Articles

Mechanisms of the Analgesic Effect of Therpeutic Lasers In Vivo

Although many aspects of the mechanisms by which LLLT attenuates pain remain unclear, enough has been shown scientifically to draw the firm conclusion that LLLT has a real role in pain therapy. From the scientific viewpoint, it is of course necessary to draw careful conclusions based on controlled double-blind studies, with, if possible, a crossover element, in order to identify the strength of the so-called ‘placebo effect’. There exist now some studies which have done just that: in LLLT for postherpetic neuralgia, acute soft tissue injuries and postoperative pain, all of which have appeared in this journal. These studies show that while there is a placebo effect, it is however extremely weak and very short-lived compared with the ‘real’ laser therapy treated groups. From the clinician’s viewpoint, however, should we really be so worried about the placebo effect of a laser? The authors would like to hope that the main aim of laser therapists is to get rid of their patients’ pain. If the placebo effect associated with the high-tech ‘laser’ can assist in this goal, particularly when it is known that LLLT goes way beyond the placebo effect only, then that is surely one more good reason why LLLT should take its rightful place in the armamentarium of those medical professionals dealing with the treatment of pain.
It has been almost unanimously stated in the literature that LLLT is easy to apply, is pain and side effect free, and is well tolerated by patients of all types and ages. As long as we remember that LLLT is not a magic wand, and is not capable of curing every single pain entity under the sun, in every single patient, then LLLT can be confidently used on its own or as an adjunctive therapeutic modality with an expectation of achieving an effective pain relief of around 70%-85% in about 80% of patients, if we look at the average values from the majority of large patient population case studies (>1000 patients per study) seen in the literature since 1988.
As a final not, we must also remember that pain is often a symptom and not the disease, so it is necessary to make sure the root cause of the painful condition is accurately identified and treated, in addition to the pain itself. The authors are confident that further scientific studies will continue to elucidate the mechanisms and pathways of LLLT pain control, and that laser therapy is poised to enter the 21st century where it will surely become even more of a leading clinical modality that it is at present.