Is More Laser Better?

Is More Laser Better?

Murphy, Daniel

On Nov. 10, 2006, I was traveling to Las Vegas to do a laser class with Jeff Spencer, DC. I have found Dr. Spencer to be a master clinician, smart and experienced. He has been profiled in numerous chiropractic magazines, primarily for his association with the seven-time Tour de France champion, Lance Armstrong. During my trip, 1 read the Dynamic Chiropractic article by Robert L. Wertz, DC (Nov. 8, 2006 issue), titled “Class IV High-Power Laser Therapy in Chiropractic and Rehabilitation.”

At the beginning of class, the attendees watched Dr. Spencer treat a chiropractor with a significant abnormal external rotation of the right hip. History revealed that the problem was chronic and the chiropractor was currently under management for the problem. After doing a few physiological tests, Dr. Spencer treated his abnormal physiological findings using a 5 mW laser for approximately five seconds on the opposite side of the body, which was consistent with his findings. On re-evaluation, the abnormal right hip external rotation finding was gone. Again, the laser used was 5 mW of power, applied for only five seconds, and the penetration at the area of complaint was zero because Dr. Spencer used the laser to treat physiological findings that happened to be on the opposite side of the body.

Next, Dr. Spencer treated a chiropractor with a significant reduction of right shoulder abduction. Once again, he tested and treated physiological findings for five seconds using a 5 mW laser in front of the class, and once again, using the laser on the opposite side of the body, an astonishing restoration of the shoulder range of motion immediately occurred. Much of the rest of the weekend, the class learned the laser protocols that Dr. Spencer uses in his management of world-class athletics, including management of acute trauma, scar tissue, tight muscles, inhibited muscles and cranial nerves.

In his article, Dr. Wertz stated, “The trend in laser therapy over the past 10 years has been to increase power density and dose, since this has been shown to improve therapeutic outcomes considerably. … The most common reason for poor clinical outcomes is related to low power or dosage.” To justify these statements, Dr. Wertz referenced the Erchonia Web page. This is abusive. Erchonia does not advocate increasing power dose and density in order to improve therapeutic outcome, nor does it agree that low power or dosage is related to poor clinical outcome. If anything, Erchonia is cautioning against using high amounts of power and dose.

Several times in his article, Dr. Wertz referenced Tuner and Hode1 in his support of using lasers with higher power and dosage, yet he fails to note that Tuner and Hode also make the following points: “Treatment with laser therapy is not based on heat development but on photochemical and photobiological effects in cells and tissues. [Lasers] cannot penetrate the tissue more than a fraction of a millimeter, so there is no other primary responding tissue other than the outer part of the dermis.”

Still, such irradiation has “secondary systemic effects.” Therefore, the light “leads in turn to a number of secondary effects (secondary responses), which have been studied and measured in various contexts: increased cell metabolism and collagen synthesis in fibroblasts, increased action potential of nerve cells, stimulation of the formation of DNA and RNA in the cell nucleus, local effects on the immune system, increased formation of capillaries by the release of growth factors, increased activity of leukocytes, transformation of fibroblasts to myofibroblasts, and a great number of other measured effects.”

Therefore, “deep light penetration is not a necessity per se in biostimulation. The possible reason for this is that cells in the tissues subjected to the light produce substances that then spread and circulate in blood vessels and lymphatic systems.”

In their literature review, Tuner and Hode also note the following:

* “There was also a group of animals on which two wounds were inflicted [bilaterally], only one of which was treated with laser. Even the untreated wound showed better results than the control group. The authors report drew the following conclusion: The laser irradiation can thus have released substances in the circulation apparatus so that the tensile strength increased even in the wound on the opposite, untreated side.”2

* Another study notes, “Laser treatment on only the righthand side of bilaterally inflicted skin wounds increased the healing process on both sides as compared to the control group. This also applied in the case of bilateral burn wounds.”3

* In a study of patients treated unilaterally with chronic neck and shoulder pain, “[t]he pressure pain threshold increased significantly on both the nontreated and the treated side, although the increase was larger on the treated side.”4

* In an animal study evaluating suppressed tuberculin reaction, “[t]he suppression was seen not only on the irradiated side but also on the contralateral, nonirradiated side.”5

* In a study evaluating the effects of laser on the treatment of an anaphylactic reaction in the eyes of rabbits, the healing effect of the laser was obvious, and “consensual co-reaction could be observed in the contralateral non-irradiated eyes in the experimental group.”6

Tuner and Hode explain these results on tissues contralateral to the side of laser irradiation, with no actual penetration, by stating: “The non-irradiated ‘control’ lesion in fact benefits from the treated lesion because of the systemic reaction just discussed. Conventional laser therapy has both a local effect in the area treated by laser, and a systemic effect through the release of metabolites. Due to transmission of neural excitation and calcium waves, photobiomodulation is a systemic effect.”

Dr. Wertz also referenced a 1998 book by Dr. Tina Karu.7 In 2003, Dr. Karu noted that lasers probably work by both direct absorption of the laser light and by “activation of cellular second messenger systems.”

In contrast to the perspective offered by Dr. Wertz, using the same references he noted, another perspective is offered, suggesting that the secondary systemic effects of laser irradiation are significant and independent of increased power or depth of penetration.

In contrast to the perspective offered by Dr. Wertz, some caution on increased power and dosage has appeared. Tuner and Hode state: “If a dose above the highest one suitable is administered, weaker or no biological effects will result. With an even greater dose, the bio-suppressive range is entered (inhibiting effect result).”

Robert Becker, MD, noted in his 1985 book, The Body Electric, Electromagnetism and the Foundation of Life,8 that plants could regenerate severed branches at three times the normal rate by applying two to three microamperes for five days. A microampere is one-millionth of an ampere. He stated: “Larger amounts of electricity killed the cells and had no growth-enhancing effect.”

In Dr. Becker’s experiments with cellular regeneration, he noted: “The best window [of current] was somewhere between 200 and 700 picoamps. This was an infinitesimal tickle of electricity, far less than anything a human could feel even on the most sensitive tissue, such as the tongue, but it was enough to goose the cell into unlocking all its genes for potential use.”

In 1972, Dr. Becker was able to repair a non-union fracture of a human leg bone with the current range between a billionth to a millionth of an ampere – extremely low amounts of energy.8 I have seen two published reports in the lay press concerning the healing of fractures using a 5 mW-powered laser. Both articles were concerning professional athletes: a bowler (published in the Indianapolis Star in 2004) and a skater (published in the Hartford Courant in 2006), and both used the Erchonia laser.

In Dr. Becker’s 1985 book, he cautioned about the dangers of applying higher amounts of energy to the human body. Dr. Becker continued with this caution in his 1990 book, titled Cross Currents, a Startling Look at the Effects of Electromagnetic Radiation on your Health.9 This book is subtitled The Perils of Electropollution and the Promise of Electromedicine.

Dr. James Oschman echoed Dr. Becker’s concerns about applying excessive energy to the body in his 2000 book, Energy Medicine, The Scientific Basis.10 Dr. Oschman noted: “Biological systems respond paradoxically to electrical fields: In living systems, extremely weak electrical fields have potent effects, while strong fields may render little or no response.”

In 2004, in an article titled “Photobiological Principles of Therapeutic Applications of Laser Radiation,”11 the authors noted that the positive action of laser biostimulation is changed “into inhibition of vital activity processes” under large doses of laser radiation, “which is a main hindrance to a successful application of laser therapy and a cause of disappointment.”

In 2006, an article published in the American Journal of Sports Medicineu indicated that ultrasound applied in doses between the standard .5 to 2 watts/cm^sup 2^ did not improve the healing of injured soft tissues, but that energy less than . 1 watts/cm^sup 2^ significantly accelerated the healing of acutely injured ligaments.

Possibly the most important article to be aware of regarding the effects of the energy output of lasers was published in the January 2006 issue of the authoritative journal Lasers in Surgery and Medicine.13 This article noted that a lower dose of laser irradiation “has a stimulatory influence on wounded fibroblasts with an increase in cell proliferation and cell viability without adversely increasing the amount of cellular and molecular damage. Higher doses were characterized by a decrease in cell viability and cell proliferation with a significant amount of damage to the cell membrane and DNA.”

These authors further noted that by spreading the light out over 3.3 cm, “the light is divergent and is not as harmful as a narrow parallel beam that allows the entire volume of intense laser light to be focused or concentrated on one small area.” The laser discussed in this study used only 3 mW of power.

In conclusion, to claim that the future of laser therapy is increased power and dose is premature. It ignores the systemic benefit of second messengers and the ability of the nervous system to influence regions of the body that are not actually irradiated; it ignores the evidence that lower amounts of energy therapeutically delivered to the body may have enhanced physiological benefit; and it ignores the potential that higher amounts of laser energy delivered into the body may actually cause harm.

References

1. Jan Tuner and Lars Mode. Laser Therapy, Clinical Practice and Scientific Background. Prima Books, 2002.

2. Braverman B., et al. Effect of heliumneon and infrared laser irradiation on wound healing in rabbits. Lasers in Surgery and Medicine, 1989;9:50-.

3. Rochkind S., et al. Systemic effects of low-power laser irradiation on the peripheral and central nervous system, cutaneous wounds and burns. Lasers in Surgery and Medicine, 1989;9:174-.

4. Airaksinen O., et al. Effects of HeNelaser irradiation on the trigger points of patients with chronic muscle tension in the neck. Scand J of A cup & Electrotherapy, 1989;4:63-5.

5. Inoue K., et al. Supressed tuberculine reaction in guinea pigs following laser irradiation. Lasers in Surgery and Medicine, 1989;9:271-5.

6. Schindl L., et al. Influence of low-power laser irradiation on “arthus phenomenon” induced in rabbit cornea. Laser Therapy, 1994;6(1):23 (abstract).

7. Tina Karu. “Low-Power Laser Therapy.” Chapter 48 in Biomedical Photonics Handbook, Tuan Vo-Dinh; CRS Press, 2003.

8. Robert Becker. The Body Electric, Electromagnetism and the Foundation of Life., Quill, 1985.

9. Robert Becker. Cross Currents: A Startling Look at the Effects of Electromagnetic Radiation on Your Health. The Perils of Electropollution and the Promise ofElectromedicine. Tarcher, 1990.

10. James Oschman. Energy Medicine: The Scientific Basis. Churchill Livingstone, 2000.

11. Yu A., Vladimirov A., Osipov N., and Klebanov G.I. Photobiological principles of therapeutic applications of laser radiation. Biochemistry. January 2004;69(1):103-13.

12. Warden SJ., Avin K.G., Beck E.M., et al. Low-intensity pulsed ultrasound accelerates and a nonsteroidal antiinflammatory drug delays knee ligament healing. American Journal of Sports Medicine, July 2006;34(7):1094-1102.

13. Hawkins D.H., Tech M., Abrahamse H. The role of laser fluence in cell viability, proliferation, and membrane integrity of wounded human skin fibroblasts following helium-neon laser irradiation. Lasers in Surgery and Medicine, 2006;38:74-83.

By Daniel Murphy, DC, DACBO

Copyright Dynamic Chiropractic Mar 12, 2007

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