Macular Degeneration

What is macular degeneration?

Located in the center of the retina, the sensitive macula provides us with sight in the center of our field of vision. When we look directly at something, the macula allows us to see the fine details. This sharp, straight-ahead vision is necessary for driving, reading , recognizing faces, and doing close work, such as sewing.

The two common types of macular degeneration are dry and wet. The dry form accounts for 90% of cases and is caused by aging and thinning of the tissues of the macula. It develops slowly and usually causes mild vision loss. People often notice a dimming of vision when they read.

Wet macular degeneration is a much greater threat to vision loss even though it accounts for only 10% of cases. With the wet form of the disease, new blood vessels grow beneath the retina where they leak fluid and blood and can create a large blind spot in the center of your visual field. If this happens, there will be a marked disturbance of vision.

Although it's more common for people over 60, it is possible to develop symptoms in your 40's or 50's. Macular degeneration often runs in families. Symptoms can include:

• blurry or fuzzy vision
• straight lines, such as sentences on a page, telephone poles, and sides of buildings, appear wavy
• a dark or empty area appears in the center of vision

If you experience any of these symptoms in either one or both eyes, schedule an appointment with your ophthalmologist for an examination immediately.

How is macular degeneration treated?

Unfortunately, the cause of macular degeneration is unknown. Although your ophthalmologist will be able to readily detect the disease during an eye exam, he or she won't be able to cure it. The goal is to help the patient see better and stabilize the condition.

Although there is no proven treatment for dry macular degeneration, some people believe that antioxidants or zinc supplements may help.

Out-patient laser surgery may be an option for people with more severe wet macular degeneration. The laser beam is used to destroy the abnormal blood vessels and works best when these vessels have not grown under the macula.

Laser surgery is less helpful when the abnormal blood vessels have already grown under the macula. In this case, the laser might cause as much damage as the presence of abnormal blood vessels. This is why early diagnosis is so important.

The "good" news about macular degeneration is that even though people who have it experience mild to severe vision loss, macular degeneration does not affect peripheral, or side vision. One does not go blind. With the help of low vision aids, people can continue to enjoy many of their favorite activities and can still lead normal, independent lives.

Most of low vision aids combine magnification and bright lights. But vision aids aren't like glasses which allow you to see whatever you're looking at when you put them on. One kind of vision aid may be helpful when you read but totally ineffective when you watch TV or focus on something in the distance. People need to try different types for different situations.

Does nutrition play a role in macular degeneration? The AREDS Study

Vitamins and Age-Related Macular Degeneration
Regarding the Age-Related Eye Disease Study (AREDS): Report #8

If you or someone you know has Age-related Macular Degeneration (AMD), you should be aware of an important recent study from the Age-related Eye Disease Study (AREDS). We are excited to discuss and comment on the recent results published in the Archives of Ophthalmology (Vol. 119, Oct. 2001: report #8). The study reports the beneficial effect of antioxidants (Vitamin C, E, beta-carotene and zinc-copper supplements) to prevent progression of AMD. We have long awaited the results of this important randomized prospective placebo controlled clinical trial. Estimates reported from the American Academy of Ophthalmology ( New Orleans, Oct. 13, 2001) indicate that if all individuals with category 3 or 4 macular degeneration took these supplements, approximately 300,000 people in the United States alone would be spared from suffering vision loss that they would have suffered had they not taken antioxidants over the ensuing 5 years. Because of this important prospective randomized clinical trial, we feel that is important to make patients aware of this study and to encourage those individuals diagnosed with category 3 or 4 macular degeneration to consider antioxidant supplements and zinc.

There are some very important issues that must be understood in the use of long-term antioxidant supplementation use based on the results of this study.

• Individuals with “intermediate” levels of AMD should consider taking vitamins.
• There is an increased association of lung cancer in smokers treated with beta carotene.
• Zinc supplements may increase the risk of genitourinary complications.
• Individuals taking cholesterol or lipid-modifying medications should consult their physician.
• Results from this study do not necessarily apply to individuals who have severe vision loss from AMD.

Comment: A vitamin pill is no substitute for a healthy lifestyle including a low-fat diet rich in fresh fruits and vegetables, avoidance of smoking, weight management and regular exercise. Many eye-care specialists recommend avoidance of sunlight by regularly wearing sunglasses and/or hat to protect against chronic sun exposure.

Common Questions about the AREDS Study:

What is AMD?

Age-related macular degeneration is an aging change in the back of the eye that may lead to loss of the central vision. It is the leading cause of ‘legal blindness’ in the western world in individuals over age 50. The early stages are extremely common. The eye is like a camera, and the retina is the film in the back of the camera. Aging results in the accumulation of yellow pigment deposits, or drusen, under the retina. Drusen are common, and they come in many shapes and sizes. The AREDS categorized and counted the drusen to determine the effects of vitamin therapy on various categories of drusen in volunteers who participated in the study.

What should I do if I may have AMD?

Contact you ophthalmologist to determine whether you have AMD, and if so, what category of drusen is present. The ophthalmologist will examine the back of your eye using dilating drops to check for drusen or other changes.

What was the beneficial effect for those with certain types of drusen?

Beneficial effect was classified as either a de decrease in the progression to advanced AMD or less progression of vision loss from AMD. For the intermediate level of drusen, the risk of reduction in progression to advanced AMD in those taking antioxidants plus zinc compared with placebo was 25%. The reduction in progression to advanced AMD is also reflected in visual acuity scores.

What was the placebo group taking?

All patients took a vitamin pill twice daily of identical size, shape and color. The placebo group did not contain antioxidants or zinc. However, in all groups (including placebo controls) patients were allowed to take a Centrum multivitamin. Approximately 68% of participants continued to take a Centrum during the coarse of the study.

Were blood tests used to document systemic levels of antioxidants performed?

Four clinical centers collected baseline samples for various antioxidants plus total cholesterol, high-density lipoproteins, triglycerides, lutein, zeaxanthin, lycopene and B-cryptoxanthin. Three centers continued to collect samples annually. Hematocrit was also measured regularly at all centers. No significant anemia or blood lipid changes were found.

What should individuals do that have “mild” drusen?

Current recommendations are to defer consideration of supplementation used in this trial until the risk of progression is higher. There is no evidence from the AREDS study at this time that either antioxidants or zinc, at the doses prescribed, decrease the rate of progression from category 1 or 2 to categories 3 or 4. Future results will help to determine the best treatment for this group. Some may suggest that this study provides “Proof of Principle” that antioxidant vitamins for the treatment of AMD and therefore taking vitamins is beneficial for decreasing progression of all AMD. The study does not support this statement. However, this is the first study to clearly demonstrate that a relatively safe systemic therapy does effectively decrease progression of AMD. Individuals with mild drusen should be aware of the study results, but a “neutral” recommendation about antioxidant therapy seems warranted at this time. Other health factors should be considered on an individual basis.

Were there safety issues involved with the use of antioxidants and/or zinc?

Individuals on zinc therapy were slightly more prone to urinary tract infections, prostatic hyperplasia (in men) and stress incontinence ( in woman). Based on the harmful effects of beta-carotene associated with smokers (New England Journal of Medicine 1996, 1150-1155; 1994, 1029-1035), participants who were current of former smokers were given the opportunity to be assigned to a study medication that excluded the antioxidant component because of the association reported with lung cancer. For these reasons, people who smoke cigarettes should avoid taking the beta-carotene component of the antioxidants.

What exactly was the dose of antioxidants used in this trial?

Antioxidants:
      Vitamin C 500 mg
      Vitamin E 400 IU
      Beta-carotene 15 mg

Zinc:
      80mg zinc oxide
      +2mg of copper as cupric oxide
      (Note: The use of zinc alone may lead to copper deficiency)

There is now a commercially available formulation of a multivitamin that uses these doses from the ARED study and is available through Bausch & Lomb, marketed as Ocuvite Preser Vision, see the web site at www.bausch.com. (Please see package insert for details. We have no financial interest in this product). There will likely be other similar products on the market soon.

Were there minor side effects or complications?

Individuals who took antioxidant vitamins had a higher incident of “yellow skin.” Also, individuals in the antioxidant groups had less frequent “circulatory” events than the placebo group. No statistical changes in mortality were reported in any of the groups as compared to controls.

What is the impact of Lutein and Zeaxanthin based on the AREDS results?

Unfortunately, neither Lutein nor Zeaxanthin were studied as part of the ARED trial, and no definitive comment can be made regarding their use. Lutein and zeaxanthin are the predominant carotenoids in the human macula. Studies have shown an increase level of macular Lutein in those supplemented with Lutein (IOVS; 41:3322-6, 2000). Theoretically, yellow macular pigment many act as a filter to the shorter wavelength, higher energy blue light. Most common multivitamins, such as Centrum, Ocuvite and I-caps include Lutein in their formulation. Again, no definitive results on the use of Lutein for the treatment of AMD can be made based on the results of the AREDS.

Are there criticisms of the AREDS Study?

We anticipate some debate on the statistics used in the clinical trial and their interpretation. However, the power of the study is supported by a large number of participants (category 1d: 1117; category 2: 1063; category 3: 1621; and category 4: 956) Another important consideration is to consider the trends of the study that do not reach statistical significance. Many trends did show a potential treatment benefit. Only time will more definitively answer questions regarding some of these trends. Alternatively, long-term effects of supplementation may reveal side effects that were not apparent in this initial report . Future results from this study will add important information to these results.

What other associations of supplementation with medical conditions should we be aware?

Recently (New England Journal of Medicine, Nov 29,2001, pp 1583-92) patients with coronary artery disease and low levels of high-density lipoprotein (HDL or “good cholesterol”) were treated with one of four treatment groups: simvastatin plus niacin, antioxidants, simvastatin + niacin + antioxidants, or placebo. They found that the protective effect of increasing HDL cholesterol was attenuated by current therapy with antioxidants. While the dosages of antioxidants were higher (vit E: 800 IU, Vit C 1000 mg, Beta-carotene 25 mg, and selenium 100 mg.), the use of antioxidants in this setting requires further patient education. Patients currently treated with lipid-modifying medication may choose to use the zinc component from the AREDS study rather than the antioxidants.

There is some evidence (Science; 265, 1994; pp 1464-67), that cerebral zinc may play a role in the neuropathogenesis of Alzheimer’s disease. Hyperzincemia has also been suggested to aggravate glucose intolerance in non-insulin dependent diabetics (Diabetes Research; 11; 73-79, 1989).

What everyone should know about macular degeneration

MACULAR DEGENERATION

An eye condition in which the macula is damaged, often causing loss of central vision. (Macula-sensitive area in the retina responsible for central and detail vision.)

TYPES

"Dry form" - usually progresses slowly and causes central vision loss. "Wet" form - rarer, and more severe. May progress rapidly causing significant central vision loss. 

WHO GETS IT

Most common in people over 60; but can appear as early as age 40. Macular degeneration is the most common cause of severe vision loss among people over 65, and, as life expectancy increases, the disease is becoming an increasingly significant problem.

CAUSES

Not certain. No conclusive proof exists, however some scientists believe heredity may play a part, as may UV light exposure and nutrition. Studies are ongoing.

SYMPTOMS

Blurred or fuzzy vision; straight lines (such as sentences on a page or telephone poles) appear wavy; blind spot in the center of vision.

PREVENTION

Not certain. Some steps may help:

• Regular eye exams by your Eye M.D. Your Eye M.D. is specially trained to detect many vision-threatening conditions even before you develop symptoms. The earlier problems are detected, the better the chance of preventing vision loss
• 
  Protection from UV-A and UV-B rays. Some studies have suggested that prolonged or frequent exposure to UV-A and UV-B rays may be a factor in macular degeneration and other eye conditions, so always wear sunglasses that block 99 to 100% of UV rays when outdoors
• 
  Proper nutrition. Although there is no concrete evidence that nutrition plays a role in macular degeneration, a healthy diet can't hurt and can prevent many other health problems. Some Eye M.D.s may recommend vitamins or minerals to supplement your diet.

TREATMENT

"Dry" form -- usually none. Low vision rehabilitation can help those with significant vision loss to maintain excellent quality of life. "Wet" form -- laser surgery may help. Low vision rehabilitation for those with vision loss.

CURRENT RESEARCH

There is a great deal of research and several major scientific studies being conducted to find the causes and develop effective treatments for all types of macular degeneration. Visit the National Eye Institute Web site for additional information at www.nei.nih.gov.

NEW DEVELOPMENTS

Photodynamic therapy (PDT) is one of the most promising new treatments for the "wet" type of macular degeneration. It involves the injection of a recently approved drug, called Visudyne, into the bloodstream, followed by a brief laser treatment. The laser "activates" the drug, which helps destroy abnormal blood vessels in the eye that damage the macula. The procedure may be done in the Eye M.D.'s office, and several treatments may be necessary for it to be effective.

Because the US Food and Drug Administration recently approved Visudyne used for PDT as safe and effective, PDT may become more widely available to patients. However, it is not a good choice for everyone. Your Eye M.D. can tell you if you might be a good candidate for treatment.

UNPROVEN TREATMENTS

Be wary of any treatment that promises to restore vision, or cure or prevent macular degeneration. There are many so-called "miracle cures" advertised (often in magazines or on the Internet) that have not been adequately tested for safety or efficacy. These treatments may be expensive, and are generally not covered by insurance. If you are considering trying a new or untested treatment, make sure you talk to your Eye M.D. to ensure they are safe and won't interfere with timely and effective treatment of any eye problems.

LOW VISION REHABILITATION

Can help people who have experienced mild to severe vision loss adjust to their condition and continue to enjoy active and independent lifestyles. Rehabilitation may involve anything from adjusting the lighting in your home to learning to use low vision aids to help you read and perform daily tasks. Your Eye M.D. can arrange rehabilitation or refer you to organizations that can help.

SUPPORT

Adjusting to vision loss can be difficult at first. Your Eye M.D. may be able to recommend some support groups for people with low vision. You can support friends and family by encouraging them in their rehabilitation efforts and providing help (such as rides to appointments) when needed.

RESOURCES

Your Eye M.D is your best resource for any eye-care question or need. (Your Eye M.D. is a medical doctor specially trained to provide the full range of eye care, from eye exams and prescribing glasses and contacts to complex surgery for eye problems.)