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Adult and Senior Eye Care
Macular Degeneration
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Macular degeneration is the most common cause of irreversible loss of central vision
for senior citizens. The macula is located in the center of the retina,
the micro-thin membrane that lines three-fourths of the back inside of the eye.
The retina is imbedded with millions of light-sensitive nerve cells that
capture images focused on the retina by the cornea and the inner lens of the eye.
The captured images are transmitted to the brain by the optic nerve, and
thus the miracle of sight is created.
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The retina performs two types of vision functions:
Central and Peripheral.
Central vision is required for highly focused, straight-on requirements,
such as reading, driving a car, operating a computer or engaging in face-to-face conversation.
Any damage to the macula will result in some loss or even total loss of
the individual's powers of central vision. Since peripheral vision is not
affected, people with macular degeneration can adapt to the loss of central
vision. By imaginative use of their remaining peripheral vision, they can
pursue many normal daily activities that do not require sharp central vision
abilities. In order to focus on a particular object, the person must turn his
head at the angle required to bring the peripheral light-sensitive cells into
play and thereby create the best possible image under the circumstances.
While there are some rare forms of macular degeneration that occur
in early in life, most cases begin to develop in later life, generally
after age 50. For this reason, the disease is often referred to as age-related
macular degeneration or ARMD. There are two types of macular degeneration:
The Dry Form and
The Wet Form.
The Dry Form
This form affects approximately 90% of those who have macular degeneration.
It is simply a case of deterioratioin of the macula. The process is gradual
and for a period of time - months or years - it may affect only one eye.
What happens in this situation is that the "good" eye often takes over the
central vision functions of the "bad" eye. Thus, the victim is not usually aware
of the loss of central vision powers in the affected eye unless there are certain
noticeable symptoms. The person may perceive that it is more diffcult to see
with one eye than the other. Some straight line types of objects, such as a
telephone, door frame or side of a building may appear to be distorted. It is
also possible that small, dark spots may appear in the field of vision. As
with all eye problems, regular examinations are the best method for early
detection and prompt treatment in order to assure the best possible chances
of preserving vision.
The dry form of macular degeneration is more prevalent, but
comparatively less serious. At this time there are few effective medical treatments.
There are some low-vision aids and devices available. The best treatment
is learning to use the remaining peripheral vision capabilities. We
provide ARMD patients with the most up-to-date vision aids and the most
current inforamtion available on the types of treatment for this
serious eye disorder.
The Wet Form
As noted, only about 10% of all victims of age-related macular
degeneration are diagnosed as having the wet form of the disease,
yet it accounts for approximately 90% of the most serious loss of vision
cases. Since the dry form is simply a matter of the macula wearing
out with age, the loss of central vision tends to happen gradually over
the years. The wet form occurs when tiny blood vessels in the
retinal pigment epithelium (RPE),
the micro-thin layer of tissue that lies beneath the retina and
provides it with nourishment, begin to degenerate with age causing
tiny leaks. This can cause the development of swellings, breaks or
lesions in the retina, thereby creating damage to the retina's
light-sensitive nerve cells. If any of this damage occurs within the
macula, serious and rapid deterioratioin of the person's central vision
capabilities can result.
Several types of lasers have been used with varying degrees of
success in treating the wet form of ARMD, but usually the best result
is a slowing down of the deterioration process. The function of the
laser is to cauterize the leaking blood vessles and/or "tack" the
detached retina back into place. The objective is to prevent further
development of the problem and hold off invasion of the macula for as
long as possible. However, if the problem is already within the macula
area, use of the laser can possibly cause more damage to the macula
than the damage being created by the leaky blood vessels. There is an
effective procedure known as a fluorescein
angiogram that allows the eye doctor to determine if there is
any hemorrhaging which may be occurring in the retina. Both the angiogram
and laser procedure are virtually painless.
Home Test For Early Dectection Of Macular Degeneration
While there is no substitute for regular examinations by your eye doctor,
there is available a simple home test for early detection of macular
degeneration. This home test, called the Amsler Grid, was developed
a number of years ago by a Swiss eye doctor. It is especially useful
if macular degeneration has already been detected in one eye with the
other eye being normal. The odds are that sooner or later the "good"
eye will also become affected and early detection increases chances
for treatment that will help preserve central vision capabilities.
When you come in for your eye examination, we will happy to provide
you with more information on the use of the Amsler Grid Chart as home
test for macular degeneration.
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