Exotropia is when the eyes appear to roll outward. Exotropia can be congenital or due to accommodative insufficiency, divergence excess, or sensory deprivation; it can be consecutive following strabismus surgery or due to neurologic disorders. 

Intermittent exotropia is the most common form of childhood exotropia. It often begins around the age of 5 with the eye intermittently rolling out during times of fatigue or stress. The intermittent exotropia can gradually progress until it becomes constant exotropia. 

Congenital exotropia presents before 6 months of age with a large degree of constant exotropia. It is often associated with craniofacial or neurologic disorders. 

Many adults with exotropia are asymptomatic because the vision in the outward rolling eye is so poor. While adults with acute onset of exotropia complain of diplopia, children compensate by suppression of one eye or abnormal retinal correspondence with reduced stereo acuity. Amblyopia is rare unless constant exotropia develops at an early age. Patients with convergence insufficiency may complain of blurred near vision or asthenopia.

Exotropia may be seen in association with the following: Duane syndrome (type 2), third nerve palsy, orbital pseudotumor, orbital tumor causing muscle restriction, myasthenia gravis, and sensory deprivation from any source (eg, cataract, central retinal vein occlusion [CRVO], central retinal artery occlusion [CRAO]).

Related topic: esotropia