Laser Therapy for Drusen
Although
laser therapy is well established for treating wet AMD, investigators
have been exploring its use in the early stages of AMD, usually before
visual symptoms occur.
In 1999, the National Eye Institute began a large, multi-center study
to determine if laser applications applied to high-risk eyes with large
drusen in the macula prevented later complications of AMD and consequently
preserved visual function. Casey's Macular Degeneration Center was a
participating clinical center in this study, in which one eye was treated
and the other eye was observed.
After closely following patients for several years, investigators found
there was no difference in vision or in progression to advanced AMD
between treated and untreated eyes. Based on results from this trial
as well as two other smaller-scale studies, it is not recommended that
people with large drusen undergo preventive laser treatment.
Anecortave Acetate (Retaane)
Investigators at Casey and other eye centers are studying the safety
and effectiveness of the steroid compound Retaane (anecortave acetate)
in stopping the development of wet AMD in high-risk eyes.
Patients who have lost vision from wet AMD in one eye are in danger
of developing the wet form in the other eye within five years. In this
multi-center study, the medication was administered to the healthier
eye in order to prevent wet AMD from developing.
This is a departure from previous drug studies because investigators
are trying to preserve vision in at-risk patients by preventing the
vulnerable eye from developing abnormal blood vessels.
Enrollment in this study is closed and study patients are continuing
to be followed.
The Role of Nutrition
Dietary Supplements
A Healthy Diet
Dietary Supplements
Age-Related Eye Disease Study (AREDS)
In
2001, the National Eye Institute completed a 10-year clinical study
to evaluate the effects of a high-potency antioxidant vitamin and mineral
supplement on AMD.
The large-scale trial showed that patients at high risk of developing
advanced AMD reduced that risk by 25 percent by taking the complete
formulation of antioxidants and zinc. For this same group, the risk
of vision loss itself was reduced by 19 percent. Those at high risk
include people with intermediate AMD in one or both eyes or those with
advanced AMD in one eye already.
Only a few possible side effects from taking the study medications were
found.
Recommendations
(1) If you are at high risk of developing advanced AMD, you should consider
taking supplements like those used in AREDS.
Supplements provide no apparent benefit for those with early AMD or
no AMD, and there is no apparent need to take them. However, yearly
eye examinations are advisable to determine if the disease is progressing.
(2) Your eye doctor can tell you if you have the high-risk level of
AMD by performing an eye examination of your retinas through dilated
pupils.
(3) Because the AREDS formulation has a high level of antioxidants and
zinc, discuss the advisability of taking them with your eye doctor and/or
primary care physician. This is especially important for individuals
with chronic diseases for which they may be taking several medications.
(4) Bausch & Lomb, the company that prepared the study formulation,
markets the supplement under the name PreserVision AREDS. It is
available over-the-counter in pharmacies and other stores that sell
dietary supplements.
PreserVision is available in two forms – with or without lutein. In
the formula containing lutein, this nutrient replaces the beta-carotene
in the original PreserVision formula. Smokers are advised to use this
formula because other studies have found that beta-carotene may increase
the risk of other health problems in smokers.
As an alternative, the ingredients can be purchased separately. The
individual supplements and the amount to be taken daily are:
Vitamin C – 500 milligrams
Vitamin E – 400 International Units (IU)
Beta-carotene – 15 milligrams (25,000 IU) – not recommended for smokers
Zinc – 80 milligrams and Copper – 2 milligrams (must be included when
taking zinc)
Lutein (optional) – 10 milligrams
Vitamin E
A study published in 2005 reported that high doses of vitamin E might
be a health concern. However, after careful study and interpretation
of the data, NEI researchers have concluded that taking the recommended
400 international units (IU) of vitamin E each day as part of the AREDS
formulation does not pose a significant health danger for persons at
risk for advanced AMD.
Age-Related Eye Disease Study II (AREDS II):
The National Eye recently has launched a second large-scale, long-term
study to refine the findings from the original study and to assess the
effects of high supplemental doses of lutein and zeaxanthin and omega-3
fatty acids for the treatment of AMD and cataract. Recent research suggests
that lutein and zeaxanthin (pigments found in green, yellow and orange
fruits and vegetables) may help protect against macular degeneration,
although this has not been proven.
Omega-3 fatty acids found in such cold-water fish as salmon and tuna,
as well as in fish oil capsules, are important in the management of
heart disease. Preliminary research also suggests they may be a protective
factor in AMD.
Until now, however, there has been no data to prove that the risk of
AMD can be reduced by taking large amounts of any of these nutrients.
To address this unanswered question, approximately 4,000 patients in
the AREDS II study will receive a placebo, lutein and zeaxanthin, omega
3, or all three nutrients assigned in a randomized fashion. Recruitment
is underway for the study,which is being conducted in clinical centers
around the United States, including Devers Eye Institute in Portland.
Click here to learn
more about participating in AREDS II.
A Healthy Diet
Eating whole, natural foods is considered the safest and most effective
way to obtaineye healthy nutrients. It is recommended that people eat
five to nine servings a day of fruits and vegetables high in lutein
and zeaxanthin. These foods include green leafy vegetables and other
yellow, orange and green fruits and vegetables. Two or more servings
of fish each week, such as salmon, tuna or sardines, or two to three
one-gram capsules of fish oil per day will also supply omega-3. For
overall health, we suggest a diet low in cholesterol, saturated and
trans fat, sugar and salt.
