Strabismus
(Crossed or turned eye)
Overview
Strabismus is a
problem caused by one or more improperly functioning
eye muscles,
resulting in a misalignment of the eyes. Normally, each eye
focuses on the same spot but sends a
slightly different message to the brain. The brain
superimposes the two images, giving vision depth and dimension.
Here's an easy way to see how the eyes work together: hold
your finger at arm's length. While looking at your finger,
close one eye, then the other. Notice how your finger changes
position. Even though the images are slightly different, the
brain interprets them as one.
Each eye has six
muscles that work in unison to control movements. The brain
controls the eye muscles, which keep the eyes properly aligned.
It is critical that the muscles function together for the brain to
interpret the image from each eye as a single one.
Strabismus must be
detected early in children because they are so adaptable. If a
child sees double, his or her brain quickly learns to suppress or
block out one of the images to maintain single vision. In a
very short time, the brain permanently suppresses vision from the
turned eye, causing a weak or amblyopic
eye. Children may also develop a head tilt or turn to
compensate for the problem and eliminate the double image.
Unlike children, adults with a newly acquired strabismus problem
typically see double.
There are many causes
of strabismus. It can be inherited, or it may be caused by
trauma, certain diseases, and sometimes eye surgery.
Signs and Symptoms
Adults are much more
likely to be bothered by symptoms from strabismus than young
children. It is unusual for a child to complain of double
vision. Children should undergo vision screening exams to
detect problems early. The younger the child is when
strabismus is detected and treated, the better the chance of normal
vision. The following are common signs and symptoms:
Detection and Diagnosis
Strabismus is detected
with a comprehensive eye exam and special tests used to evaluate the
alignment of the eyes such as: the Krimsky test and
prism testing.
Treatment
The appropriate
treatment for strabismus is dependent on several factors including
the patient's age, the cause of the problem, and the type and degree
of the eye turn. Treatment may include patching, corrective
glasses, prisms, or surgery.
With patching, the
better eye is covered, forcing the child to use the weaker eye.
Over time, the brain adjusts to using the weaker eye and vision
gradually improves. For this treatment to be effective, it
must be done at a young age before the child can develop amblyopia.
Surgery is sometimes
performed for both adults and children to straighten a crossed eye.
The procedure may be done with local or general anesthesia.
There are several different surgical techniques used to correct
strabismus. The appropriate one is dependent on the muscle
involved and the degree of the eye turn.
St. Luke's Cataract & Laser
Institute provides this on-line information for educational and
communication purposes only and it should not be construed as
personal medical advice. Information published on this St.
Luke's website is not intended to replace, supplant, or augment a
consultation with an eye care professional regarding the
viewer/user's own medical care. St. Luke's disclaims any and
all liability for injury or other damages that could result from use
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