Age-Related Macular Degeneration (AMD) 
What is age-related macular degeneration (AMD)?
Age-related macular degeneration (AMD) is a disease that affects an individual’s
central vision. AMD is the most common cause of severe vision loss among people over 60.
Because only the center of vision is affected, people rarely go blind from this disease.
However, AMD can make it difficult of read, drive, or perform other daily activities that
require fine, central vision.
AMD occurs when the macula, which is located in the center of the retina and provides
us with sight in the center of our field of vision, begins to degenerate. With less of the
macula working, central vision -- which is necessary for driving, reading, recognizing
faces, and performing close-up work -- begins to deteriorate.
What are the different types of AMD?
There are two primary types of AMD:
- dry AMD
This type of AMD is responsible for 90 percent of disease cases. While its cause is
unknown, it occurs as the light sensitive cells in the macula slowly deteriorate,
generally occurring in one eye at a time.
- wet AMD
This type of AMD is responsible for 10 percent of disease cases, but accounts for 90
percent of all severe vision loss caused by either type of AMD. Wet AMD occurs when new
blood vessels behind the retina start to grow beneath the retina where they leak fluid and
blood and can create a large blind spot in the center of the visual field. If this
happens, there is a marked disturbance of vision in a short period of time.
What are the symptoms of AMD?
The following are the most common symptoms of AMD. However, each individual may
experience symptoms differently. Symptoms may include:
- difficulty recognizing familiar faces
- straight lines, such as sentences on a page, telephone poles, and the sides of
buildings, appear wavy
- a dark or empty area (blind spot) appears in the center of vision
- rapid loss of central vision - vision necessary for driving, reading, recognizing faces,
and performing close-up work
 The presence of
drusen, tiny yellow deposits in the retina, is one of the most common early signs
of AMD. These will be visible to your physician during an eye examination. While the
presence of drusen alone does not indicate the disease, it may mean the eye is at risk for
developing more severe AMD.
The symptoms of AMD may resemble other eye conditions. Consult a physician for
diagnosis.
How is AMD diagnosed?
In addition to a complete medical history and eye examination, your eye care professional
may perform the following tests to diagnose AMD:
- visual acuity test -
the common eye chart test (see right), which measures vision
ability at various distances.
- pupil dilation -
the pupil is widened with eyedrops to allow a close-up examination
of the eye's retina.
- Amsler grid - used to detect wet AMD, this diagnostic test uses a
checkerboard-like grid (reduced size shown here; normal vision on the left and vision with
AMD on the right) to determine if the straight lines in the pattern appear wavy or missing
to the patient -- both indications may signal the possibility of AMD.
 
- fluorescein angiography - used to detect wet AMD, this diagnostic test involves a
special dye injected into a vein in the arm. Pictures are then taken as the dye passes
through the blood vessels in the retina, helping the physician evaluate if the blood
vessels are leaking and whether or not the leaking can be treated.
| What is a risk factor? A risk factor is anything that may increase a person’s chance of
developing a disease. It may be an activity, such as smoking, diet, family history, or
many other things. Different diseases, including cancers, have different risk factors.
Although these factors can increase a person’s risk,
they do not necessarily cause the disease. Some people with one or more risk factors never
develop the disease, while others develop disease and have no known risk factors.
But, knowing your risk factors to any disease can help to
guide you into the appropriate actions, including changing behaviors and being clinically
monitored for the disease. |
What are the risk factors for AMD?
Possible risk factors for AMD include:
- gender
According to some studies, women are at greater risk than men.
- age
Although AMD can occur during middle age, the risk for developing the disease increases as
a person ages. Studies have shown that while persons in their 50s have only a two percent
risk of developing AMD, that rises to nearly 30 percent in persons over 75.
- smoking
Smoking may increase risk of AMD.
- family history
Persons with a family history of AMD may have a higher risk of developing AMD.
- high blood cholesterol levels
Persons with elevated blood cholesterol levels may be at higher risk for wet AMD.
Treatment for AMD:
Specific treatment for AMD will be determined by your physician based on:
- your age, overall health, and medical history
- extent of the disease
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Treatment for wet AMD may includeone type of laser surgery in which a high
energy beam of light is aimed directly onto the leaking blood vessels to deter further
leaking.
Currently, there is no treatment for dry AMD. This does not, however, indicate that
sight will automatically be lost, particularly if the AMD affects only one eye. Central
vision may eventually be lost or diminished, but generally the rate of loss is slow.
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