28.01.2011
Dr. Jean Luc Levy, MD, Laser Dermatology Center, Marseille, France
Introduction
Laser
hair removal is still the most popular laser cosmetic procedures
worldwide. Now a broad assortment of devices for hair removal is
available on the market.
There is a large number of working
protocols with the peculiarities of the procedures on different areas of
the body with different skin phototypes and the different hair
characteristics. This clinical report will not include a statistically
significant amount of samples, but will be restricted by the only
specific area of treatment, the axillary area.
Laser hair removal is
often associated with the procedure of removing unwanted hair, but it
is also an integral part of hirsutism and hypertrichosis treatment.
The
main objectives of laser hair removal are well pigmented and thick
terminal hairs, with a dense keratinized melanocytes column. It is well
known that hair growth cycle consists of 3 phases: anagen, catagen and
telogen. Laser hair removal should be handled during the anagen phase, a
phase of active growth.
Hair follicles vary even on the same
area of skin, which affects the subsequent transfer of heat. Hair
follicles are usually located at a depth of 1 to 6 mm, the papilla,
located more surfactant than hair bulb. Both dermal papilla and hair
bulb are the targets for laser hair removal.
The theory of
selective photothermolysis is the basis of laser hair removal procedure,
when the laser beam is focused on the melanin in the hair shaft, as the
main chromophore for laser hair removal, perifollicular dermis of the
surrounding tissue remains unaffected. In order to avoid undesirable
side effects after laser hair removal pulse duration should be shorter
than the thermal relaxation time of hair follicle (between 20 and 80
ms).
While wavelength is increasing, absorption of laser light
by melanin decreases. Additionally, during the procedure of laser hair
removal, the ray dispersion mechanism reduces depending on the
wavelength, which leads to deeper penetration into the dermis. The
increasing during laser hair removal spot size ensures improving of the
optical penetration into skin 1,5,6. Alexandrite Long-pulse Laser with a
wavelength of 755 nm is the best choice for an effective procedure of
laser hair removal. Its distribution and recognition in the market began
in 1996. Excellent absorption in melanin and low absorption in
oxyhemoglobin makes it an ideal wavelength for laser hair removal of
Fitzpatrick I-IV skin phototypes.
Additionally, the side
effects of alexandrite laser with a properly regulated cooling system
using is minimal, even for dark skin phototypes 5,8.
Quanta
System is one of a few alexandrite laser manufacturers. Laser Light A
platform and Domino, produced by Quanta System - is a modern alexandrite
platform, which guarantee the highest success degree of laser hair
removal procedures. During this clinical study we used the Light A
laser. Nevertheless, the alexandrite laser can also be found among other
Quanta System laser platforms, such as Light A *, Light 4V, Matisse HR,
Q-Plus * 2, DaVinci A and Duetto MT
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