Trajectory of Refractive Change and Its Influencing Factors in Preschool Children: A Longitudinal Study

Background Early-onset myopia increases the risk of high myopia in adolescence. This study aimed to identify heterogeneous trajectories of refractive change in preschool children using the Latent Growth Mixture Model (LGMM) and to explore their associated influencing factors, thereby providing a scientific basis for precise myopia prevention and control. Methods Cluster sampling was used to recruit 956 preschool children from 27 kindergartens in Haidian District, Beijing, between October 2021 and October 2023. A basic information questionnaire was administered to collect general demographic data. Ocular refractive biometry was performed annually to track the changes in refractive status over the 2-year follow-up period. LGMM was used to identify heterogeneous refractive trajectories. Multinomial logistic regression analysis was subsequently used to explore the factors associated with trajectory membership. Results Three distinct refractive change trajectories were identified: the slow change group ( n  = 111, 11.6%), the stable change group ( n  = 714, 74.7%), and the rapid change group ( n  = 131, 13.7%). Multinomial logistic regression revealed that children’s age, sex, parental moderate-to-high myopia, and daily outdoor activity duration were independent predictors of latent classes for refractive development trajectories in preschool children. Conclusions Preschool children exhibit three distinct trajectories of refractive change, demonstrating significant population heterogeneity. Myopia prevention strategies may benefit from risk stratification based on early refractive trajectories.