Myopia and axial length in school-aged children before, during, and after the COVID-19 lockdown-A population-based study

Compensatory Interactions between Corneal and Internal Astigmatism despite Lifestyle Changes

This study explores whether children's refractive errors and visual behaviors reverted to pre-COVID-19 levels a year after normal schooling resumed in Hong Kong as well as the impact of corneal and internal astigmatism on refractive astigmatism development. Vision survey data and questionnaire results collected in 2022 (n = 119) and 2020 (n = 173) were compared. Cross-sectional data showed similar proportions of astigmatism (cylindrical power ≥ 0.75 D) in the 2020 (49.1%) and 2022 cohorts (55.5%). Despite a 0.28 D increase in corneal astigmatism, a compensatory 0.24 D increase in internal astigmatism of opposite direction kept refractive astigmatism relatively stable. The questionnaire data showed that children spent an additional 0.5 h/day outdoors on weekends post-resumption of normal schooling but engaged in more near-work activities, especially non-screen near-work, by approximately 1 h/day on both weekdays and weekends. These findings were supported by longitudinal data from 72 children who participated in both surveys. This study highlights the significant role of corneal and internal astigmatism in refractive astigmatism changes. Despite the return to in-person classes, children's total near-work time increased and astigmatism remained high. These findings underscore the need for comprehensive strategies to reduce the high environmental risks for refractive error development in children.

Comparison of myopia progression among Chinese schoolchildren before and during COVID-19 pandemic: a meta-analysis

AIM

To compare myopia progression in Chinese schoolchildren before and after the COVID-19 pandemic home confinement.

METHODS

This study was done through the data searched from PubMed, Embase, Cochrane Library, and Web of Science from January 2022 to March 2023 related to the COVID-19 pandemic home confinement and myopia progression among Chinese schoolchildren. Myopia progression was evaluated by the mean change of spherical equivalent refraction (SER) and axial length (AL) before and during the COVID-19 pandemic. Sex and regional differences in myopia progression among schoolchildren before and during the COVID-19 pandemic were also analyzed.

RESULTS

A total of eight eligible studies were included in this study. There was a significant difference in SER before and during home confinement during the COVID-19 pandemic (OR = 0.34; 95%CI = [0.23, 0.44]; Z = 6.39; P < 0.00001), but no significant difference in AL (OR = 0.16; 95%CI = [- 0.09, 0.41]; Z = 1.22, P = 0.22). There was a significant difference in SER between male and female groups during the COVID-19 home confinement (OR = 0.10; 95%CI = [0.00, 0.19]; Z = 1.98, P = 0.05). As for regional analysis, there was a significant difference in SER between urban and rural areas during the COVID-19 quarantine period (OR = -0.56; 95%CI = [- 0.88, - 0.25]; Z = 3.50, P = 0.0005).

CONCLUSIONS

Compared with the time before the COVID-19 home confinement, a higher rate of myopic progression among Chinese schoolchildren during the period of the COVID-19 pandemic was demonstrated.

Progression and incidence of myopia among schoolchildren in the post-COVID-19 pandemic period: a prospective cohort study in Shantou, China

OBJECTIVES

To determine the progression and incidence of myopia in Chinese schoolchildren in the post-COVID-19 pandemic period in Shantou, China.

DESIGN

Prospective cohort study.

SETTING

Shantou Myopia Study, China.

PARTICIPANTS

1-year follow-up data were available for 621 881 schoolchildren (301 999 females). Data on spherical equivalent refraction (SER) were collected.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes were myopia progression and incidence. Myopia progression is defined as a change of SER towards the negative direction in the follow-up visit. Incidence is defined as the proportion of schoolchildren who were not myopic but developed myopia in the follow-up study. Age, sex and SER at baseline were evaluated as associated factors for myopia burden, which were defined as the secondary outcomes.

RESULTS

Mean progression of SER was -0.35±0.97 D for the population (ranging from -0.06 D at 18 years of age to -0.46 D at 11 years of age), with a rapid myopic progression for students at the age of 10-12 years (-0.50 D in girls and -0.44 D in boys). A myopic shift greater than -0.50 D/year occurred in 256 299 eyes (41.21%). Myopic progression in refraction was associated with the 10-12 years age groups (OR 1.42; 95% CI 1.39 to 1.45, p<0.001), female sex (OR 1.09; 95% CI 1.08 to 1.10, p<0.001) and higher refractive errors at baseline (OR>1.00, p<0.001). The annual incidence of myopia among schoolchildren was 24.85%, with an incidence of 26.69% in girls and 23.02% in boys.

CONCLUSIONS

Our study revealed an annual myopia progression of -0.35 D and an incidence of 24.85% among schoolchildren in the post-COVID-19 pandemic period. Myopia progressed rapidly at 10-12 years of age, with -0.50 D in girls and -0.44 D in boys. The incidence was higher for children aged 10-11 years and for girls.