Macular Degeneration
that our muscles are not as strong as
they once were. Aging also occurs in the eye; Macular degeneration is
one form of aging in the eye. To better understand macular degeneration
and how aging can affect your eyes, you must first understand how the
eye works.
How The Eye Works
Your eye is a lot like a camera. In the front of the eye there is a
clear window called the cornea. The cornea lets light into the eye. The
amount of light entering the eye is controlled by the iris, the colored
part of the eye. The lens of the eye focuses the light after it enters
the eye.
At the back of the eye there is a very important layer of tissue
called the retina. The retina covers the inside wall of the eye like
wallpaper covers the walls of a room. The retina's job is a lot like
film in a camera: it "takes a picture" by turning light into nerve
impulses. It then sends the impulses through the optic nerve to the
back of the brain where "seeing" actually occurs. Below is a figure
which depicts this process.
In the Center of the retina there
is a special area called the macula. The macula is responsible for our
detailed, straight ahead sight and for most of our color vision. When
this special area of the eye begins to age, we call it macular
degeneration.
How is Macular Degeneration detected?
When your eye doctor examines the inside of your eye, he or she can
tell if you have macular degeneration. The doctor may also perform a
special test called a fluorescein angiogram to get more information
about your macula. For this test, a special fluorescent dye is injected
into the patient's arm. As the dye circulates through the eye a series
of photographs are taken with a special camera. The photographs show
the exact condition of your macula, whether any new blood vessels are
growing under the retina, and the exact location and extent of those
new blood vessels.
How is Macular Degeneration treated?
There is no specific treatment for thinning of the retina (atrophic
macular degeneration). However, you doctor may be able to prescribe
special glasses or magnifying lenses to help you see better, especially
for reading. Some doctors also recommend certain vitamins and minerals.
If you have developed leakage or bleeding in the macula from new blood
vessels (exudative macular degeneration), retina specialist often
recommend laser treatment.
What is Laser Treatment?
A laser is a very concentrated light that can be used to cauterize
or seal leaking blood vessels. Laser treatments usually causes no pain
and are performed in your eye doctors office or outpatient clinic.
Laser
treatment is only helpful in certain cases of exudative macular
degeneration. Whether laser treatment should be performed depends on
the exact location and degree of leakage or bleeding. The fluorescein
angiogram test can help your doctor determine whether laser surgery
should be used to treat exudative macular degeneration.
If
laser treatment is performed, you must see your doctor frequently
following treatment to be sure that more blood vessels are not starting
to grow. The fluorescein angiogram test to is often performed in each
follow-up visit.
Can anything be done to prevent Macular Degeneration?
Although degeneration is part of the aging process of the retina,
research by retina specialists has shown that certain vitamins and
minerals may slow down this aging and help preserve sight. Other
research into the effects of light on the retina suggest that certain
parts of light spectrum may be damaging to tissue already weakened by
the aging process. Special sunglasses that block the blue end of the
light spectrum (ultraviolet light) are often prescribed for patients
with macular degeneration.
Finally, retina specialists have
found that in exudative macular degeneration, the earlier that leakage
and bleeding are detected and treated, the better the chance of
preventing loss of sight. Because early detection is so important you
should perform a simple test at home each day to check your macula.
This test is called the Amsler Grid Test.
What is the Amsler Grid Test?
The Amsler Grid is a series of vertical and horizontal lines forming many small squares.
To
use the grid, hold it at a comfortable reading distance - like you were
reading a magazine. If you wear reading glasses or contact lenses, be
sure to wear them. If you wear bifocals, look through the bifocal
section. Be sure to have good, consistent lighting. Test one eye at a
time. Close one eye and focus on the spot in the center of the grid. As
you keep your eye focused on the spot, notice if:
1. You can see all four corners of the grid square.
2. All the lines on the grid appear straight.
3. All the squares appear perfectly square.
4. There are no missing the areas in the grid.
If there is an abnormal area on the grid and you've never seen an eye doctor, you need an immediate check-up.
