Vitamins and AMD
Wet AMD Treatments
The eye is essentially a camera. The role of the eye is to focus light
and images from the outside world onto the retina. This is analogous to
the role of a camera, which is to focus light and images onto the film.
In the eye, the cornea and lens are responsible for focusing light to a
pinpoint focus on the retina.
<<back to
questions
The retina is the part of the eye that is like the film of a camera.
Important vision cells in the retina, notably the rods and cones,
convert the focused light into an electrical signal which then travels
to the brain through the optic nerve. In the brain that electrical
signal is experienced as vision. There are two parts of the retina: the
macular retina (responsible for straight-ahead central vision) and the
peripheral retina (responsible for side vision).
<<back to questions
The macula is the part of the retina responsible for straight-ahead
central vision. The macula is used for reading, recognizing faces and
watching television. Any disease that affects the macula, such as
age-related macular degeneration, will cause a change and impairment in
the central vision.
<<back to questions
AMD is the leading cause of central vision loss in the Western world in
persons over the age of 55. It is an age-associated degenerative
disorder of the macula, the part of the retina responsible for
straight-ahead, central vision. As some people age, the macula weakens
and its cells begin to break down. This may result in the loss of
central vision.
<<back to questions
Macular degeneration currently affects approximately 12 million people
in the United States. Over the next 20 years, as our population ages,
the number of people with AMD is expected to more than double.
<<back
to questions
There are a number of reasons why people may develop AMD, but age
appears to be the main risk factor. In fact, the chance of developing
AMD increases with each passing decade after age 50, with 30 percent of
people over age 70 exhibiting some sign of the disease.
There are genetic and environmental risk factors as well. Since pigment
in the eyes appears to be protective, Caucasians, particularly women,
appear to be at a greater risk. Smoking, family history and sunlight
exposure over the course of a lifetime also play a role.
<<back
to questions
Dry AMD is the most common form of macular degeneration, affecting 90
percent of people with the disease. In the dry form, aging changes
called "drusen" become deposited underneath the macula. The changes that
AMD patients develop as they age don't necessarily affect quality of
life. In fact the vast majority of patients with drusen have no visual
changes. However in some AMD patients, drusen can cause the
macula to thin resulting in a gradual decrease in central vision. This
late stage of the dry type is called geographic atrophy. If the drusen
cause substantial weakening of important layers of the macula, they can
set the stage for the "wet" form of AMD.
<<back to questions
Wet AMD develops when abnormal blood vessels start to grow through
important layers of the macula that have been weakened by the dry form
of AMD. This abnormal-growth blood vessels, called choroidal
neovascularization (CNV), can cause bleeding, leakage of fluid, and
scar tissue formation in highly sensitive parts of the macula. When this
happens, loss of central vision can be rapid and severe.
Although only 1 in 10 patients with AMD will convert from the dry
to the wet form, the wet form accounts for 90 percent of the vision loss
associated with AMD.
<<back to questions
The average chance of converting from the dry to the wet form of AMD is
about 2 percent per year. If you have already developed wet AMD in one
eye, the chance of developing wet AMD in the other eye can range from
10-75 percent over the next five years depending on certain findings in
the retina.
<<back to questions
The vast majority of patients with dry AMD will not notice any change in
their central vision. However, patients with advanced dry
AMD may notice a gradual decrease in their central vision over
many months to years. This decline in vision is often accompanied
by blank spots that slowly develop in and around the central vision. The
most common symptom of wet AMD is the sudden onset of
blurred or distorted central vision that may occur over days to weeks.
<<back
to questions
Because AMD is a relatively silent disease until advanced stages
develop, the only way to know if you have it is to visit your eye care
specialist for a dilated eye examination. By dilating the eyes, your
doctor can look at the macula for signs of AMD. In some circumstances,
your doctor may recommend special photographs to see if there are signs
of the wet form of AMD.
It is recommended that all patients over the age of 55 have a
dilated eye examination on an annual basis to look for signs of AMD. Now
that treatments are available for most patients with either the dry or
the wet form of AMD, it is important that AMD be diagnosed as early as
possible so that appropriate treatments can be started promptly.
<<back
to questions
If you have dry macular degeneration and you suddenly notice new
distortion or a new blank spot in your vision, you should notify your
eye care professional immediately. These symptoms may suggest the
development of wet AMD.
You can monitor your vision by either regularly covering one eye and
looking at a straight object (e.g. a door frame) and asking yourself if
it appears straight. Alternatively, you may use an Amsler grid to
monitor your vision.
<<back to questions
Although AMD can significantly challenge a person's central vision, it
is important for patients with AMD to understand that this disease only
affects the center of the vision and will not cause them to go
"completely blind." In fact, in 99 percent of the cases,
the side vision remains unaffected, allowing for independent living and
getting around. Furthermore, vision rehabilitation specialists can often
assist AMD patients who have sup-optimal central vision to learn how to
use their side vision more effectively. This can result in enhanced
quality of life for many patients with AMD.
<<back
to questions
The various treatment options for AMD depend on the type and stage of
AMD that is present.
At this time, the only treatment for dry AMD is high dose anti-oxidant
vitamin therapy.
In 2005, proven treatment options for the wet form of AMD include:
-
Observation
-
Hot laser therapy
-
Cold laser therapy - also knows as Photodynamic Therapy or Visudyne™
Therapy
-
Macular Translocation surgery
-
Macugen
-
Lucentis
-
Avastin
<<back to questions
Vitamins and AMD
The Age-Related
Eye Disease Study (AREDS) showed that taking high-dose anti-oxidant
vitamins and zinc significantly slowed the rate of progression of vision
loss in patients who had more advanced forms of AMD.
AREDS II is an ongoing study to understand the role of certain other
vitamins. More
information
<<back to questions
The following vitamin combination was proven effective in the AREDS
study:
-
Vitamin C, 500 mg
-
Vitamin E, 400 IU
-
Beta-Carotene, 15 mg
-
Zinc, as zinc oxide, 80 mg
-
Copper, as cupric oxide, 2 mg
<<back to questions
Vitamin therapy for AMD will help slow the progression of AMD. Vitamins
are not a cure for AMD and will not give back any vision that has
already been lost.
<<back to questions
Only those patients with intermediate to advanced forms of AMD should be
taking the high-dose multivitamin formula. Ask your doctor if you should
be taking this vitamin supplement.
<<back
to questions
AREDS researchers say it is unclear if the possible increased risk
associated with very high doses - 500IU to 2000IU - of vitamin E applies
to people taking 400IU. An increased risk of mortality was not found
among those taking about 400IU of vitamin E.
The National Institutes of Health Office of Dietary Supplements has a fact
sheet on vitamin E that summarizes the research on vitamin E and
different chronic diseases.
<<back to
questions
We do not believe that people who do not have AMD should supplement with
the high dose vitamin formula in the hopes of preventing AMD from
developing.
<<back to questions
The AREDS vitamin formula is available over the counter without a
prescription in most pharmacies, retailers, and grocery stores. Common
brand names include Ocuvite Preservision and Alcon AREDS I-CAPS.
<<back
to questions
Lutein and zeaxanthin are natural pigments that are normally found in
the human macula. They are thought to play a protective role in the
macula. The effects of lutein and zeaxanthin in AMD have never been
scientifically studied. If a patient chooses to supplement with these
compounds based on anecdotal evidence, they should only take the amount
recommended for that particular supplement.
<<back
to questions
Most patients in the AREDS study continued to take their regular
multivitamins in addition to the AREDS formula. We recommend that you
check with your family medical doctor or internist to be sure that it is
OK for you to continue to take all of these vitamins.
<<back
to questions
Wet AMD Treatments
In hot laser therapy, a laser is used to cauterize the abnormal blood
vessels growing underneath the retina in the wet form of AMD.
Unfortunately, hot laser therapy also burns through the overlying retina
in order to cauterize the blood vessels beneath. In doing so, hot laser
therapy creates a permanent blank spot in a person's vision.
Hot laser therapy continues to be used in many patients when the
abnormal blood vessels are not growing directly underneath the center of
the macula (center of the vision).
The greatest reason for hot laser treatment failure is that the blood
vessels can grow back up to 50 percent of the time. If you undergo hot
laser treatment, your doctor will be following you closely to look for
any signs of the blood vessels growing back.
<<back to questions
Cold laser therapy was developed for blood vessels that lie directly
underneath the center of the vision. In cold laser treatment, a
light-sensitive drug is injected into your arm vein and travels with
your circulation to the abnormal blood vessels underneath the retina. A
cold laser is then directed at this area of your macula. This laser,
unlike the hot laser, does not burn your overlying retina. When the cold
laser light hits the light-sensitive drug in the abnormal blood vessels,
it turns the drug "on." Once the drug is turned on, it causes a chemical
reaction to occur, which leads to a blood clot forming in the blood
vessels, closing them down.
Unfortunately, in cold laser therapy, the blood vessels have a tendency
to "open up again." If this happens, a repeat cold laser therapy may be
recommended again until the blood vessels stay closed. Your doctor will
determine at regular intervals whether this therapy needs to be
repeated. The goal of cold laser therapy is not to make the vision
better, but to decrease the rate of the vision getting worse.
With the advent of newer anti-angiogenesis therapies (i.e. Macugen,
Lucentis, and Avestin), this method of treatment is used less
frequently. However, your doctor may use this for certain types of vew
vessel growth or in certain locations. Also, your doctor may recommend a
combination of treatment modalities.
<<back to questions
Macugen was the first anti-vascular endothelial growth factor (VEGF)
therapy that used to target the underlying leaky blood vessels in the
"wet" form of macular degeneration. This drug works by blocking vascular
endothelial growth factor (VEGF165) protein that promotes blood vessel
growth. Macugen is administered by intravitreal injection every six
weeks for the course of a year. While Macugen is used less frequently
than Lucentis and Avastin, it may still be used in certain health
settings.
<<back to questions
What is Lucentis?
Lucentis is another drug that blocks vascular endothelial growth factor
(VEGF). It also works to decrease blood vessel growth and leakage.
Lucentis offers hope of improvement in vision for some patients and
helps to stabilize vision for most patients. In the early treatment
stages, Lucentis is repeated every four weeks. For subsequent
treatments, reinjections may be performed based on the activity of the
blood vessels or on a scheduled maintenance therapy. Optimal timing of
retreatments is still under investigation.
Top
of page
What is Avastin?
Before Lucentis was available, retina specialists started to use a
similar drug called Avastin, which was available for cancer treatment.
The results that retinal specialists have seen with Avastin appear to be
similar to Lucentis. While both drugs are made by the same company,
there is a large difference in cost: Lucentis is very expensive while
Avastin is relatively inexpensive.
Top
of page
Why might my doctor combine treatments or add a steroid injection?
Depending on the type of new blood vessels and the location, your doctor
may talk to you about combining treatments to optimize treatment effect.
Steroids work by decreasing inflammation and are sometimes used with
combination therapy.
<<back to questions
In macular translocation surgery, which was developed at Duke Eye
Center, a surgical procedure is performed to rotate the macula away from
the abnormal blood vessels and to a healthier part of the back of the
eye. This surgery is useful for patients who have:
-
Age-Related Macular Degeneration in BOTH eyes
-
Vision loss in BOTH eyes (unable to read with either eye)
-
Vision loss in the second eye for less than 6 months (persons with
vision loss for greater than 6 months are unlikely to recover vision
after macular translocation surgery)
Cynthia Toth, MD is a
world leader in this surgical procedure and continues to perform ground
breaking discoveries in this area. Your doctor will tell you if macular
translocation is an option for you. To learn more about macular
translocation surgery please visit our
website.
<<back to questions
Although several treatments have been developed for wet AMD over the
years, most of them remain sub-optimal for either very late stages of
wet AMD or certain types of wet AMD that can remain stable.
In such circumstances your doctor may recommend observation rather than
a treatment that will either have no benefit to you or potentially make
the problem worse.
If your doctor has recommended observation, he/she will follow you
closely to watch for any change in your blood vessels. Should your blood
vessel characteristics change, your doctor may recommend a different
course of therapy.
<<back to questions
At the Duke Center for Macular Diseases, retina experts will be focusing
on the treatment of your AMD. You will continue to see your general
ophthalmologist or other eye care provider for all other routine eye
care.
<<back to questions
The treatment options for dry and wet AMD are still sub-optimal and aim
to stabilize vision. Low vision services are often helpful for patients
who have or may develop sub-optimal levels of vision secondary to AMD. A
low vision specialist can train patients to use the vision they do have
more effectively. Such an evaluation is custom-tailored to the specific
needs of the patient.
See information about vistion rehabilitation specialist Diane
Whitaker, OD.
<<back to questions
 | 
