Purpose: To determine the risk factors for strabismus and amblyopia in young Singapore Chinese children.
Methods: A total of 3009 children were recruited for the population-based cross-sectional Strabismus, Amblyopia and Refractive Error in Singaporean Preschoolers Study (STARS). Strabismus was defined as any tropia identified on cover test. Visual acuity was measured in children aged 30-72 months with a logMAR chart where possible and the Sheridan-Gardiner test if not. Amblyopia was defined based on visual acuity and refractive error or presence of strabismus or past/present visual axis obstruction. Parents completed questionnaires on family, prenatal and birth histories.
Results: Our study showed that 24 children aged 6-72 months (1.2%) had strabismus (20 with exotropia), and 20 children aged 30-72 months (0.8%) were amblyopic. After multivariate analysis, strabismus was associated with astigmatism ≥1.00 diopter (D; p = 0.03), amblyopia (p = 0.003), a sibling with strabismus (p < 0.001), and families with lower parental education (p = 0.04). In addition to strabismus, amblyopia was associated with anisometropia ≥1.00 D (p < 0.001) and astigmatism ≥1.00 D (p < 0.001). No association was noted between either strabismus or amblyopia and prematurity, maternal age or smoking.
Conclusion: This study highlights the importance of family history in strabismus, and the close associations between refractive error and strabismus with amblyopia. These factors play a more important role in young Singapore Chinese children.