Prevalence of myopia in 3–14-year-old Chinese children: a school-based cross-sectional study in Chengdu

Abstract

Background The prevalence of myopia among children in Chengdu is unknown. The aim of this study was to determine the prevalence of myopia in 3- to 14-year-old Chinese children in Chengdu. Methods This study was a school-based cross-sectional study in children aged 3–14 years. Visual acuity (VA), spherical equivalent error (SER) with noncycloplegic autorefraction, axial length (AL) and corneal radius (CR) were measured. Results A total of 19,455 children were recruited for this study. The prevalence of myopia was 38.1 %; the prevalence of low myopia was 26.6 %, that of moderate myopia was 9.8 %, and that of high myopia was 1.7 %. The prevalence of myopia and SER increased with age from 6 years old. The prevalence of myopia was higher, and the SER indicated more severe myopia in the girls than in the boys (40.1 % vs. 36.2 %, χ2 = 30.67, df = 1, P < 0.001; -0.93 D ± 1.75 D vs. -0.84 D ± 1.74 D, t = 3.613, df=19,453, P < 0.001). The girls had a higher prevalence of myopia and myopic SER than did the boys aged 9 years and older (P < 0.05). Among the myopic children, the rates of uncorrected, undercorrected and fully corrected myopia were 54.8 %, 31.1 and 14.1 %, respectively. AL and AL/CR increased with age from 6 years old, but CR remained stable after 4 years old. The AL was longer, and the CR was flatter in the boys than in the girls aged 3 to 14 years old (P < 0.05). Conclusions The prevalence of myopia, AL and AL/CR increased, and the SER became more myopic with age from 6 years old. The girls had a higher prevalence of myopia and myopic SER than did the boys, but the boys had a longer AL, flatter CR and higher AL/CR ratio than did the girls. The rate of uncorrected myopia was very high in the myopic children. More actions need to be taken to decrease the prevalence of myopia, especially uncorrected myopia in children.

Prevalence of myopia: A large-scale population-based study among children and adolescents in weifang, china

“…There were 532,851 boys, accounting for 50.28% of the study participants. The mean age was 11.57 ± 3.36 (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) years.…”

“…Another school-based cross-sectional study enrolled 3–14-year-old Chinese children in Chengdu by Wang et al demonstrated that the prevalence of low myopia in the girls was higher than that in the boys (28.4 vs. 25.0%), while the prevalence of moderate myopia (9.5 vs. 10.1%), and high myopia (SE ≤ −6.00 D, 1.7 vs. 1.7%) did not significantly differ between the girls and boys ( 15 ). In our study, the total prevalence of myopia in the girls was higher than that in the boys, which is consistent with those in previous studies ( 16 , 17 ).…”

Prevalence of Myopia and Its Associated Factors Among Japanese Preschool Children

“…To reduce the effect of strong accommodation, myopia was additionally assessed by both non-cycloplegic autorefraction and visual acuity in our study. In the report by Wang et al, which assessed myopia in a similar manner, myopia was prevalent in 2.6% and 1.7% of children aged 4 and 5 years, respectively ( 18 ). Relatively close values were obtained in the current study.…”

“…Additionally, the criteria for younger children aged 3–6 years should be determined carefully for each age group because the average visual acuity varies with age ( 16 ). Hence, following the previous method, myopia was defined as SE ≤ – 0.50 D + uncorrected visual acuity > 0.3 logMAR for children aged 3 years, > 0.2 logMAR for children aged 4–5 years, and > 0 logMAR for children aged 6 years ( 18 ). Analysis was performed on the worse eye only in view of the correlation in parental myopia, outdoor time and near work between right and left eyes ( 2 , 18 , 19 ).…”

“…Hence, following the previous method, myopia was defined as SE ≤ – 0.50 D + uncorrected visual acuity > 0.3 logMAR for children aged 3 years, > 0.2 logMAR for children aged 4–5 years, and > 0 logMAR for children aged 6 years ( 18 ). Analysis was performed on the worse eye only in view of the correlation in parental myopia, outdoor time and near work between right and left eyes ( 2 , 18 , 19 ). The worse eye with higher myopic SE was chosen for analysis.…”