Three-year efficacy and safety of repeated low-level red-light therapy for myopia control: a multicentre real-world study

Background: To evaluate the efficacy and safety of repeated low-level red-light (RLRL) therapy for controlling myopia progression over 3 years in real-world settings. Methods: This multicentre cohort study included participants currently undergoing RLRL treatment, identified from electronic medical databases in three hospitals (myopic children and adolescents aged 7-18 years, who were prescribed RLRL therapy from 1 June 2018 to 1 June 2023), using stratified random sampling based on RLRL treatment duration (≥0.5-1 year, ≥1-2 years, ≥2-3 years and ≥3 years), with approximately 90 participants in each group. All participants voluntarily received RLRL therapy twice a daily (3 min/session, ≥4-hour interval), 5-7 days/week. Results: Among 362 participants, 90 were treated for ≥0.5-1 year (median 0.64 year), 91 for ≥1-2 years (median 1.40 years), 90 for ≥2-3 years (median 2.30 years) and 91 for ≥3 years (median 3.65 years). The satisfactory myopia control rate (defined as annual axial elongation ≤0.10 mm) was 72.53% (95% CI 62.17 to 81.37) over ≥3 years of RLRL treatment, with annual axial length change of 0.06 mm/year (95% CI 0.03 to 0.08). No subjective visual function damage was documented by best-corrected visual acuity, and no treatment duration-dependent changes in objective full-field electroretinogram were observed. A minimal, reversible optical coherence tomography change was noted in four eyes which did not impact visual function. Conclusions: This real-world study demonstrates that RLRL therapy provides promising long-term efficacy and safety in myopia control over 3 years among Chinese myopic children and adolescents.