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Prevalence and causes of decreased visual acuity in Singaporean Chinese preschoolers
  1. M Dirani1,2,
  2. B Zhou3,
  3. D Hornbeak4,
  4. B C Chang5,
  5. G Gazzard6,
  6. A Chia7,
  7. Y Ling7,
  8. P Selvaraj3,
  9. T L Young4,8,
  10. R Varma9,
  11. T Y Wong1,2,
  12. S M Saw3
  1. 1Singapore Eye Research Institute, Singapore, Singapore
  2. 2Center for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
  3. 3Department of Community, Occupational and Family Medicine, National University of Singapore, Singapore, Singapore
  4. 4Duke-NUS Graduate Medical School, Singapore, Singapore
  5. 5Department of Ophthalmology and Visual Sciences, Alexandra Hospital and Jurong Medical Center, Singapore, Singapore
  6. 6Glaucoma Research Unit, Moorfields Eye Hospital, London, UK
  7. 7Department of Ophthalmology, Singapore National Eye Center, Singapore, Singapore
  8. 8Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA
  9. 9Doheny Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
  1. Correspondence to Dr Mohamed Dirani, Department of Community, Occupational and Family Medicine, Yong Loo Lin School of Medicine, National University of Singapore, MD3, 16 Medical Drive, Singapore 117597, Singapore; dirani{at}


Aims To describe the prevalence and causes of decreased visual acuity (VA) in Singaporean Chinese children.

Methods A population-based survey of Singaporean Chinese children aged 6 to 72 months was conducted. Participants underwent an orthoptic evaluation, cycloplegic refraction and biometric measurements. A sub-group of children aged 30 to 72 months with presenting logMAR VA were included in this analysis. Retesting was performed on the same day or another day by predefined criteria with best refractive correction. Decreased VA was 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 examined 3009 children (participation rate 72.3%) of which 2017 children aged 30 to 72 months were eligible for VA testing and completed in 1684 (83.5%). In children aged 30–47 months, the prevalence of decreased presenting VA was 2.1%, and in children 48–72 months, it was 2.05%, with no significant difference between boys and girls in both age groups (p=0.15 and p=0.85). Causes for decreased presenting VA in those 30–47 months were refractive error (7/11, 63.6%), amblyopia (1/11, 9.1%) and “no explanation” (3/11, 27.3%), and 17/24 (70.8%), 5/24 (20.8%) and 2/24 (8.3%), respectively, for those aged 48–72 months. The types of refractive error were astigmatism (15/24, 62.5%), myopia (6/24, 25.0%), hyperopia (2/24, 8.3%) and hyperopia with astigmatism (1/24, 4.2%).

Conclusions The prevalence of decreased VA among Singaporean Chinese preschoolers is low, with uncorrected refractive error being the main cause in both children 30–47 and 48–72 months.

  • Vision
  • optics and refraction
  • public health
  • epidemiology

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  • Competing interests None.

  • Ethics approval Approval was obtained from the Institutional Review Boards of the Singapore Eye Research Institute (SERI) and the Singapore National Healthcare Group (NHG).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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