Phototherapy: Medicine for the new Millennium

Abstract

Phototherapy has been around in clinical practice for more than 5,000 years, but has not shown consistent clinical results or attracted continuous real attention until the last 5 decades, since just before the ´birth´ of the laser. Although phototherapy can be construed to mean therapy delivered with any kind of light, including lasers, intense pulsed light (IPL) systems, various incandescent and arc lamps and most recently, light-emitting diodes (LEDs), a gradual consensus has formed that ´phototherapy´ means the treatment of a disease or condition with the delivery of athermal and atraumatic levels of photon energy. This rules out IPL systems and laser systems specifically designed for so called nonablative skin rejuvenation, but does not however rule out surgical lasers used in a defocused mode so that the incident power density or irradiance is well below the photodestructive cellular survival threshold. Phototherapy with the new generation of quasimonochromatic LEDs with much greater and more stable output power compared with their earlier generations, is currently attracting a great deal of attention, and indeed controversy, in clinical practice for skin conditions such as acne, skin rejuvenation and wound healing. Pain attenuation has also been reported with a near infrared LED source. It has become evident from the literature that LED therapy works best when two or more wavelengths are combined in a sequential manner, not simultaneously, in a photobiologically appropriate manner for the target cells and tissues. Perhaps an even greater potential for LED therapy exists in its being incorporated into our conventional clinical practice as an adjunctive treatment to improve our already good results, particularly when the cost-effectiveness of these systems is considered. Some of the mechanisms by which this athermal and atraumatic light source can beneficially affect targeted tissues have already been elucidated, but much more work awaits before we can unlock the full scientific potential behind the good clinical results. There is no doubt that LED therapy has arrived, but its impact remains to be maximized. © 2006, International Phototherapy Association. All rights reserved.