Duration‐Dependent Efficacy and Clinical Safety of Repeated Low‐Level Red‐Light Therapy for Paediatric Myopia: A Systematic Review and Meta‐Analysis

BACKGROUND: Repeated low-level red-light (RLRL) therapy is a novel, non-invasive intervention for controlling paediatric myopia progression. Despite increasing clinical use, questions remain regarding the magnitude, durability, and safety of treatment effects. This study evaluated its efficacy and safety based on randomised controlled trial (RCT) evidence. METHODS: PubMed, Embase, and the Cochrane Library were searched through August 2025 for RCTs comparing RLRL with control in children (< 18 years). The primary outcome was spherical equivalent refraction (SER); secondary outcomes included axial length (AL), choroidal thickness (ChT), anterior chamber depth (ACD), central corneal thickness (CCT), lens thickness (LT), and uncorrected visual acuity (UCVA). Evidence certainty was assessed using the GRADE framework. RESULTS: Twenty-eight RCTs (3573 participants) were included. RLRL therapy achieved duration-dependent myopia control (p < 0.05), with pooled improvements versus control at 12 months of +0.68 D in SER, -0.30 mm in AL, and +26.7 μm in ChT. Subgroup analysis showed greater efficacy in children with higher baseline myopia (p < 0.0001), with comparable effects between 5- and 7-day regimens. UCVA was higher with RLRL therapy. ACD, CCT, and LT were unchanged. Reported adverse events were mild and transient, with no consistent structural or functional abnormalities described. CONCLUSIONS: RLRL was associated with duration-dependent reductions in myopia progression up to 1 year. Reported structural parameters remained stable and adverse events were generally mild. Moderate-certainty evidence supports improvement in SER and ChT, whereas evidence for AL remains of lower certainty. Longer-term trials incorporating comprehensive retinal safety assessment are required. TRIAL REGISTRATION: PROSPERO CRD420251112677.