Laser Therapy and the Diabetic Foot

Non-healing skin wounds are a potentially serious complication of diabetes. Recent studies have shown the effectiveness of laser therapy to increase the healing response for diabetic patients suffering with skin ulcers. Diabetes is the most common western disease. Today, about one in ten Americans lives with diabetes. Fifteen percent of diabetics develop foot ulcers and 25% of non healing ulcers require amputation, leading to approximately 73,000 amputations annually.¹  

Etiology of Diabetic Foot Ulcers

diabetic foot ulcers healed with laser therapy

Non-healing wounds arise because of the limited blood flow to the extremities. In persons with diabetes, sugar-based complexes narrow the arteries, restricting blood flow. Additionally, high blood sugar levels trigger an inflammatory response, further narrowing the arteries. Without adequate blood flow, the body cannot deliver the necessary nutrients and specialized cells for wound repair. A small foot sore can take months or years to fully heal. Open wounds must be carefully maintained to prevent infection, which adds a huge economic burden.²

Laser Therapy and Wound Care

A 2011 study in Photomedicine and Laser Surgery showed the positive effect of laser therapy for patients experiencing non-healing foot ulcers for over 12 weeks. This double-blind randomized study showed a statistically significant improvement after two weeks for patients receiving laser therapy versus placebo. Patients in the treatment group received laser therapy from a 685 nm diode, 6 days per week for the first 2 weeks then every other day for 20 weeks at an energy density of 10J/㎠. After 20 weeks, more patients in the treatment group experienced complete wound healing compared to placebo.³

How Does Laser Therapy Facilitate the Wound Healing Process?

anatomy of an animal cell showing mitochondria and other cell structures which interact with infrared laser light

Infrared light of certain wavelengths interacts with the mitochondrial membrane in eukaryotic cells, releasing nitric oxide (NO) into the bloodstream. NO increases vasodilation which allows specialized cells like leukocytes and keratinocytes to migrate to the wound. Leukocytes protect the body from infection by clearing out debris. Keratinocytes provide the structure of our skin and the first line of defense against foreign pathogens. Crucial for wound healing, keratinocytes activate Langerhans cells which process microbial antigens if there is a skin breach. Vasodilation from NO increases blood flow to the area, increasing cell signalling and leading to the migration and proliferation of epithelial cells.⁴  This interaction between infrared light and the cells at the surface of our skin increases the healing response in other epithelial pathologies such as oral mucositis.

Cancer Treatment and Oral Mucositis

Oral mucositis is a common complication for cancer patients undergoing chemotherapy and radiation. These aggressive cancer treatments target rapidly dividing cells to decrease tumor size, and consequently break down the rapidly dividing epithelial cells of the mucosal membrane. Our entire digestive tract is covered with a thin layer of epithelial cells. This membrane keeps digestive organs hydrated and while keeping pathogens out of the blood stream. If this protective layer deteriorates, as with cancer treatment, patients experience difficulty swallowing or talking and pain when eating. White lesions may form, increasing the risk of infection and leading to a interruption of cancer treatments.

Laser Therapy Decreases Lesions in Oral Mucositis

laser therapy used to prevent lesions in oral mucositis

Laser therapy has been shown to help prevent the formation of oral mucositis lesions, while decreasing pain. Twenty-five patients undergoing treatment of head and neck cancer participated in a 2010 study which compared the efficacy of laser treatment and aluminum hydroxide (AH) to prevent oral mucositis. The laser group was treated with a 15 milliwatt, 830 nm wavelength laser 5 days per week for the duration of radiation therapy. Researchers found laser therapy to be more effective than AH in delaying the appearance of lesions.⁵

Laser Therapy for Wound Care

Nitric oxide played a key role in delaying the appearance of oral mucositis lesions. As with diabetic skin ulcers, vasodilation from NO release and the proliferation of epithelial cells speeds recovery and prevents the appearance of lesions for patients experiencing oral mucositis related to cancer treatment. With this basic understanding of the interaction between skin cells and infrared light, researchers could begin to examine other situations where rapid wound healing increases quality of life. For example, future studies could analyze the potential for laser therapy to increase healing responses in postoperative incisions and for burn victims.

References

  1. Yazdanpanah, Leila, Morteza Nasiri, and Sara Adarvishi. “Literature Review on the Management of Diabetic Foot Ulcer.” World Journal of Diabetes 6.1 (2015): 37–53. PMC. Web. 6 Mar. 2018. [ncbi]
  2. Labovitz, Jonathan DPM. “The Cost of the Diabetic Foot.” New Cardiovascular Horizons 16th Annual Conference. 27-29 May 2015. [ncvh.org]
  3. Ahmad Kaviani, Gholamreza Esmaeeli Djavid, Leila Ataie-Fashtami, Mohsen Fateh, Maryam Ghodsi, Maliheh Salami, Nasrin Zand, Nasim Kashef, and Bagher Larijani. A Randomized Clinical Trial on the Effect of Low-Level Laser Therapy on Chronic Diabetic Foot Wound Healing: A Preliminary Report. Photomedicine and Laser Surgery. Feb 2011.109-114. [liebertpub]
  4. Rocha júnior AM, Vieira BJ, De andrade LC, Aarestrup FM. Low-level laser therapy increases transforming growth factor-beta2 expression and induces apoptosis of epithelial cells during the tissue repair process. Photomed Laser Surg. 2009;27(2):303-7. [ncbi]
  5. Lima AG, Antequera R, Peres MP, Snitcosky IM, Federico MH, Villar RC. Efficacy of low-level laser therapy and aluminum hydroxide in patients with chemotherapy and radiotherapy-induced oral mucositis. Braz Dent J. 2010;21(3):186-92. [scielo]