Prevalence of strabismus among preschool, kindergarten, and first-grade Tohono O'odham children.

BACKGROUND Although the prevalence of strabismus is 2% to 5% in European-based and African-American populations, little is known about the prevalence of strabismus in Native-American populations. We report the prevalence of strabismus in children who are members of a Native-American tribe with a high prevalence of astigmatism. METHODS Subjects were 594 children enrolled in Head Start and 315 children enrolled in kindergarten or first grade (K/1) in schools on the Tohono O'odham Reservation. Distance and near cover tests were performed on each child by an ophthalmologist or optometrist, and cycloplegic refraction was obtained. RESULTS Strabismus was detected in 9 Head Start children (1.5%) and 3 K/1 children (1.0%). Ratio of esotropia to exotropia was 1:3 in Head Start and 1:2 in K/1. Anisometropia >or=1.00 diopter (D) spherical equivalent was present in 2 children with strabismus, and anisometropia >or=1.00 D cylinder was present in 4 with strabismus. CONCLUSION The prevalence of strabismus in Tohono O'odham children is at the low end of the prevalence range reported in studies of European-based and African-American populations.