Exotropia

Reviewed by Monte A. Del Monte, M.D.

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What Is Exotropia?

Exotropia—or an outward turning of the eyes—is a common type of strabismus accounting for up to 25 percent of all ocular misalignment in early childhood. Transient intermittent exotropia is sometimes seen in the first 4 - 6 weeks of life and, if mild, can resolve spontaneously by 6 - 8 weeks of age. Constant exotropia is only rarely present at birth (congenital). More commonly, exotropia develops between 1 - 4 years of age, first seen only intermittently, particularly when the child is daydreaming, ill, tired, or when a child is focusing on distant objects. It will often disappear when the child is focusing on close objects, as when talking to you, making discovery difficult. Bright light can also induce wandering and parents often report that the child squints or closes one eye in bright sunlight. The frequency and size of the deviation can increase with time making it more noticeable. Your child will often not report double vision or other symptoms when the eye deviates because the developing visual system has the ability to turn off the wandering eye. This, however, can inhibit the eyes connection to the brain resulting in amblyopia (poor vision in one eye from disuse) or loss of depth perception. If untreated, these changes can become permanent.

Symptoms

  • Decreased vision
  • Decreased depth perception
  • Outward deviation of the eyes, often intermittently at first
  • Sensitivity (closing one eye) in bright light

The symptoms described above may not necessarily mean that your child has exotropia. However, if you observe one or more of these symptoms, see an ophthalmologist for a complete exam.

Causes

Exotropia may be seen in children with very poor vision in one eye (sensory exotropia) or in association with certain genetic disorders that affect the eyes. It may also occur in association with a 3rd cranial nerve palsy or previous eye muscle surgery for strabismus. But, most often, childhood intermittent exotropia has no known cause so, if outward wandering of the eyes is suspected and persistent, your child should be evaluated by an ophthalmologist or orthoptist.

Risk Factors

  • Positive family history of strabismus (misaligned eyes), amblyopia, childhood cataract, or glaucoma
  • Some genetic disorders that affect the eyes
  • Pediatric cataracts or glaucoma
  • But most often there are no known risk factors in children with exotropia

Tests and Diagnosis

  • Visual acuity measurement in each eye and both eyes together (age appropriate)
  • Cycloplegic refraction (with dilating eye drops)
  • External or slit lamp exam
  • Fundus (retina) examination
  • Complete eye exam (age appropriate)

Treatment and Drugs

In some children, where the exotropia is infrequent or “well-controlled,” close observation by an orthoptist or ophthalmologist, without other specific treatment, is warranted. When the exotropia appears more frequently and is “poorly-controlled,” other treatment may be necessary. Although glasses, exercises, or prisms are sometimes prescribed to reduce or help control the outward turning eye in some children, surgery is often needed to properly re-align the eyes while still young enough to allow development of stereopsis (3-dimensional vision) and prevent permanent vision loss from amblyopia. Surgery, if indicated, involves weakening the lateral rectus muscle on one or both eyes or sometimes strengthening the medial rectus instead or both. It is usually performed by your ophthalmologist as an outpatient with minimal pain and a rapid recovery allowing children to return to school or day care in just 2 - 3 days.

Clinic Information

For more information, see the Pediatric Ophthalmology & Adult Strabismus Clinic and the complete Clinic Services listing of the U-M Kellogg Eye Center.

Last Modified: Wednesday, 19-Feb-2014 08:42:44 EST