Should your veterinary practice become laser-focused?
Laser therapy. We don’t really know exactly how it works just yet, but we know it does work—just ask the veterinary technician in the laser therapy room using it on herself (shhhhh!). We still also don’t really know what all it can help with, but let’s see what we can find out.
You think you know lasers? Do you really?
Did you know that laser is an acronym? Quick, what does it stand for? (No peeking.)
Light amplification by stimulated emission of radiation
But basically, a laser is any coherent beam of light. That is, the light doesn’t scatter like it does with a flashlight. The overall classes of lasers are based on how likely they are to damage tissue. How cool, err, hot is that?
Lasers split off into four classes:
• Class 1 lasers are incapable of causing enough radiation to harm tissue.
• Class 2 lasers emit visible light and are potentially harmful to tissue if exposed for an extended period. Laser pointers fall into this class.
• Class 3 lasers—we’re starting to get more harmful to tissue; this class has two subdivisions: 3A (visible light) and 3B (nonvisible light). Some therapeutic lasers fall in this class.
• Class 4 contains surgical and therapeutic lasers. They are nonvisible and are so intense they can start fires (don’t worry, you can avoid that).
What we think we know about how lasers work
Not to be persnickety but… keep in mind that very few laser studies have been done in dogs and cats. The rest of the information is extrapolated from work with humans and horses. So much of the information, when applied to dogs and cats, should be considered anecdotal.
Generally, lasers are used to speed wound healing, which includes surgically induced wounds (incisions), and to decrease pain. In treating the tissue around a wound, the treatment with the laser is not doing anything new to the tissue, it is just speeding up the normal repair process. (Hint: This is why you never use lasers near neoplasia—cancer doesn’t need any help speeding up!) When using lasers to treat pain, the mechanisms by which they work are thought to be related to the inhibition of neuronal activity and potentially through endorphin release. The end result appears to be blocking pain transmission to the brain.
Wardlaw uses laser therapy for her patients with osteoarthritis, tendonitis, wounds and edema. She quotes a human study on arthritis where some participants got anywhere from two months’ to a year’s worth of a reduction in pain from arthritis from just two weeks of laser therapy. She also sees great results with surgical and traumatic wound healing and says that you can almost watch the edema disappear from affected areas as you treat them with the laser.
The geeky stuff that you need to know before you purchase one
|When they talk about:||It's referring to:|
|Joules||The energy the laser emits|
|Time||The duration of time it takes for the energy to reach the target tissue—how long does it take to treat that animal in one spot?|
|Wavelength||The depth of penetration of the laser: blue light = superficial; red = deeper; nonvisible = deeper|
|Frequency||The number of impulses emitted per second|
|Power (Watts)||The rate at which the energy is delivered|
|Emission mode||Continuous or pulsatile|
|Dosage||Joules/cm2 << The most important thing because, like medication, the dosage needs to be adequate for treatment success|
Putting it into practice
What effective treatment all boils down to is delivering the correct effective dosage to the correct area for the correct amount of treatments.
Wavelength dictates how deep the penetration is—different wavelengths determine which processes occur at what tissue level. But keep in mind that some energy is lost when you encounter hair and melanin.
Let’s talk diodes. The more diodes, the bigger the treatment area for a single treatment cycle. The number of diodes is part of the equation that determines how long it will take you to treat a certain area. And that matters. To you, your employees, the animal (certainly) and the owner. This is where dollars and cents come into play. How long are you going to have to pay for that trained technician (or doctor) to perform the procedure?
Keeping this in mind, financially when it comes to lasers, in general, you get what you pay for. There are inexpensive lasers out there, but it’s going take you a really long time to get an appropriate dosage, says Wardlaw. For example, if you get a weak laser with a small diode, it may take you 45 minutes to treat a 5-cm surgical incision with the correct dosage of 4 to 6 J/cm2. But if you get a more powerful laser with a bigger diode, it may only take you five minutes to treat the same patient.
Dr. Wardlaw’s recommended starting dosages (which she says will likely change as more research is published and we learn more):
- Arthritis: Start at 6 to 8 J/cm2 every other day for two weeks
- Wound healing: 8 J/cm2 once a day for seven days
- Tendonitis: 6 J/cm2 every other day for two weeks
There are two different ways to administer the dosage, you can administer it in a grid-like fashion, where the delivery is pulsatile and you treat one spot at a time. Or you can administer it in a sweeping motion, where movement is slow but constant. Wardlaw says the sweeping technique is really good for edema.
“The laser bottom line equals this: the differences among commercially available lasers lie only in the wavelength, power density, pulse modulation—and how cute they are,” Wardlaw says.