Macular degeneration
is a deterioration or breakdown of the macula. The
macula is a small area in the retina at the back of
the eye that allows you to see fine details clearly
and perform activities such as reading and driving.
When the macula does not function correctly, your
central vision can be affected by blurriness, dark
areas or distortion. Macular degeneration affects
your ability to see near and far, and can make some
activities — like threading a needle or reading —
difficult or impossible.
Although macular degeneration reduces vision in the
central part of the retina, it does not affect the
eye's side, or peripheral, vision. For example, you
could see the outline of a clock but not be able to
tell what time it is.
Macular degeneration alone does not result in total
blindness. Even in more advanced cases, people
continue to have some useful vision and are often
able to take care of themselves. In many cases,
macular degeneration's impact on your vision can be
minimal.
The eye care specialists at Advanced Eye Center can
help slow the process of macular degeneration
through use of dietary supplements and ongoing
state-of-the-art care.
What Causes
Macular Degeneration?
Many older people develop macular degeneration as
part of the body's natural aging process. There are
different kinds of macular problems, but the most
common is
age-related macular degeneration (AMD).
Exactly why it develops is not known, and no
treatment has been uniformly effective. Macular
degeneration is the leading cause of severe vision
loss in caucasians over 65.
The two most common types of AMD are "dry"
(atrophic) and "wet" (exudative):
"Dry" Macular
Degeneration (atrophic)
Most people have the "dry" form of AMD. It is caused
by aging and thinning of the tissues of the macula.
Vision loss is usually gradual.
Wet" Macular
Degeneration (exudative)
The "wet" form of macular degeneration accounts for
about 10 percent of all AMD cases. It results when
abnormal blood vessels form underneath the retina at
the back of the eye. These new blood vessels leak
fluid or blood and blur central vision. Vision loss
may be rapid and severe.
What Are the
Symptoms of Macular Degeneration?
Macular degeneration can cause different symptoms in
different people. The condition may be hardly
noticeable in its early stages. Sometimes only one
eye loses vision while the other eye continues to
see well for many years.
But when both eyes are affected, the loss of central
vision may be noticed more quickly. Following are
some common ways vision loss is detected:
* words on a page look blurred;
* a dark or empty area appears in the center of
vision;
* straight lines look distorted, as in the following
diagram.
Amsler Grid with wavy lines
How Is Macular
Degeneration Diagnosed?
Many people do not realize that they have a macular
problem until blurred vision becomes obvious.
Our
ophthalmologist can detect early stages
of AMD during a medical eye examination that
includes the following:
* a simple vision test in which you look at a chart
that resembles graph paper (Amsler grid)
* viewing the macula with an ophthalmoscope;
* taking special photographs of the eye called
fluorescein angiographs to find abnormal blood
vessels under the retina.
How Is Macular
Degeneration Treated?
Nutritional
Supplements
Although the exact causes of macular degeneration
are not fully understood, antioxidant vitamins,
Lutien, green leafy vegetables and
zinc may reduce the impact of AMD in some people.
A large scientific study found that people at risk
for developing advanced stages of AMD lowered their
risk by about 25 percent when treated with a
high-dose combination of vitamin C, vitamin E, beta
carotene and zinc. Among those who have either no
AMD or very early AMD, the supplements did not
appear to provide an apparent benefit.
Deposits under the retina called
drusen are
a common feature of macular degeneration. Drusen
alone usually do not cause vision loss, but when
they increase in size or number, this generally
indicates an increased risk of developing advanced
AMD. People at risk for developing advanced AMD have
significant drusen, prominent dry AMD, or abnormal
blood vessels under the macula in one eye ("wet"
form).
It is very important to remember that vitamin
supplements are not a cure for AMD, nor will they
restore vision that you may have already lost from
the disease. However, specific amounts of these
supplements do play a key role in helping some
people at high risk for advanced AMD to maintain
their vision. You should speak with your
ophthalmologist to determine if you are at risk for
developing advanced AMD, and to learn if supplements
are recommended for you.
Laser Surgery and
Photodynamic Therapy
Certain types of "wet" macular degeneration can be
treated with laser surgery, a brief outpatient
procedure. Laser surgery and another form of
treatment called photodynamic therapy use a focused
beam of light to slow or stop leaking blood vessels
that damage the macula. These procedures may
preserve more sight overall, though they are not
cures that restore vision to normal.
Despite advanced medical treatment, many people with
macular degeneration still experience some vision
loss.
To help you adapt to lower vision levels, our
ophthalmologists can prescribe optical devices or
refer you to a low-vision specialist or center. A
wide range of support services and rehabilitation
programs are also available to help people with
macular degeneration maintain a satisfying
lifestyle.
Because side vision is usually not affected, a
person's remaining sight is very useful. Often,
people can continue with many of their favorite
activities by using low-vision optical devices such
as magnifying devices, closed-circuit television,
large-print reading materials, and talking or
computerized devices.
Testing Your
Vision With the Amsler Grid
You can check your vision daily by using an Amsler
grid like the one pictured below. You may find
changes in your vision that you wouldn't notice
otherwise. Putting the grid on the front of your
refrigerator is a good way to remember to look at it
each day.
Amsler Grid
To use the grid:
1. Wear your reading glasses and hold the grid 12
to 15 inches away from your face in good light.
2. Cover one eye.
3. Look directly at the center dot with the
uncovered eye.
4. While looking directly at the center dot, note
whether all lines of the grid are straight or if any
areas are distorted, blurred or dark.
5. Repeat this procedure with the other eye.
6. If any area of the grid looks wavy, blurred or
dark, contact your ophthalmologist immediately.
Resources
For more information, please contact:
The American
Academy of Ophthalmology
P.O. Box 7424
San Francisco, CA 94120
www.aao.org
The American
Macular Degeneration Foundation
P.O. Box 515
Northampton, MA 01061-0515
Phone: 413-268-7660
www.macular.org
Foundation
Fighting Blindness
11435 Cronhill Drive
Owings Mills, MD 21117-2220
1-888-394-3937
www.blindness.org
|
