In strabismus, one or both of the eyes turn in, out, up, or down. It usually occurs in children but may occur in adults. Permanent vision loss may result if strabismus is not detected and treated in a timely manner.
There are two types:
Constant Strabismus--the eye turns all the time
Intermittent Strabismus--the eye turns only some of the time, like in times of stress, illness, or when tired
Causes
Strabismus is caused by a lack of coordination between the muscles in the eyes. This can happen due to:
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Problems, imbalances, or injuries of the muscles that move the eyes
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Uncorrected refractive errors (ie, the need for glasses)
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Nervous system disorders that affect vision, such as:
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Hormone problems, such as:
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Vision loss in one eye (one blind eye will often turn in or out)
Risk Factors
A risk factor is something that increases your chances of getting a disease or condition.
Risk factors for strabismus:
Symptoms
Symptoms may include:
Diagnosis
The doctor will ask about your symptoms and medical history, and perform a physical exam. You should be examined by an ophthalmologist, who will test your visual acuity, measure your strabismus, examine your eye for other problems, and check for the need for glasses. You may also be given a neurologic exam and other tests to rule out other possible causes.
Treatment
Treatment may include:
Glasses
Glasses or contact lenses may be prescribed to improve your ability to focus and help overcome poor vision. With better eyesight, strabismus may improve.
Patching
In children, an eye that is not properly aligned may not mature visually. If this is not corrected, permanent visual loss can occur (amblyopia). In some cases, a patch is applied over the good eye. This forces you to fixate and use the affected eye, therefore promoting visual development. The length of time the patch is worn depends on the severity of the condition and the age of the child.
Medication
Eye drops or ointment may be put in the good eye to blur the vision (usually by making the pupil large and preventing the eye from focusing well). This forces the affected eye to fixate properly and may be used as a substitute for patching.
In rare cases, injections of botulinum toxin may also be used to treat strabismus.
Surgery
Surgery may be used to straighten the eyes if nonsurgical means are not successful. Strabismus surgery may improve the ability of the eye muscles to bring the eyeball into proper alignment. During strabismus surgery, the eye surgeon generally moves one or more of the eye muscles to a different location on the eyeball.
Prevention
There is no known way to prevent strabismus. However, it is important to evaluate and treat strabismus as soon as it occurs. If you notice that you or your child’s eyes are not properly aligned, visit your eye doctor immediately.
RESOURCES:
National Eye Institute, National Institutes of Health
http://www.nei.nih.gov
Optometrist's Network
http://www.strabismus.org
References:
Journal of Pediatric Ophthalmology and Strabismus
Optometrist's Network website. Available at: http://www.strabismus.org.
Pediatric Ophthalmic Consultants website. Available at: http://www.pedseye.com/.
