Q: What is it?
A: Amblyopia
is commonly known as "lazy eye". It
occurs when the eyes, for some reason, have not learned to work
together. There are two types. One is caused by toxic substances
such as alcohol or tobacco. The second type is caused by lack
of use. Amblyopia can effect almost everyone, but it is most
prevalent among children and infants. The majority of cases
are caused by lack of use and are found in children. Children
do not outgrow it and early detection is the best way of avoiding
additional complications. Usually aging is not a factor unless
it is accompanied by a corresponding increase in the use of
toxic substances such as alcohol or tobacco. Individuals with
a family history of strabismus or amblyopia are more likely
to suffer this condition.
Amblyopia is a relatively common condition, affecting approximately
4 out of every 100 people.
Q: What causes it?
A: Amblyopia
occurs most commonly with misaligned eyes such as crossed
eyes. The crossed eye "turns off" to avoid
double vision, becoming lazy or amblyopic, and the child prefers
the better eye. Amblyopia may also occur when one eye is out
of focus because it is more nearsighted, farsighted or astigmatic
than the other. The unfocused (blurred) eye "turns off" and
becomes amblyopic. Sometimes the eye can look normal but one
eye has poor vision. An eye disorder such as a cataract (a clouding
of the lens which prevents light from being focused properly
by the eye), may lead to amblyopia.
Q: What are the signs or symptoms?
A: Because amblyopia usually causes no symptoms, it often goes
undetected. Unless the child has a misaligned eye or other obvious
abnormality, there is nothing to suggest the condition to even
the most perceptive parents. The child accepts having one good
eye and one poor eye as the normal situation. In most cases,
amblyopia must be detected through vision testing. A routine
examination will determine if both eyes are being used and to
what extent, and if each eye sees what it should. Consequently,
the cause of the amblyopia can be identified and a treatment
devised.
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Q: How is
it treated?
A: Before
amblyopia can be treated, the underlying cause must first
be determined and corrected. If it is due to crossed eyes,
it may be necessary to surgically repair the muscles that
control eye position and movement. If the amblyopia is due
to a vision imbalance between the eyes, a corrective lens
may be required for theweaker one.
Once the
underlying cause has been identified and corrected, amblyopia
is customarily treated by covering the good eye with a patch
and forcing the weaker eye to work. If the weaker eye requires
correction, eyeglasses are prescribed. Correcting amblyopia
may require special glasses, surgery, patching of the eye
or a combination of these methods.
Q: Can it
be prevented?
A: In many
cases, yes. Imbalance in vision between the eyes can be detected
even in an infant, and once detected can be treated and corrected.
Parents with a family history of strabismus should plan on
eye examinations for their children during infancy.
Q: Can it
always be corrected?
A: No! If
too much time elapses, it may no longer be possible to teach
the brain "to see" the images it receives from an
eye it has never really used or used correctly. Generally,
treatment must begin within the first five to six years of
a child's life for there to be any chance of restoring vision. |
