The Clinical Efficacy Of LED Red/Blue Light Irradiation Therapy In Wound Healing

Soft tissue injuries caused by various kinds of trauma,diabetes mellitus,lower extremity venous ulcer are the common wounds in clinic.The therapy of the wounds especially the treatment of chronic wounds has become a worldwide health problems.At present,there are many methods that have been applied to promote the healing of wound in clinic,,such as debridement,pressure adjustment,hyperbaric oxygen therapy,application of growth factors,new functional wound dressing,etc.However,the healing of wound still needs expensive cost and the amount of time.In recent years,physical therapy has been widely used in the treatment of wounds;the red-light(wavelength 600-700nm)and blue-light(405-470 nm wavelength)irradiation therapies have gained widely recognition by researchers and health care providers.Although red-light irradiation has been proved to be effective in reducing the pain of the wound and promoting the wound healing,the available studies about red light assisting treatment in wound healing were lack of an uniform evaluation standard,and the design of experiment,the qualities of methodology and sample size in these studies need further improvement.Therefore,the application of red-light therapy in clinic is still lack of evidence of evidence-based medicine.Blue light can kill gram positive and gram negative bacteria,and shares a wide spectrum of antimicrobial effect.It has been widely used in treatment of acne and neonatal jaundice in clinical.It has been proved that blue-light irradiation can promote wound healing especially the healing of infected wounds in animal models,however,clinical research about the efficacy of blue-light irradiation therapy in wound healing is almost blank.Section 1:In the first section of this study,we evaluated the efficacy of red-light irradiation therapy in wound healing by a meta-analysis and systematical review of the collected randomized controlled clinical studies about red-light irradiation therapyMethods: We extracted the studies about red-light irradiation therapy on wound healing that were published between January 2004 and December 2014 from the databases including PubMed,EMBASE,Cochrane database,Wanfang,VIP,CBM and CNKI database.The outcome evaluation index of the included studies was the effective rate of wound healing or the healing time.Variables and attributes data were accessed using standardized mean difference(SMD)and relative risk(RR)and their 95% confidence interval,respectively.Results: Total 994 studies were obtained by database retrieval.After reading the full-texts,17 studies and 1389 patients were included according to the inclusion and exclusion criteria.There were 8 studies where the outcome evaluation index was the effective rate of wound healing.The meta-analysis of these studies indicated that the red-light irradiation therapy could effectively promote wound healing(RR=1.21,95% CI(1.14-1.27),p<0.05).There were 11 studies where the outcome evaluation index was the healing time.The meta-analysis of these studies indicated that the red-light irradiation therapy could shorten the healing time of the wounds(SMD=-2.66,95% CI(-3.49,-1.83),p<0.05).Section2:In the second section of this study,combing the active effect of red-light on wound healing and the broad spectrum antimicrobial effect of blue-light,we carried out a randomized clinical study on the effects of red/blue-light combined irradiation therapy on healing of the chronic post-traumatic wounds,where the red-light irradiation therapy was used as a control method.Methods: In this clinical randomized controlled trial,Patients were divided into two groups using random stratification method based on the wound types: the control group(21 cases)and experimental group(19 cases).Baseline data such as the age,sex and body mass index(BMI)of patients,and the area,temperature and pain score of the wounds were comparable in the two groups(p>0.05).Patients in control group received 20 minutes of red-light irradiation per day,whereas patients in experimental group received 20 minutes of red-light irradiation followed by 20 minutes of blue-light irradiation per day.Wounds in both groups were treated with unified disposal option except the light irradiation and the treatment was lasted 10 days for a course.The temperatures before and after irradiation,the pain scores(NRS)and the areas of the wounds were measured on the 1st,3rd,5th,7th and 10 th days,and the local or systemic adverse reactions after light irradiation were also considered.The results were analyzed using software SPSS 22.0.Comparisons between two groups were performed as following: χ~2 test was used for enumeration data,rank-sum test was used for ranked data and measurement data that do not conform to the normal distribution,t-test was used for the measurement data meeting the normal distribution and homogeneity of variance,and the repeated measurement analysis was used for multi-period measurement data.Results: After 10 days of irradiation treatment,significantly decreases of the areas and pain scores of the wounds were observed in both groups(time effect P<0.05).Significant differences between the control and experiment groups were observed in the ratio of wound contraction(P=0.000),relative rate of wound healing(P=0.003),efficacy of wound healing(P=0.016)and pain score(P=0.11),which indicated that the red/blue-light combined therapy is more effective than the red-light irradiation therapy in assisting the healing of wounds.Moreover,there were no local and systemic adverse reactions were observed in both groups,which indicated that ten days of the irradiation treatment was safe for both methods.ConclusionsIn this study,the meta-analysis and systematical review of the randomized controlled clinical studies about red-light irradiation therapy on wound healing indicated that the red light irradiation therapy that could shorten the healing time of the wounds was a promoting factor of wound healing,which provided an important evidence for the application of red-light irradiation therapy in clinic.The results of our clinical randomized controlled trial indicated that the red/blue-light combined therapy which bridged the active effect of red-light on wound healing and the broad spectrum antimicrobial effect of blue-light,was more effective in promoting the wound healing and relieving the pain of wounds than the red-light irradiation therapy.Moreover,ten days of the irradiation was safe for both treatment methods.