Mechanism of Laser Therapy Copy

LOLA December 18, 2020

Watch this VIDEO from MultiRadiance Medical Lasers for a better understanding of how laser therapy works!

Laser therapies are treatments that use focused light. Unlike most light sources, light from a laser (which stands for light amplification by stimulated emission of radiation) is tuned to specific wavelengths. This allows it to be focused into powerful beams. Surgical levels of laser light is so intense that it can be used to shape diamonds or cut steel.

During the past 20 years, lasers have become easier to use, less expensive, and more available to the community than in the past. The high-power applications (10 to 100+ W) for surgical procedures and hemostasis are well known; however, less dramatic but potentially important biologic effects at powers as low as fractions of milliwatts have also been reported.

Although the medical applications of low-power lasers remain controversial, the clinical use of these devices for a variety of analgesic and wound-healing applications is steadily increasing.

Numerous biologic and physiologic effects have been reported and are summarized in Table 1. In the United States, low-power laser treatment tends to be limited to muscular strain and overuse syndromes, degenerative arthritis, rheumatoid arthritis, neuropathic pain, and healing of wounds.

In other countries, treatment indications are broader and include such exotic applications as some forms of baldness, “facial toning,” and “bowed tendons” in racehorses.

Table 1Reported Biochemical and Physiologic Effects of Low-Energy Laser Irradiation

Reported effect	Animal model	References
Cellular processes
Stimulated production of collagen and fibroblast activity	Human, rat, mouse	7 , 8 , 9
Altered prostaglandin content	Human	7
Increased tissue concentrations of succinic dehydrogenase and lactic dehydrogenase	Human	7
Altered rates of DNA synthesis	Guinea pig, Chinese hamster	6 , 10
Cytoplasmic histologic changes	Human	7
Accelerated cellular proliferation	Rat	8
Physiologic changes
Stimulated neuronal activity	Mollusk (Aplysia), guinea pig	5 , 11
Improved function and repair of damaged peripheral nerves	Rat	12 , 13
Improved function and repair of damaged optic nerves	Rabbit	14
Altered distal nerve latencies (results contradictory)	Human	15 , 16
Increased superficial vascularity	Human	7
Improved wound healing	Human, mouse	7 , 9
Accelerated fracture healing	Human, mouse	17
Humoral and immune system effects
Increased concentrations of mast cells	Rat	6
Decreased concentrations of immune complexes in patients with rheumatoid arthritis	Human	7 , 18
“Systemic” effects (at sites distant from the treated areas)	Human, rat	7 , 8 , 18

Lasers are classified by safety (Class 2, 3 and 4). Surgical lasers are generally Class 4 and can only be used in proper settings. “Cold-lasers” occupy Classes 2 and 3 and offer a wide range of non-surgical benefits. Lasers vary widely in cost and efficacy. Even the least expensive and low-powered lasers offer some pain management and superficial tissue benefits.