Comitant Horizontal Strabismus in South African Black and Mixed Race Children—A Clinic-based Study

Abstract

Purpose: To examine the types of comitant horizontal strabismus in children belonging to the two largest ethnic groups of the Western Cape, South Africa.Methods: Retrospective review of 2371 children presenting with comitant horizontal strabismus to a single, large, pediatric tertiary referral center in Cape Town, South Africa, between 1997 and 2007.Results: 81% of children were of mixed race and 19% were black. The overall esotropia:exotropia ratio was 73:27. For black children this was 85:15 and for mixed race, 71:29. The overwhelming majority of black children had congenital esotropias (74%), whereas accommodative esotropia was rare (9%). In mixed race children, esotopias were more equally divided between congenital (46%) and accommodative types (35%). Exotropias were uncommon in black children, and were mainly constant (61%). Intermittent exotropias predominated in mixed race children (55%).Conclusion: Congenital esotropia remains common in South African black children, and of the few who presented with exotropia, most had constant type. Accommodative esotropias were more prevalent in South African mixed race children, but in smaller proportions than in other studies. Exotropias were mostly intermittent in this ethnic group, and showed a similar profile to that in white American children.