Low Level Laser Therapy in Treatment of Diabetic Foot Ulcer: Quantitative Microbiologic Study

Diabetes Mellitus is a common metabolic disorder around the world. Chronic foot ulcers are one of the debilitating complications in patients with diabetes. Several studies have shown that bacterial colonization and bacterial load can affect healing process in these patients. In this study, the effect of low level laser therapy on bacterial load of diabetic foot ulcers was evaluated.

In this pilot study, patients with stage I and II Wagner chronic diabetic foot ulcer (more than 3 months) were enrolled. Patients were randomly assigned in two laser and placebo groups. Laser parameters used in laser group were wavelength 670 nm, output power 30 mW, fluence 10 J/cm2. Bacterial load assessment was done through post debridement wound fluid collection. Three samples from 3 different sites of each wound were collected on day 0, 7, 14 after beginning of treatment.

Single and average intraclass correlation coefficients (ICC) for 32 samples were 0.7 and 0.873, respectively. There was no statistically significant difference between laser and placebo groups before and aftertwo week-treatment according to bacterial count.

Our findings showed that post-debridement wound fluid could be used asa reproducible and noninvasive method for detecting bacterial load accurately. Further studies are needed to evaluate the effect of low level laser therapy on growth of bacteria in clinical conditions.