Your Health - Strabismus

Strabismus

(Tropia; Crossed Eyes)

Pronounced: Stra-BIZ-mus

Definition

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.

Appearance of Strabismus

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, concentration, or when tired

Causes

Strabismus is caused by a lack of coordination between the muscles in the eyes. This can happen due to:

Problems, imbalances, or injuries of the muscles that move the eyes
Uncorrected refractive errors (ie, the need for glasses)
Nervous system disorders that affect vision, such as:
- Problems or injury of the nerves that control the eye muscles
- Tumor in or near the eye or brain
- Strokes or bleeding in the brain
- Increased pressure in the brain
- Myasthenia gravis
Hormone problems, such as:
- Diabetes
- Thyroid disease
Vision loss in one eye (one blind eye will often turn in or out)

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

Risk factors for strabismus:

Family member with strabismus
Diabetes
High blood pressure

Symptoms

Symptoms may include:

Double vision
Crossed eyes
Eyes that do not align properly
Uncoordinated eye movements
Squinting
Favoring a head position

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. For some conditions, special prism lenses can be placed in the glasses to help reduce double vision that may occur with strabismus.

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

CANADIAN RESOURCES:

Canadian Association of Optometrists
http://www.opto.ca/en/public/

Canadian Health Network
http://www.canadian-health-network.ca/

References:

Journal of Pediatric Ophthalmology and Strabismus website. Available at: http://www.journalofpediatricophthalmology.com/ .

Optometrist's Network website. Available at: http://www.strabismus.org .

Pediatric Ophthalmic Consultants website. Available at: http://www.pedseye.com/ .

Last reviewed September 2009 by Christopher Cheyer, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.