The use of low level laser to reduce pain, inflammation and edema, to promote wound, deeper tissues and nerves healing, and to prevent tissue damage has been known for almost forty years since the invention of lasers. Near Infrared (NIR) therapy has been cleared by the FDA for improving local circulation and relieving pain and inflammation. Tingling and numbness are common complaints that occur in a large number of medical situations including diabetic, statin and chemotherapy related peripheral neuropathy. These symptoms can also be seen in patients after sports injuries, car accidents or overuse injuries.
How does the laser increase circulation
The infrared light energy releases nitric oxide from hemoglobin and endothelial cells. Nitric oxide is a signaling molecule that relaxes smooth muscle cells found in the arteries, veins, and lymph vessels. When these muscles relax, the vessels dilate, thus allowing increased circulation.
Why is Nitric Oxide important
Nitric oxide been found to be essential in many bodily systems (such as the immune system and the nervous system, including the brain) and in many chronic conditions and diseases (such as chronic inflammation, erectile dysfunction, and cancer). A reduction in nitric oxide production can lessen blood flow to the brain, as well as possibly increase inflammation and oxidative stress, and thus may contribute to cognitive problems. In addition, nitric oxide in the endothelium can modulate a protein that’s a precursor to amyloid (found in plaques that are a hallmark of Alzheimer’s.
Certain immune cells generate nitric oxide, which is important as a defense molecule against bacteria and other pathogens. It also regulates the activity, growth, and death of many immune and inflammatory cell types. Nitric oxide can cause cancer cells to destroy themselves (apoptosis). But it can also promote growth of blood vessels (angiogenesis), which cancer needs in order to grow.
There are two main factors to maximize the benefits of light therapy: the wavelength and intensity of light energy
While most devices deliver red light between 630-700nm, you will see ranges from almost orange (600nm) all the way to 800-900nm, which is in the near-infrared range. The bulk of clinical literature suggests that light in the mid-600nm range and low to mid-800nm range is most effective. That is because these wavelengths have the greatest effect on the cellular respiration process. At certain wavelengths, there are several peaks in the cytochrome c oxidase (CCO) absorption of photons. The highest of these peaks are in the ranges of 660-670nm and 830-850nm. These wavelengths have been proven to produce substantial improvements in cellular function. Other wavelengths such as 700nm or 720nm have almost no biological effects.