Aier Institute of Optometry and Vision Science, Aier Eye Hospital Group, Changsha, China.
Chengdu Aier Eye Hospital, Chengdu, China.
Front Public Health. 2022 Dec 15;10:992784. doi: 10.3389/fpubh.2022.992784. eCollection 2022.
Myopic shift had been observed during the COVID-19 lockdown in young school children. It remains unknown whether myopic shift is accompanied with increase in axial length. We aimed to evaluate the impact of the COVID-19 lockdown on myopia and axial length of school children in China by comparing them before, during and after the lockdown.
In this population-based cross-sectional study, school-based myopia screenings were conducted in the Fall of 2019, 2020, and 2021 (representing before, during and after COVID-19 lockdown respectively) in Chengdu, China. Myopia screenings were performed on 83,132 students aged 6 to 12 years. Non-cycloplegic refractive error was examined using NIDEK auto-refractor (ARK-510A; NIDEK Corp., Tokyo, Japan) and axial length was measured using AL-Scan (NIDEK Corp., Tokyo, Japan). Spherical equivalent (SER, calculated as sphere+ 0.5cylinder), prevalence of myopia (SER ≤ -0.50 D), and axial length were compared across 3 years stratified by age.
Myopia prevalence rate was 45.0% (95% CI: 44.6-45.5%) in 2019, 48.7% (95% CI: 48.3-49.1%) in 2020, and 47.5% (95% CI: 47.1-47.9%) in 2021 ( < 0.001). The mean non-cycloplegic SER (SD) was -0.70 (1.39) D, -0.78 (1.44) D, and -0.78 (1.47) D respectively ( < 0.001). The mean (SD) axial length was 23.41 (1.01) mm, 23.45 (1.03) mm, and 23.46 (1.03) mm across 3 years respectively ( < 0.001). From the multivariable models, the risk ratio (RR) of myopia was 1.07 (95% CI: 1.06-1.08) times, the SER was 0.05 D (95% CI: 0.04 D to 0.06 D) more myopic and the mean axial length increased by 0.01 mm (95% CI: 0.01 mm to 0.02 mm) in 2020 compared to 2019. In 2021, the risk ratio (RR) of myopia was 1.05 (95% CI: 1.04-1.06), the mean SER was 0.06 D (95% CI: 0.05 D to 0.07 D) more myopic, and the mean axial length increased by 0.03 mm (95% CI: 0.02 mm to 0.04 mm) compared to 2019.
The COVID-19 lockdown had significant impact on myopia development and axial length, and these impacts remained 1 year after the lockdown. Further longitudinal studies following-up with these students are needed to help understand the long-term effects of COVID-19 lockdown on myopia.
在新冠疫情封锁期间，青少年学生的近视程度发生了变化。目前尚不清楚近视的变化是否伴随着眼轴长度的增加。我们旨在通过比较封锁前后的近视和眼轴长度，评估新冠疫情封锁对中国学童近视和眼轴长度的影响。
在这项基于人群的横断面研究中，我们在 2019 年秋季、2020 年和 2021 年（分别代表新冠疫情封锁前、封锁中和封锁后）在成都进行了学校近视筛查。共有 83132 名 6 至 12 岁的学生接受了近视筛查。使用 NIDEK 自动折射仪（ARK-510A；NIDEK 公司，东京，日本）检查非睫状肌屈光不正，使用 AL-Scan（NIDEK 公司，东京，日本）测量眼轴长度。球面等效值（SER，计算为球镜+ 0.5 柱镜）、近视患病率（SER≤-0.50 D）和眼轴长度按年龄分层在 3 年期间进行比较。
2019 年近视患病率为 45.0%（95%CI：44.6-45.5%），2020 年为 48.7%（95%CI：48.3-49.1%），2021 年为 47.5%（95%CI：47.1-47.9%）（<0.001）。非睫状肌 SER 的平均（标准差）分别为-0.70（1.39）D、-0.78（1.44）D 和-0.78（1.47）D（<0.001）。3 年间的平均（标准差）眼轴长度分别为 23.41（1.01）mm、23.45（1.03）mm 和 23.46（1.03）mm（<0.001）。从多变量模型来看，2020 年近视的风险比（RR）为 1.07（95%CI：1.06-1.08）倍，SER 增加 0.05 D（95%CI：0.04 D 至 0.06 D），平均眼轴长度增加 0.01 mm（95%CI：0.01 mm 至 0.02 mm）。2021 年，近视的风险比（RR）为 1.05（95%CI：1.04-1.06），平均 SER 增加 0.06 D（95%CI：0.05 D 至 0.07 D），平均眼轴长度增加 0.03 mm（95%CI：0.02 mm 至 0.04 mm）。
新冠疫情封锁对近视发展和眼轴长度有显著影响，封锁结束 1 年后仍存在这些影响。需要对这些学生进行进一步的纵向研究，以帮助了解新冠疫情封锁对近视的长期影响。
