The effectiveness of laser in re-generating tissue, controlling inflammation and managing pain has been demonstrated in multiple laboratory experiments and clinical trials. Over the past 20 years, advances in technology have accelerated its use in clinics. Nonetheless, while clinical use of lasers has become more prevalent in certain parts of the world, it is still a niche tool in Canada. However, I anticipate it will to gain prominence over the next few years as awareness of its effectiveness and versatility increases.
With so many manufacturers out there promoting their products, it can get a little confusing to determine which type of laser would be most relevant for you to use clinically. The rest of this post will aim to clear up certain misconceptions and facilitate the decision-making process when looking at purchasing a laser unit. Current and future uses of the modality will also be presented.
Class issues
One of the questions we get frequently when discussing lasers with customers is about the class of lasers. Many people believe that higher (i.e. Class III & IV) lasers are more efficient clinically. Well, about that… Not the case. At all. In fact, the classification of lasers is simply a safety rating, meaning that greater precautions need to be taken when using the higher-class lasers. Further to that, as higher-class lasers are more powerful, this increased power brings a risk of detrimental effects by heating up the tissue rather than stimulating their regeneration. So, score one for the little guys! Here’s more information on laser classes: https://www.lasersafetyfacts.com/laserclasses.html .
Mode of Action
Contrary to many therapeutic modalities (Ultrasound, Shockwave) lasers do not act physically on tissue, but rather through a chemical reaction promoted by the photons delivered by the lasers or LEDs. This process is referred to as Photobiomodulation or PBMT. When the photons react with select components within the body, the reactions release various compounds, which in turn promote the healing process. Through PBMT, healing is accelerated, and, in certain reported cases, quite significantly. Among these compounds are nitrous oxide (NO) and cytochrome c-oxidase which are believed to have an impact on cellular activity and subsequent tissue regeneration. A very good overview of the mechanisms of action of laser therapy is presented in this paper: https://doi.org/10.1007/s10439-011-0454-7
Are multiple wavelengths better than one?
Yes, they are. Multiple wavelengths promote what is called the cascading effect, which in turn reduces tissue saturation from photons. Since tissue react differently to the various wavelengths, the depth of photon penetration is increased when using this technology. This cannot be achieved with single wavelength lasers nor with continuous-wave lasers. So, super-pulsed lasers with multiple wavelengths are the technology of choice to promote the fastest healing. With both features combined, optimal laser energy delivery is promoted, as is tissue regeneration, pain management and healing.
Is laser better for acute or chronic conditions?
Both. Depending on the goal of the treatment, a change in pulse frequency will have a varying effect on the tissue being treated. To inhibit inflammation for example, treatments would use lower frequencies, which have shown to have an inhibitory effect of cellular activity. On the flip side, if a practitioner is looking to promote tissue regeneration, using higher frequencies would be the way to go! Here’s a nice overview of the many uses of LLLT in MSK pain management: https://dx.doi.org/10.15406%2Fmojor.2015.02.00068. More and more research is also coming out supporting using LLLT in cases of TBI, stroke & neurodegenerative disease: https://doi.org/10.1089/pho.2011.9908
Where do we go from here?
Recent research using lasers has shown they may be useful in the treatment of a variety of conditions that have historically been hard to manage. An experimental protocol using laser acupuncture probes to stimulate the sphenopalatine ganglion, had some very encouraging preliminary results in clinical testing, reducing headache pain significantly and with lasting effects. The authors of that trial report patients returning to work after years of disability. The results from this trial were presented in a webinar from Laser Therapy U and have yet to be published unfortunately. Another study showed that cranial stimulation using red LED devices helped brain injured patients regain cognitive function and real-life capacity (https://www.liebertpub.com/doi/full/10.1089/pho.2018.4489). This 2014 publication by Burkow et al reviews new uses for red light therapy as an effective, non-invasive treatment in sport related injuries with very interesting results: http://labome.org/research/The-use-of-near-infrared-light-emitting-diodes-in-treating-sports-related-injuries-a-review.html.
With LLLT gaining prominence, showing promise as an alternative to addicting pain medication and being shown as a useful modality for therapists in many different fields, adding a super-pulsed laser to your practice should be only a matter of time.