Efficacy of low-level light therapy for improving healing of diabetic foot ulcers: A systematic review and meta-analysis of randomized controlled trials

Diabetic foot ulcers are prevalent among patients with diabetes and negatively affect mortality and life expectancy. This study aimed to synthesize and systematically review the best evidence to assess the efficacy of low-level light therapy in improving healing of diabetic foot ulcers. We search CINAHL, Cochrane Library, EMBASE, ProQuest, PubMed, Scopus, and Web of Science from inception until September 30, 2019. Meta-analysis was performed using the Comprehensive Meta-analysis 3.0 software. Overall effect was measured using Hedges' g and determined using the Z-statistic at a significance level of P < .05. Heterogeneity was assessed using chi(2) and I-2 statistics. Twelve randomized controlled trials were included. Meta-analysis revealed that 30.90% of the ulcer area was significantly reduced in the therapy group compared with the control group (Z = 3.95, P < .001) with a very large effect (g = 2.81). A 4.2 cm(2) reduction of the ulcer area was observed in the therapy group compared with the control group (Z = 2.17, P = .03) with a very large effect (g = 1.37). In addition, diabetic foot ulcers in the therapy group was 4.65 times more likely to heal completely than those in the control group (Z = 3.02, P = .003). Low-level light therapy accelerates wound healing and reduces the size of diabetic foot ulcers. However, our review does not allow any recommendation for the best treatment parameters required to achieve improved healing. Future trials need to include a good design and large sample size in defining the optimal treatment parameters for ulcers of different sizes.