Strabismus

Alternative names:

crossed eyes; esotropia; exotropia; squint; walleye

Definition:

A condition of abnormal deviation or alignment of one eye in relation to the other.

Causes, incidence, and risk factors:

Strabismus is caused by a lack of muscle coordination between the eyes, causing the eyes to point in different directions. The eyes are unable to focus simultaneously on a single point.

Strabismus may result from problems with the extraocular muscles (the six muscle pairs that move the eyes), problems with neurological control of the extraocular muscles, neurotoxins, blindness, mechanical problems in the eye, or mechanical obstruction to vision in one eye during early life. In adults, strabismus may be a symptom of various brain disorders or systemic diseases.

Some of the disorders that can be associated with strabismus include:

• amblyopia
• paralytic shellfish poisoning (PSP)
• botulism
• hemangioma near eye during infancy
• Guillain-Barre
• congenital strabismus (50% of all cases of strabismus)
• Apert syndrome
• Noonan syndrome
• Prader-Willi syndrome
• trisomy 18
• congenital rubella
• incontinentia pigmenti syndrome
• cerebral palsy
• strabismus
• Laurence-Moon-Biedl syndrome
• pseudohyperparathyroidism

Strabismus causes a double image to form, and the brain suppresses the image of the diverting eye, causing amblyopia. Strabismus may lead to vision loss in the nondominant eye.

A family history of the disease is a risk factor. farsightedness may be a contributing factor.