Repeated low-level red-light therapy combined with orthokeratology for myopia control in Spain: a randomised controlled study

AIM: To evaluate the 12-month efficacy and safety of repeated low-level red-light (RLRL) therapy combined with orthokeratology (ortho-k) (RCO) for controlling myopia in Spanish children. METHODS: In this single-site, randomised, parallel-group, non-blinded clinical trial (NCT06899139), eligible myopic children aged 10-13 years were recruited and assigned randomly either to the RCO group or the ortho-k group. Follow-up assessments were conducted at 6, 9 and 12 months after baseline. The primary outcome and secondary outcome were the axial length (AL) and macular thickness (MT) changes at 12 months estimated by longitudinal mixed model. RESULTS: All participants (n=26; 11 in the RCO group and 15 in the ortho-k group) were included in the analysis. After 12 months, the adjusted mean AL change was -0.124 mm (95% CI -0.164 to -0.084) in the RCO group, whereas the ortho-k group continued to exhibit a modest axial elongation of 0.102 mm (95% CI 0.068 to 0.136). The adjusted mean difference in AL change was -0.226 mm (95% CI -0.279 to -0.174) between the groups (p<0.001). Additionally, the adjusted mean change in MT showed no significant difference between groups at 12 months. In the RCO group, 80% of children achieved AL shortening >-0.05 mm, whereas no children in the ortho-k group showed AL shortening. No severe adverse events were reported during the study. CONCLUSIONS: Combining RLRL therapy with ortho-k is an effective and safe myopia control strategy in Caucasian Spanish children, supporting the potential generalisability of the synergistic effect across diverse ethnic groups.