Prevalence of Myopia and Axial Length Distribution in China: The Wuhu Children and Adolescents Eye Study

To re-assess myopia prevalence, update the database of ocular biometric parameters, and assess the prevalence of fundus abnormalities in schoolchildren and adolescents in Wuhu, Anhui Province, China.

The Wuhu Children and Adolescents Eye Study (WCAES) is a longitudinal population-based cohort study, and the cross-sectional analysis results of the baseline assessment are reported here. It included 315,569 out of 330,173 eligible children and adolescents (95.6%), ages 2 to 19 years, from 513 schools with measurements of presenting distance visual acuity (PDVA) and uncorrected distance visual acuity (UDVA), non-cycloplegic autorefractometry, ocular biometry, and color fundus photography. Fundus abnormalities were assessed by an artificial intelligence-based system.

Prevalences of likely myopia (-1.00 D < refractive error ≤ -0.50 D), myopia (refractive error ≤-1.00 D), low myopia (-3.00 D < refractive error ≤ -1.00 D), moderate myopia (-6.00 D < refractive error ≤ -3.00 D), and high myopia (refractive error ≤ -6.00 D) were 13.58% (95% confidence interval [CI], 13.46-13.70), 56.92% (95% CI, 56.74-57.10), 32.87% (95% CI, 32.70-33.04), 19.74% (95% CI, 19.60-19.88), and 4.31% (95% CI, 4.24-4.38), respectively. Among high-school students, myopia prevalence was 92.18% (95% CI, 91.68-92.68). High myopia prevalence rates in kindergarten, elementary, middle, and high schools were 0.30% (95% CI, 0.18-0.43), 1.53% (95% CI, 1.48-1.59), 9.05% (95% CI, 8.86-9.24), and 18.57% (95% CI, 17.84-19.29), respectively. Higher prevalence of overall myopia and high myopia was associated (all P < 0.001) with female sex (odds ratio [OR] = 0.81 and OR = 0.91, respectively), older age (OR = 1.45 and OR = 1.48, respectively), longer axial length (OR = 3.71 and OR = 5.89, respectively), and higher prevalence of fundus tessellation (OR = 1.10 and OR = 1.21, respectively.). The percentage of myopic individuals using vision correction and the prevalence of an age-dependent defined suboptimal PDVA in the myopic population were 48.05% (95% CI, 47.81-48.28) and 65.84% (95% CI, 65.51-66.16), respectively.

Compared with previous studies, the present investigation suggests a further rise in the prevalence of myopia, particularly high myopia, in the younger generations in China.