Light Years Ahead
Class IV Laser Therapy FAQ
John C. Godbold, Jr. D.V.M.
Stonehaven Park Veterinary Hospital
Laser Surgery Center
Jackson, Tennessee
Copyright © 2013
What is Class IV laser therapy?
Class IV laser therapy is the use of an intense beam of laser light directed into tissues to reduce
pain, reduce inflammation and accelerate healing.
Laser therapy is the result of electromagnetic energy interacting chemically and biologically with
tissue causing “photobiostimulation” or “photobiomodulation.” The involvement of
electromagnetic energy in biological processes is not a novel concept – it fills our environment
as photosynthesis occurs in plants and literally surrounds us as Vitamin D is formed in our skin
cells.
The idea of light producing healthful tissue effects is as old as science itself, noted, but not
understood, by early Greek physicians. Medical use of light in the modern era predates the
development of lasers, which have transformed light therapy. Lasers allow light therapy to be
targeted, specific and quick.
Lasers produce a single wavelength (monochromatic) beam of light, collimated as it is generated.
Laser light has the property of being coherent, or in phase, which in simple terms means it is
uniform and very orderly light. Class IV laser therapy uses a simple beam of light monochromatic, coherent, collimated light – to penetrate deeply into tissues and produce positive
tissue changes.
What does the term “Class IV” mean?
Lasers are classified as Class I, II, IIIa, IIIb and IV based on their ability to do harm if used
improperly. Class I are enclosed lasers as in CD players and laser printers. Class II are diffuse
beam lasers as in grocery store scanners and bar code readers.
Class III lasers are higher in power, ranging from 5 milliWatts to 500 milliWatts (0.5 Watt).
Laser pointers are Class III, as are some medical devices.
Class IV lasers – those over 500 milliWatts in power – are used in medicine and surgery, as well
as in military and industrial applications.
What equipment is used for Class IV laser therapy?
Class IV therapy lasers are usually diode lasers emitting light in the 790 – 980 nanometer
wavelength range. The longer wavelengths in this spectrum have the deepest tissue penetration
and produce excellent photobiomodulation. Class IV therapy lasers currently range in power
from as low as 1.1 Watt up to 12 Watts.
Low power Class IV therapy lasers, those with 1 to 2 Watts of power, are applicable for
treatment of
superficial lesions and wounds. Although they can be used for treatment of deeper tissue and
musculoskeletal conditions, to achieve effective target doses, required treatment times are
prolonged.
The better quality and more effective Class IV devices have power capabilities of 6, 8, 10, 12 or
15 Watts, with wavelengths in the far end of the diode laser spectrum. Those Class IV devices
with power lower than 6 Watts, or, with shorter wavelengths, have limited applicability in
veterinary practice because of the long time required for treatment of deep tissue conditions.
What about Class III Therapy lasers?
Class III therapy laser devices are available, but have limited applicability for the diversity of
deep tissue conditions seen in general veterinary practices. Under 500 milliW in power, they are
referred to as “low power”, “LLLT” (Low Power Laser Therapy) or “cold laser” devices. Very
low power Class IIIa therapy laser devices use the same 5 milliWatt laser diodes used in laser
pointers.
Like lower power Class IV therapy lasers, Class III therapy lasers are applicable for treatment of
superficial lesions and wounds only. They can be used for treatment of deeper tissue and
musculoskeletal conditions, but, like the lower power Class IV therapy lasers, to achieve
effective target doses, treatment times are prohibitively long.
Why am I just now hearing about Class IV laser therapy?
Class IV laser therapy is a new technology in the United States. Although therapy laser devices
have been used outside of the United States for many years, Class III therapy lasers were FDA
approved in the United States in 2002. Because of their low power, use of Class III therapy
lasers has been limited.
After the FDA approved Class IV therapy lasers in 2005, the science of laser therapy really
began emerging in this country. Acceptance has been rapid on the human side in rehabilitation,
wound care and sports medicine programs. In the veterinary profession Class IV laser therapy
has rapidly developed, with practitioners leading the way in beta testing, protocol development,
case reporting and dissemination of information about the technology.
What does Class IV laser therapy accomplish?
Laser therapy reduces pain, reduces inflammation and accelerates healing.
How does it reduce pain? Through its effect on nerve cells and nociceptors, increased
stimulation thresholds, reduced neuronal impulses, and increased release of tissue endorphins,
pain perception is decreased.
How does it reduce inflammation? Inflammation is reduced by decreasing release of
prostaglandins and inflammatory mediators, by increasing macrophage activity and leukocytic
phagocytosis, and, by reducing edema through dilation of lymphatics.
How does it accelerate healing? Healing is accelerated by increased blood flow from
vasodilation, by increased angiogenesis and capillary production, by increased release of
cytokines, and by stimulation of fibroblast activity and collagen production.
How do photons (little packets of electromagnetic energy) produce such dramatic biological
changes? The list of documented mechanisms and effects in laser treated tissue is extensive.
Electrical, temperature and pressure gradients are created as coherent laser light is polarized by
the mixed density of tissue. Chromophores - photon absorbing chemicals and structures in
tissue, cells, and sub-cellular organelles - absorb the electromagnetic energy. Electron chain
transport mechanisms in mitochondria, cell membranes and epithelial tissues are stimulated.
ATP production increases, and DNA and RNA synthesis is increased. Enzymes (such as the
cytochrome oxidases) are directly stimulated. With further research, a more complete
understanding of this exciting technology will emerge.
What patients can I treat with Class IV laser therapy?
Patients presenting with pain, inflammation or healing tissue are candidates for Class IV laser
therapy.
Incorporation of Class IV laser therapy into routine pain control protocols is appropriate. As an
adjunct to medical protocols, laser therapy is helpful in reducing pain and inflammation and
accelerating healing after surgery and dental procedures.
Patients with a wide variety of acute problems benefit from Class IV laser therapy. Common to
these problems are the components of pain, inflammation and tissue healing. These conditions
may be treated only once, or, multiple times over several days or weeks. A few examples
include wounds, fractures, abscesses, anal sacculitis, acute otitis, hematomas, sprains, strains,
muscle discomfort, cystitis, urethritis, injection site soreness, pyotraumatic dermatitis, venomous
bites and pododermatitis.
Chronic conditions involving pain, inflammation and healing may also be helped, although
treatment has to extend over a longer time, and frequently will be followed by on-going
treatment to maintain effect. Osteoarthritis, elbow hygromas, lick granulomas and neuropathies
are examples.
How do I treat patients with Class IV laser therapy?
The laser hand piece is moved in a scanning motion over the affected tissue. Treatments take 3-5
minutes for each affected area. Patients tolerate treatments very well, experiencing a gentle and
pleasant warming sensation in the tissue. Most patients relax as treatments are administered.
Treatment success depends on delivering an appropriate amount of laser energy to affected
tissues. Laser energy is measured in Joules, one Joule being one Watt delivered for one second.
Total energy delivered to an area of affected tissue is expressed in Joules per square centimeter
(J/cm2). Treatments should deliver 3-5 J/cm2 for wounds and conditions affecting superficial
tissues, and 8-10 J/cm2 for musculoskeletal conditions and those affecting deeper tissues.
Protocols for treatment are available in menu format in therapy laser devices. These software
defined treatment protocols have proven very effective when used to treat appropriately sized
areas of affected tissues.
In addition, treatments can be administered using operator-defined protocols. Experienced
veterinary laser therapists shorten treatment times by increasing the rate of delivery of energy to
the target tissues using custom settings available in therapy laser devices. Treatment charts and
easy to calculate custom protocols have been published and are readily available.
Are there contraindications and safety concerns with Class IV laser therapy?
Eye protection is critical when using any Class IV laser. All persons in the treatment area should
wear appropriate safety glasses and pay strict attention to avoiding direct exposure of the
patient’s eyes.
Darkly pigmented hair and skin more readily absorb diode laser wavelengths of light. To avoid
overheating pigmented tissue faster scanning treatment technique is used.
Most contraindications for laser therapy are based on prudence rather than clinical data.
Treatment of malignancy, thymus and thyroid glands, epiphysitis, testicles, pregnancy, and
active hemorrhage are historical contraindications.
Treatment after administration of
photosensitizing medications is a definitive contraindication.
How do I assign fees for Class IV laser therapy treatments?
When using Class IV laser therapy as part of a pain control protocol, the fee for the entire
protocol can be increased by $18.
Treatment for acute conditions usually involves 1-3 treatments.
These are invoiced either
individually at $48 per treatment or as a group at $43 per treatment.
Treatment of chronic conditions is invoiced as a protocol that averages $43 per treatment during
the induction period. The entire fee for the induction is invoiced at the start of treatment to
encourage client compliance through the entire protocol. Individual long term maintenance
treatments are invoiced at $48 per treatment.
Where can I receive in-depth training and certification in laser therapy?
Online training for a variety of medical laser applications is available from the independent
American Institute of Medical Laser Applications (http://www.aimla.org/). Continuing
education credits are available for AIMLA’s on-line multi-media courses. Completion of course
modules can lead to certification by AIMLA.
What are some articles I can read in the scientific literature?
There is a vast amount of published information about laser therapy. A convenient way to access
abstracts of thousands of publications is through the internet search portal
http://www.ncbi.nlm.nih.gov/pubmed/
The site can easily be found by simply doing an internet search for “PubMed”. A short list of
examples of available publications follows:
Bjordal J, Couppo C, Chow R, Tuner J, Ljunggren E. A systemattc review of low level laser
therapy with location specific doses for pain from chronic joint disorders. Aust JPhysiother 2003
;a9Q: 107 -I 6.
Bjordal JM, Lopes-Martins R, Joensen J, et al. A systematic review with procedural assessments
and meta-analysis of low level laser therapy in lateral elbow tendonopathy (tennis elbow). BMC
Musculoskeletal Disorders 2008 ;9:7 5-l 00.
Bjordal JM, Lopes-Martins R, Iverson VV. A randomized, placebo controlled trial of low level
laser therapy for activated Achilles tendonitis with microdialysis measurement of peritendinous
prostaglandin E2 concentrations. Br J Sports Med 2006;4A:7 6-80.
Carcia C, Martin R, Houck J, Wukich D. Achilles Pain, Stiffness, and Muscle Power Deficits:
Achilles Tendonitis. Journal of Orthopedic Spoorts and Physical Therapy 2012 40(9):A1-A26.
Chow RT, Johnson MI, Lopes-Martin R, Bjordal JM. Efficacy of low-level laser therapy in the
management of neck pain: a systematic review and meta-analysis of randomized placebo or
active-treatment controlled trials. Lancet 2009: V374: 1897-1908.
Crawford F. Plantar heel pain (including plantar fasciitis). Clinical Evidence, Issue 7. Tavistock
Square, UK: BMJ Publishing Group; June 2002.
de Bie RA, de Vet HC, Lenssen AF, et al. Low-level laser therapy in ankle sprains: a randomized
clinical trial. Arch Phys Med Rehabil 1998;79(1 1):1415-142A.
Draper WE, Schubert TA, Clemmons RM, Miles SA. Laser Therapy Reduces Time to
Ambulation in Dogs after Hemilaminectomy, J Small Anim Pract. 2012 Aug;53(8):465-9.
Gerritsen AA, de Krom MC, Struijs MA, et al. Conservative treatment options for carpal tunnel
syndrome: A systematic review of randomized controlled trials. J Neural 2002;2a9Q):272-28A.
Godbold, Jr., John C., Atlas of Class IV Laser Therapy – Small Animal, CD ROM Edition,
Southern Digital Publishing, Jackson, Tennessee, 2012.
Gross AR, Aker PD, Goldsmith CH, et al. Physical medicine modalities for mechanical neck
disorders (Cochrane Review). The Cochrane Lrbrary, Issue 3, 2002. Oxford, UK: Update
Software.
Hawkins, D, Abrahamse, H. The role of laser fluence in cell viability, proliferation, and
membrane integrity of wounded human skin fibroblasts. Lasers Surg. Med. 38:74-83, 2006
Karu T. Low-Intensity Laser Light Action Upon Fibroblasts and Lymphocytes. Progress in Laser
Therapy. Ed. by T. Ohshiro, R.G. Calderhead: J, J.Wiley and Sons: Chichester, New York,
Brisbane, Toronto. Singapore, 1991, pp. 175-180.
Kuslich AD, Ulstrom CL, Michael CJ. The tissue origin of low back pain and sciatica. Ortho Cln
North Am I99L;22: 181- 187.
Lord M, Barnsley L, Wallis BJ, Boughton N. chronic cervical zygapophyseal joint pain after
whiplash: a placebo controlled prevalence study. Spine 1996;21(15):1737-45.
Marks R, de Palma F. Clinical efficacy of low power laser therapy in osteoarthritis. Physiother
Res Int 1999:4(2):14lt57.
Moges H, Wu X, McCoy J, Vasconcelos OM, Bryant H, Grunberg NE, Anders JJ. Effect of
810 nm light on nerve regeneration after autograft repair of severely injured rat median nerve.
Lasers Surg Med. 2011 Nov:43(9):901-6
Nussbaum EL, Lilge L, Mazzulh T. Effects of 630-,66A-,810-, and 905-nm laser irradiation
delivering radiant exposure of 1-50 llcm2 on three species of bacteria in vttro ICUn Laser Med
Surg 2002 Dec:20(6):325-33.
Naeser M, Photobiomodulation of pain in carpal tendon syndrome: a review of seven laser
therapy studies. Photomedicine and Surgery 2006; V24, N2:101-110.
O'Connor D, Marshall S, Massy-Westropp N. Nonsurgical treatment (other than steroid
injection) for carpal tunnel syndrome. Cochrane Database Syst Rev 2003;(1):CD003219.
Puett DW, Griffin MR. Published trials of non-medicinal and non-invasive therapies for hip and
knee osteoarthritis. Ann Intern Med 1994;12l(2):133-140.
Roberts D, Kruse R, Petznick M, Kiefer J, Alaskym P. A randomized controlled trial for the
efficacy of therapeutic laser treatment for tendinosis. Proceedings of the International
Association for the Study of Pain 2010.
Speed C, Hazleman B. Shoulder pain. Clinical Evidence, Issue 7 . Tavtstock Square, UK: BMJ
Publishing Group; June 2002.
van der Heijden GJ, van der Windt DA, de Winter AF. Physiotherapy for patients with soft tissue
shoulder disorders: a systematic review of randomized clinical trials. Br Med J 1997;3 1(s):2530.
Williams K, Mathis R, Kingsley JD, Simonavice E, Charles F, Mojock C, Kim J, McMillan V,
Panton L. Effects of Class IV laser therapy on disease impact and function in women with
fibromyalgia. Proceedings of the American College of Sports Medicine 2010
Wu X, Dmitriev AE, Cardoso MJ, Viers-Costello AG, Borke RC, Streeter J, Anders JJ. 810 nm
Wavelength light: an effective therapy for transected or contused rat spinal cord. Lasers Surg
Med. 2009 Jan;41(1):36-41.