[Effects of eye exercises on axial eye elongation in junior students]

Objective: To evaluate the association between the eye exercises and one-year axial eye elongation in grade 7 students in Beijing. Methods: Sampling was performed using a multistage random cluster approach, and 1 443 students of grade 7 were selected from 9 middle schools in 6 districts for the baseline survey. Data were collected by questionnaires and axial length measurement. Multiple linear regression analysis was used to evaluate the association between eye exercises and excessive axial eye elongation. Results: Among 1 197 (82.95%) students with complete information, the median (Q) age was 12.00 (1.00) years old, girls accounted for 44.28%, and the median (Q) axial eye elongation was 0.22 (0.18) mm. In the multiple linear regression analysis, the frequency of eye exercises was significantly correlated with excessive axial eye elongation in boys (β=-0.135, 95%CI:-0.253--0.018) but not in girls (β=-0.075, 95%CI:-0.207- 0.058) after adjusting for sex, age, body height, the number of myopic parents, time spent outdoors and time spent on reading and writing outside class; while the seriousness of eye exercises was not significantly associated with axial eye elongation in boys (β=-0.028, 95%CI: -0.114-0.058) and girls (β=-0.035, 95%CI: -0.134-0.064). Conclusion: The increased frequency of eye exercises is beneficial to control the axial eye elongation in boys in Beijing.