Prevalence and Causes of Decreased Visual Acuity in Singaporean Chinese Children: The Strabismus, Amblyopia and Refractive Error in Singaporean Preschoolers (STARS) Study

Abstract

Purpose: : To investigate the prevalence and causes of decreased visual acuity (VA) in young Singaporean Chinese children.

Methods: : A population-based survey of Chinese children aged 6 to 72 months was conducted in Southwestern Singapore with disproportionate sampling by 6-month age groups. Participants underwent an administered questionnaire and a comprehensive eye examination, including an orthoptic evaluation, cycloplegic refraction and biometric measurements. Subjects aged 30 to 72 months had presenting VA assessed in logMAR units. Decreased VA is defined as worse than 20/50 (0.4 logMAR) for ages 30 to 47 months and worse than 20/40 (0.3 logMAR) for ages 48 to 72 months.

Results: : The study recruited 3009 children (participation rate 72.3%) of which 2017 children aged 30 to 72 months had VA testing, which was successful in 1684 (83.5%). The overall prevalence of decreased presenting VA (better eye) was 2.1% (35/1684), with no significant difference between boys 42.9% (15/35) and girls 57.1% (20/35), p>0.05. The prevalence for each age group was 5.8% (30-35.9mths), 1.3% (36-47.9mths), 3.3% (48-59.9mths) and 0.9% (60-72mths). Causes for decreased VA were ametropia (26/35, 74.3%), amblyopia (4/35, 11.4%) and ‘no obvious cause’ (5/35, 14.3%). Forms of ametropia were astigmatism (15/26, 57.7%), myopia (8/26, 30.8%), hyperopia (2/26, 7.7%) and hyperopia with astigmatism (1/26, 3.8%). After retesting, only 0.3% (5/1684) had decreased VA.

Conclusions: : The prevalence of decreased presenting VA among Singaporean Chinese preschoolers was low, with refractive error being the main cause.

Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • myopia • refractive error development