Cold Laser Therapy And Applications in Canine Rehabilitation Therapy
Presented by Deanna Clark DVM, CCRT of 4 Paws Swim and Fitness
10/26/2011
What is Laser Phototherapy?• Low Level Laser Therapy • Low light intensity influences
cell/tissue functions• Heating is negligible • Effects due to photochemical
or photobiologic reactions like effect of light in plants
The Power of Light
• Remember atoms?• Photon energy excites an atom and electrons
change their energy level• Electron jumps from inner to outer orbit then
back—gives off energy!
Physiological Effects
• Visible red light absorbed in mitochondria• Infra red light absorbed at cellular membranes• Increases ATP• DNA production• Opens Ca channels• Increases cellular proliferation• Increase in release of growth factor• Increased myofibroblast activity• Alters pain threshold
What Defines Laser Light?
• Light Amplification by Stimulated Emission of Radiation
• Monochromic - the color of light/wavelength• Coherent—laser light sticks together/amplifies
Coherency is Special
• Waves have the same frequency and phase• Polarized light—light moves together• Almost parallel beam—Moves together
without spread (collimating)
Laser Light
• Visible: Helium Neon (HeNe) 400-700 nm• Invisible: Infrared 750nm-950nm• 600-1000 nm is therapeutic window• < 600 nm Bactericidal• 600 nm Skin repair and acupoint stim• 600-1000 nm tissue repair
Does it have to be Laser?
• Monochromatic (non coherent light) light from LED's can give good effect on superficial tissues such as wounds
• In comparative studies lasers have shown to be more effective especially in deep tissue
How Deep can Laser Penetrate?
• Long wavelength penetrates deeper than short
• 808-904 nm is ideal?• “Penetration depth, its accurate definition, its
measurement, and even its importance in phototherapy, are hotly debated topics” http://www.spectramedics.com/index.php?id=105
Power of Penetration
• Still a lot to learn!• One study shows 904nm with super pulsing is
best• Twice the power isn’t twice as deep (5-10% ) • Wavelength, super pulsing, power, intensity,
tissue contact and compression
What about Absorption?
• Light is weaker further from surface it penetrates• Tissue type (bone,fat,muscle), pigment, dirt, hair,
clothes decrease penetration • Clothes reduce penetration between 80 and 100%
http://www.youtube.com/watch?v=MkGJvvWD1vw
• Blood absorbs energy-pushing lightly pushes blood away
What does this Imply?
• Due primarily to absorption by water in tissue, 980 nm (class IV) penetrates less than 808 nm, and this is not compensated by the higher power
• Holding space between laser and skin to avoid heating will further decrease penetration
Does LLLT Cause Heating of Tissue?
• Yes - all light causes heating if absorbed • GaAlAs (3B) lasers in 300-500 mW range cause
noticeable heat sensation, particularly hairy areas, tattoo
• Melanin important factor; dark skin > fair skin• Increased circulation causes increase
0.5-1 °C local
The Laser Class
• Classified by wavelength/max output power into four classes (subclasses)
• Ability to produce damage in exposed people • Class 1 (no hazard during normal use) to class
4 (severe hazard for eyes and skin)• Classification is not effectiveness
Laser Classes
• Class I 0.4 mW• Class II 0.5-1.0 mW blink
adequate• Class IIIa 1-5 mW eye caution• Class IIIb 5-500 mW eye danger• Class IV >500 mW fire hazard,
Danger
Class 1 (less than 0.5 mW)
• Visible and non visible• No eye or skin danger• Laser printers, car entry, CD players• No heating/no healing• Safe in all uses unless focused through
magnifier
Class 2 (less than 1 mW)
• Visible• Safe for short periods on eyes and extended
on skin• Safe because blink reflex limits retina
exposure• No healing/no heating
Class 3 (1mW to 500 mW)includes 3a and 3b
• Visible and invisible• Helium neon (HeNe)• Galium Arsenide (GaAs)--infrared• GaAluminumAs (GaAlAs)—infrared• MPE can be exceeded with limited
effects (skin)• Protective eye ware if direct viewing of
beam
Class 4 (>500 mW)
• Increases tissue temperature--can burn• Dehydrates tissue• Coagulates protein• Thermolysis• CO2, Argon, YAG laser• Eye danger can result from indirect or
reflected beam
The Calculations
• Energy is power over time• Energy (Joules) = Watt (W) x second• Lasers come in mW and 1000 mW= 1 watt• 1 joule from 5 mW laser requires 200 seconds
of time (3.3 minutes)• 50 mW laser requires 20 seconds• 500 mW laser requires 2 seconds
More Power is Not Better
• More Power means shorter treatment time• More Power is more cost!• More Power is more dangerous!
It Comes Down to Dose
• Class 3 and 4 can deliver same dose• http://www.laser.nu/lllt/pdf/theimpossibledose.pdf
Dosage
• Doses—Respond 904 nM, 500 mW, IIIb• 1-3 j/cm(2) circulation• 1-6 j/cm(2) acute pain• 2-4 j/cm(2) muscle pain• 4-6 j/cm(2) neurological indications• 4-8 j/cm(2) joint pain• 5-6 j/cm(2) wounds• 8-12 j/cm(2) chronic pain and OA• Acu-points @ 60 mW = 33 sec = 2J• Laurie Edge-Hughes
Laser Dosing is Cumulative
• Repeated dose 1-7 day intervals has stronger effect then given at once
• Recent research hints low power and long exposure -better than high power/short time for tissue regeneration
• Treatment times in excess of 15-20 minutes may produce systemic effects
Can you use too high of a dose?
• With Class IV it would burn• May have bio-suppressive effect or non
optimal effect• The healing of a wound may take longer• Found evidence that 16j/cm(2) is inhibitory
Can Laser Light Cause Cancer?
• No mutational effects with wavelengths in red or infra-red range
• No mutational effects with doses used within LLLT• Cancer cells in vitro have shown stimulation • Rat studies shown small tumors can recede or
completely disappear• Rat studies shown no effect on tumors over a certain
size • Probably local immune system is stimulated more
than the tumor
What about Bacteria
• The situation is the same for bacteria and virus in culture--stimulated by laser light in certain doses
• Bacterial or viral infection is cured much quicker after treatment with LLLT
• Study on MRSA-one positive and other refuted http://www.stanford.edu/~kendric/PDF/B57.pdf
Can Lasers Really Damage your eyes?
• Any strong light source can injure eyes• Powerful laser (many watts) is more hazardous • Parallel light enters--further focused to concentrated
spot• To burn the retina, certain energy or time is needed• With visible wavelength range, we blink• Lasers in general are much less dangerous than people
think--But I wouldn’t want to experiment!• Japanese researcher treated calves with KCS with
excellent results (HeNe)
Is Laser Therapy Proven?
• Mostly yes• More than 130 double-blind
positive studies confirming clinical effect of LLLT
• About 250 papers annually published in peer reviewed scientific papers
• www.pubmed.com• www.laser.nu
And the Flip Side
• Many studies prove it doesn’t work• Closer look reveals serious study flaws • Don’t clearly indicate dose or are under-
dosed • LLLT will not work on everything• Matter of dosage, diagnosis, treatment
technique, individual reaction for any modality
Biological Effects
• Heals leg ulcers• Accelerates collagen synthesis• Accelerates inflammation phase of wound healing• Enhances immune cells to combat invading
pathogens• Increases vascularity of healing tissue• Pain reduction from endorphin release• Fibroblast production• Cartilage stimulation
Indications
• Arthritis• Tendonitis• Wounds• Edema• Contractures/scar tissue• Increase circulation• Pain• Muscle spasms
Contraindications• Dr. Laurie Edge-Hughes says….• Eye• On cancerous lesions• Pregnant abdomen (no testing)• Unclosed fontanels• Over Vagus nerve• Over sympathetic ganglia• Cardiac region of heart patients• Areas of hemorrhage• Over thyroid/endocrine glands• Areas treated with recent cortisone injection (wait 1 week as may flare
site)• Stem cell therapy—wait 6-8 weeks
Contraindications?
• www.lasernu.com says….• None medical • In most countries-legal, i.e. you should not treat
cancer or some other serious diseases• Pregnancy is not-if treatment done with common
sense • Pacemakers are electronic -not influenced by light• Most valid contraindication is possible lack of
adequate medical treatment
Actually Using Laser!
• We use a Class 3b (Chattanooga)• I diagnose my patients and set up treatment
plan• My technicians or myself carry out plan
What Dose Do We Use?
• Changed dose for each indication- depth etc.• Generally 8 J/cm(2) routine• 10 J/cm(2) for spine • Long treatment duration• Recently changed to 5 J/cm(2)• Changing back?
Post-operative
• Treat operated joint• Base dose on depth of concern• Caution lateral suture surgery as
may actually prevent fibrous tissue needed!
• Treat compensatory concerns
Dakota
• TPLO (failed Lateral suture) 8 weeks post-op
Osteoarthritis
• Treat joints affected based on depth• Treat local muscles that are affected• Acupuncture points?
Maddie
• Bilateral cruciate tears—no surgery—recent concern for meniscus, bilateral severe hip DJD
• Does great with just recent once monthly visit!
Muscle injuries
• Laser really seems to heal muscle strains• Great success with iliopsoas in 4-6 weeks• Combined with other physical therapy
modalities of course!• Treat compensatory concerns
Cutter
• Iliopsoas and gracilis strain with return to agility in 8 weeks!
Myofascial pain/trigger points
• Complete “trigger point massage”• Laser affected areas• Complete gentle range of motion and
stretching at same time• Acupuncture points?
Sadie Mae
• My own girl and reason for rehab—tolerated nothing else!
Tendonitis
• Laser can be used similar to ultrasound• Supraspinatus/Biceps• Diagnose specific area of discomfort-anatomy• True P.T. Exam crucial to diagnosis
Frannie vs. Angus
• Laser vs. Ultrasound
Performance Athletes
• Laser over trigger points and sore muscles• Stretch and assess at same time• Baltimore VOSM
Helmet
• Does one time laser session work?• Study suggests endurance training
program combined with LLLT lead to greater reduction in fatigue http://www.ncbi.nlm.nih.gov/pubmed/21870127
How long does it take?
• Intense osteoarthritis patient may take upwards of 30-40 minutes for laser alone
• Combine with other exercises?• Combine with underwater Treadmill?
How to charge?
• Some charge per time• Some charge per modality• At 4 Paws we designate Level which is
basically time and includes more modalities
References
• http://www.laser.nu/lllt/pdf/Confounders.pdf• http://www.laser.nu/lllt/pdf/Penetration.pdf• Laurie McCauley, DVM TOPS Veterinary
rehabilitation• www.laser.nu• Dr. Laurie Edge-Hughes• CRI—likes Spectra-Vet laser• Swedish Laser-Medical Society
Questions?