Laser Hair Removal

Author: Mounir Bashour, MD, CM, FRCS(C), PhD, FACS, Assistant Professor of Ophthalmology, McGill University; Clinical Assistant Professor of Ophthalmology, Sherbrooke University; Medical Director, Cornea Laser and Lasik MD

The laser hair-removal systems currently used are relatively new; therefore, long-term results have not been reported. However, many reports about the efficacy of these systems have recently been published.

Success is typically reported in terms of permanent hair elimination or in terms of marked delay in its growth. Most investigators have assessed patients with light skin types (ie, Fitzpatrick skin types I-III), but recent groups have studied newer lasers for Fitzpatrick skin types IV-VI.

History of the Procedure

Goldman et al first described ruby-laser injury to pigmented hair follicles in 1963.1 In 1983, Oshiro and Maruyama noted hair loss from nevi after treatment with a ruby laser.2 However, at fluences affecting hair follicles, the epidermis was severely damaged.

The theory of selective photothermolysis that Anderson and Parrish developed in 1983 was based on a laser of particular wavelength and a pulse duration of light to target a particular chromophore.3 By applying this theory, the target can be destroyed selectively, sparing the surrounding tissue.

Use of a topical suspension of carbon particles followed by treatment with a Q-switched Nd:YAG laser was the first laser treatment for hair removal the US Food and Drug Administration (FDA) approved. This initial method reportedly delayed regrowth by 3 months, but it did not provide permanent hair reduction.

In 1996, Grossman and associates, who used a normal-mode ruby laser, reported the first application of Anderson and Parrish's theory for hair removal.4 In 1998, Dierickx and associates published their report of a 2-year follow-up study demonstrating long-term, permanent hair removal with this laser.

Hair-removing lasers and light sources

Since then, the market has been flooded with numerous hair-removing lasers and light sources.

Initial laser systems, such as the Q-switched Nd:YAG (1064 nm, Soft Light system; Thermolase Corp, San Diego, CA), used a suspension of carbon mineral oil to penetrate the hair follicle and to act as an energy-absorbing chromophore.

An optically filtered xenon flashlamp (Epi Light, ESC Luxar; Energy Systems Corp, Needham, MA) uses filters to select operating wavelengths of light at a cutoff of 690 nm, allowing light above this wavelength to pass through to affect hair.

The long-pulse ruby laser (EpiLaser 694 nm, Palomar Technologies, Lexington, MA; EpiTouch, Sharplan Laser, Allendale, NJ) uses the principle of selective thermolysis in which melanin acts as the target chromophore.

The long-pulse alexandrite laser (PhotoGenica LPIR 755 nm; Cynosure Inc, Chelmsford, MA) is based on the principle of thermokinetic selectivity and targets melanin in the hair follicle. In this way, the epidermis is allowed to cool efficiently while the melanin in the hair follicle is heated.

Coherent Medical (Santa Clara, CA) and Palomar (Lexington, MA) have introduced the LightSheer, a diode laser operating at 800 nm that has pulse durations of as long as 30 ms. This technology minimizes the size of the laser by replacing the laser tube in place of solid-state diode circuitry.

Lasers available or once available

The following is a list of lasers available at the time of this writing. Most technical improvements in devices have been incremental in terms of improving efficacy and reducing side effects. Some new models combine light- and heat-based methods by using radio-frequency (RF) energy; these are based on the theory that the heated areas can be further heated without causing damage to surrounding skin.

New devices are frequently introduced, and old models may be discontinued but still available as after market products. Check with the manufacturers for latest information.

Currently manufactured models of lasers are the following (by brand name - type of laser - manufacturer):

Discontinued models include the following:

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