. Call your phone company, too, to find out about free directory assistance if you can't read the type or turn pages in a phone book."
American Foundation for the Blind, 800-AFB-LINE, www.afb.org
American Nystagmus Network, www.nystagmus.org
American Printing House for the Blind, 800-223-1839, www.aph.org
The Lighthouse, 800-829-0500, TTY: 212-821-9713, www.lighthouse.org
The Low Vision Gateway, www.lowvision.org
Low Vision Information Center , 301-951-4444, www.lowvisioninfo.org
The National Association for the Visually Handicapped, 800-677-9965, www.navh.org
The National Federation of the Blind, 410-659-9314, www.nfb.org
The National Eye Institute, 301-496-5248, www.nei.nih.gov
"Living with Low Vision"-a feature story in the Winter 2001 issue of InsideMS, by Joyce Render Cohen, a veteran of MS and low vision-describes many more techniques and resources. "The most important resource is your attitude," she said. "Whether you regain full vision or don't, life can be good-life is good. Just try not to let low vision take over."
For additional information
|Copyright © National Multiple Sclerosis Society, 2002|