title: Prevalence of amblyopia and strabismus in young singaporean chinese children.
abstract: PURPOSE. To determine the prevalence of amblyopia and strabismus in young Singaporean Chinese children. METHODS. Enrolled in the study were 3009 Singaporean children, aged 6 to 72 months. All underwent complete eye examinations and cycloplegic refraction. Visual acuity (VA) was measured with a logMAR chart when possible and the 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 (> or =1.00 D for hyperopia, > or =3.00 D for myopia, and > or =1.50 D for astigmatism), strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40 (in children 48-72 months) and <20/50 (<48 months), with coexisting hyperopia > or =4.00 D, myopia < or = -6.00 D, and astigmatism > or =2.50 D, or past or present visual axis obstruction. RESULTS. The amblyopia prevalence in children aged 30 to 72 months was 1.19% (95% confidence interval [CI], 0.73-1.83) with no age (P = 0.37) or sex (P = 0.22) differences. Unilateral amblyopia (0.83%) was twice as frequent as bilateral amblyopia (0.36%). The most frequent causes of amblyopia were refractive error (85%) and strabismus (15%); anisometropic astigmatism >1.50 D (42%) and isometropic astigmatism >2.50 D (29%) were frequent refractive errors. The prevalence of strabismus in children aged 6 to 72 months was 0.80% (95% CI, 0.51-1.19), with no sex (P = 0.52) or age (P = 0.08) effects. The exotropia-esotropia ratio was 7:1, with most exotropia being intermittent (63%). Of children with amblyopia, 15.0% had strabismus, whereas 12.5% of children with strabismus had amblyopia. CONCLUSIONS. The prevalence of amblyopia was similar, whereas the prevalence of strabismus was lower than in other populations.
authors.affiliation: Singapore National Eye Center, Singapore. wla_chia@yahoo.com
authors.forename: Audrey
authors.initials: A
authors.lastname: Chia
authors.forename: Mohamed
authors.initials: M
authors.lastname: Dirani
authors.forename: Yiong-Huak
authors.initials: YH
authors.lastname: Chan
authors.forename: Gus
authors.initials: G
authors.lastname: Gazzard
authors.forename: Kah-Guan
authors.initials: KG
authors.lastname: Au Eong
authors.forename: Prabakaran
authors.initials: P
authors.lastname: Selvaraj
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Ling
authors.forename: Boon-Long
authors.initials: BL
authors.lastname: Quah
authors.forename: Terri L
authors.initials: TL
authors.lastname: Young
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
authors.forename: Rohit
authors.initials: R
authors.lastname: Varma
authors.forename: Tien-Yin
authors.initials: TY
authors.lastname: Wong
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
mesh_terms: D017677:Age Distribution; D000550:Amblyopia / Q000208:ethnology*; D044466:Asian People / Q000208:ethnology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D017678:Sex Distribution; D012846:Singapore / Q000453:epidemiology; D013285:Strabismus / Q000208:ethnology*; D014792:Visual Acuity / Q000502:physiology