Puberty could regulate the effects of outdoor time on refractive development in Chinese children and adolescents

To explore the impact of puberty on refractive development and its interaction with outdoor time in children and adolescents.

In this 2-year observational study, students aged 7-13 years were selected with cluster sampling. All participants underwent cycloplegic refraction and axial length measurements once every year. Information of related factors was acquired through proper questionnaire or inquiry. The level of testosterone/estradiol was detected from the saliva of the subjects using the ELISA kit. Multiple linear regression and generalised estimating equation (GEE) were used to analyse the relationship among puberty, outdoor activities and refractive indicators.

A total of 776 children and adolescents were included, with an average baseline age of 9.64±1.54 years and 53.6% boys. There were 350 myopes (55.2% of the 634 cyclopleged subjects) at baseline. There was a significant difference in the mean axial length changes and outdoor time among different puberty groups (for axial length: p=0.017, for outdoor time: p=0.015). Myopic parents, less outdoor time and more changes in estradiol were associated with greater changes in axial length and spherical equivalent (SE) (axial length changes: parental myopia β=0.230, outdoor time β=-0.250, changes in estradiol β=0.261; SE changes: parental myopia β=-0.267, outdoor time β=0.256, changes in estradiol β=-0.297). In the GEE model, the interaction between outdoor time and puberty was significantly associated with axial length (p=0.024, β=1.199).

This study implies puberty may play a regulating role on the relationship between outdoor time and refractive development among Chinese children and adolescents, which provides clues for in-depth mechanism interpretation and efficient intervention strategies.