Prevalence of amblyopia and its association with refraction in Chinese preschool children aged 36-48 months.

PURPOSE: To determine the prevalence of amblyopia and its association with refraction in Chinese preschool children. METHODS: The Yuhuatai Pediatric Eye Disease Study, a cross-sectional, population-based study, was conducted in children aged 36-48 months in Yuhuatai District, Nanjing, China, in 2015. Visual acuity was measured in 1695 eligible children. RESULTS: Of the 1695 subjects, manifested amblyopia was detected in 25 children (1.47%, 95% CI 0.90% to 2.05%), including 11 and 14 with bilateral and unilateral amblyopia, respectively. Amblyopia prevalence did not differ by gender (p=0.77). Significant refractive errors were found in 22 (88.0%) of children with amblyopia, and strabismus was found in 6 (24.0%) children with amblyopia. In multivariate analysis, amblyopia was significantly associated with hyperopia (≥+2.00 dioptres (D); OR 8.81, 95% CI 3.27 to 23.69, p<0.0001), astigmatism (≥2.00 D; OR 17.90, 95% CI 6.78 to 47.21, p<0.0001) and anisometropia (≥2.00 D; OR 5.87, 95% CI 1.52 to 22.77, p<0.05). CONCLUSIONS: The prevalence of amblyopia in children 36-48 months old in Eastern China was 1.47%. The refractive error is a major risk factor for amblyopia.