Clinical research continues to demonstrate that low-power lasers (less than 500 mW) affect the cellular energy of tissue without thermally harming the tissue, opening up a host of potential therapeutic applications. It has even become clear to the FDA that low-level laser therapy (LLLT), also known as biostimulation, can promote healing in many conditions, and the agency has actually begun to grant marketing clearances to laser-based biostimulation products for use in the treatment of chronic pain and various consumer-based applications.
The concept of using low levels of light-based energy for therapeutic purposes was first proposed by Albert Einstein in 1917, but the technology was not developed until the 1960s, when a Hungarian surgeon named Endre Mester first reported on his experiments with using laser energy to treat infections and inflammations in rats. This work led to the development of laser biostimulation as a science; since 1967 more than 2000 clinical studies have been published worldwide on cold lasers, and biostimulation lasers have been used for years in Europe, Japan, and Russia. In the U.K., for example, LLLT has become a preferred treatment for whiplash.
Even so, for years the mainstream medical community in the United States has been reluctant to accept biostimulation as a legitimate medical treatment. But proponents of this technology and its applications believed that once the FDA finally gave its stamp of approval (in 2002), doctors across the country would begin adopting LLLT into their practices.
In essence, LLLT/biostimulation works by penetrating the skin and activating enzymes in the targeted cells, which in turn leads to protein synthesis that can enhance growth-factor response within cells and tissues (see "Explaining how low-level lasers work," above). Benefits include improved cell proliferation, pain relief from increased endorphin release, and better immune system response due to increasing levels of lymphocyte activity.
So far, most early adopters of this technology in the United States are sports trainers and chiropractors. The first FDA-approved biostimulation laser was the MicroLight diode-laser system for the treatment of carpal tunnel syndrome; among other things, the device has been used by the New England Patriots prior to the Super Bowl, when more than 10 members of the team were treated with the MicroLight for tendon and muscle injuries. Another firm, Erchonia Medical Laser (Mesa, AZ), gained notoriety last year when its 635-nm diode-laser device was used by the U.S. cycling team during the Tour de France to relieve muscle pain. In addition, the U.S. Olympic training centers Colorado Springs, CO, and Chula Vista, CA, are using cold lasers for pain relief and increased range of motion, and the Olympic training center in Lake Placid, NY, is expected to follow suit this year.
But all of these companies are hoping to see their products adopted for medical treatments outside of the sports arena. Erchonia, for example, currently has FDA clearance for the treatment of chronic pain, but the company is working on additional clearances to market the device for use in wound healing and to assist in liposuction operations. Another firm, Quantum Devices (Barneveld, WI), uses near-IR LEDs to treat chronic pain, providing temporary relief of minor muscle and joint pain, including arthritis and oral mucositis. Originally developed under a contract for DARPA, the company's technology is also designed to assist military personnel on the front lines with immediate first aid and care for minor injuries and pain. It is also in Phase II clinical trials as an aid in healing for bone-marrow-transplant patients.
Biostimulation products are also emerging for use in cosmetic applications. Cynosure (Chelmsford, MA) recently received FDA clearance of its Tri-Active LaserDermology system for the treatment of cellulite. The system uses energy from six diode lasers to enhance microcirculation, in conjunction with mechanical massage and localized cooling. In addition to cellulite treatment, the system can be used for facial and body smoothing, pre- and post-liposuction therapy, and therapeutic massage.
"The TriActive is used not only to tighten cellulite on the body, but can be used to tighten facial skin," said Michael Davin, president and CEO of Cynosure. "Patients can also combine TriActive LaserDermology treatments with other facial treatments, liposuction, and other procedures as they wish."
Meanwhile, other companies are working to gain FDA clearance for their biostimulation products for other more general consumer-based applications. Lexington International (Boca Raton, FL), for example, has developed, and is marketing outside the U.S., a biostimulation device called the HairMax LaserComb that uses diode-laser energy to stimulate hair growth. According to the company and some clinical studies, the LaserComb has been shown to yield healthier, fuller, stronger hair by stimulating the hair follicles and increasing blood flow under the skin.
Similarly, Sanacea International (Austin, TX) offers a laser hair-therapy program designed to stop hair loss; according to the company, the LLLT approach reduces inflammatory white blood cells that infiltrate the hair follicle, reduces excess levels of scalp dihydrotestorone hormones that contribute to genetic thinning and normalizes scalp sebum production, reduces or eliminates tight, tender, or burning scalp, enhances the body's natural anti-inflammatory responses, increases scalp blood flow and follicle microcirculation, increases nutrient supply to enhance hair growth, and stimulates and accelerates hair growth.
Another company, LaserTouch (Sonoma, CA), has opened a series of laser clinics that offer LLLT to help people stop smoking, lose weight, and reduce/manage stress. According to the company, the laser therapy works by stimulating the production of endorphins, which in turn helps diminish nicotine and other cravings. LaserTouch is currently involved in U.S. clinical trials of this technique for smoking cessation, which is already available in Canada.
Explaining how low-level lasers work
Several theories have been postulated about the mechanism of action for low-level lasers in biostimulation, which is not fully understood. Kevin Slattery, medical director of Erchonia Medical Laser (Mesa, AZ), lists three: a bioluminescence theory in which laser stimulation accelerates DNA replication; a cellular oscillation theory in which electromagnetic oscillations excite single cells; and a biological field theory in which the electromagnetic field of the laser exerts an influence upon the "biological field" of various organs and cells.1