The Benefits of Laser Therapy
So what have lasers got to do with healing things, anyway? Who came up with the idea of zapping tissues with lasers? There is a strange story behind that:
In 1967, when lasers were starting to be used for all sorts of applications, a doctor in Hungary, called Endre Mester, wanted to study if exposure to laser light would produce cancer. He shaved the backs of test mice, and started exposing them to laser light. None of them got cancer, but he did notice that the laser treated mice grew back their hair faster! That finding brought about the study of Biostimulation – the “boost” given to cellular metabolism by appropriate wavelengths of light.
So why did the mice grow their hair back faster?
All their hair follicle cells were working at full metabolic capacity!
Every cell in the body has “fuel factories” called mitochondria. These mitochondria contain an enzyme, called Cytochrome C, that bonds to paired oxygen molecules. It uses the oxygen to drive a chemical reaction that makes the chemical fuel packets, called ATP, that cells use to drive all their functions. This is why we need oxygen! Without oxygen, their is no usable form of energy for the cells.
The binding site that fits the two oxygen molecules, however, can also fit a “lookalike” molecule, Nitrous Oxide (NO), made of one oxygen atom and one nitrogen atom.
An enzyme that is holding onto an NO molecule is doing diddly-squat – NO means NO energy!
The wavelength of light used in laser therapy is the right size to get absorbed by the Cytochrome C enzyme. Absorbing this energy causes a subtle change in shape in the enzyme, that affects the binding site: the binding site lets go of NO, and preferentially binds with O2.
Now every mitochondrion is firing on all cylinders. The cells have the maximum amount of energy available: for making healing materials, such as the fibrin that patches up wounds; for running the immune functions that clear up infections; and for cell division, to repair and re-populate the site of tissue injury.
The revved-up use of oxygen results in increased production of leftover molecules called Reactive Oxygen Metabolites (ROMs). ROMs affect the cell’s control centre, the nucleus, which releases biochemical signals involved in:
- Control of inflammation: the nucleus produces less of the chemicals Bradykinin and Interleukin 1, that increase symptoms such as swelling, fever and pain perception; and produces more of a class of chemicals called Prostacyclins that tone down the adverse effects of inflammation.
- Opening up vessels: the nucleus releases serotonin, which, along with the NO that was released, causes vessels to dilate. This means that blood vessels can bring in more oxygen, nutrients, and healing cells; and that lymphatic vessels, which drain fluid from tissues, open up and give the fluid of swelling somewhere to go.
- Pain Control: The nucleus releases endorphins, the body’s natural pain blocker; and the neurotransmitter acetylcholine, which, along with NO, helps normalize nerve transmission. These factors, along with the direct nerve effect mentioned next, contribute to significant and immediate pain relief.
Direct Nerve Effect
Nerves fire when there is enough stimulus to bring the nerve’s electrical charge up to a certain threshold. When there is inflammation in the tissue, the ions (charged particles) that maintain the electrical charge leak across the cell membrane. This brings the nerve cell’s resting potential up closer to the threshold – now it takes hardly any stimulus for the nerve to fire.
Laser therapy affects transport of the ions across the cell membrane. It causes the ions to move back and re-establish a normal resting potential – far away from the firing threshold, so that once again it takes a big signal to make the pain nerves fire.
This results in an immediate decrease in the “over-firing” of the pain nerves – pain is diminshed right away.
So what can I expect to see in my pet with Laser Therapy?
- For acute (new, short duration) problems, relief is almost immediate. Pain is diminished, and redness and swelling are significantly reduced. Conditions such as a surgical incision or a “Hot Spot” may need only one treatment.
- For chronic (longstanding) conditions, improvement is generally seen by the 3rd to 6th treatment, after some healing and re-modelling have had a chance to take effect.
- Pain relief may still be immediate even in the first treatment, but lasts only a little while as the underlying condition has not had a chance to heal yet.
- In a small percentage of chronic cases, they may actually feel worse after the first 1-2 treatments; this has to do with the restoration of blood supply where scar tissue had been choking it off (think of pins and needles after you have sat on your leg funny and cut off its blood supply).
- The standard treatment protocol is every second day for a week, then twice a week for a week, then once a week. Treatments may discontinue after the problem is resolved (eg skin conditions, soft tissue trauma) or may taper down to a maintenance protocol that maintains optimum function (eg osteoarthritis may continue to be treated every 2-8 weeks, depending on response).
Laser Therapy In Action
Dawn is a 12 year old Golden Retriever with arthritis of her elbows, spine and hips. She is being treated with Laser Therapy (in addition to her anti-inflammatory and glucosamine supplement).
|Dawn Walking – Before and After||Dawn Down Stairs – Before and After|