Abstract
Purpose
The aim of this study was to understand the trends of myopia prevalence among children and adolescents in Shihezi, China.
Methods
This was a cross-sectional study using data from 2018 to 2023 from the Vision Surveillance Research Program for Students in Shihezi City. Describe the prevalence of myopia with 95% CIs in 31,265 children and adolescents in urban and rural areas, by sex and age. The prevalence rate and chain growth rate of myopia and spherical equivalent refraction in different ages were described the development of myopia.
Results
A total of 31,265 children and adolescents with a mean age of 11,91 ± 3.67 years were included in the study. The overall prevalence of myopia was 50.93%(15924/31265, 95% CI: 50.38 − 51.49%). The prevalence of myopia was 55.18% (8348/15128, 95% CI: 54.39 − 55.98%) for girls and 46.95% (7576/16137, 95% CI: 46.18 − 47.72%) for boys. Prevalence of overall, mild, moderate, and high myopia is higher in urban than in rural areas. The prevalence of myopia increases with age, with the highest chain growth rate of myopia of 69.18% at the age of 6 years, slowing down at the age of 12 years. Spherical equivalent refraction changes from positive to negative at 6–7 years of age.
Conclusions
The prevalence of myopia is higher in Shihezi, and myopia develops at an earlier age and the farsighted disappears earlier. The development of myopia begins to increase sharply at the age of 6 years and slows down by the age of 12 years, and the spherical equivalent refraction changes from positive to negative at the age of 6 to 7 years. For policy makers, it is even more important to prevent and control myopia at a younger age.
Keywords: Children and adolescents, Myopia, Hyperopia reserve, Prevalence rate
Introduction
Myopia is a common refractive error, when the human eye is in a relaxed state of adjustment, light rays parallel to the visual axis are focused in front of the retina after passing through the refractive system of the eye, which is called myopia. Compared to other countries, myopia is growing fastest in East Asian countries [1]. Some studies suggest that by 2050, half of the people on the planet will be nearsighted and myopia will become a common eye disease [2]. In China, myopia is a major public health problem that jeopardizes the visual health of Chinese residents, especially children and adolescents. According to data released by China’s National Health Commission, the overall myopia rate among children and adolescents in China in 2020 will be 52.7%, with primary school students at 35.6%, junior high school students at 71.1%, and high school students at 80.5% [3]. Myopia constantly affects the physical and mental development of children and adolescents, and high levels of myopia may lead to retinal detachment, macular degeneration and other diseases [4, 5], myopia is becoming a common condition in the student population.
In the neonatal stage, the eye is hyperopic, with an average refractive error of + 2.50 to + 3.00 D, this physiologic hyperopia is called hyperopic reserve [6, 7]. Changes in age-corresponding reserve values signal the emergence of vision problems in children. Decrease in hyperopic reserve value is a risk factor for the development of myopia, which may indicate the onset of myopia. Due to the high plasticity of visual development in children aged 0–6 years, the key to preventing myopia should be placed in the age group where the incidence of myopia increases the fastest, and the time of loss of the hyperopic reserve value is also the fastest time of myopia incidence, therefore, it is necessary to study the incidence and development of myopia in children and adolescents.
Although many studies on the prevalence of myopia or the factors influencing it have been conducted in inland China, relatively few trend studies have been conducted on the growth rate of the prevalence of myopia and the reserve of hyperopia with such a large sample size. The distribution of myopia among children and adolescents may also be different in Xinjiang, which is less developed and more culturally diverse than inland Chinese cities.
The aim of this study is to focus on the occurrence and development of myopia in children and adolescents in Xinjiang, and to provide relevant scientific basis for myopia prevention and control.
Method
Study population
This is a cross-sectional study with data from the National Student Common Diseases and Vision Program in Shihezi City. This large-scale study was conducted in October of each year from 2018 to 2023 in 20 primary and secondary kindergarten students in Shihezi, China. Exclusion criteria: Students with previous cataract surgery, laser myopic surgery, low-dose atropine, and use of orthokeratology lenses were excluded.
Visual acuity test and refraction screening
Students were asked to remove their eyeglasses (including contact lenses) for refraction and uncorrected visual acuity (UCVA) examinations, and all subjects had refraction and visual acuity examinations performed by professional optometrists with standardized training. Uncorrected visual acuity was tested using a standard logarithmic visual acuity E chart. When testing the vision of the right eye, a non-contact black spoon-shaped ocular occluder was used to cover the left eye at a distance of 5 m. After the right eye was tested for 5 to 10 s, the left eye was tested in the same way.
Non-cycloplegic refraction were detected using an autorefractor of the TOPCON KR-1 (Tokyo, Japan). Each subject was tested three times per eye, and the results were averaged. If the difference between the three results re any two results was greater than 0.5 diopters (D), each subject was re-examined. Spherical equivalent (SE) was determined using the algebraic sum of the refractive errors of the spherical and cylindrical lenses (spherical + 0.5 cylindrical) [8]. Myopia is defined as uncorrected visual acuity < 5.0 in either eye and spherical equivalent (SE) <-0.50D, and is categorized as mild myopia (-3.00D ≤ SE <-0.50D), moderate myopia (-6.00D ≤ SE <-3.00D) and high myopia (SE <-6.00D) [9].
Statistical anaylses
Data were analyzed using IBM SPSS V.27.0 and graphed using Graphpad Prism V.9.5.1. Normally distributed continuous variables were described by mean and standard deviation and skewed continuous variables were described by median and interquartile range (IQR). Categorical variables were described by the number of cases and percentages. Normally distributed measures between the two groups were analysed by independent samples t-test, non-normal measures were analysed by Mann-Whitney U-test and count data were analysed by chi-square test, Comparison of left and right eye SE was performed using the Wilcoxon test. The growth rate of myopia in children and adolescents of different ages was used to characterize myopia in children and adolescents in Shihezi City, and the decrease in SE in different ages was used to characterize the changes in hyperopic in children and adolescents in Shihezi City.
Rusults
Primary and secondary school students aged 5–16 years in Shihezi City were included in this study. A total of 31,265 subjects with a mean age of 11.91 ± 3.67 years were included in this study. Among them, 16,137 (51.61%) were males and 15,128 (48.39%) were females. The overall prevalence of myopia was 50.93% (15924/31265, 95% CI: 50.38 − 51.49%). Characteristics of subjects with and without myopia are shown in Table 1, the prevalence of myopia by age group for each year 2018–2023 is shown in Schedule 1.
Table 1.
Characteristics of participants
| Characteristics | Total | No myopia | Myopia | t/Z/χ2 | P |
|---|---|---|---|---|---|
| Age, mean ± SD, years | 11.91 ± 3.67 | 10.23 ± 3.48 | 13.53 ± 3.08 | 88.489 | 0.001 |
| Sex | |||||
| Male(%) | 16,137(51.61) | 8561(55.80) | 7576(47.58) | 211.848 | 0.001 |
| Female (%) | 15,128(48.39) | 6780(44.20) | 8348(52.42) | ||
| SE of right eye, M(P25,P75), D | −1(−2.69,−0.06) | −0.12(−0.50,0.38) | −2.62(−4.13,−1.38) | −134.041 | 0.001 |
| SE of left eye, M(P25,P75), D | −0.75(−2.38,0) | 0.00(−0.44,0.38) | −2.25(−3.88,−1.13) | −128.948 | 0.001 |
| UCVA of right eye, mean ± SD | 4.71 ± 0.38 | 4.97 ± 0.12 | 4.46 ± 0.36 | -169.722 | 0.001 |
| UCVA of left eye, mean ± SD | 4.73 ± 0.37 | 4.97 ± 0.12 | 4.50 ± 0.38 | -148.876 | 0.001 |
| Urban/rural areas | |||||
| Urban area, no(%) | 21,357(68.31) | 9795(63.85) | 11,562(72.61) | 276.907 | 0.001 |
| Rural area, no(%) | 9908(31.69) | 5546(36.15) | 4362(27.39) | ||
SE: Spherical equivalent; UCVA: uncorrected visual acuity
Schedule 1.
Prevalence of Myopia by age group by year 2018 to 2023
| Age | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Myopia | Total | % | Myopia | Total | % | Myopia | Total | % | Myopia | Total | % | Myopia | Total | % | Myopia | Total | % | |
| 5 | 28 | 111 | 25.23 | 27 | 211 | 12.8 | 15 | 215 | 6.98 | 10 | 284 | 3.52 | 3 | 73 | 4.11 | 17 | 452 | 3.76 |
| 6 | 61 | 304 | 20.07 | 52 | 449 | 11.58 | 49 | 455 | 10.77 | 53 | 381 | 13.91 | 71 | 602 | 11.79 | 28 | 307 | 9.12 |
| 7 | 63 | 298 | 21.14 | 58 | 437 | 13.27 | 87 | 439 | 19.82 | 99 | 444 | 22.30 | 83 | 322 | 25.78 | 62 | 300 | 20.67 |
| 8 | 100 | 357 | 28.01 | 82 | 414 | 19.81 | 110 | 449 | 24.50 | 139 | 470 | 29.57 | 129 | 344 | 37.5 | 94 | 248 | 37.90 |
| 9 | 130 | 366 | 35.52 | 133 | 414 | 32.13 | 148 | 435 | 34.02 | 162 | 437 | 37.07 | 180 | 364 | 49.45 | 114 | 243 | 46.91 |
| 10 | 157 | 364 | 43.13 | 162 | 466 | 34.76 | 205 | 428 | 47.90 | 194 | 431 | 45.01 | 220 | 387 | 56.85 | 138 | 263 | 52.47 |
| 11 | 170 | 348 | 48.85 | 230 | 488 | 47.13 | 217 | 475 | 45.68 | 251 | 447 | 56.15 | 208 | 343 | 60.64 | 196 | 321 | 61.06 |
| 12 | 182 | 328 | 55.49 | 260 | 479 | 54.28 | 272 | 463 | 58.75 | 275 | 475 | 57.89 | 247 | 374 | 66.04 | 261 | 411 | 63.50 |
| 13 | 192 | 340 | 56.47 | 313 | 509 | 61.49 | 356 | 552 | 64.49 | 367 | 545 | 67.34 | 366 | 530 | 69.06 | 366 | 560 | 65.36 |
| 14 | 219 | 357 | 61.34 | 327 | 467 | 70.02 | 351 | 493 | 71.20 | 392 | 523 | 74.95 | 395 | 524 | 75.38 | 372 | 558 | 66.67 |
| 15 | 250 | 325 | 76.92 | 314 | 439 | 71.53 | 294 | 402 | 73.13 | 428 | 534 | 80.15 | 404 | 504 | 80.16 | 251 | 344 | 72.97 |
| 16 | 538 | 295 | 77.41 | 771 | 376 | 74.64 | 578 | 364 | 73.35 | 786 | 551 | 77.82 | 716 | 355 | 80.09 | 346 | 207 | 81.80 |
| Total | 2090 | 4193 | 49.84 | 2729 | 5806 | 47.00 | 2682 | 5594 | 47.94 | 3156 | 5981 | 52.77 | 3022 | 5261 | 57.44 | 2245 | 4430 | 50.68 |
The prevalence of myopia was 54.14% (11562/21357, 95% CI: 53.47 − 54.81%) in urban areas and 44.03% (4362/9908, 95% CI: 43.04 − 45.01%) in rural areas, which was higher than that in rural areas (χ2 = 276.090, P = 0.001). The composition of mild myopia was lower in urban areas 52.09% (6023/11562, 95% CI: 51.18 − 53.01%) than in rural areas 63.64% (2776/4362, 95% CI: 62.19 − 65.07%) (χ2 = 170.815, P = 0.001), while the composition of moderate 36.90% (4266/11526, 95% CI: 36.02 − 37.78%) and high myopia 11.01% (1273/11526, 95% CI: 10.45 − 11.59%) were higher than in rural areas 30.44% (1328/4362, 95% CI: 29.08 − 31.83%), 5.91% (258/4362, 95% CI: 5.23 − 6.66%) (χ2Moderate = 57.854, P = 0.001;χ2High = 94.627, P = 0.001). (Table 2; Fig. 1).
Table 2.
Composition of myopia severity between urban and rural areas
| Variables | Urban area(N=21357) | Rural area(N=9908) | χ2 | P |
|---|---|---|---|---|
| Myopia | 11,562 | 4362 | 276.907 | 0.001 |
| Mild myopia | 6032 | 2776 | 170.815 | 0.001 |
| Moderate myopia | 4266 | 1328 | 57.854 | 0.001 |
| High myopia | 1273 | 258 | 94.627 | 0.001 |
Fig. 1.
The distribution of severity of myopia in urban/rural areas
The prevalence of myopia was higher among girls 55.18% (8348/15128, 95% CI: 54.39 − 55.98%) than boys 46.95% (7576/16137, 95% CI: 46.18 − 47.72%) (χ2 = 211.848, P = 0.001). The composition of moderate myopia was higher in girls 35.94% (3000/8348, 95% CI: 34.91 − 36.98%) than in boys 34.24% (2594/7576, 95% CI: 33.17 − 35.32%) (χ2 = 5.019, P = 0.025), while there was no statistically significant difference in the composition of mild and high myopia by sex(P>0.05) (Table 3; Fig. 2).
Table 3.
Composition of myopia severity between urban and rural areas
| Variables | Male(N=16137) | Female(N=15128) | χ2 | P |
|---|---|---|---|---|
| Myopia | 7576(46.95) | 8348(55.18) | 211.848 | 0.001 |
| Mild myopia | 4247(56.06) | 4552(54.53) | 3.763 | 0.052 |
| Moderate myopia | 2594(34.24) | 3000(35.94) | 5.019 | 0.025 |
| High myopia | 735(9.70) | 796(9.54) | 0.127 | 0.722 |
Fig. 2.
The distribution of severity of myopia in different sexes
The prevalence of myopia, stratified by age, tended to increase with age. This trend was observed in the composition of moderate and high myopia. The prevalence of myopia among 5-year-olds was 7.43% (100/1346, 95% CI: 6.09 − 8.96%) and among 16-year-olds was 77.12% (3735/4843, 95% CI: 75.91 − 78.30%). By age 16, the composition of moderate myopia reached 44.31% (1655/3735, 95% CI: 42.71 − 45.92%), and high myopia reached 17.59% (657/3735, 95% CI: 16.38 − 18.85%) (Fig. 3, Schedule 2). Further analysis of the data showed that the chain growth rate of myopia peaked at 69.18% at the age of 6 years and slowed down at the age of 12 years (Fig. 4).
Fig. 3.
Composition of different severities of myopia by age group
Schedule 2.
Composition of myopia of different severities in different age groups
| Age | Myopia | Mild | Moderate | High |
|---|---|---|---|---|
| 5 | 100 | 88(88.00) | 11(11.00) | 1(1.00) |
| 6 | 314 | 289(92.04) | 20(6.37) | 5(1.59) |
| 7 | 452 | 404(89.38) | 43(9.51) | 5(1.11) |
| 8 | 654 | 550(84.10) | 97(14.83) | 7(1.07) |
| 9 | 867 | 664(76.59) | 179(20.65) | 24(2.77) |
| 10 | 1076 | 752(69.89) | 288(26.77) | 36(3.35) |
| 11 | 1272 | 800(62.89) | 409(32.15) | 63(4.95) |
| 12 | 1497 | 895(59.79) | 501(33.47) | 101(6.75) |
| 13 | 1960 | 1050(53.57) | 739(37.70) | 171(8.72) |
| 14 | 2056 | 1011(49.17) | 819(39.83) | 226(10.99) |
| 15 | 1941 | 873(44.98) | 833(42.91) | 23512.11) |
| 16 | 3735 | 1423(38.10) | 1655(44.31) | 657(17.59) |
| Total | 15,924 | 8799(55.26) | 5594(35.13) | 1531(9.61) |
Fig. 4.
The prevalence and chain growth rate of myopia in different ages
And based on the trend of SE, it was found that after the age of 6 years, students’ hyperopia gradually disappeared and gradually progressed to myopia, and the overall SE of the right eye was lower than that of the left eye (Table 4; Fig. 5).
Table 4.
SE of left and right eye at different ages
| Age | SE of right eye, M(P25,P75), D | SE of left eye, M(P25,P75), D | Z | P |
|---|---|---|---|---|
| 5 | 0.375(-0.125,0.625) | 0.375(0,000.625) | -2.979 | 0.003 |
| 6 | 0.125(-0.250,0.500) | 0.125(-0.250,0.500) | -4.707 | 0.001 |
| 7 | -0.125(-0.731,0.375) | -0.125(-0.625,0.375) | -3.506 | 0.001 |
| 8 | -0.250(-1.000,0.185) | -0.250(-0.875,0.250) | -4.723 | 0.001 |
| 9 | -0.500(-1.500,0.060) | -0.435(-1.375,0.125) | -4.688 | 0.001 |
| 10 | -0.750(-2.000,-0.125) | -0.625(-1.805,0.000) | -7.167 | 0.001 |
| 11 | -1.000(-2.500,-0.250) | -0.875(-2.250,-0.125) | -8.812 | 0.001 |
| 12 | -1.250(-2.750,-0.375) | -1.000(-2.556,-0.250) | -10.367 | 0.001 |
| 13 | -1.625(-3.250,-0.625) | -1.375(-3.000,-0.375) | -11.531 | 0.001 |
| 14 | -2.000(-3.625,-0.750) | -1.625(-3.375,-0.625) | -13.119 | 0.001 |
| 15 | -2.443(-4.000,-1.000) | -2.0275(-3.750,-0.750) | -13.604 | 0.001 |
| 16 | -2.750(-4.625,-1.125) | -2.375(-4.375,-0.875) | -18.551 | 0.001 |
| Total | -1.000(-2.690,-0.060) | -0.750(-2.380,0.000) | −32.747 | 0.001 |
Fig. 5.
The spherical equivalent (SE) of right/left eyes in different ages
Discussion
This study was a large-scale school-based cross-sectional study of children and adolescents in Shihezi to understand the prevalence of myopia, the development of myopia, and changes in SE among children and adolescents in Shihezi city. The overall prevalence of myopia in Shihezi was 50.93%, with a higher prevalence in urban than in rural areas, a higher prevalence in girls than in boys. The prevalence of myopia increases sharply at the age of 6 years, and the trend slows down at the age of 12 years.
Consistent with a large body of research, the present study found that the prevalence of myopia increases gradually with age. There is growing evidence that more schooling, rather than age, leads to myopia [10, 11]. The trend of myopia with age is due to increased study time and academic stress. The older the age, the longer the school years, and the more time spent in close proximity, the more high myopia becomes.
The prevalence of myopia among children and adolescents in Shihezi City is higher than the prevalence of myopia among preschoolers, primary and secondary school students in China in 2019 (50.2%) [12]. The prevalence of myopia in Shihezi is higher than in Kazakhstan(31.6%) [13], which has a similar climate and geographic location in the Xinjiang region, but the Kazakhstan study was conducted under conditions of cycloplegic refraction, and the quality of the evidence has some limitations. Compared with the findings of Wang et al., the period of sharp increase in myopia prevalence among children and adolescents in Shihezi appeared at an earlier age and slowed down at an earlier age [14], which is consistent with the findings of Hu et al. [15]. Age 6 is the period when the prevalence rate of myopia experiences the fastest growth. This may be due to the fact that 6 years of age marks the beginning of mandatory schooling, when children start attending elementary school and are exposed to more intensive educational demands.
It has been shown that monitoring hyperopic refractive error in children is beneficial in preventing myopia and high myopia, and that children with lower baseline hyperopic refractive error have a higher incidence of myopia [16]. In this study, we found that the SE in children and adolescents in Shihezi City became 0 at the age of 6 to 7 years, which is consistent with the sharp increase in the prevalence of myopia at the age of 6 years in our results. Therefore, it is important to implement interventions for the development of myopia in younger children, especially before the third grade of elementary school [17].
According to the results of this study, the current situation of myopia among children and adolescents in Shihezi City is not optimistic. In China, the high prevalence of myopia among children and adolescents in Xinjiang, a region that is relatively backward in terms of economic and cultural development, may be due to a relatively backward education model, insufficient knowledge of myopia prevention and control among the children’s parents, poor eye habits among the children, and insufficient attention to myopia prevention and control as an initiative in society.
The strength of this study lies in the large sample size; in addition, we characterized the onset and progression of myopia by calculating the prevalence of myopia and the growth rate of myopia, and we understand changes in SE in children and adolescents. However, there are limitations to this study. First, like most studies, as a screening study, cycloplegic refraction was not used in this study due to the large sample size; therefore, non-cycloplegic refraction may exaggerate the prevalence of myopia in children and inflate the SE. In our study we used UCVA in combination with non-cycloplegic refraction to minimize the screening error in myopia prevalence [5]. Finally, the study population was all from Xinjiang, which is in northwestern China and has a lower economic level compared with the interior, and the results have limited representation in China.
Conclusions
Our study demonstrated that the prevalence of myopia is higher in Shihezi, and myopia develops at an earlier age and the farsighted disappears earlier. The development of myopia begins to increase sharply at the age of 6 years and slows down by the age of 12 years, and the spherical equivalent refraction changes from positive to negative at the age of 6 to 7 years. For policy makers, it is even more important to prevent and control myopia at a younger age.
Acknowledgements
All authors have approved the manuscript for submission without any potential competing interests.
Abbreviations
- UCVA
Uncorrected visual acuity
- SE
Spherical equivalent
- D
Diopters
- IQR
Interquartile range
Author contributions
Xp Hu: Resources, Conceptualization, Methodology, Formal analysis, Writing - Original Draft; Xy Yuan: Investigation, Funding acquisition; H Li: Writing - Original Draft; Hx Gong: Investigation; Zc Fu: Investigation; Yt Xie: Investigation; lq Wang: Data Curation; Ds Rui: Supervision, Project administration, Conceptualization.
Funding
Research reported in this publication received financial support from the Chinese Centre for Disease Control and Prevention (CDC); however, there was no CDC involvement of influence with any aspect of the study/initiative/activity supported by grant.
Data availability
The dataset used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Declarations
Ethics approval and consent to participate
Informed consent was obtained from the parents of the respondents in all our studies. This study followed the tenets of Declaration of Helsinki and was approved by the Ethical Review Committee of The First Affiliated Hospital of Shihezi University. Participants gave informed consent to participate in the study before taking part(KJ2024−036−02).
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Xiaopeng Hu, Xianyan Yuan and Hua Li have contributed equally to this work and share frst authorship.
References
- 1.Yam JC, Tang SM, Kam KW, Chen LJ, Yu M, Law AK, Yip BH, Wang YM, Cheung CYL, Ng DSC, et al. High prevalence of myopia in children and their parents in Hong Kong Chinese population: the Hong Kong children eye study. Acta Ophthalmol. 2020;98(5):e639–48. [DOI] [PubMed] [Google Scholar]
- 2.Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, Wong TY, Naduvilath TJ, Resnikoff S. Global prevalence of myopia and high myopia and Temporal trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036–42. [DOI] [PubMed] [Google Scholar]
- 3.Zhang D, Wu M, Yi X, Shi J, Ouyang Y, Dong N, Gong G, Guo L, Zhou L. Correlation analysis of myopia and dietary factors among primary and secondary school students in Shenyang, China. Sci Rep. 2024;14(1):20619. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Haarman AEG, Enthoven CA, Tideman JWL, Tedja MS, Verhoeven VJM, Klaver CCW. The complications of myopia: A review and Meta-Analysis. Invest Ophthalmol Vis Sci. 2020;61(4):49. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Morgan IG, Ohno-Matsui K, Saw S-M. Myopia. Lancet 2012, 379(9827):1739–1748. [DOI] [PubMed]
- 6.Rozema JJ, Herscovici Z, Snir M, Axer-Siegel R. Analysing the ocular biometry of new-born infants. Ophthalmic Physiol Opt. 2018;38(2):119–28. [DOI] [PubMed] [Google Scholar]
- 7.Axer-Siegel R, Herscovici Z, Davidson S, Linder N, Sherf I, Snir M. Early structural status of the eyes of healthy term neonates conceived by in vitro fertilization or conceived naturally. Invest Ophthalmol Vis Sci. 2007;48(12):5454–8. [DOI] [PubMed] [Google Scholar]
- 8.Ye L, Yang Y-Q, Zhang G-Y, Wang W-J, Ren M-X, Ge P, Zhang J, Zhang N, Liu X-Z, Zhang M-L, et al. Increasing prevalence of myopia and the impact of education in primary-school students in Xi’an, north-western of China. Front Public Health. 2022;10:1070984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Appropriate technical guidelines for the prevention and control of myopia in children. and adolescents. [http://www.nhc.gov.cn/jkj/s5898bm/201910/c475e0bd2de444379402f157523f03fe.shtml [Accessed 15 Oct 2019]].
- 10.Morgan IG, French AN, Rose KA. Intense schooling linked to myopia. BMJ. 2018;361:k2248. [DOI] [PubMed] [Google Scholar]
- 11.Ding X, Morgan IG, Hu Y, Tang X, Zhang J, Guo L, Guo Y, Deng N, Du X, Zheng Y, et al. The causal effect of education on myopia: evidence that more exposure to schooling, rather than increased age, causes the onset of myopia. Invest Ophthalmol Vis Sci. 2023;64(4):25. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Li T, Wei R, Du B, Wu Q, Yan J, Meng X, Liu Y, Yang Q, Kee C-S, Huang G, et al. Prevalence of myopia among children and adolescents aged 6–16 during COVID-19 pandemic: a large-scale cross-sectional study in Tianjin, China. Br J Ophthalmol. 2024;108(6):879–83. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Mukazhanova A, Aldasheva N, Iskakbayeva J, Bakhytbek R, Ualiyeva A, Baigonova K, Ongarbaeva D, Vinnikov D. Prevalence of refractive errors and risk factors for myopia among schoolchildren of Almaty, Kazakhstan: A cross-sectional study. PLoS ONE. 2022;17(6):e0269474. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Wang J, Li Y, Zhao Z, Wei N, Qi X, Ding G, Li X, Li J, Song L, Zhang Y, et al. School-based epidemiology study of myopia in Tianjin, China. Int Ophthalmol. 2020;40(9):2213–22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Hu Y, Ding X, Guo X, Chen Y, Zhang J, He M. Association of age at myopia onset with risk of high myopia in adulthood in a 12-Year Follow-up of a Chinese cohort. JAMA Ophthalmol. 2020;138(11):1129–34. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Li S-M, Wei S, Atchison DA, Kang M-T, Liu L, Li H, Li S, Yang Z, Wang Y, Zhang F, et al. Annual incidences and progressions of myopia and high myopia in Chinese schoolchildren based on a 5-Year cohort study. Invest Ophthalmol Vis Sci. 2022;63(1):8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Wang J, Qi Z, Feng Y, Chen J, Du L, Yang J, Xie H, Zhu J, Zou H, He X, et al. Normative value of hyperopia reserve and myopic shift in Chinese children and adolescents aged 3–16 years. Br J Ophthalmol. 2024;108(7):1024–9. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
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Data Availability Statement
The dataset used and/or analyzed during the current study are available from the corresponding author on reasonable request.