Abstract Background and Objectives: Low-level laser therapy (LLLT) has been shown to promote chronic wound healing in conditions of reduced microcirculation. In this preliminary study, we report the results of using LLLT to heal foot ulcers in patients with diabetes mellitus.
Materials and Methods: Twenty-three patients with a diabetic foot wound for at least 3 months were included in this double-blind randomized clinical trial. Patients were randomized to receive placebo treatment (n = 10) or LLLT (n = 13) (685 nm, energy density 10 J/cm(2)) in addition to conventional therapy. Patients were followed for 20 weeks. Ulcer size reduction and the number of patients with complete healing were compared between the LLLT and placebo groups.
Results: There were no significant differences in baseline characteristics of patients and foot ulcers receiving LLLT and placebo treatment. At week 4, the size of ulcers decreased significantly in the LLLT group (p = 0.04). After 20 weeks, in the LLLT group, eight patients had complete healing and in the placebo group only three patients experienced complete wound healing. The mean time of complete healing in LLLT patients (11 weeks) was less than that in placebo patients (14 weeks) though the difference was not statistically significant.
Conclusions: The study provides evidence that LLLT can accelerate the healing process of chronic diabetic foot ulcers, and it can be presumed that LLLT may shorten the time period needed to achieve complete healing.
BACKGROUND AND OBJECTIVE: Impaired wound healing is a complication of diabetes and is a serious problem in clinical practice. The purpose of this study was to evaluate the effect of biostimulation on wound healing in diabetic rats.
MATERIAL AND METHODS: Thirty-six female Wistar rats weighting 250 to 300 g were used for this study. Diabetes was chemically induced with streptozotocin. Eighteen nondiabetic and 18 diabetic rats were included in the analysis. One incision was performed on the dorsum of each nondiabetic rat and the wound served as a control. Two parallel incisions were performed on the dorsum of each diabetic rat. The laser treatments were started immediately after surgery and were repeated on the second, fourth, sixth, and eighth days. A GaAlAs laser was used with an 808 nm wavelength. One wound of each diabetic rat received 10 J/cm(2) laser stimulation.
RESULTS: Inflammation and re-epithelialization were evaluated in all groups, and there was a significant difference between the nondiabetic scalpel, diabetic scalpel, and diabetic scalpel + biostimulation groups.
CONCLUSIONS: Treatment with laser biostimulation showed a beneficial effect on wound healing in diabetic rats. It can be concluded that low-level laser therapy (808 nm laser at 10 J/cm(2)) can have a beneficial effect on diabetic wound healing, when used at 2 d intervals over 5 d.
OBJECTIVE: The effects of wound healing acceleration on diabetic rats were determined and compared using different laser wavelengths and incident doses.
BACKGROUND DATA: Many studies have demonstrated that low-level laser therapy (LLLT) can promote the wound healing on non-diabetic animals.
METHODS: Male Sprague-Dawley rats were used. Streptozotocin (70 mg/kg) was applied for diabetes induction. An oval full-thickness skin wound was created aseptically with a scalpel in 51 diabetic rats and six non-diabetic rats on the shaved back of the animals. The study was performed using 532, 633, 810, and 980 nm diode lasers. Incident doses of 5, 10, 20, and 30 J/cm(2) and treatment schedule of 3 times/week were used in the experiments. The area of wound on all rats was measured and plotted on a slope chart. The slope values (mm(2)/day), the percentage of relative wound healing, and the percentage of wound healing acceleration were computed in the study.
RESULTS: Mean slope values were 6.0871 in non-diabetic control and 3.636 in diabetic control rats (p > 0.005). The percentages of wound healing acceleration were 15.23, 18.06, 19.54, and 20.39 with 532-nm laser, 33.53, 38.44, 32.05, and 16.45 with 633-nm laser, 15.72, 14.94, 9.62, and 7.76 with 810-nm laser, and 12.80, 16.32, 13.79, and 7.74 with 980-nm laser, using incident doses of 5, 10, 20, and 30 J/cm(2), respectively. There were significant differences (p > 0.001) in the mean slope value of wound healing on diabetic rats between control groups and treatment groups in 532, 633, 810, and 980 nm lasers.
CONCLUSION: The wound healing on control rats with diabetes was slower than on control rats without diabetes. LLLT at appropriate treatment parameters can enhance the wound healing on diabetic rats. The optimum wavelength was 633 nm, and the optimum incident dose was 10 J/cm(2) in our study.
OBJECTIVE: We have determined optimal laser dosimetric parameters in comparison with polychromatic light-emitting diodes (LEDs) that can speed up healing in four animal models: non-diabetic oval full-thickness wounds, diabetic oval full-thickness wounds, non-diabetic burns, and diabetic burns in Sprague-Dawley rats.
MATERIALS AND METHODS: This series of studies used 532-, 633-, 810-, 980-, and 10,600-nm lasers (visible to far infrared) and polychromatic LED clusters (510-872 nm, visible to infrared) as photon sources. Sprague-Dawley rats (n = 893) were used; however, animals that died before and during the experiments from anesthesia accidents and for any other reason were excluded from statistical analysis.
RESULTS: The improvements seen (>10% improvement of impairment) show that phototherapy with the 633-nm laser is quite promising for alleviating diabetic wound and burn healing, and exhibited the best results with 38.5% and 53.4% improvements, respectively.
CONCLUSION: In this induced-diabetes model, wound and burn healing were improved by 40.3% and 45%, respectively, in 633-nm laser dosimetry experiments, and diabetic wound and burn healing was accelerated by phototherapy. This indicates that the healing rate was normalized in the phototherapy-treated diabetic rats. In view of these interesting findings, 633-nm laser therapy given three times per week at 4.71 J/cm(2) per dose for diabetic burns, and three times per week at 2.35 J/cm(2) per dose for diabetic wound healing are recommended as actual doses for human clinical trials, especially after major surgery in those with impaired healing, such as diabetics and the elderly.
OBJECTIVE: We investigated the effects of photobiomodulation (PBM) on cutaneous wound healing in an animal model of type II diabetes, Psammomys obesus (Sand Rats).
BACKGROUND DATA: 632-nm light has been established as the most effective wavelength for treatment of cutaneous wounds; however, the inconsistent efficacy of PBM may be due to inadequate treatment parameter selection.
METHODS: Using 632-nm light, an initial series of experiments were done to establish optimal treatment parameters for this model. Following creation of bilateral full-thickness skin wounds, non-diabetic Sand Rats were treated with PBM of differing dosages. Wound healing was assessed according to wound closure and histological characteristics of healing. Optimal treatment parameters were then used to treat type II diabetic Sand Rats while a diabetic control group received no irradiation. In order to elucidate the mechanism behind an improvement in wound healing, expression of basic fibroblast growth factor (bFGF) was assessed.
RESULTS: Significant improvement in wound healing histology and wound closure were found following treatment with 4 J/cm(2) (16 mW, 250-sec treatments for 4 consecutive days; p < 0.05). The 4 J/cm(2) dosage significantly improved histology and closure of wounds in the diabetic group in comparison to the non-irradiated diabetic group. Quantitative analysis of bFGF expression at 36 h post-injury revealed a threefold increase in the diabetic and non-diabetic Sand Rats after PBM.
CONCLUSIONS: The results demonstrate that PBM at an energy density of 4 J/cm(2) is effective in improving the healing of cutaneous wounds in an animal model of type II diabetes, suggesting that PBM (632 nm, 4 J/cm(2)) would be effective in treating chronic cutaneous wounds in diabetic patients.
BACKGROUND AND OBJECTIVE: To investigate the effect of low-level laser therapy (LLLT) on healing of skin incisions made using a diode laser in diabetic rats.
MATERIAL AND METHODS: Eighteen diabetic Wistar rats were used for this study. One incision was performed on the left side of the dorsum using a diode laser, and the other two incisions were made with a scalpel and diode laser on the right side of each rat. The wound on the left side of each rat received laser stimulation (10 J/cm(2)). The rats were assigned to three experimental groups. Group 1, scalpel (n = 18); Group 2, diode (n = 18); Group 3, diode + biostimulation (n = 18).
RESULTS: Reepithelialization was fastest in Group 2 than Group 1 at day 10. The difference between Groups 1 and 3 was also statistically significant in reepithelialization at day 10. There was a significant difference between Groups 1 and 2 and between Groups 2 and 3 in inflammation at day 10. There was no difference between any of the groups in inflammation and reepithelialization at day 20.
CONCLUSIONS: Scalpel incisions heal more slowly than diode and diode + biostimulation incisions in diabetic rats. We can suggest that diode + biostimulation may produce the least amount of tissue injury, with the fastest resolution of inflammatory response in diabetic rats. Diode laser incision (4 W) with 10-J/cm(2) LLLT seems to have a beneficial effect on skin incisions in diabetic rats.
OBJECTIVES: To evaluate the effect of laser irradiation (LI) on the glycemic state and the histological and ionic parameters of the parotid and submandibular glands in rats with diabetes.
METHODS: One hundred twenty female rats were divided into eight groups. Diabetes was induced by administration of streptozotocin and confirmed later according to results of glycemia testing. Twenty-nine days after the induction, the parotid and submandibular glands of the rats were irradiated with 5, 10, and 20 J/cm2 using a laser diode (660 nm/100 mW) (without diabetes: C5, C10, and C20; with diabetes: D5, D10, and D20, respectively). On the following day, the rats were euthanized, and blood glucose determined. Histological and ionic analyses were performed.
RESULTS: Rats with diabetes without irradiation (D0) showed lipid droplets accumulation in the parotid gland, but accumulation decreased after 5, 10, and 20 J/cm2 of laser irradiation. A decrease in fasting glycemia level from 358.97+/-56.70 to 278.33+/-87.98 mg/dL for D5 and from 409.50+/-124.41 to 231.80+/-120.18 mg/dL for D20 (p < 0.05) was also observed.
CONCLUSION: LI should be explored as an auxiliary therapy for control of complications of diabetes because it can alter the carbohydrate and lipid metabolism of rats with diabetes.