Age-Related Macular Degeneration (AMD)
Age-related macular degeneration (AMD)
is a disease that gradually destroys sharp, central vision. Central vision
is needed for seeing objects clearly and for common daily tasks such as
reading and driving. AMD affects the macula, the part of the eye that
allows you to see fine detail. AMD causes no pain.
In this simulation, how a person with AMD sees the world is presented graphically. As the disease progresses the area of central vision deteriorates. The gradual destruction of light sensitive cells continues until large areas are totally lost. Peripheral vision remains, but the ability to clearly see straight ahead is gradually lost. Credit: National Eye Institute, National Institutes of Health
In some cases, AMD advances so slowly that people
notice little change in their vision. In others, the disease progresses
faster and may lead to a loss of vision in both eyes. AMD is a leading
cause of vision loss in Americans 60 years of age and older.
Wet AMD versus dry AMD
Wet AMD occurs when abnormal
blood vessels behind the retina start to grow under the macula. These new
blood vessels tend to be very fragile and often leak blood and fluid. The
blood and fluid raise the macula from its normal place at the back of the
eye. Damage to the macula occurs rapidly.
With wet AMD, loss of central vision can occur
quickly. Wet AMD is also known as advanced AMD. It does not have stages
like dry AMD.
An early symptom of wet AMD is that straight lines
appear wavy. If you notice this condition or other changes to your vision,
contact your eye care professional at once. You need a comprehensive
dilated eye exam.
Dry AMD occurs when the
light-sensitive cells in the macula slowly break down, gradually blurring
central vision in the affected eye. As dry AMD gets worse, you may see a
blurred spot in the center of your vision. Over time, as less of the
macula functions, central vision is gradually lost in the affected eye.
The most common symptom of dry AMD is slightly
blurred vision. You may have difficulty recognizing faces. You may need
more light for reading and other tasks. Dry AMD generally affects both
eyes, but vision can be lost in one eye while the other eye seems
unaffected.
| Normal vision and the same scene as
viewed by a person with age-related macular degeneration. |
Normal vision |
|
The same scene as viewed by a person with age-related macular
degeneration |
Causes and Risk Factors
Who is at risk for AMD?
The greatest risk factor is age. Although AMD may
occur during middle age, studies show that people over age 60 are clearly
at greater risk than other age groups. For instance, a large study found
that people in middle-age have about a 2 percent risk of getting AMD, but
this risk increased to nearly 30 percent in those over age 75.
Other risk factors include:
- Smoking. Smoking may increase
the risk of AMD.
- Obesity. Research studies
suggest a link between obesity and the progression of early and
intermediate stage AMD to advanced AMD.
- Race. Whites are much more
likely to lose vision from AMD than African Americans.
- Family history. Those with
immediate family members who have AMD are at a higher risk of developing
the disease.
- Gender. Women appear to be at
greater risk than men.
- Aspirin.
A new study links daily aspirin use to an increased
risk of macular degeneration.16
Can my lifestyle make a difference?
Diet and lifestyle can play a role in reducing your
risk of developing AMD.
- Eat a diet high in green leafy vegetables and
fish.
- Don't smoke.
- Avoid daily aspirin use.16
Conventional Medical Treatment for Macular
Degeneration
Wet AMD can be treated with laser surgery,
photodynamic therapy, and injections into the eye. None of these
treatments is a cure for wet AMD. The disease and loss of vision may
progress despite treatment.
- Laser surgery. This procedure
uses a laser to destroy the fragile, leaky blood vessels. A high energy
beam of light is aimed directly onto the new blood vessels and destroys
them, preventing further loss of vision. However, laser treatment may
also destroy some surrounding healthy tissue and some vision. Only a
small percentage of people with wet AMD can be treated with laser
surgery. Laser surgery is more effective if the leaky blood vessels
have developed away from the fovea, the central part of the macula. (See
illustration at the beginning of this document.) Laser surgery is
performed in a doctor's office or eye clinic.
The risk of new blood vessels developing after laser treatment is high.
Repeated treatments may be necessary. In some cases, vision loss may
progress despite repeated treatments.
- Photodynamic therapy. A drug
called verteporfin is injected into your arm. It travels throughout the
body, including the new blood vessels in your eye. The drug tends to
"stick" to the surface of new blood vessels. Next, a light is shined
into your eye for about 90 seconds. The light activates the drug. The
activated drug destroys the new blood vessels and leads to a slower rate
of vision decline. Unlike laser surgery, this drug does not destroy
surrounding healthy tissue. Because the drug is activated by light, you
must avoid exposing your skin or eyes to direct sunlight or bright
indoor light for five days after treatment.
Photodynamic therapy is relatively painless. It takes about 20 minutes
and can be performed in a doctor's office.
Photodynamic therapy slows the rate of vision loss. It does not stop
vision loss or restore vision in eyes already damaged by advanced
AMD. Treatment results often are temporary. You may need to be
treated again.
- Injections. Wet AMD can now be
treated with new drugs that are injected into the eye (anti-VEGF
therapy). Abnormally high levels of a specific growth factor occur in
eyes with wet AMD and promote the growth of abnormal new blood vessels.
This drug treatment blocks the effects of the growth factor.
You will need multiple injections that may be given as often as monthly.
The eye is numbed before each injection. After the injection, you will
remain in the doctor's office for a while and your eye will be
monitored. This drug treatment can help slow down vision loss from AMD
and in some cases improve sight.
Age-Related Eye Disease Study (AREDS)
The National Eye Institute's
Age-Related Eye Disease Study (AREDS)
found that taking a specific high-dose formulation of antioxidants and
zinc reduces the risk of advanced AMD and its associated vision loss by
25%, slowing AMD's progression from the intermediate stage to the advanced
stage.
The specific daily amounts of
antioxidants and zinc used by the study researchers were 500 milligrams of
vitamin C, 400 International Units of vitamin E, 15 milligrams of
beta-carotene (often labeled as equivalent to 25,000 International Units
of vitamin A), 80 milligrams of zinc as zinc oxide, and two milligrams of
copper as cupric oxide. Copper was added to the AREDS formulation
containing zinc to prevent copper deficiency anemia, a condition
associated with high levels of zinc intake.
Can diet alone provide the same high levels
of antioxidants and zinc as the AREDS formulation?
No. The high levels of vitamins and minerals are difficult to achieve from
diet alone. However, previous studies have suggested that people who have
diets rich in green leafy vegetables have a lower risk of developing AMD.
Can a daily multivitamin alone provide the
same high levels of antioxidants and zinc as the AREDS formulation?
No. The formulation's levels of antioxidants and zinc are considerably
higher than the amounts in any daily multivitamin.
If you are already taking daily multivitamins and
your doctor suggests you take the high-dose AREDS formulation, be sure to
review all your vitamin supplements with your doctor before you begin.
Because multivitamins contain many important vitamins not found in the
AREDS formulation, you may want to take a multivitamin along with the
AREDS formulation. For example, people with osteoporosis need to be
particularly concerned about taking vitamin D, which is not in the AREDS
formulation. 1
How to Make Vision Supplements Work Better
Many people who take the AERDS nutritional
supplement formula do not benefit from it and the disease progresses. Only about 25% of study participants benefited. Also note that this
formula often slows the advancement of the disease. Just because
you don't notice improvement doesn't mean it isn't working.
Some holistic physicians, myself included, have
found that poor assimilation --- especially a decrease of gastric acid
function in the stomach --- is an important factor in the development of
AMD. No matter how many supplements one takes, if they are not
assimilated, they are of no value.
It is probably no coincidence that the risk of AMD
increases with age and so does the decline of stomach acid production.
Contrary to popular belief, most people who experience "heartburn"
actually have too little stomach acid, not too much. Find out how
that happens in this article:
What's
Burning You?
So, in addition to taking eye nutrients,
improving digestion and assimilation is also highly recommended.
Dr. Myatt's Recommendations for
Macular Degeneration
- Diet: eat a diet high in antioxidant
nutrients (especially green vegetables), high in Omega-3 fatty acids (from
fish) and low in Omega-6 fatty acids.
- Gastric function: Perform a
Gastric Acid Self-Test or ask
your holistic physician to perform a Heidleberg gastric analysis. Make
corrections to gastric acid function as indicated by the test.
- Vision supplements: The following are specifically
recommended for macular degeneration:
I)
Maxi Multi-
optimal potency multiple vitamin / mineral / trace mineral supplement. 3
caps, 3 times per day with meals.
Vision was the same or better in 88% of people with AMD who
took a multiple vitamin / mineral supplement compared with 59% of those
who those who did not take the supplement. This is a statistically
significant difference. The supplement used in this study contained
beta-carotene, vitamin C, vitamin E, zinc, copper, manganese, selenium,
and riboflavin. 2 Other studies
have confirmed the importance of vitamins A, C, E, zinc and other
nutrients found in a quality multiple vitamin/ mineral formula.
3,5 More recent studies have also shown the
importance of B complex vitamins in AMD.4
II.)
Maxi Marine O-3:
(high potency fish oil). 1 cap, 2 times per day. A diet high in omega-3
fatty acids, especially from fish oil, has been associated with lower risk
of macular degeneration in multiple studies.
5-10
III.)
Lutein Plus (lutein
and zeaxanthin). 1 cap, 1-2 times per day with meals. Lutein and
zeaxanthin are two carotenoids that act directly in the macula to protect
it from damaging effects of excess light. Along with vitamins C and
E, they are part of the antioxidant defense system of the macula.11
Studies have shown that lutein and zeaxanthin reduce the risk of AMD and
may slow progression. 3-5, 11-14
Smokers have an increased need for these carotenoids.
14
How Long to See Results?
One study suggests that it takes at least 6
months of supplementation to see results. 15
