Low-intensity, Long-wavelength Red Light Slows the Progression of Myopia in Children: an Eastern China-based Cohort

Abstract

Myopia is prevalent worldwide, particularly in East and Southeast Asia. Recent studies have suggested that the spectral composition of ambient lighting influences refractive development, especially in humans. We aimed to determine the effect of 650-nm single-wavelength red light on the inhibition of myopia progression in children. In this retrospective cohort study, 105 myopic children (spherical equivalent refractive error [SER], -6.75 to -1.00 dioptres (D)) aged from 4 to 14 years old were retrospectively reviewed. Subjects were treated with 650-nm, low-intensity, single-wavelength red light twice a day for 3 minutes each session, with at least a 4-hour interval between sessions. IOL Master was utilized to measure the axial length (AL) and corneal curvature. Choroidal images were assessed using enhanced depth imaging optical coherence tomography (EDI-OCT), and the luminal area (LA) and stromal area were converted to binary images by the Niblack method. At baseline, the mean SER was -3.09 ± 1.74 D and -2.87 ± 1.89 D at 9 months, and significant changes occurred over time (P = 0.019). The AL increased by -0.06 ± 0.19 mm for 9 months (0.21 ± 0.15 mm pretreatment; P＜0.001). The subfoveal choroidal thickness (SFChT) had changed by 45.32 ± 30.88 μm at the 9-month examination (P＜0.001). Repetitive exposure to 650-nm, low-intensity, single-wavelength red light effectively slowed the progression of myopia and reduced axial growth after short treatment durations. These results require further validation in a longitudinal study, as well as further research in animal models.

Photobiomodulation therapy retarded axial length growth in children with myopia: evidence from a 12-month randomized controlled trial evidence

“…As shown in Table 5, those results were consistent with our previous report and the studies of Xiong et al 3,4,20 . It was shown that myopia among children could be controlled or reversed to some extent by PBM therapy, resulting in a mean decrease in the AL.…”

“…A previous study found that the rate of AL change was approximately 0.25 mm/year (0.13 mm/year vs. 0.38 mm/year) slower in participants treated with repeated low-level red light than in controls 5 . The mean AL progression was 0.13 mm and 0.38 mm with a standard deviation (SD) of 0.15 mm after 1 year in the control group based on previous findings 3,4 . This was based on a two-sided statistical test with a 1% type I error threshold, 90% power and a 20% drop-out rate.…”

“…Previously, we published a retrospective cohort study 4 of 105 myopic children, and we found that their AL was decreased by − 0.06 ± 0.19 mm for 9 months after PBM therapy. To overcome the limitations of previous studies that lacked control groups, the high possibility of long-term observation of the tendency of AL growth in children with myopia, and AL circadian rhythm fluctuations 10 , we conducted the current prospective study to examine whether the AL of individuals with myopia might be decreased extent after 12 months of repeated PBM treatment twice a day.…”

Efficacy in Myopia Control: Does Race Matter?

“…Also, there have been multiple single-center clinical trials of other multifocal soft contact lenses in China, the United States, and Europe, but the variation in lens designs makes comparisons untenable. Likewise, emerging spectacle technologies 53,54 and low-level red-light therapy 55,56 have only been evaluated in Chinese children.…”

Daily Low-Level Red Light for Spherical Equivalent Error and Axial Length in Children With Myopia

“…A n increasing amount of attention has been devoted to interventions for myopia control in children, among which low-level red light (LLRL) [1][2][3][4][5][6] has recently attracted widespread interest. LLRL works by concentrating a specific band of light, typically 650 nm, into a laser beam to irradiate the retina.…”