AUTHOR=Wang Wujiao , Xiang Yongguo , Zhu Lu , Zheng Shijie , Ji Yan , Lv Bingjing , Xiong Liang , Li Zhouyu , Yi Shenglan , Huang Hongyun , Zhang Li , Liu Fangli , Zhang Tong , Wan Wenjuan , Hu Ke 

TITLE=Myopia progression and associated factors of refractive status in children and adolescents in Tibet and Chongqing during the COVID-19 pandemic

JOURNAL=Frontiers in Public Health

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.993728

DOI=10.3389/fpubh.2022.993728

ISSN=2296-2565

ABSTRACT=To investigate myopia progression and associated factors of refractive status among children and adolescents in Tibet and Chongqing in China during the COVID-19 pandemic. A population-based cross-sectional study was conducted to compare rates of myopia and high myopia, axial length (AL), spherical equivalent (SE), outdoor activity time, digital device use, and frequency of visual examinations for children and adolescents affected by myopia in Chongqing and Tibet in 2021. 
A total of 2303 students from Chongqing and 1687 students from Tibet were examined. The overall prevalence of myopia and high myopia in these two groups were 53.80% and 7.04% versus 43.86% and 1.30%, respectively. The mean SE of the students with myopic parents in Tibet was lower than that of the students in Chongqing with myopic parents (-2.57 ± 2.38 D vs.-2.30 ± 2.34 D, respectively) (P < 0.001). A total of 61.35% of the students in Tibet spent more than 2.5 h outdoors daily, compared with 43.04% of the students in Chongqing. Correspondingly, the proportion of students using digital devices in Tibet (64.43%) was lower than that in Chongqing (100%). For the latter, 38.62% of the students in Chongqing spent more than 2.5 h online using digital devices compared to 10.49% of the students in Tibet. Greater monitoring of visual status was observed for the Chongqing students (mean SE: -1.90 ± 1.98 D) compared with students in Tibet (mean SE: -2.68 ± 1.85 D) (P = 0.0448), with the frequency of optimal examinations being every six months. Outdoor activity time was identified as a common risk factor for myopia in both of the populations examined, with odds ratios (ORs) of 1.84 (95% CI:1.79–1.90) in Chongqing and 0.84 (95% CI: 0.73–0.96) in Tibet. Digital screen time was associated with myopia and high myopia in Chongqing, with ORs of 1.15 (95% CI:1.08–1.22) and 1.06 (95% CI: 0.94–1.77), respectively. Based on our data, we observe that the prevalence of refractive errors in children and adolescents was significantly lower in Tibet than in Chongqing. It is recommended that parents and children in Chongqing would benefit from increased awareness regarding myopia progression and its prevention.