Axial Length Control Using Repeated Low-Level Red Light Combined with Orthokeratology in Children with Rapid Myopia Progression: A Retrospective Cohort Study

Background Children with rapidly progressing myopia are at increased risk of high myopia and associated ocular complications. While orthokeratology (OK) is widely used to slow axial elongation, some children exhibit suboptimal responses. This study aimed to evaluate the efficacy and safety of combining repeated low-level red light (RLRL) therapy with OK to enhance myopia control in this high-risk population. Methods This retrospective cohort study included 72 children assigned to an RLRL + OK group or an OK-only group. Axial length (AL) was measured at baseline and at 3, 6, and 12 months. Mann–Whitney U tests with Hodges–Lehmann estimates were used for between-group comparisons. Longitudinal AL changes were assessed using linear mixed-effects models adjusting for age, sex, and baseline AL. Subgroup analyses were performed based on age and baseline AL. Results At 12 months, the RLRL + OK group showed significantly less axial elongation compared to the OK-only group (median: 0.00 mm vs. 0.24 mm; p < 0.001). Linear mixed-effects modeling revealed significant group × timepoint interactions favoring the RLRL + OK group (p < 0.001). Subgroup analyses demonstrated consistent treatment effects across age groups, with a more pronounced benefit in children with shorter baseline axial lengths. Conclusion RLRL combined with OK effectively slowed axial elongation compared to OK alone, particularly in children with faster progression. Both treatments were safe and well tolerated.