In our innovative use of the ND:YAG laser for hair removal, we have had notable results in patients with dark or pigmented skin which is prevalent in South Florida. Most of the lasers currently available are difficult to use in darker skinned patients without burning the skin. The ND:YAG laser, manufactured by Candela, has a special cryogen spray to cool the skin and prevent possible skin burns in these darker skinned patients. The laser light is absorbed by melanin that is associated with the hair. In the melanin, the laser energy travels down the hair shaft into the hair bulb where the blood supply is localized. When the laser energy is absorbed it is converted into heat energy. This raises the temperature of the bulb and causes the blood vessels that supply nutrients to the bulb to be cauterized. As a result, the hair follicle dies and hair growth is stunted. This is a selective process – it does not damage the epidermis or the surrounding tissues which are protected by the cooling cryogen spray.
Hair grows in a cyclic, nonsynchronized fashion. Therefore, at any given time, each hair is at a different stage of the growth process and is subject to varying degrees of response with the laser. Usually patients require up to 5 treatments to achieve the desired effect. Here are pictures of the axilla in which we treated 3 round spots in a dark skinned patient. It is clear that the treated areas had no hair growth after 3 weeks while the surrounding areas showed normal hair growth.