Short-term Clinical Effects Of Photobiomodualtion On Low-to-moderate Myopia

Background: Photobiomodulation(PBM)may play an important role in the prevention and control of myopia and the treatment of other ocular diseases.However,there are no relevant clinical studies on whether there is damage to visual function,retinal morphology,and whether it can help improve retinal circulation.Based on the above problems,in order to further explore the effects of PBM on retinal tissue morphology,visual function,fundus microcirculation,and the effects of PBM on AL and refraction,we carried out this clinical study.Objective: To observe and evaluate the clinical effects of short-term PBM treatment on low and moderate myopia in children and adults.Methods: Patients with low-to-mild myopia were recruited into the clinical study,and were divided into children PBM group,children control group,adult PBM group and adult control group according to age(7 to 17 years old for children group,18 to 45 years old for adult group)and whether to receive PBM treatment.The PBM group was treated with650 nm low energy semiconductor laser for 3 months,while the control group received no other intervention except routine wearing of single-focus spectacle.At the end of follow-up treatment,the children PBM group and the adult PBM group were self-comparison before and after treatment for best corrected visual acuity(BCVA),nerve fiber layer thickness(RNFLT),ganglion cell layer thickness(GCLT),central point retinal thickness(CPRT)and 3-mm subfield central retinal thickness(3mm-CRT).To evaluate the safety of PBM.In the second,the circulation indicators of the children PBM group and the adult PBM group were self-comparison before and after treatment.Include Superficial retinal vascular density(SCP)and center choroid thickness(CCT).To evaluate the effects of PBM on macular mircrocirculation.In the end,the change of SER and AL before and after treatment were compared between children PBM group with children control group or adult PBM group with adult control group to evaluate the effectiveness of PBM on AL or Spherical equivalent refractive(SER).Results: After 3 months of treatment,the BCVA,RNFLT,GCLT,CPRT and 3mm-CRT were almost unchanged before treatment,1 month and 3 months after treatment both in children and adult PBM groups,no statistical difference.In the second,SCP of children PBM group decreased slightly from 0.366±0.004 before treatment to 0.356±0.003,CCT increased from 255.81±34.92μm before treatment to278.52±29.31μm,there was statistical difference before and after of CCT(p<0.05),but no statistical difference before and after of SCP.SCP and CCT of adult PBM group increased slightly,there were no significant difference between SCP and CCT before and after treatment.In the end,the AL decreased by 0.07±0.11 mm and diopter decreased by-0.12±0.39 D in children PBM group.In adult PBM group,AL was decreased by0.06±0.07 mm and SER was decreased by-0.01±0.27 D.The differences were statistically significant compared PBM groups with control groups(p<0.01).Conclusion: 3 months of PBM treatment had no significant effect on visual acuity and retinal morphology,but showed a trend of improvement in choroidal microcirculation and a possibility of reduction in retinal microcirculation,and it has a significant inhibitory effect on the increase of AL and diopter.