Short-term effectiveness and safety of photobiomodulation on low-to-moderate myopia.

To find and assess the effectiveness and safety of short-term Photobiomodulation (PBM) treatment in children with low-to-moderate myopia. Children with low-to-moderate myopia were recruited and divided into PBM or control groups based on whether they received PBM treatment. The PBM group underwent a three-month treatment with a 650 nm low-energy semiconductor laser, while the control group did not receive any therapeutic intervention. At the end of the trial, the changes in spherical equivalent refractive (SER) and axial length (AL) before and after treatment were compared between the PBM group and the control group to evaluate the effectiveness of PBM in preventing myopia. The best corrected visual acuity (BCVA), nerve fiber layer thickness (RNFLT), ganglion cell layer thickness (GCLT), central point retinal thickness (CPRT), 3-mm subfield central retinal thickness (3 mm-CRT), superficial retinal vascular density (SCP), and central choroid thickness (CCT) were self-compared to assess the safety of PBM. A total of 57 subjects were prospectively followed from October 2020 to September 2021, comprising 28 participants (56 eyes) in the PBM group and 29 participants (58 eyes) in the control group. After three months of treatment, the AL decreased by 0.07 ± 0.11 mm, and the SER decreased by -0.12 ± 0.39 D in the PBM group. However, both SER and AL increased in the control group. Furthermore, there were statistically significant differences between the PBM and control groups (p < 0.01). The BCVA, RNFLT, GCLT, CPRT, and 3 mm-CRT remained almost unchanged in the PBM group; The SCP decreased from 0.37 ± 0.03 to 0.35 ± 0.02 in the PBM group with a statistically significant difference before and after treatment (p = 0.045). The CCT increased from 255 ± 41 µm to 274 ± 29 µm in the PBM group without any significant difference before and after treatment. The administration of PBM significantly suppresses the elevation of AL and SER following a three-month duration. No significant adverse effects were observed on visual function and retinal morphology.Trial Registration: This study is registered at https://clinicaltrials.gov/ (registration number: NCT04604405).