Associations between anthropometric indicators and refraction in school-age children during the post-COVID-19 era.

Purpose: To explore the associations between anthropometric indicators and refraction in school-aged children in the post-COVID-19 era. Methods: Data were collected from 25,644 children aged 7 to 12 years in 48 elementary schools in Tianjin. The comprehensive examination included height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), refraction, and calculation of BMI, with a follow-up visit after 6 months. Myopia was defined as spherical equivalent refraction (SER) ≤-0.50 diopter (D). Bivariate correlation coefficients and multiple linear regression models were used to explore the cross-sectional and longitudinal associations between anthropometric indicators (height, weight, BMI, SBP, and DBP) and refraction. Results: The mean changes in height, weight, BMI, SBP, DBP, and SER of the participants were 4.03 ± 2.18 cm, 3.10 ± 2.39 kg, 0.45 ± 1.16 kg/m2, 2.26 ± 14.74 mmHg, 2.18 ± 11.79 mmHg and -0.17 ± 0.51 D, respectively. Overall, height, weight, BMI, SBP, and DBP were all correlated with SER (r = -0.324, r = -0.234, r = -0.121, r = -0.112, r = -0.066, both p < 0.001), and changes in height and weight were correlated with changes in SER (r = -0.034, -0.031, both p < 0.001). Furthermore, multiple linear regression analysis revealed that the association of BMI, SBP, and DBP with SER was significant in myopic children but not in non-myopic children. The association between changes in weight and changes in SER was only present in non-myopic children but not in myopic children. Conclusion: Height and weight were negatively correlated with SER in both cross-sectional analysis and longitudinal changes, indicating that children's height, weight and growth rate may be used as a reference indicator for myopia risk prediction and myopia progression monitoring.

Evaluation and Follow-up of Myopia Prevalence Among School-Aged Children Subsequent to the COVID-19 Home Confinement in Feicheng, China.

Importance: Progression of myopia in a school-aged population due to home confinement (January to May 2021) during the COVID-19 pandemic has been previously reported. A key remaining question was whether the myopia spike in children aged 6 to 8 years persisted. Objective: To investigate the changes in refractive status and prevalence of myopia in school-aged children 1 year after home confinement ended in China. Design, Setting, and Participants: This cross-sectional study with a cohort substudy prospectively evaluated data from school-based photoscreening in Feicheng, China. Children aged 6 to 13 years participated in 8 screenings from 2015 to 2021. Exposures: Noncycloplegic photorefraction was conducted using the Spot Vision photoscreener. Main Outcomes and Measures: The main outcomes were the differences in spherical equivalent refraction (SER) and prevalence of myopia between 2020 (during home confinement) and 2021 (after home confinement). The SER was recorded for each child, and the prevalence of myopia was calculated annually for each age group. Results: A total of 325 443 children participated in the study (51.4% boys, 48.6% girls; age range, 6 to 13 years). Compared with 2020, the mean SER of children in 2021 increased significantly for those aged 6 (0.42 diopters [D]), 7 (0.41 D), and 8 (0.33 D) years. The prevalence of myopia in 2021 was similar to in 2019 for each age group (aged 6 years: 7.9% vs 5.7%; aged 7 years: 13.9% vs 13.6%; aged 8 years: 29.5% vs 26.2%). Both the prevalence of myopia and mean SER for these children returned to their prepandemic levels. Conclusions and Relevance: Compared with 2020, the prevalence of myopia among children aged 6 to 8 years in the 2021 screenings decreased, and the mean SER returned to prepandemic level. The refractive development in children aged 6 to 8 years may be most susceptible to environmental changes. These findings support the premise that age 6 to 8 years is a critical period for myopia development and suggest a need to focus preventive interventions for myopia control on children in this age range.

Associations between anthropometric indicators and refraction in school-age children during the post-COVID-19 era

Purpose To explore the associations between anthropometric indicators and refraction in school-aged children in the post-COVID-19 era. Methods Data were collected from 25,644 children aged 7 to 12 years in 48 elementary schools in Tianjin. The comprehensive examination included height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), refraction, and calculation of BMI, with a follow-up visit after 6 months. Myopia was defined as spherical equivalent refraction (SER) ≤-0.50 diopter (D). Bivariate correlation coefficients and multiple linear regression models were used to explore the cross-sectional and longitudinal associations between anthropometric indicators (height, weight, BMI, SBP, and DBP) and refraction. Results The mean changes in height, weight, BMI, SBP, DBP, and SER of the participants were 4.03 ± 2.18 cm, 3.10 ± 2.39 kg, 0.45 ± 1.16 kg/m2, 2.26 ± 14.74 mmHg, 2.18 ± 11.79 mmHg and −0.17 ± 0.51 D, respectively. Overall, height, weight, BMI, SBP, and DBP were all correlated with SER (r = −0.324, r = −0.234, r = −0.121, r = −0.112, r = −0.066, both p < 0.001), and changes in height and weight were correlated with changes in SER (r = −0.034, −0.031, both p < 0.001). Furthermore, multiple linear regression analysis revealed that the association of BMI, SBP, and DBP with SER was significant in myopic children but not in non-myopic children. The association between changes in weight and changes in SER was only present in non-myopic children but not in myopic children. Conclusion Height and weight were negatively correlated with SER in both cross-sectional analysis and longitudinal changes, indicating that children's height, weight and growth rate may be used as a reference indicator for myopia risk prediction and myopia progression monitoring.

Progression of Myopia in School-Aged Children After COVID-19 Home Confinement.

Importance: Time spent in outdoor activities has decreased owing to home confinement for the coronavirus disease 2019 (COVID-19) pandemic. Concerns have been raised about whether home confinement may have worsened the burden of myopia owing to substantially decreased time spent outdoors and increased screen time at home. Objective: To investigate the refractive changes and prevalence of myopia in school-aged children during the COVID-19 home confinement. Design, Setting, and Participants: A prospective cross-sectional study using school-based photoscreenings in 123 535 children aged 6 to 13 years from 10 elementary schools in Feicheng, China, was conducted. The study was performed during 6 consecutive years (2015-2020). Data were analyzed in July 2020. Exposures: Noncycloplegic photorefraction was examined using a photoscreener device. Main Outcomes and Measures: The spherical equivalent refraction was recorded for each child and the prevalence of myopia for each age group during each year was calculated. The mean spherical equivalent refraction and prevalence of myopia were compared between 2020 (after home confinement) and the previous 5 years for each age group. Results: Of the 123 535 children included in the study, 64 335 (52.1%) were boys. A total of 194 904 test results (389 808 eyes) were included in the analysis. A substantial myopic shift (approximately -0.3 diopters [D]) was found in the 2020 school-based photoscreenings compared with previous years (2015-2019) for younger children aged 6 (-0.32 D), 7 (-0.28 D), and 8 (-0.29 D) years. The prevalence of myopia in the 2020 photoscreenings was higher than the highest prevalence of myopia within 2015-2019 for children aged 6 (21.5% vs 5.7%), 7 (26.2% vs 16.2%), and 8 (37.2% vs 27.7%) years. The differences in spherical equivalent refraction and the prevalence of myopia between 2020 and previous years were minimal in children aged 9 to 13 years. Conclusions and Relevance: Home confinement during the COVID-19 pandemic appeared to be associated with a significant myopic shift for children aged 6 to 8 years according to 2020 school-based photoscreenings. However, numerous limitations warrant caution in the interpretation of these associations, including use of noncycloplegic refractions and lack of orthokeratology history or ocular biometry data. Younger children's refractive status may be more sensitive to environmental changes than older ages, given the younger children are in a critical period for the development of myopia.