Homogeneous Photothermolysis Case Study

DAC uses Nd YAG laser having homogeneous photothermolysis principle for removal of hair. Homogeneous photothermolysis is based on the fact that laser energy acts on a certain tissue volume homogeneously. Rapidly dividing cells with high cellular metabolism are the first to be affected by absorbed laser energy. The hair bulb cells in the anagen phase (period of active stable growth) have a high metabolic rate and are much more sensitive to heat. Surrounding tissue is preserved, while at the same time, hair follicles are irreversibly destroyed. Due to the very low absorption in melanin, competition between skin and hair pigment is less, which makes this method more suitable for darker skin types.
1. How does laser remove hair?
Highly controlled flashes of laser beams are selectively absorbed by the melanin pigment in the hair follicles lying below the surface of the skin. The absorbed light heats the hair which damages and destroys the regrowth potential of the follicle without damaging surrounding tissue. Hair follicles are usually in different growth cycles different times in relation to one another. Since the hair follicles must be in active growth in order to be affected by the laser, several treatments spread over several months are required to assure the destruction of all hair follicles.
2. What is electrolysis?

Only follicles in the growth phase are destroyed by laser light. Resting hair follicles need to enter the growth phase before they can be destroyed by the laser treatment. It is therefore necessary to repeat the treatment at 1-2 months intervals until all the hair follicles have been through the active phase. The length and timings of the growth cycles are affected by numerous factors such as body site, hair density and thickness, ethnic origin, hormonal status and age. Usually 6-8 sessions are required to get a desirable result. Some cases it has gone upto 10-12