Age-related macular degeneration (AMD) is a disease that affects your
central vision. It is a common cause of vision loss among people over
the age of 60. Because only the center of your vision is usually affected,
people rarely go blind from the disease. However, AMD can sometimes
make it difficult to read, drive, or perform other daily activities
that require fine, central vision.
What is the macula?
The macula is in the center of the retina, the light-sensitive layer
of tissue at the back of the eye. As you read, light is focused onto
your macula. There, millions of cells change the light into nerve
signals that tell the brain what you are seeing. This is called your
central vision. With it, you are able to read, drive, and perform
other activities that require fine, sharp, straight-ahead vision.
How does AMD damage vision?
AMD occurs in two forms:
Dry AMD affects about 90 percent of those with the disease. Its cause
is unknown. Slowly, the light sensitive cells in the macula break down.
With less macula working, you may start to lose central vision in the
affected eye as the years go by. Dry AMD often occurs in just one eye
at first. You may get the disease later in the other eye. Doctors have
no way of knowing if or when both eyes may be affected.
Wet AMD. Although only 10 percent of all people with AMD have this
type, it accounts for 90 percent of all severe vision loss from the
disease. It occurs when new blood vessels behind the retina start to
grow toward the macula. Because these new blood vessels tend to be
very fragile, they will often leak blood and fluid under the macula.
This causes rapid damage to the macula that can lead to the loss of
central vision in a short period of time.
Who is at risk for AMD?
Although AMD can occur during middle age, the risk increases as a person
gets older. Results of a large study show that people in their 50s
have about a two percent chance of getting AMD. This risk rises to
nearly 30 percent in those over age 75. Besides age, other AMD risk
What are the symptoms of AMD?
Neither dry nor wet AMD causes any pain. The most common symptom of
dry AMD is slightly blurred vision. You may need more light for reading
and other tasks. Also, you may find it hard to recognize faces until
you are very close to them.
As dry AMD gets worse, you may see a blurred spot in the center of
your vision. This spot occurs because a group of cells in the macula
have stopped working properly. Over time, the blurred spot may get
bigger and darker, taking more of your central vision.
People with dry AMD in one eye often do not notice any changes in
their vision. With one eye seeing clearly, they can still drive, read,
and see fine details. Some people may notice changes in their vision
only if AMD affects both of their eyes.
An early symptom of wet AMD is that straight lines appear wavy. This
happens because the newly formed blood vessels leak fluid under the
macula. The fluid raises the macula from its normal place at the back
of the eye and distorts your vision. Another sign that you may have
wet AMD is rapid loss of your central vision. This is different from
dry AMD in which loss of central vision occurs slowly. As in dry AMD,
you may also notice a blind spot.
If you notice any of these changes in your vision, contact your eye
care professional at once for an eye exam.
How is AMD detected?
Eye care professionals detect AMD during an eye examination that
One of the most common early signs of AMD is the presence of drusen.
Drusen are tiny yellow deposits in the retina. Your eye care professional
can see them during an eye examination. The presence of drusen
alone does not necessarily indicate a disease, but it might mean
eye is at risk for developing more severe AMD.
While conducting the eye examination, your eye care professional my
ask you to look at an Amsler grid. This grid is a pattern that resembles
a checkerboard. You will be asked to cover one eye and stare at a black
dot in the center of the grid. While staring at the dot, you may notice
that the straight lines in the pattern appear wavy to you. You may
notice that some of the lines are missing. These may be signs of wet
If your eye care professional suspects you have wet AMD, you may need
to have a test called fluorescein angiography. In this test, a special
dye is injected into a vein in your arm. Pictures are then taken as
the dye passes through the blood vessels in the retina. The photo help
your eye care professional locate and evaluate leaking blood vessels
to determine whether they can be treated.
How is AMD treated?
Dry AMD currently can not be treated. But this does not mean that
you will lose your sight. Fortunately, dry AMD develops very
You may lose some of your central vision over the years. However,
most people are able to lead normal, active lives–especially
if AMD affects only one eye.
Some cases of wet AMD can be treated with laser surgery. The treatment
involves aiming a high-energy beam of light directly onto the leaking
blood vessels. Laser treatment is more effective if the leaky blood
vessels have developed away from the fovea–the central part
of the macula. But even if the blood vessels are growing right behind
the fovea, the treatment can be of some value in stopping further
How is laser surgery performed?
Laser surgery is performed on site at Tri-County Eye Clinic. Before
the surgery, your eye care professional will: (1) dilate your pupil
and (2) apply drops to numb the eye. In some cases, we also may numb
the area behind the eye to prevent any discomfort.
The lights in the office will be dim. As you sit facing the laser
machine, your eye care professional will hold a special lens to your
eye. You may see flashes of light. You can leave the office once the
treatment is done, but you will need someone to drive you home. Because
your pupils are dilated, you should also bring a pair of sunglasses.
You will need to make frequent follow-up visits to make sure the blood
vessels are not still leaking, or that new blood vessels have not developed.
It is important to realize that laser surgery is not a cure for AMD.
It is only a treatment to help stop further vision loss. The risk of
new blood vessels growing back after laser treatment is relatively
What can you do to protect your vision?
Dry AMD. If you have dry AMD, you should have your eyes examined through
dilated pupils at least once a year. This will allow your eye care
professional to monitor your condition and check for other eye diseases
Wet AMD. If you have wet AMD, it is important not to delay laser surgery
if your eye care professional advises you to have it. After surgery,
you will need to have frequent eye examinations to detect any recurrence
of leaking blood vessels. Studies show that people who smoke have a
greater risk of recurrence than those who don't.
What can you do if you have already lost vision to AMD?
Normal use of your eyes will not cause further damage to your vision.
Even if you have lost sight to AMD, you should not be afraid to use
your eyes for reading, watching TV, and other usual activities.
Low vision aids are also available to help you make the most of your
remaining vision. Low vision aids are special lenses or electronic
systems that make images appear larger. If you need low vision aids,
click here to see low vision aids available from Tri-County Eye Clinic.