Prevalence of refractive error in Singaporean Chinese children: the strabismus, amblyopia, and refractive error in young Singaporean Children (STARS) study

Abstract

Purpose: To determine the prevalence of refractive error types in Singaporean Chinese children aged 6 to 72 months.

Methods: The Strabismus, Amblyopia and Refractive Error in Singaporean Children (STARS) is a population-based study in southwest Singapore. Door-to-door recruitment of participants was used, with disproportionate random sampling in 6-month increments. Parental questionnaires were administered. Participant eye examinations included logMAR visual acuity, cycloplegic autorefraction, and ocular biometry. Overall and age-specific prevalences of myopia (spherical equivalence [SE] <or= -0.50 D), high myopia (SE <or= -6.00 D), hyperopia (SE >or= +3.00 D), astigmatism (cylinder >or= +1.50 D), and anisometropia (SE difference between each eye >or=2.00 D) were calculated.

Results: A total of 3009 children were examined (participation rate, 72.3%). Right eye (OD) cycloplegia data were available for 1375 boys and 1264 girls (mean age, 41 months). Mean OD SE was +0.69 D (SD 1.15). Overall myopia prevalence was 11.0% with no variance between the sexes (P = 0.91). The prevalence of high myopia (at least -6.00 D) was 0.2%. The prevalences of hyperopia, astigmatism, and anisometropia were 1.4%, 8.6%, and 0.6%, respectively. Most astigmatism (>95%) was with-the-rule (cylinder axes between 1 degrees and 15 degrees or 165 degrees and 180 degrees ). Myopia was present in 15.8%, 14.9%, 20.2%, 8.6%, 7.6%, and 6.4% of children aged 6 to 11, 12 to 23, 24 to 35, 36 to 47, 48 to 59, and 60 to 72 months, respectively. Prevalence increased with age for astigmatism (P < 0.001), but not for hyperopia or anisometropia (P = 0.55 and P = 0.37), respectively.

Conclusions: The prevalences of myopia and astigmatism in young Singaporean Chinese children are high, but that of hyperopia is low. Age effects were observed for each refractive error category, but differences between the sexes were not significant. Age-related variation in myopia prevalence may be influenced by ocular development, environment, and/or testability.