Healing of diabetic ulcers using photobiomodulation.

At the end of 2013, The United Nations (UN) General Assembly 68th Session proclaimed 2015 to be the International Year of Light (IYL). Various scientific organizations, institutions, and societies are to all be brought together to raise global awareness about light (and lasers) and its uses in technology, including medicine, and everyday use. This worldwide program will highlight our dependence on light, and its importance to our lives. John Dudley, Chairman of the IYL 2015 Steering Committee stated that ‘‘An International Year of Light is a tremendous opportunity to ensure that international policymakers and stakeholders are made aware of the problem-solving potential of light technology. We now have a unique opportunity to raise global awareness of this.’’ The IYL has given us all a unique opportunity to showcase our research and the importance and usefulness of light in medicine. Since the development of the first laser, the use of lasers and light in medicine has made great strides; new technologies have since been developed and continue to advance. Today, photomedicine is practiced in a wide variety of fields, including but not limited to ophthalmology, dermatology, dentistry, veterinary science, somatology, regenerative medicine, physiotherapy, surgery, and oncology. One area of research that has been receiving much attention is the use of light [both lasers and light emitting diodes (LED)] in improving and speeding up wound healing. A wound is a pathological state in which tissue integrity has been lost. Wound healing is an intricate process aimed at reversing the loss of this tissue integrity, and is directed toward closure of the defect, usually by replacement with scar-forming connective tissue, and is highly coordinated and controlled at the wound site. If there is a delay or disruption to this process, delayed wound healing ensues; a complication that is frequently seen in diabetes. As defined by the International Diabetes Federation (IDF), diabetes mellitus (DM) is a chronic disease that occurs as a result of the pancreas failing to make insulin. or when the body can no longer make use of the insulin that is produced. DM is a threat to global development and has been declared as a global burden, with 382,000,000 cases worldwide in 2013. Because of the damage inflicted on the blood vessels (angiopathy) and nerves (neuropathy), diabetic patients often experience sensory loss in the lower extremities, and as a result, small sores go unnoticed and develop into non-healing chronic ulcers. The ulcer recurrence rate over 5 years is as high as 70%, and these ulcers often require amputation. Diabetic foot ulcers are one of the most costly complications of the disease, accounting for 50% of all nontraumatic amputations. Diabetic foot ulcers require extensive long-term treatment by clinicians, and they impact heavily on the quality of life of the patient, comparable with that of a patient with breast cancer. The treatment of diabetic foot ulcers includes wound dressing, debridement, off-loading, corrective shoe wear, infection control, and surgery. New advances in the treatment of diabetic foot ulcers have been developed, such as hyperbaric oxygen therapy (HBOT), and dressings that have growth factors incorporated into them. Advances in the area of photonics and photobiomodulation have led to the use of lasers and LEDs in the treatment of diabetic ulcers. A number of clinical studies in animal models and humans have shown the beneficial effects of photobiomodulation in speeding up the healing process in slow-to-heal diabetic foot ulcers. There is an increase in wound closure, collagen production, epithelization, and granulation tissue, and a decrease in inflammatory cells and oxidative stress. AlWatban conducted a large study on Sprague–Dawley rats (n= 893) using various wavelengths at 532 (20.4 mW/cm), 633 (15.56 mW/cm), 810 (22.22 mW/cm), 980 (22.22 mW/ cm), and 10,600 nm (66.37 mW/cm), as well as LED clusters (510–872 nm, 13.6 mW/cm). A full-thickness wound or burn was created and treated three times a week at incident doses of 5, 10, 20, and 30 J/cm. The best results were seen with the 633 nm laser, and it was recommended that a dose of 4.71 J/cm, three times per week be used for diabetic burn wounds, and a dose of 2.35 J/cm three times per week be used for diabetic wounds for human clinical trials. Another study showed that daily irradiation with a 660 nm (80 mW) diode laser at a dose of 1.6 J/day (3.7–5.0 J/cm) for 7 days resulted in healing of splinted wounds in genetic diabetic mice, and that healing was mainly caused by reepithelization and granulation tissue formation. Another study looked at the effect of laser irradiation on oxidative stress in diabetic rats. Diabetic (streptozotocin) induced male Wistar rats (n = 42) were wounded with a 3 mm punch biopsy and irradiated at 940 nm at a dose of 10 J/cm (0.1 W) immediately after surgery and again on days 2, 4, and 6 post-surgery. On day 14, there was a significant decrease in inflammatory cells and increased collagen synthesis and vascularization in the irradiated group compared with the unirradiated, control group as determined by