Repeated Low-Level Red Light Therapy for the Control of Myopia in Children: A Meta-Analysis of Randomized Controlled Trials

Background: Repeated low-level red light (RLRL) therapy has been suggested to be effective in children with myopia. However, evidence from randomized controlled trials (RCTs) is still limited. We performed a meta-analysis of RCTs to systematically evaluate the efficacy of RLRL on changes of axial length (AL) and cycloplegic spherical equivalent refraction (SER) in children with myopia. Methods: Relevant RCTs were obtained through a search of electronic databases including PubMed, Embase, Cochrane Library, Wanfang, and China National Knowledge Infrastructure from inception to September 15, 2022. A random-effects model was used to pool the results after incorporating the influence of potential heterogeneity. Subgroup analyses were performed according to the control treatment and follow-up duration. Results: A total of seven RCTs involving 1,031 children with myopia, aged 6 to 16 years, were included in the meta-analysis. Compared with control treatment without RLRL, treatment with RLRL was associated with a significantly reduced AL (mean difference [MD]: -0.25 mm, 95% confidence interval [CI]: -0.32 to -0.17, P,<0.001; I-2=13%) and a significantly increased cycloplegic SER (MD: 0.60 D, 95% CI: 0.44-0.76, P,<0.001; I-2=20%). Further subgroup analyses showed consistent results in studies comparing children wearing single vision lenses and those receiving active treatment including orthokeratology or low-dose atropine eye drops, as well as studies of treatment duration of 6 and 12 months. Conclusions: Results of the meta-analysis suggested that RLRL treatment is effective for slowing down the progression of myopia in children aged 6 to 16 years.