School-based epidemiology study of myopia in Tianjin, China

Int Ophthalmol. 2020 Sep;40(9):2213-2222. doi: 10.1007/s10792-020-01400-w. Epub 2020 May 29.


Purpose: To study the epidemiology of myopia in school-aged children in Tianjin and the relationship between visual acuity-based screening and refraction-based screening.

Method: This school-based prospective cohort study was performed on children from 42 elementary schools and 17 middle schools in Tianjin, China. Totally 14,551 children, ages ranging from 5 to 16 years, were included in this study. Uncorrected visual acuity (UCVA) was determined by logarithmic tumbling E chart. Non-cycloplegic photorefraction was examined by the Spot (v2.1.4) photoscreener. The relationship between the UCVA and refractive error was investigated for different age groups.

Results: The overall prevalence of myopia at this school based screen is 78.2%, ranged from 10% at age of 5 to 95% at age of 16. The most dramatic increase in prevalence is from age of 6 (14.8%) to age of 7 (38.5%). The overall prevalence of high myopia is 2.5%. UCVA is found corresponding to spherical equivalent refraction (SER) in a manner of normal distribution and is significantly affected by age. When using UCVA to estimate the prevalence of myopia, the overall sensitivity and specificity are 0.824 and 0.820, respectively. Age-dependent optimal cutoff points and 95% confident intervals of such estimation are reported.

Conclusions: Myopia is heavily affecting school-aged children in Tianjin, China. The refraction screening is preferable for myopia screening, whereas the UCVA screening results need to be interpreted in an age-dependent manner for myopia estimation.

Keywords: Children; Epidemiology; Myopia; Photoscreen; Refractive error; Visual acuity.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • China / epidemiology
  • Humans
  • Myopia* / diagnosis
  • Myopia* / epidemiology
  • Prevalence
  • Prospective Studies
  • Refraction, Ocular
  • Refractive Errors*
  • Schools