Prevalence, incidence, and risk factors for myopia among urban and rural children in southern China: protocol for a school-based cohort study

Study of myopia progression and risk factors in Hubei children aged 7-10 years using machine learning: a longitudinal cohort

BACKGROUND

To investigate the trend of refractive error among elementary school students in grades 1 to 3 in Hubei Province, analyze the relevant factors affecting myopia progression, and develop a model to predict myopia progression and the risk of developing high myopia in children.

METHODS

Longitudinal study. Using a cluster-stratified sampling method, elementary school students in grades 1 to 3 (15,512 in total) from 17 cities in Hubei Province were included as study subjects. Visual acuity, cycloplegic autorefraction, and height and weight measurements were performed for three consecutive years from 2019 to 2021. Basic information about the students, parental myopia and education level, and the students' behavioral habits of using the eyes were collected through questionnaires.

RESULTS

The baseline refractive errors of children in grades 1 ~ 3 in Hubei Province in 2019 were 0.20 (0.11, 0.27)D, -0.14 (-0.21, 0.06)D, and - 0.29 (-0.37, -0.22)D, respectively, and the annual myopia progression was - 0.65 (-0.74, -0.63)D, -0.61 (-0.73, -0.59)D and - 0.59 (-0.64, -0.51)D, with the prevalence of myopia increasing from 17.56%, 20.9%, and 34.08% in 2019 to 24.16%, 32.24%, and 40.37% in 2021 (Χ2 = 63.29, P < 0.001). With growth, children's refractive error moved toward myopia, and the quantity of myopic progression gradually diminished. (F = 291.04, P = 0.027). The myopia progression in boys was less than that in girls in the same grade (P < 0.001). The change in spherical equivalent refraction in myopic children was smaller than that in hyperopic and emmetropic children (F = 59.28, P < 0.001), in which the refractive change in mild myopia, moderate myopia, and high myopia children gradually increased (F = 73.12, P < 0.001). Large baseline refractive error, large body mass index, and high frequency of eating sweets were risk factors for myopia progression, while parental intervention and strong eye-care awareness were protective factors for delaying myopia progression. The nomogram graph predicted the probability of developing high myopia in children and found that baseline refraction had the greatest predictive value.

CONCLUSION

Myopia progression varies by age, sex, and myopia severity. Baseline refraction is the most important factor in predicting high myopia in childhood. we should focus on children with large baseline refraction or young age of onset of myopia in clinical myopia prevention and control.

Urban Living Environment and Myopia in Children

Importance

The global prevalence of myopia has shown a steady increase over recent decades, with urban areas seemingly experiencing a more significant impact.

Objective

To assess the association between urbanization and the prevalence, incidence, progression, and severity of myopia.

Design, Setting, and Participants

This cohort study included students in grades 1 to 6 in Tianjin, China, who underwent 3 vision examinations conducted over a 2-year period, from March 1, 2021, to March 31, 2023. Participants from grades 1 to 4 completed the 2-year follow-up.

Exposures

Urban living environment.

Main Outcomes and Measures

The association of urbanization with the incidence, progression, prevalence, and severity of myopia. To quantify urbanization, an urban score was constructed using satellite data and an iterative exploratory factor analysis.

Results

Of 177 894 students (51.7% male; mean [SD] age, 10.27 [1.75] years) included in the study, 137 087 students (52.3% male; mean [SD] age, 8.97 [1.21] years) were followed up for 2 years. A positive association was identified between myopia incidence and urbanization. Specifically, each 1-unit increment in the urban score was associated with an increased risk of myopia over a 1-year period (odds ratio [OR], 1.09; 95% CI, 1.01-1.15; P = .02) and a 2-year period (OR, 1.53; 95% CI, 1.50-1.57; P < .001). Conversely, each 1-unit increase in the urban score was associated with a significant decrease in myopia progression at 1 year (OR, 0.84; 95% CI, 0.82-0.86; P < .001) and 2 years (OR, 0.73; 95% CI, 0.70-0.75, P < .001). In a cross-sectional data analysis, the urban score was positively associated with myopia prevalence (OR, 1.62; 95% CI, 1.08-2.42; P = .02) and negatively associated with myopia severity, as indicated by spherical equivalent refraction (OR, 1.46; 95% CI, 1.07-1.99; P = .02).

Conclusions and Relevance

This study exploring urban living environments and myopia revealed dual associations of urban living with both the incidence and the progression of myopia. The observed patterns emphasize the urgency of promptly implementing myopia control strategies in less urbanized regions, where myopia progression may be accentuated.

Establishment and validation of a risk assessment model for myopia among Chinese primary school students during the COVID-19 pandemic: A lasso regression approach

Purpose

To construct a risk assessment model for forecasting the likelihood of myopia in elementary school students.

Design

A cross-sectional study.

Methods

This study utilized convenient sampling and questionnaire survey to collect data from eligible elementary students and their parents during the coronavirus disease 2019 (COVID-19) pandemic period from March to December 2020. The data were divided into training and testing sets in a 7:3 ratio. Lasso regression was employed to screen variables for inclusion in the model to establish a generalized linear model, with a nomogram model as the final result.

Results

The study included 1139 elementary students, comprising 54.5 % male and 45.5 % female participants. A total of 37 variables were obtained, which were analyzed using lasso regression. Cross-validation revealed that the best lambda value was 0.04201788. Five variables affecting myopia were identified: three risk and two protective factors. The three risk factors were student age (OR = 1.32), family location (urban vs. rural, OR = 2.33), and parents' occupation (compared with farmer: worker, OR = 2.03; teacher, OR = 1.62; medical worker, OR = 5.64; self-employed, OR = 1.78; civil servant, OR = 1.65; company employee, OR = 1.45; service industries, OR = 3.38; and others, OR = 3.20). The two protective factors were eye distance score (OR = 0.83) and eye health exercise score (OR = 0.95). The model was verified and showed good accuracy with an AUC of 0.778 and Brier score of 0.122 in addition to satisfactory clinical effects.

Conclusions

The model effectively predicted the risk of myopia in elementary school students during the COVID-19 pandemic. Using this model, high-risk groups can be identified to provide a foundation for early intervention and follow-up, thereby reducing the incidence of myopia in this population.

Effect of the COVID-19 Lockdown on Myopia Progression of School-aged Children: A Retrospective Chart Review

PURPOSE

To study the effect of the coronavirus disease 2019 (COVID-19)-related lockdown on myopia progression of school-aged children, comparing across the years and within different age groups.

METHODS

This was a retrospective chart review of school-aged children with myopia who presented to the pediatric ophthalmology clinic at the American University of Beirut between January 2020 and December 2021 (during COVID-19 lockdown). Annual myopia progression rate (back to January 2016) was computed by dividing the absolute value of the spherical equivalent (SE) difference of two consecutive visits by the duration (in years). Demographic data were retrieved. Patients were then divided into three age groups (3 to 10, 11 to 14, and 15 to 18 years) for analysis.

RESULTS

A total of 443 charts of myopic school-aged children were reviewed. Their average age was 11.81 ± 3.67 years with an average of 3.85 ± 1.67 visits across the years. The mean myopic SE increased over time: SE in 2021 was significantly higher than the mean SE in 2016, 2017, 2018, and 2019. Mean SE in 2020 was significantly higher than that in 2016 and 2017. There was no statistically significant difference in the mean annual progression (in diopters/year). For the 3 to 10 years group, the annual SE progression tended to be highest for 2020-2021 and 2019-2020 compared to previous years.

CONCLUSIONS

Children had more myopia in 2021 and 2020 (during lockdown) compared to previous years. The myopia annual progression tended to be highest in 2020-2021, especially for the younger age group, but the difference was not statistically significant. [J Pediatr Ophthalmol Strabismus. 2023;60(5):353-358.].