Association between myopia and refractive parameters with eye behaviors in childhood aged 6 ~ 9 years: a follow-up study in Beijing.

BACKGROUND

The prevalence of myopia in children has become a major public health concern globally, with a notably rapid increase in China. This study aimed to investigate the association between myopia and refractive parameters, as well as eye health behaviors in childhood.

METHODS

We performed two cross-sectional assessments at the same school, the first involving 921 children aged 6 ~ 9 years initially, and the second 6 months later involving 1073 children. A total of 271 children participated in both surveys, providing longitudinal data on eye function measures and eye-related behaviours. Refractive parameters, including spherical equivalent (SE) and axial length (AL), were measured using standard optometric equipment. Multiple linear regression and logistic regression models were used to analyze eye parameters and myopia respectively. Furthermore, stratification was performed based on whether or not there was hyperopic reserve at baseline.

RESULTS

In our longitudinal analysis, a higher prevalence of myopia was observed in girls compared to boys at both baseline (37.80% vs. 33.69%, respectively) and at a 6 months follow-up (35.50% vs. 31.21%, respectively). A notable correlation was found between increased screen time and myopia development, with the OR at 1.49 (95% CI: 1.00 to 2.23; P = 0.049). Notably, prolonged use of electronic devices was associated with a decrease in SE (β=-0.20, 95% CI: -0.37 to -0.02; P = 0.029), while poor reading and writing postures were linked to an increase in AL (β = 2.14, 95% CI: 0.69 to 3.59; P = 0.004). In the context of hyperopic reserve, adequate sleep was found to be protective against increases in AL (β=-8.90, 95% CI: -16.92 to -0.89, P = 0.042). Conversely, the use of fonts that are too small or otherwise inappropriate was associated with increased SE (β = 0.68, 95% CI: 0.12 to 1.24, P = 0.029).

CONCLUSION

These findings underscore the importance of promoting healthy eye behaviors in early childhood and could inform the design of interventions aimed at preventing myopia in this vulnerable age group. Specifically, behavioral modifications can serve as an effective measure to preserve the eyesight of students who possess hyperopic reserve.