What is macular degeneration?
Macular degeneration is damage or breakdown of the macula
of the eye. The macula is a small area at the back of the eye that allows
us to see fine details clearly. When the macula doesn't function correctly,
we experience blurring or darkness in the center of our vision. Macular
degeneration affects both distance and close vision, 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. People
continue to have some useful vision and are able to take care of themselves.
What causes macular degeneration? 
Many older people develop macular degeneration as part
of the body's natural aging process. The two most common types of age-related
macular degeneration are "dry" (atrophic) and "wet"
(exudative):
"Dry" macular degeneration (atrophic)
Most people have "dry" macular degeneration.
It is caused by aging and thinning of the tissues of the macula. Vision
loss is usually gradual.
"Wet" macular degeneration (exudative)
"Wet" macular degeneration accounts for about
10% of all cases. It results when abnormal blood vessels form 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 looked blurred;
- A dark or empty area appears in the center of vision;
- Straight lines look distorted.
How is macular degeneration diagnosed?
Many people do not realize that they have a macular problem
until blurred vision becomes obvious. Your Ophthalmologist (medical eye
doctor) can detect early stages of macular degeneration during a medical
eye examination that includes the following:
- Viewing the macula with an ophthalmoscope;
- A simple vision test in which you look at a grid resembling graph
paper;
- Sometimes special photographs, called angiograms, are taken to
find abnormal blood vessels under the retina. Fluorescent dye is injected
into your arm and your eye is photographed as the dye passes through
the blood vessels in the back of the eye.
How is macular degeneration treated?
Despite ongoing medical research, there is no cure yet
for "dry" macular degeneration. Some doctors believe that nutritional
supplements may slow macular degeneration, although this has not yet been
proven. Treatment of this condition focuses on helping a person find ways
to cope with visual impairment.
In its early stages "wet" macular degeneration can be treated
with laser surgery, a brief and usually painless outpatient procedure.
Laser surgery uses a highly focused beam of light to seal the leaking
blood vessels that damage the macula. Although a small, permanently
dark "blind spot" is left at the point of laser contact, the
procedure can preserve more sight overall.
Despite advanced medical treatment, people with macular degeneration
still experience some vision loss. Your ophthalmologist 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 can be 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.
- Wear your glasses and hold this grid at 12-15 inches
in good light.
- Cover one eye.
- Look directly at the center dot with the uncovered
eye.
- 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.
- Repeat this procedure with the other eye.
- If any area of the grid looks wavy, blurred or
dark, contact your Ophthalmologist immediately.
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