Cold laser, also referred to as low level laser light therapy (LLLT), has been used in doctors offices as early as the late 1970s for treatment of pain and to accelerate healing. It has only been since 2002 that specific lasers have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of various pain and health conditions. Even with FDA approval, however, there is controversy about the effects of and uses of cold laser.
Cellular Effects
Laser used for therapeutic purposes is not ablative or thermal in nature but photochemical. The light causes a chemical reaction in the cells exposed to light similar to that of plant photosynthesis. The spectrum of this light is red to nearly infrared. In the study "Biphasic Dose Response in Low Level Light Therapy" published by Harvard in 2009, researchers found that LLLT reduced pain, decreased inflammation and edema (swelling), preventing death of cells and promoting tissue healing for deep wounds, superficial wounds and nerves. Further investigation by this study reveals that the mitochondrion, or the energy producers of the cells, are stimulated to make more energy and help with waste removal.
Dose Effects
The same Harvard study found that dose was an important factor in the useful effects of cold laser. It showed that, when treating tissues with LLLT, dosage affected whether a response was helpful or harmful. With cold laser specifically there needs to be enough of a dose to get the tissues to respond, but if the dose is too high, the cells will be inhibited rather than stimulated. What the specific dose is for each area of the body is different, which is why there is still controversy about LLLT. One dose may help one problem and area of the body, but not be as effective on other areas of the body. The lasers that have FDA approval have recommendations specific to different areas of the body.
Side Effects
There are no reported negative side effects from cold laser therapy. Since the therapy uses light waves and not heat, there is little concern over harmful side effects. What is of concern is producing a positive response on different areas of the body. There have been reports of the laser not being effective for a specific area with multiple treatments consisting of the same dose. Whether this lack of response is due to an incorrect dosage or general unresponsiveness of some conditions to cold laser is not known. A study published in "Clinical Rheumatology" in January 2010 looked at the use of low-level laser therapy and patients with rheumatoid arthritis of the hands. At the end of the treatment, it was concluded that the wavelength, dosage and power used by the study was not effective for this condition.
Treatment and Specific Effects
The FDA has approved LLLT for carpal tunnel treatments and is in phase III and IV studies ( animal and human) for chronic neck pain and osteoarthritis pain. Doctors and physical therapists use the laser for many other conditions, most notably strains and sprains to ligaments and tendons.
References
- "Dose Response;" Biphasic dose response in low level light therapy; Huang YY et. al.; 2009
- "Clinical Rheumatology;" Assessment of the effectiveness of low-level laser therapy on the hands of patients with rheumatoid arthritis: a randomized double-blind controlled trial.; Meireles SM, et. al.; January 16 2010.
Member Comments