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

Purpose: To test the hypothesis that photobiomodulation (PBM) therapy could retard ocular axial length (AL) in children with myopia. Methods: A randomized controlled clinical trial was conducted on two groups of 50 consecutive eligible children aged 8 to 12 years with ≤ - 0.75 Diopter (D) of spherical equivalent refraction（SER）. Participants were randomly assigned half to the intervention group (n = 25) treated with PBM therapy and half to the control group (n = 25) with single vision spectacles (SVS) only. At the 12-month follow-up, the changes of AL and cycloplegic SER from the baseline were both compared between the two groups. In addition, the subfoveal choroidal thickness (SFChT), anterior chamber depth (ACD), and central corneal refractive power (CCP) were analyzed at 3-, 6-, 9-, and 12-month follow-ups, respectively. Results: Among 50 children, 78% were included at final follow-up with the mean age of 9.7 ±1.5 years and mean SER of -2.56 ±1.70D. The mean difference between two groups at 12-month from baseline in AL elongation was 0.50mm (PBM vs Control, -0.016mm ± 0.11 versus 0.48mm ± 0.16, P < .001); And the mean difference between two groups at 12-month from baseline in cycloplegic SER was +1.25D (PBM vs Control, +0.28D ± 0.26 versus -0.97D ± 0.25, P < .001). None of other parameters（including SFChT, ACD, and CCP）at any timeline demonstrated statistically significant difference between two groups. Conclusions: Photobiomodulation therapy is an efficacy intervention with slightly shortened AL to control myopia in children. Trial registration Chinese Clinical Trial Registration Number: ChiCTR2100043619. Registered on 23/02/2021 ; prospectively registered. http://www.chictr.org.cn/showproj.aspx?proj=121302