R. Glen Calderhead, MSc PhD and David B. Vasily, MD
Before discussing either the photobiological basics or clinical applications of light-emitting diode photo-therapy for the ageing face, the author believes that the title itself raises three major questions to which the reader needs an answer prior to proceeding. First, what is ‘low level light therapy?’ Second, what are light-emitting diodes (LEDs)? And third, what is the rationale behind using LEDs in phototherapy (or photobiomodulation) when there are other well-established light sources such as laser diodes, filtered xenon lamps, and even defocused surgical lasers? With these three pivotal points having been addressed, the application of this non-invasive modality in clinical practice, particularly in photorejuvenation of the ageing face, can then be discussed together with the science behind it.