What is age-related macular degeneration?
This is a common ocular disease associated with aging that
gradually destroys sharp, central vision. The retina is the very
thin tissue that lines the back of the eye and contains the
light-sensing cells that send visual signals to the brain. Sharp,
clear, 'straight ahead' vision is processed by the macula, which is
the central part of the retina. When the macula becomes damaged
through ocular disease, many daily activities such as driving and
reading become increasingly difficult.
Are there effective treatments for macular degeneration?
If dry age-related macular degeneration (AMD) reaches the
advanced stages, there is no current treatment to prevent vision
loss. However, a specific
high-dose formula of antioxidants and zinc may delay or
prevent intermediate AMD
from progressing to the advanced stage.
The wet form of the disease can be treated with Lucentis, Macugen,
photodynamic therapy, and laser photocoagulation.
(ranibizumab injection) is an antibody fragment that
binds to and inhibits the biologic activity of human vascular
endothelial growth factor A (VEGF-A), a protein that is believed
to play a critical role in the formation of new abnormal leaky
blood vessels, which can damage the area of the eye responsible
for central vision. Lucentis is injected into the vitreous
portion of the eye (the clear jelly-like substance that fills
the eye from the lens back to the retina). Due to the fact that
the production of VEGF-A is ongoing, routine administration of
this drug is required. In clinical trails, the treatment
prevented further vision loss in most patients and improved the
vision of some.
(pegaptanib sodium injection) works by blocking vascular
endothelial growth factor (VEGF), a protein that promotes blood
vessel growth. According to the data collected during the
clinical trials, patients receiving Macugen were less likely to
progress to legal blindness and experience severe vision loss.
Macugen is injected into the vitreous portion of the eye (the
clear jelly-like substance that fills the eye from the lens back
to the retina). Routine adminitration of Macugen is required due
to the fact that the production of VEGF is ongoing.
- Photodynamic therapy works by injecting a
light-sensitive drug called
Visudyne (verteporfin) into the patient's bloodstream. The
drug circulates throughout the blood vessels, including the
abnormal vessels growing beneath the eye's retina. Once the drug
has had time to permeate the tiny vessels beneath the retina,
the light of a low-intensity laser is shined into the eye. The
Visudyne absorbs the light, destroying the abnormal or leaky
vessels. Photodynamic therapy has an advantage over
photocoagulation because less heat is required from the laser,
meaning that healthy tissues around the site of the procedure
receive less "collateral damage." One limitation of photodynamic
therapy is that it treats only the symptoms of wet macular
degeneration. New vessels will continue to grow, and the
procedure will have to be repeated. Other light-sensitive drugs
are in various stages of evaluation. Researchers are also
studying the use of verteporfin in combination with other types
- Photocoagulation requires the eye doctor to
focus a high-energy laser onto the abnormal blood vessels in the
macular region. The laser heats and destroys the abnormal blood
vessels and prevents them from leaking blood and fluid, which
can help to prevent or slow down further damage; however, it can
scar parts of the macula resulting in some central vision loss.
There can be a recurrence of blood vessel leaking and repeating
photocoagulation treatment may not always be possible. The
treatment is not available to patients when the abnormal blood
vessels are located in the center of the macula (called the
fovea), therefore, only a small percentage of patients are
candidates for this procedure.
If vision loss is permanent, low-vision aids exist that can help
improve the quality of life.
How many people suffer from age-related macular degeneration ?
Age-related macular degeneration (AMD) is a major cause of visual
impairment in the United States. Approximately 1.8 million Americans
age 40 and older have advanced AMD, and another 7.3 million people
with intermediate AMD are at substantial risk for vision loss. The
government estimates that by 2020 there will be 2.9 million people
with advanced AMD.
What are wet and dry macular degeneration?
There are two forms of age-related
macular degeneration (AMD): dry and wet. It is possible for a person
to suffer from both forms and AMD can affect one or both eyes. The
disease can also progress slowly or rapidly. Dry AMD may advance and
cause loss of vision without turning into the wet form of the
disease. However, it is also possible for early-stage dry AMD to
suddenly change into the wet form of the disease.
Dry macular degeneration is the most
common type of macular degeneration, affecting approximately 90
percent of people who suffer from the disease. Yellow deposits
called "drusen" form under the retina between the retinal pigmented
epithelium (RPE) and Bruch's membrane, which supports the retina.
Drusen deposits are "debris" associated with compromised cell
metabolism in the RPE and are often the first sign of macular
degeneration. Eventually, there is a deterioration of the macular
regions associated with the drusen deposits resulting in a spotty
loss of "straight ahead" vision.
Wet macular degeneration occurs when
abnormal blood vessels grow behind the macula. These vessels are
very fragile and can leak fluid and blood, resulting in scarring of
the macula and the potential for rapid, severe damage. There is a
breakdown in Bruch's membrane, which usually occurs near drusen
deposits. This is where the new blood vessel growth occurs
(neovascularization). "Straight ahead" vision can become distorted
or lost entirely in a short period of time, sometimes within days.
Wet macular degeneration accounts for approximately 10 percent of
the cases, however it results in 90 percent of the cases of legal
blindness. All wet AMD is considered advanced.
Do wet and dry macular degeneration have early,
intermediate and advanced forms?
All wet age-related macular degeneration (AMD) is considered
advanced; however, the dry form of AMD has three stages:
- Early Dry AMD - patients have several small drusen
or a few medium-sized drusen. There is no vision loss or
symptoms at this stage.
- Intermediate Dry AMD - patients have many
medium-sized drusen or one or more large drusen. Some people may
need more light for tasks such as reading. A blurry spot may
appear in the center of the visual field.
- Advanced Dry AMD - patients exhibit a large number
of drusen deposits and a breakdown of the light-sensitive cells
(photoreceptors) and supporting tissue in the retina. A large
blurry spot occurs in the center of the visual field and can
become larger and darker, eventually causing a complete loss of
How is macular degeneration diagnosed?
An eye care professional will perform a dilated eye exam, visual
acuity test, and view the back of the eye using a procedure called
fundoscopy to help diagnose age-related macular degeneration (AMD).
If wet AMD is suspected fluorescein angiography may also be
What new research is being done to find a cure for macular
Ongoing research continues with studies exploring environmental,
genetic, and dietary factors that may contribute to AMD. New
treatment strategies are also being explored, including retinal cell
transplants, drugs that will prevent or slow down the progress of
the disease, radiation therapy, gene therapies, a computer chip
implanted in the retina that may help simulate vision and agents
that will prevent the growth of new blood vessels under the macula.
Is macular degeneration
There are several different types of macular disease. The
majority of the conditions that affect individuals under 50 years of
age are believed to be hereditary and, in many cases, the genes
involved have been identified. These conditions are commonly
referred to as macular dystrophies.
Age-related macular degeneration (AMD) usually affects
individuals older than 50 years of age, and scientific evidence
shows that genes may play a role in the development of nearly three
out of four cases of this devastating eye disease.
Scientists have also identified two genes, called Factor H and
Factor B, which are strongly associated with a person's risk for
developing AMD. The Factor H and Factor B genes are responsible for
proteins that help regulate inflammation in the part of the immune
system that attacks diseased and damaged cells. According to
research at Columbia University, 74 percent of AMD patients carry
certain variants in one or both of these genes that significantly
increase their risk of this disease.
Researchers have also identified a gene on chromosome 10, called
PLEKHA1, which is also associated with a personís risk of developing
AMD. PLEKHA1, like Factors H and B, appears to be involved in the
cellular processes related to inflammation.
A variation of a gene called LOC387715 increases the risk of
developing AMD, and the risk increases dramatically if a person also
For the most part, the identities of other genes are unknown, but
there are several gene candidates that are being studied to
determine their role in AMD. There is also evidence that other
factors, such as sunlight exposure, diet and cigarette smoking may
play a role in the development of AMD.
Can diet prevent macular degeneration?
Some limited studies appear to indicate that eating a diet high
in antioxidants may reduce the risk of developing age-related
macular degeneration. More research is needed before definitive
recommendations can be made concerning diet and its role in macular
degeneration. Fruits and vegetables, especially those high in lutein
and zeaxanthin, appear to provide the best protection. Lutein and
zeaxanthin are also the primary pigments in the macula.
Lutein can be found in spinach, collard greens, kale, broccoli,
papaya, oranges, kiwi, mango, green beans, peaches, sweet potatoes,
lima beans, squash, red grapes, and green bell pepper.
Zeaxanthin can be found in yellow corn, honeydew melon, squash,
oranges, mango, kale, apricots, peaches, and orange bell pepper.
The USDA recommends that adults should be eating three to five
servings of vegetables and two to four servings of fruit each day.
Plant foods contain phytochemicals (non-nutrient substances), which
have been associated with protection not only from macular
degeneration, but from cancer, heart disease, diabetes, and a number
of other medical conditions. There are many families of
phytochemicals; they include indoles, saponins, flavonoids,
carotenoids, and others. Lutein and zeaxanthin are both carotenoids.
How all of these phytochemicals work together to provide health
benefits is not currently known. The good news is that you will be
healthier and may be decreasing your risk of developing a number of
diseases simply by eating a diet rich in fruits and vegetables.
supplements help treat macular degeneration?
The National Eye Instituteís Age-Related Eye Disease Study
(AREDS) found that taking a specific high dose formula of
antioxidants and zinc (500 milligrams of vitamin C, 400
International Units of vitamin E, 15 milligrams of beta-carotene, 80
milligrams of zinc as zinc oxide, and two milligrams of copper as
cupric oxide) may delay or prevent intermediate AMD from progressing
to the advanced stage. There is no evidence, however, that the AREDS
formula provided any benefit to people with early stage AMD.
Patients with intermediate AMD in one or both eyes or advanced AMD
(dry or wet) in one eye but not the other eye should consider taking
the formula. You should always talk with your physician before
taking any supplements because the formula may be contraindicated
due to other medical conditions that you have or medications that
you are taking.
Can you get macular degeneration in one eye or does it usually
happen in both?
You can get macular degeneration in one eye. However, as the
disease progresses, both eyes may become affected.
Can younger people get macular degeneration?
Yes. Early onset macular degeneration (birth to age 7) is a
genetic disease. It is called Best disease or vitelliform macular
degeneration. Middle onset macular degeneration (age 5 to 20) is
also a genetic disorder. This is commonly called Stargardt's
disease, fundus flavimaculatus, or macular dystrophy. Finally,
people in their thirties or forties can develop a form of the
disease that is also inherited. It may be called Sorsby's dystrophy,
Behr's dystrophy, Doyne's dystrophy, or honeycomb dystrophy.
Finally, myopic macular degeneration can occur in people who are
severely near-sighted due to extreme elongation of the eyeball. This
condition can result in tears in the macula and bleeding beneath the
Can visual hallucinations occur in people with macular
Yes, the condition is called Charles Bonnet Syndrome. In patients
who have eye diseases that prevent the normal nerve impulses from
reaching the brain, there is speculation that spontaneous nerve
activity may be generated by the brain, causing the visual
hallucinations. The syndrome appears to be more common in women than
men and it is more likely to occur if both eyes are affected by
disease. The hallucinations are complex and fully formed images.
They are most frequently of animals, people, faces, or scenery.
Patients know that the hallucinations are not real. They are not
associated with any other sensory hallucinations (such as
experiencing sounds or odors), nor are they associated with
delusions. The hallucinations may last for seconds or for most of
the day. They tend to disappear when people close their eyes. The
syndrome may be experienced for a period ranging from days to years.
For most people with macular degeneration, the condition is managed
by educating the patient and their family and reassuring them that
they are not "going insane" or suffering from a psychotic disorder.