Common Forms of Childhood Exotropia

Objective: To determine the most common forms of childhood exotropia.

Design: Retrospective, consecutive, observational case series.

Participants: All exotropic children (with >/=10 prism diopters) younger than 19 years from a predominantly rural Appalachian region evaluated from August 1, 1995 through July 31, 2001.

Methods: Demographic and clinical data were collected on all patients.

Main Outcome Measures: The relative proportion of the various forms of childhood exotropia.

Results: Two hundred thirty-five consecutive children without prior surgical treatment were evaluated for exotropia. Of the 235 study children, the specific forms of exotropia diagnosed and numbers were as follows: intermittent exotropia, 112 (47.7%); exotropia associated with congenital or acquired abnormalities of the central nervous system (CNS), 50 (21.3%); convergence insufficiency, 27 (11.5%); sensory exotropia, 24 (10.2%); paralytic exotropia, 5 (2.1%); congenital exotropia, 4 (1.7%); neonatal exotropia that resolved after 4 months of age, 3 (1.3%), whereas the remaining 10 (4.3%) had an undetermined form of exodeviation.

Conclusions: Intermittent exotropia was the most common form of divergent strabismus in this population. Exotropia associated with an abnormal CNS, convergence insufficiency, and sensory exotropia were also relatively common, whereas the congenital, paralytic, and late-resolving neonatal forms were uncommon.