Exotropia

What is exotropia?

Exotropia is a type of strabismus, a condition in which the eyes point in different directions. In exotropia, one or both eyes turn out toward the ear. It is sometimes called wall-eye.

In children, exotropia happens most often when the child is focusing on distant objects. It may occur only when the child is daydreaming, ill, or tired. It may get worse as the child gets older. In adults, it usually occurs if vision is lost in one eye.

How does it occur?

The cause of exotropia is not known. Most experts believe that the brain has trouble controlling the position of the eye. This problem may run in families.

Sometimes when a child's eyes are not aligned on the same target, the brain ignores the image from one eye. That eye works less, and vision stops developing in that eye. This problem (called amblyopia or lazy eye) occurs rarely with exotropia. It is more common with other forms of strabismus.

Exotropia may result from:

• nerve problems
• eye socket or eye deformities
• eye injuries
• head injuries

These problems, as well as diabetes, myasthenia gravis, multiple sclerosis, brainstem aneurysms, stroke, circulation problems, poor vision in one or both eyes, and thyroid disease, can cause exotropia in adults.

What are the symptoms?

One or both eyes appear to be turned out. They do not appear to be pointing in the same direction. Many children with exotropia shut one eye in outdoor light or squint one or both eyes.

How is it diagnosed?

An ophthalmologist (medical eye doctor) will test the person's overall vision and ability to follow objects with each eye.

How is it treated?

Children with occasional exotropia may not need treatment as long as their eyes are developing the ability to work together (called binocular vision). More frequent drifting of the eye requires treatment.

Treatment of more severe exotropia when it is first detected in young children may bring about normal binocular vision. Treatment may include:

• patching the "good" eye
• eye exercises
• use of glasses with lenses that are too strong (called minus lenses)

If the eyes are always misaligned, surgery may be needed. During surgery, the doctor will tighten or loosen the eye muscles to change the alignment of the eyes. Sometimes the doctor will operate on muscles of both eyes even though only one eye is turned out.

Strabismus surgery is not cosmetic surgery. Having eyes that are not aligned normally interferes with your ability to communicate with others through eye contact. Most insurance plans reimburse for this surgery for children and adults who do not have binocular vision.