Many people remain in the dark regarding the use of light and laser for medicinal purposes. Many practitioners often use the terms ‘light therapy’ and ‘laser therapy’ interchangeably without truly understanding the difference between the two. Light has been used for medicinal purposes for centuries. However, laser therapy is a field that continues to expand. True lasers are used for various applications such as laser printers, CD players, laser pointers, and even surgical lasers for the precise removal of specific tumors. The purpose of this article is to differentiate between ‘light therapy’ which is simply the use of light emitting diodes sometimes called superluminous diodes and true laser therapy.
Clearly, there is a place in the rehabilitation field for both light-emitting devices and laser therapy. However, each form of treatment has specific properties that are suited to the treatment of specific diagnoses. When fully understood and used properly, both light and laser therapy can greatly accelerate recovery in certain conditions. However, the sole use of either light or laser therapy is by no means a solitary treatment capable of producing therapeutic effects independent of other treatments.
In general terms, superluminous therapy or light-emitting diode therapy is beneficial for more superficial conditions such as peripheral neuropathy. Anodyne therapy is an example of light emitting diode therapy that has been proven to be very effective for the treatment of peripheral neuropathy due to diabetes and other conditions. However, anodyne therapy is not laser therapy. Laser stands for “light amplification through simulated emission of radiation.” There are distinct differences between the light emitted by superluminous and light emitting diode therapies and true laser therapy. The chief difference is the concentration of light emitted. Light emitting diodes are similar to light bulbs in that the light is scattered over multiple wavelengths in multiple directions, resulting in a very superficial penetration of the light source. Laser light, on the other hand, is a very concentrated beam of light with a single wavelength aimed in a single direction or culminated in a single direction with greater coherence resulting in greater depth of penetration. Light emitting diodes have the capability to penetrate through the skin on millimeters, whereas true laser light has the ability to penetrate up to 5 centimeters, depending on the laser that is being used.
One of the key differences between light-emitting diodes and laser is that the light-emitted in the light-emitting diode device is non-coherent light and the light source emitted in a laser is coherent light.
As stated above, light therapy using superluminous diodes typical of those used in anodyne therapy have a low to medium power range with a relatively scattered or non-coherent beam of light penetrating somewhat superficially. In contrast, laser has a higher power level, a very focused beam of light, and greater depth of penetration. This is not to say that one form of treatment is better than the other in general terms. Simply stated, each has its own therapeutic benefit for specific conditions. As mentioned above, anodyne therapy has been very beneficial to people who suffer from peripheral neuropathy and superficial conditions such as superficial wounds. Anodyne or superluminous-emitting devices do not appear to have the effectiveness of laser light for treating tissue of any significant depth. Examples of conditions that appear to benefit more from true laser therapy are tendinitis, bursitis, and any soft tissue inflammation that requires a greater and deeper stimulative effect.
It is the opinion of the therapists at Progressive Physical Therapy that most orthopedic conditions benefit from a laser device that utilizes not only a single beam of light, but an applicator that utilizes a combination of cluster applicators of both laser diodes and superluminous diodes which covers a larger treatment area and at the same time offers greater depth of penetration than a light-emitting device only. There are many theories behind the physiological and therapeutic benefits of light and laser therapy. It is in general agreement that people benefit from light and laser therapy due to the stimulation of collagen synthesis which promotes healing, the stimulation of ATP production which is the energy source of all cells, the acceleration of the inflammatory process which accelerates wound healing, and an overall decrease in inflammatory pain and swelling, in part due to increased lymphocyte activity which helps modulate the inflammatory process.
The FDA has cleared the use of low-level laser therapy for increasing local blood circulation, relief of minor muscle aches and joint aches, pain and stiffness, relaxation of muscles, muscle spasm and minor pain and stiffness associated with arthritis. Light and low-level laser therapy is considered contraindicated in cancer, photophobia, or sensitivity to light, or to the fetus or the uterus during pregnancy, when a patient is utilizing photosensitizing medications, over a hemorrhage or over a thyroid or endocrine gland. Patients must also wear protective eyewear during laser treatment, and laser treatment is obviously contraindicated over the eyes.
In review, light and low-level laser therapy are both very beneficial modalities in treating various musculoskeletal conditions. However, the best affect is achieved with each modality when the proper choice is made regarding which type of therapy will be most beneficial for a specific diagnosis. The therapy staff at Progressive Physical Therapy & Sports Medicine Clinic have found low-level laser therapy to be a great adjunct in the care of its physical and occupational therapy patient population when combined with traditional therapies of exercise prescription, patient education, and hands-on soft tissue and joint mobilization techniques. To read other articles related to this topic and others, please our web site at progressive-pt.net.