title: Age of onset of myopia predicts risk of high myopia in later childhood in myopic Singapore children.
abstract: To investigate the effect of age of myopia onset on the severity of myopia later in life among myopic children.
  
  
  
  In this prospective study, school children aged 7-9 years from the Singapore Cohort Of the Risk factors for Myopia (SCORM) were followed up till 11 years (n = 928). Age of myopia onset was defined either through questionnaire at baseline (age 7-9 years) or subsequent annual follow-up visits. Age of onset of myopia was a surrogate indicator of duration of myopia progression till age 11 years. Cycloplegic refraction and axial length were measured at every annual eye examination. High myopia was defined as spherical equivalent of ≤-5.0 D. A questionnaire determined the other risk factors.
  
  
  
  In multivariable regression models, younger age of myopia onset (per year decrease) or longer duration of myopia progression was associated with high myopia (odds ratio (OR) = 2.86; 95% CI: 2.39 to 3.43), more myopic spherical equivalent (regression coefficient (β) = -0.86 D; 95% CI: -0.93 to -0.80) and longer axial length (β = 0.28 mm; 95% CI: 0.24 to 0.32) at aged 11 years, after adjusting for gender, race, school, books per week and parental myopia. In Receiver Operating Curve (ROC) analyses, age of myopia onset alone predicted high myopia by 85% (area under the curve = 0.85), while the addition of other factors including gender, race, school, books per week and parental myopia only marginally improved this prediction (area under the curve = 0.87).
  
  
  
  Age of myopia onset or duration of myopia progression was the most important predictor of high myopia in later childhood in myopic children. Future trials to retard the progression of myopia to high myopia could focus on children with younger age of myopia onset or with longer duration of myopia progression.
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
authors.forename: Sharon Y L
authors.initials: SY
authors.lastname: Chua
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
authors.forename: Charumathi
authors.initials: C
authors.lastname: Sabanayagam
authors.affiliation: Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore.
authors.forename: Yin-Bun
authors.initials: YB
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Audrey
authors.initials: A
authors.lastname: Chia
authors.affiliation: Genome Institute of Singapore, A*STAR, Singapore, Singapore.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Valenzuela
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Donald
authors.initials: D
authors.lastname: Tan
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
authors.forename: Tien-Yin
authors.initials: TY
authors.lastname: Wong
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Cheng
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.|Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore, Singapore.
authors.forename: Seang-Mei
authors.initials: SM
authors.lastname: Saw
mesh_terms: D017668:Age of Onset; D002648:Child; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D009216:Myopia / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012029:Refraction, Ocular; D012307:Risk Factors; D012720:Severity of Illness Index; D012846:Singapore / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: age of myopia onset; axial length; children; high myopia; myopia; spherical equivalent