What Treatments Are Available for Dry Macular Degeneration?
The dry (atrophic) type of AMD affects approximately 80-90% of individuals with AMD. Its cause is unknown, it tends to progress more slowly than the wet type, and there is not - as of yet - an approved treatment or cure; however, there are a number of clinical trials underway.
In dry age-related macular degeneration, small white or yellowish deposits, called drusen, form on the retina, beneath the macula, causing it to deteriorate or degenerate over time.
Drusen are the hallmark of dry AMD. These small yellow deposits beneath the retina are a buildup of waste materials. They are made up of cholesterol, protein and fats. Typically, when drusen first form, they don't cause any vision loss. However, they are a risk factor for progressing to vision loss. When a person has more advanced dry macular degeneration, there are many more of these small yellowish deposits and they are larger.
Nutrition and Weight Control
- Studies suggest that eating antioxidant-rich foods, such as fresh fruits and dark green leafy vegetables (kale, collard greens, and spinach, for example), may delay the onset or reduce the severity of dry AMD. These types of vegetables contain lutein, which may protect the macula from sun damage, just as it protects the leaves of these vegetables from sun damage.
- Eating at least one serving of fatty fish per week may also delay the onset or reduce the severity of dry AMD. These types of fish are high in omega-3 fatty acids, which help decrease inflammation and promote eye health.
- Avoid packaged foods as much as possible. It's important to keep a balance between omega-6 fatty acids and omega-3 fatty acids in our diets. Virtually every food in a package contains omega-6 fatty acids in the form of vegetable oil. We need to increase our intake of omega-3s and decrease our intake of omega-6s.
- Avoid artificial fats. Low-fat foods are good options if they've achieved their low-fat status through a process that physically removes the fat. Skim milk and low fat cottage cheese are examples of these types of good low-fat foods.
- A low-fat cookie or a no-fat cake, however, is a nutritional contradiction. Usually a low-fat or no-fat label on baked goods doesn't mean less fat was used in the production of the food, but that an artificial fat was used, usually partially hydrogenated vegetable oil. These types of fats are artificial ingredients made in a laboratory and our bodies can't metabolize them. So it's best to eat real cookies – just don't eat the whole dozen!
- Incorporate exercise into your everyday life. Obesity may increase the risk for progression to advanced AMD.
The AREDS Formulation
- The primary goal of the AREDS2 study was to determine if (a) adding omega-3 fatty acids or (b) lutein and zeaxanthin (the anti-oxidants found in dark green leafy vegetables) to the original AREDS formulation would make it more effective for reducing the risk of advanced AMD and cataract.
- The AREDS2 research group also substituted lutein and zeaxanthin for beta-carotene, which prior studies had associated with an increased risk of lung cancer in smokers.
The researchers concluded that while omega-3 fatty acids had no effect on the formulation, lutein and zeaxanthin together appeared to be a safe and effective alternative to beta-carotene. Therefore, the addition of lutein and zeaxanthin to, and the subtraction of beta carotene from, the AREDS supplement formula was recommended by AREDS2.
The AREDS2 formulation now includes:
- 500 milligrams (mg) of vitamin C
- 400 international units of vitamin E
- 80 mg zinc as zinc oxide
- 2 mg copper as cupric oxide (to avoid anemia with high zinc intake)
- 10 mg lutein
- 2 mg zeaxanthin
Be sure to talk with your doctor before adding any nutritional or vitamin supplements to your diet. If you don't have AMD and wish to take nutritional supplements, take a good multiple vitamin/mineral combination with additional lutein and omega-3 fatty acids. The AREDS formula is not recommended for persons who do not have macular degeneration because it contains a high dose of zinc.
Please note: There is some new evidence that individuals whose AMD progression is slowed by the supplements were of a particular genetic makeup and that the supplements may speed its progression in those with a different genetic makeup. This has prompted some scientists to call for genetic testing of everyone with macular degeneration before prescribing supplements, but the evidence is not sufficient for all scientists to agree on this. Individuals should discuss this with their ophthalmologists.
Mesoxanthin and MacuHealth
John Nolan, Ph.D., came from Ireland to speak at our hospital by invitation of the MacuHealth company and I found his research to be very solid and convincing. While the MacuHealth company paid for his research, Dr. Nolan stated that he agreed to do the research only on the basis that he would publish his findings no matter what they were.
What he showed was that another cousin of lutein and zeaxanthin named "mesoxanthin" is actually the most active of the three specifically in the macula and that the combination of lutein, zeaxanthin, and mesoxanthin is what's needed. That's what the MacuHealth supplement contains.
Mesoxathin has not heretofore been commercially available and the MacuHealth company now has the sole right to manufacture and distribute it. It has not been subjected to a randomized, masked study so whether – and to what degree – it may be helpful is unknown. It is unlikely to do harm, however, and the research suggests that it may help.
Additional Factors to Control
Avoid ultraviolet and blue light (light waves that make the sky, or any object, appear blue) as much as possible and wear sunglasses that block blue light. In commercial sunglasses, this is usually in the yellow-orange-amber tints. Read Artificial Lighting and the Blue Light Hazard from Prevent Blindness for more information.
Control Blood Pressure
In the AREDS trial, individuals with hypertension were 1.5 times more likely to have wet AMD than persons without hypertension.
If you do smoke, stop – and avoid secondhand smoke as well.
Clinical Trials for Macular Degeneration
In order to receive approval from the U.S. Food and Drug Administration (FDA), a new drug or treatment must be proven to be both safe and effective by undergoing a rigorous series of controlled unbiased studies. To prevent bias, neither the patient nor the examiners can know which patients received the actual treatment and which were the untreated (or "control") subjects.
These are called "double blind" or "double masked" studies and usually yield the most reliable results. The medication is coded and patients are placed at random into either the treatment or control group. When the study is concluded, the code is revealed and it is then possible to determine who received the actual drug and who received the inactive substance, or placebo.
As defined by the U.S. National Institutes of Health, most clinical trials are designated as Phase I, II, or III, based on the questions the study is seeking to answer:
- In Phase I clinical trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe and effective dosage range, and identify possible side effects.
- In Phase II clinical trials, the study drug or treatment is given to a larger group of people (100-300) to determine if it is effective and to further evaluate its safety.
- In Phase III studies, the study drug or treatment is given to even larger groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
- In Phase IV studies, after the Food and Drug Administration has approved the drug, continuing studies will determine additional information, such as the drug's risks, side effects, benefits, and optimal use.
To learn more about clinical research on treatments for macular degeneration, you can visit the following resources:
- Clinical trial research on the VisionAware blog
- Macular degeneration research on the VisionAware blog
- The National Eye Institute website for information on clinical studies.
- The FDA has approved the Implantable Miniature Telescope (IMT) for end-stage AMD
- ClinicalTrials.gov provides a searchable list of all current clinical trials related to AMD.
- Macular Degeneration Partnership provides information on clinical trials for wet AMD, dry AMD, and a list of frequently asked questions about clinical trials.
Have an Eye Examination
If you have not had an eye exam by an ophthalmologist in three or more years, you may qualify for help from the AMD Eye Care Program, offered through the American Academy of Ophthalmology. The program provides free eye exams for individuals who have not been diagnosed with AMD, are age 65 and older, are U.S. citizens or legal residents, and do not belong to an HMO or the Veterans' Administration (VA). Call the toll-free helpline at 1-866-324-EYES (3937) for more information.
- New Research: Statins May Show Promise as a Treatment for Dry Age-Related Macular Degeneration
by Maureen Duffy on 2/23/2016
- New Genetic Research in Macular Degeneration: The International AMD Genomics Consortium
by Maureen Duffy on 12/22/2015
- Author Ed Henkler Helps Readers Support Parents with Age-related Vision Loss
Ed Henkler, son of a mother with age-related macular degeneration, writes an e-book for helping families with useful tips and resources on dealing with vision loss. Read about his journey and his book.