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?