Low-level red-light therapy may limit myopia incidence in pediatric patients with premyopia (spherical equivalent refraction [SER], −0.50-0.50 diopters [D]; parental myopia, ≤−3.00 D), according to a study published in JAMA Network Open.
Researchers enrolled 278 children with premyopia in the 12-month, parallel-group, school-based randomized clinical trial and randomly assigned them to treatment with repeated low-level red-light therapy (mean age, 8.3 years; 51.1% boys) or to an age- and sex-matched control group (mean age 8.3 years; 48.9% boys). Participants assigned to the intervention group underwent 3 minutes of treatment, twice per day, 5 times per week. The investigation’s primary outcome measure was 12-month myopia incidence and secondary outcomes included SER, axial length, vision function, and optical coherence tomography (OCT) scan changes.
Myopia incidence was 40.8% (49 of 120) in the intervention group and 61.3% (68 of 111) in the control group, a relative 33.4% reduction in incidence at the 12-month study conclusion. The COVID-19 pandemic interrupted treatment for a majority of those treated with repeated low-level red-light therapy, but for those who did not experience this treatment interruption, myopia incidence was 28.1% (9 of 32), a relative 54.1% reduction in incidence.
The intervention significantly reduced axial progression compared with no repeated low-level red-light treatment (mean [SD] axial growth, 0.30 [0.27] vs 0.47 [0.25] mm; difference, 0.17 mm; 95% CI, 0.11-0.23 mm; P <.001). SER progression was also significantly lower among children treated who received the intervention compared with the control group (mean [SD] SER, –0.35 [0.54] D vs –0.76 [0.60] D; difference, –0.41 D; 95% CI, –0.56 to –0.26 D; P <.001).
No significant changes in visual acuity or OCT scans were observed during the investigation.
The team highlights the importance of early repeated low-level red-light intervention for reducing myopia incidence.
“The [repeated low-level red-light] intervention was more effective among children with an SER of 0.01 to 0.50 D at baseline than those with an SER of −0.50 to 0.00 D at baseline,” the study authors explain. “Therefore, prophylactic intervention, including [repeated low-level red-light therapy] and increased outdoor time, may need to be implemented earlier, at least among those with an SER in the range of 0.01 to 0.50 D, or even earlier.”
Study limitations include an open-label design, treatment disruptions among a majority of the cohort due to the COVID-19 pandemic, and the use of only 1 wavelength in the treatment cohort.
He X, Wang J, Zhu Z, et al. Effect of repeated low-level red light on myopia prevention among children in China with premyopia: a randomized clinical trial. JAMA Netw Open. Published online April 26, 2023. doi:10.1001/jamanetworkopen.2023.9612