1. The Target

Unwanted hair is carried out by transfer of laser energy to the hair follicle which absorbs the laser energy. This target is melanin, the pigment which is responsible for hair color. Melanin absorbs laser energy to a much more extent than other surrounding skin structures. When laser is fired energy is absorbed by hair melanin energy is converted into heat destroys the reproductive system of hair .

2. The Hair Follicle Structure

Hair follicle has germinative apparatus which is responsible for producing hair growth . Germinative apparatus is covered by melanin, it contains in the hair follicle. When laser is fired energy is transferred the to germinative apparatus and melanin causes very quickly increase in temperature. When there is enough laser energy is absorbed the high temperature rising can cause irreversible destruction to the hair germinative apparatus, resulting in permanent destruction of hair growth.

3. Melanin

Melanin ( color pigments) exists in the hair follicle and in the skin . Melanin amount changes person the person . Tanning is a extra melanin production by melanocytes, which produce melanin response to sun exposure or taning beds . The laser energy needs to go through the epidermis to reach the hair follicle, which resides within 2 to 5 millimeters deeper within the skin. Some Laser energy will be partially absorbed by epidermal melanin before it reaches the hair follicle. For a good treatment technician must exploit the differential absorption characteristics of melanin in the hair follicle vs. epidermal melanin, and also exploit the differential cooling characteristics of these two structures.

4. Cooling skin

The skin has a greater surface area compared to the cylindrical hair follicle, and will therefore cool faster. Hair follicle heat faster in response to laser energy, it will also cool slower. To further exploit this difference the skin surface can be cooled before, during, or after the laser fired by applying either a cooling spray (cryogen ) such as Candela corporation gentel lase, blowing cold air ( such as cynosure company ), cool and glide such as Cutera (altus corporation) or after treatment with ice packs . This will reduce the temperature of the skin surface, allowing more energy to be delivered to the hair follicle without producing damage to the overlying skin.

5.Treating high melanin skin (African Americans , dark skin types , Tanned skin) 

Lasers are well suited for the removal of unwanted hair, because with the right selection of parameters, they can be used as a non-invasive method to disable the hair structure without damaging the surrounding dermis and epidermis. Numerous hair follicles can be treated simultaneously allowing for rapid coverage of large areas.

Our CoolGlide Excel systems were the first Nd:YAG systems approved for use on all skin types and tanned skin, allowing treatment of a wider patient base than other systems. Independent control of pulse width and fluence allow effective treatment on a range of hair thicknesses, including the often difficult-to-treat finer hairs that are left by other systems after a number of treatments. As dark as skin type 6 African Americans can be easily and safely treated .

6.Treating low melanin skin such as skin types 2 , 3 (Caucations)  

We prefer to use Alexanderite laser by Candela corporation 755 nm wavelength cooling with crayogen . Over the years It has proven efficiency for permanent laser hair removal. It could easily treat skin type 2 to 4 fine hair to coarse hair very effectively .  

This entry was posted on Monday, October 16th, 2006 at 10:45 am and is filed under Laser Hair Removal. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.