Light therapy has been used for centuries beginning with the ancient Greeks. The use of sunlight has been thought to be useful for many medical therapies. The healing affects of light have taken on greater focus in the last 50 years and more recently, research has focused on the part of the light spectrum that is not visible to the eye, and to the use of therapeutic low power lasers (LPL).
A few definitions are in order to understand the concept of light therapy. Light is an energy force that is transmitted in wavelengths, just as sound waves. A wavelength is a term to describe the distance of energy from one peak to the next peak in that amount of energy. Those wavelengths are measured in nanometers (nm). If we were to take a prism and shine sunlight through it we would see the colors of the rainbow. The colors we see are the different visible wavelengths of light divided up so that we can see them separately. Those wavelengths that we can see go from 393 nm of violet to 759 nm of red. Above 770 nm is termed infrared, and below 390 nm is termed ultraviolet. Another term we need to understand is the frequency that those waves travel. That is the number of wavelengths that are measured per second or cycles per second. This is also known as Hertz (Hz). Humans perceive sound from 16 Hz to about 18,000 Hz. LPL uses a spectrum of light from 660 nm to 905 nm and from 5 Hz to 5000 Hz. Another term that you will see is wattage or watts. That is the power that is used to “push” the light through the media it is directed towards. When we think of a light bulb we can visualize that a 100 watt bulb is stronger and brighter than a 60 watt or 35 watt bulb. The wavelength of light and the frequency (Hz) from each bulb is the same but the wattage is different.
What is a laser? We see lasers all the time, from grocery store checkouts, to laser pointers in class rooms to laser target finders on for weapons in the military, lasers even play our favorite CD’s or DVD’s. The word “Laser” is acronym for Light Amplification by Stimulated Emissions of Radiation. The three characteristics of a laser light are non-divergence, coherence, and monochromatic. Non-divergent means that the laser beam is focused, with little spreading from its origin. This is similar to a flashlight beam, as opposed to sun light. Coherent means that the wavelengths of the beam are all in phase, in so that the wavelengths are all matched peak to peak going the same speed or hertz. Monochromatic means the laser is all one wavelength, one color on the light spectrum. These characteristics make laser light stronger, or having more energy than ordinary light. The power of lasers can range from milliwatts to thousands and millions of watts. Surgical lasers are rated from 30-100watts of average power and are called “hot” lasers, while therapeutic, low power lasers use from 1 milliwatt to 25000 milliwatts (25 watts) and are considered “cold”. LPL use either a gallium arsenide (GaAs) and/or helium neon (HeNe) diodes to produce the laser beams. GaAs lasers produce an infrared beam at 905 nm, while the HeNe lasers produce a red light beam at 633 nm.
Laser light works on the body at the cellular level. In basic terms, the light particles from the laser beam stimulate the cells in the body to increase cellular metabolism, increasing energy output from cells, which then reduces inflammation, increases anti-inflammatory mediators, and increases microcirculation, which in turn decreases edema. In the big picture, laser therapy decreases pain, reduces inflammation, promotes wound healing, tissue regeneration and stimulates acupuncture points.
Conditions that are frequently treated with laser light therapy include osteoarthritis, skin conditions including open wounds, severe inflammation (snakebite), generalized pain, bone fractures, tendon conditions, ligament sprains-tears, bowed tendons, post-op surgical incisions, muscle stiffness, and acupuncture points.
The laser that Dr. Landes uses is the Multi Radiance MR4 ACTIVet and it combines 4 different radiances of light therapy into one machine. It starts with Super Pulsed Laser (905nm) that produces a high power level of impulse light at a billionth of a second. It is the high power during each pulse that drives the photons, or light energy, down to the target tissues, to 10-13cm (4-5 inches) deep. The MR4 ACTIVet high peak power of up to 25,000mW creates higher photon density, delivering the highest concentration of photons for healing and providing the deepest tissue penetration. Super Pulsed Laser strongly influences pain reduction, the improvement of microcirculation and increases cellular metabolism. Pulsed Broad Band Infrared Emitting Diodes (875nm) is used to penetrate shallower tissue depths than the laser but provide an overall broader spectrum, when compared to laser radiation, gently heating the surface tissue layer. At the next level a Pulsed Red Light (660nm) penetrates shallower tissue depth and has beneficial anti-inflammatory effects and initiates tissue repair.
Unique in the industry, MR4 ACTIVet also has Blue 470nm for treating bacterial infections caused by Staph and MRSA. Working synergistically, the multiple radiances of the Multi Radiance Technology create the optimal biological environment for accelerated healing and pain relief. The use of the preset frequencies, allows clinicians to control the depth of the therapeutic energy from the surface up to 13 cm (5 inches) deep.
Including laser therapy into the treatment plan for your horse can greatly reduce the time for healing when your horse is coming off an injury using a simple, non-invasive, and safe therapy.