Low Power Laser Therapy: A Noninvasive highly effective therapeutic modality Giovanni Galletti Centre for Laser R&D, Institurte of experimental Surgery, University of Bologna, Bologna, Italy
Since the laser's first appearance in 1960, laser instrumentation for medical use has produced considerable research activity with the production of various laser sources with a range of wavelengths, which has been accompanied by a quite rapid development of laser instruments for therapeutic application. Although initially these laser instruments were at high power, subsequently numerous low power lasers became available. Even those intended for high power use, were employed at low power with reliable results.
With such a wide spectrum of laser sources at hand, the following definition has been proposed: any laser light of any wavelength is suitable for therapy as long as the energy density delivered does not produce significant direct photothermal and photodestructive effects in the target tissues.
However, all this has not been free from criticism and controversies. Many authors have studied the amount of energy which should be delivered to tissue per unit of time (the energy density). This aspect of the matter has been considered by most a major issue. However, looking at the results reported in the literature, the results are anything but clear. Since Mester, the energy delivered on tissue has been expressed as joules per square centimetre, but the results been that every author reports different and personal data, causing considerable confusion. Thus, the following question can be posed: although the different energy densities and wavelengths of the various laser instruments used as therapeutic tools for variable pathology, can we get the same results?
From our own clinical experience consisting of 1572 patients affected by various pathologies, treated with different laser light sources and energy densities, 5 minutes exposure time per session, we have achieved in all cases satisfactory results. Even the defocused scanning CO2 laser at 0.5 W output power has proven to be an optimum tool for deep tissue stimulation.
Therefore, all different laser instruments used for LPL therapy, are just as efficient and produce satisfactory results, as long as they deliver an incident energy density which is not capable of inducing direct photothermal effects in the target tissues.
Laser Therapy 1997:9:131-136