Age-Related
Macular Degeneration: Dry
Age-related macular degeneration
(AMD) is the result of damage to the nerve cells in a small area
at the back of the eye called the macula. AMD causes blurring of
your central vision, making it harder to do things that require
sharp vision such as reading, driving, and recognizing faces.
There are two types of macular
degeneration - dry (atrophic) and wet (exudative). The dry form
accounts for about 9 out of 10 cases of AMD. The wet form is much
less common, but it happens more quickly and is more severe.
The dry form of macular degeneration
occurs gradually and usually begins with the formation of tiny yellow
deposits called “drusen” in the macula. Drusen usually
do not cause serious loss of vision, but can cause distortion of
vision. Sometimes drusen will cause the macula to thin and break
down, slowly leading to vision loss.
Several factors are thought to
play a part in the development of macular degeneration.
Those who are more likely to have AMD:
- Are older adults - the risk increases as
you age, starting at around age 50.
- Have a close family member who has macular
degeneration.
- Smoke.
- Eat a diet that is low in antioxidant vitamins
(A,C,E) and the mineral zinc
The symptoms of dry macular degeneration
Those with macular degeneration
first notice dim or fuzzy central vision. Things may look warped
or smaller than they really are, and they may notice a blank or
blind spot in the center of their fields of vision. As the disease
gets worse, those with AMD have trouble with tasks like reading
and driving.
If you have the dry form of AMD,
your vision will probably become blurry so slowly that you won't
notice it for a long time. You may have dry macular degeneration
for several years before it becomes apparent.
How is AMD diagnosed?
A doctor can usually detect AMD
by doing a regular eye exam and asking questions about your past
health. You may have some vision tests, including an ophthalmoscopy.
This test lets the doctor look at the inside of your eye. If you
have macular degeneration, your physician may see drusen, the yellowish
waste deposits that build up at the back of the eye.
The doctor may have you look at
a chart with lines and a dot at the center called an Amsler grid.
It can help detect AMD or other changes in central vision.
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