Dermatology Made Easy is based on the most popular topics from DermNet NZ's vast array of material. The book combines the essential focus of the ‘Made Easy’ book series with the authority and knowledge base of DermNet NZ's unparalleled resources.
Author: Anoma Ranaweer B.V.Sc; PhD (Clinical Biochemistry, University of Liverpool, UK); Chief Editor: Dr Amanda Oakley, Dermatologist, Hamilton New Zealand, January 2014.
A LASER (light amplification by stimulated emission of radiation) works by emitting a wavelength of high energy light, which when focused on a certain skin condition will create heat and destroy diseased cells. Wavelength is measured in nanometres (nm).
Various kinds of lasers are available for use in skin surgery. They are differentiated by the medium that produces the laser beam. Each of the different types of lasers has a specific range of utility, depending on its wavelength and penetration. The medium amplifies the light of a particular wavelength as it passes through it. This results in the release of a photon of light as it returns to a stable state.
The duration of the light pulses affects the laser’s clinical applications in skin surgery.
An alexandrite laser is one that uses an alexandrite crystal is used as the laser source or medium. The alexandrite laser produces a specific wavelength of light in the infrared spectrum (755 nm). It is considered a red light laser.
Alexandrite lasers are also available in the Q-switched mode. Q-switching refers to the technique of making the laser produce a high intensity beam in very short pulses.
The wavelength of high energy light emitted by the laser is converted to heat energy and this damages the specific target area. Thus alexandrite lasers work by a process of photothermolysis: this means using light (photo) to heat (thermo) a selected area for destruction (lysis).
Alexandrite lasers cause very precise tissue destruction of the lesion and leave tissue in the surrounding area undamaged.
The US Food and Drug Administration (FDA) has approved a range of alexandrite laser machines emitting infrared light (wavelength 755 nm) for various skin disorders. These include Ta2 Eraser™ (Light Age, California, USA), Apogee® (Cynosure, Massachusetts, USA) and Accolade™ (Cynosure, MA, USA), Individual machines may be specially designed to focus on specific skin problems.
The following skin disorders can be treated with Alexandrite laser beams.
Side effects from alexandrite laser treatment are usually minor and may include:
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