Strabismus in Adults

What is Adult Strabismus?

Strabismus is a condition in which the eyes are misaligned and point in different directions. Adult strabismus occurs in approximately one percent of the population.

What causes adult strabismus?

Most adult strabismus is simply persistent childhood strabismus. Strabismus which occurs in adulthood without a history of childhood strabismus should be carefully evaluated for medical or neurological causes such as diabetes, thyroid disease, myasthenia gravis, brain tumors or strokes.

What are the symptoms of adult strabismus?

If strabismus has been present since childhood, symptoms are usually minimal. If the strabismus develops in late childhood or adulthood, the most common symptom is double vision. Some adults with strabismus will have eye strain, discomfort with reading, headaches, or may even or turn or tilt their head to use their eyes together. Children and adults who turn their eyes outward (exotropia) often squint or close one eye in bright sunlight.

What causes double vision?

When the eyes are misaligned, each eye sees a separate image. Infants and children whose eyes are misaligned can learn to suppress or ignore the image from one eye and consequently avoid seeing a double image. However, adults are unable to suppress one image. The resulting double vision can be relieved by closing one eye, wearing a patch, or aligning the eyes.

How is adult strabismus treated?

There is a common misconception that strabismus in adults is difficult or impossible to treat. Actually, adults with strabismus have many treatment options including eye exercised, prism glasses, eye muscle surgery and botulinum toxin injections.

Eye muscle exercises may be helpful in treating special problems such as convergence insufficiency, a condition in which the eyes do not function well for close work or reading.

Glasses with prisms are most useful for correcting small deviations. Images are realigned by the prisms to compensate for the misalignment of the eyes and may relieve double vision.

The eye muscle can be injected with botulinum toxin, a drug that is used to paralyze the muscle. The temporary effect wears off in a few months but may result in permanent change in the eye alignment. This technique is useful in very specific cases usually associated with nerve palsies.

Eye muscle surgery is the most common treatment for strabismus at any age. Muscles are either tightened or weakened by repositioning them on the eyeball to better align the two eyes. Please see our section on muscle surgery for additional information.

Usually strabismus surgery is performed under general anesthesia, but some cases can be done with local anesthesia.

The use of a special surgical technique allows some post-operative adjustment of eye alignment, by using adjustable sutures. The operation is performed in two stages. The first stage one or more of the muscles are repositioned with “slip knot” sutures.

The second phase is usually performed some hours later, or even on the following day with a topical anesthetic. If small realignments are necessary, the “slip knot” suture allows adjustment to be made. This technique requires cooperation from the patient and is not suitable for everyone.