Abstract
Purpose: :
To determine the risk factors for amblyopia and strabismus in very young Singapore Chinese Children
Methods: :
A total of 3005 children aged 6 to 72 months (response rate 74%) were recruited for the Strabismus, Amblyopia and Refractive error (STAR) study in Singapore. All children underwent a detailed ophthalmological assessment. Visual acuity (VA) was measured with logMAR chart when possible, and Sheridan Gardner test when not. Strabismus was defined as any manifest tropia. Unilateral amblyopia was defined as a 2-line difference between eyes with VA<20/30 in the worse eye, and with coexisting anisometropia (≥1.00D for hyperopia, ≥3.00D for myopia, ≥1.50D for astigmatism), strabismus or past/present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40 (in children 48-72months) and <20/50 (<48months), with coexisting hyperopia ≥ 4.00D, myopia ≤ -6.00D and astigmatism ≥2.50D, or past/present visual axis obstruction. Parents of children were asked to complete questionnaires detailing relevant family, prenatal and birth histories.
Results: :
The prevalence of amblyopia in children aged 30-72 years was 1.19% (95%CI, 0.73-1.83) while the prevalence of strabismus in those aged 6-72 months was 0.80% (95%CI 0.51-1.19). After regression modeling, children with amblyopia were significantly more likely to have myopia<-3D (<0.001) and astigmatism>2.5D (p<0.001). Children with strabismus were more likely to have astigmatism>2.5D (p<0.001), amblyopia (p=0.04) and a sibling (p<0.001) or parent (p=0.02) with strabismus. Child’s age, gender, birth weight/gestational age, household income, maternal and paternal education levels, maternal factors such as maternal age, prenatal medical problems, smoking/alcohol and breast-feeding were not associated with the child’s risk of developing amblyopia or strabismus.
Conclusions: :
Amblyopia and strabismus were associated with refractive errors, and children with strabismus were more likely to have a family history of strabismus.
Keywords: amblyopia • strabismus