Comitant horizontal strabismus: an Asian perspective

Aim: Recent studies suggest that Asian strabismus patterns are different from those in the West. This study aims to determine the profile of children with comitant horizontal strabismus in Singapore. Method: 682 children aged <= 16 years presenting with strabismus for the first time between 2000 and 2002 were included in this study. The type and size of the squint, visual acuity, refractive error and stereopsis were noted. Results: 493 children (72%) were exotropic, the majority (92%) of whom had intermittent exotropia, X(T). The divergence excess type X( T) was most common (59.5%), followed by basic (29.0%) and convergence-weakness (11.5%). Children with X( T) demonstrated stereopsis for near in 92% and distance in 50%. Esotropia was present in 191 (28%) children (23% infantile and 53% accommodative). Children with infantile esotropia presented significantly younger (2.8 years vs 4.5 years), had larger squint size (35D vs 26D) and were less hyperopic (+0.78D vs +2.79D). Amblyopia or ocular preference was noted in 50% of children with infantile esotropia, and 43% with accommodative esotropia. Conclusion: Twice as many Singaporean children presented with exotropia than esotropia. However, within the exotropia and esotropia groups, the distribution and characteristics of various strabismus subtypes bore similar characteristics to those described in the West.