Meta-analysis of repeated low-level red light therapy for retarding myopia progression in children

Objective

To systematically evaluate the effect of repeated low-level red light (RLRL) therapy on controlling the progression of myopia in children.

Methods

Medline, Embase, Cochrane Library, Web of Science, ClinicalTrial.gov and the CNKI, VIP, Wanfang database, and Chinese Clinical Trial Registry (www.chictr.org.cn) were searched from their establishment to September 2022 to obtain the randomized controlled trial (RCT) about RLRL controlling myopia progression in children.Grey literature was also searched.Inclusion and exclusion criteria were developed according to the PICOS principle.Two researchers screened the literature independently, extracted data, and assessed the risk of bias in the included studies using the Cochrane collaboration tool for assessing risk of bias.The data were imported into RevMan 5.4 software for meta-analysis.Mean and standard deviation of data were used to obtain mean differences and 95% confidence intervals of included studies.Changes in spherical equivalent (SE) and axial length (AL) were compared between before and after the intervention in RLRL and single-vision spectacle (experimental group) and single-vision spectacle (control group). The GRADE system was used to grade the quality of evidence for the outcome indicators.

Results

A total of 157 studies were obtained.After the screening, 7 RCT studies including 1 038 study subjects met the inclusion criteria.Meta-analysis results showed that retarded SE progression was retarded and AL elongation was reduced significantly after different follow-up durations (1, 3, 6, 12 and 24 months) in experimental group compared with control group.As the follow-up duration extended from 1 month to 24 months, the retard of SE progression increased from 0.14 to 0.93 D, and the reduction of AL increased from 0.07 to 0.48 mm.Both 635 and 650 nm red light significantly retarded SE progression and reduced AL elongation.The two outcome indicators, SE change and AL change were moderate-strength evidence by GRADE.

Conclusions

The current moderate-strength evidence shows that RLRL can better retard myopia progression in children than single-vision spectacle glasses.

Myopia; Children; Prevention and control; Repeated low-level red light; Refraction, ocular; Axial length; Meta-analysis