ABSTRACT
Light has long been used as a tool for the restoration of health. The healing powers of sunlight became one of the earliest recorded treatments in Western medicine (Bettman 1979; Kelly 2009), used for a wide variety of medical conditions, such as smallpox and tuberculosis (Bettman 1979). In 1963, Goldman et al. (1963a) first clearly described ruby laser-induced injury to pigmented skin, including hair follicles. In the following years, the ruby laser was explored as a treatment for many conditions, with little regard for absorption of light energy by various tissues. A historical case reported in 1983 was that of a young boy treated for a vascular malformation that resulted in severe epidermal damage. In the same year, Anderson and Parrish (1983) published the theory of selective photothermolysis (SP), which describes a strategy for using optical pulses to selectively affect pigmented “targets.” A wavelength(s) is chosen that is preferentially absorbed by a particular chromophore associated with the target (melanin, hemoglobins, tattoo inks, or other pigments), and a pulse duration is chosen that is sufficiently short to limit heat transfer from the target structure during the laser pulse. By providing a microscopic target-selective treatment, SP enabled new laser treatments to be developed with minimal risk of gross tissue injury, for example, treatment of microvascular skin malformations and removal of pigmented hair follicles, pigmented lesions, and tattoos (Anderson and Parrish 1983; Grossman et al. 1996). With this concept came an explosion in the number of lasers and light sources in dermatology to accommodate a spectrum of aesthetic procedures with minimal pain (Bashkatov et al. 2005; Tanzi, Lupton, and Alster 2003; Tseng et
al. 2009). In 2008, nearly 75 million aesthetic light procedures were performed, and the number is expected to double because of a growing and demanding young consumer market. Herein we introduce the applications of lasers and intense pulsed light in dermatology, including the potential for further development.
