J. Frank Nash1, Melea Ward1, and Gurpreet S. Ahluwalia2
1 The Procter and Background
The use of light energy as a treatment modality in dermatology is as old as civilization itself. The therapeutic properties of sunlight, alone or in combination with exogenously applied compounds have been used in the treatment of skin conditions for centuries. The earliest suspected application of light therapy was by the Egyptians, who used the interaction between sunlight and exogenously applied plant materials to treat skin disease [1]. With the development of artificial light sources, the practice of phototherapy has evolved to a point where, for example, the standard treatment of psoriasis is “PUVA” or 8-methoxypsor – len + ultraviolet (UV)-A [2]. In many cases, the therapeutic benefit of light-based treatments is achieved with a nonspecific broadband, that is, a range of wavelengths such as 320-400 nm, light source. Thus, there is a greater potential to interact with multiple chromophores and elicit both beneficial and adverse effects. Technological advances have transformed phototherapy, making diverse light sources more readily available and practical to use.
It has been over forty years since Dr. Leon Goldman working at the University of Cincinnati School of Medicine published a series of papers describing the use of lasers in dermatology [3-7]. Dr. Goldman largely recognized as the father of laser therapy in dermatology, opened the door for multiple researchers/clinicians and helped establish the principles for dermatological treatments using lasers. As with many innovations, the early years of laser treatment were filled with trial and error, refining therapy and reducing the adverse effects, particularly nontarget tissue damage, contributing to scarring and pigmentary changes. Many of the advancements have also been in the laser systems, for example, pulse- duration, waveband versatility, electronics, etc., and for some systems, skill of the operator.
Today, there are multiple lasers in use with wavelengths at the end of visible radiation and into the infrared. The breadth of electromagnetic radiation and the portion where lasers for dermatology are highlighted in Fig. 23.1. The most common lasers used in cosmetic dermatological practice is briefly reviewed.