Efficacy and safety of repeated low-level red light therapy in myopia control: an updated and comprehensive systematic review and meta-analysis

Abstract

This study aims to assess the therapeutic effectiveness and safety of repeated low-level red light for myopia management in children and adolescents. Multiple databases were systematically searched for studies evaluating the efficacy of RLRL in myopia control among children and adolescents. Data were extracted and analyzed using RevMan 5.4. The primary outcomes included axial length (AL), spherical equivalent refraction (SER), and subfoveal choroidal thickness (SFCT), while secondary outcomes included corneal curvature (K1, K2) and anterior chamber depth (ACD). A total of 19 studies were included. This study employed meta-analysis and subgroup analyses to evaluate the efficacy and to explore heterogeneity based on intervention duration and myopia severity. The results showed that, compared with single-vision spectacles, RLRL reduced axial length (AL) elongation (MD=-0.36, 95%CI -0.44 to -0.29), slowed myopic progression in spherical equivalent refraction (SER) (MD = 0.65, 95% CI 0.38 to 0.92), and increased subfoveal choroidal thickness (SFCT) (MD = 20.63, 95% CI 6.74 to 34.53). The therapeutic effect appeared to accumulate over time. This meta analysis suggests that, in the short term (within 12 months of follow up), RLRL may be associated with slower axial length elongation, less myopic refractive progression, and increased choroidal thickness in children with myopia. However, these findings should be interpreted with caution due to substantial heterogeneity among studies and limited evidence beyond 12 months of follow up. Further long term studies with standardized protocols are warranted to confirm the efficacy and safety of RLRL.