INTRODUCTION
The demand for effective removal of unwanted body hair is an increasing trend promoting photoepilation by laser or other light-based technology as the fastest growing procedure in cosmetic dermatology.1
Photoepilation utilizes light to cause photo-thermal or photo-mechanical damage to the hair follicles. Selective photothermolysis of the hair unit is aimed to achieve a permanent damage of the hair follicle, specifically to the follicle stem cells within the hair bulge, with the surrounding tissue held intact. Light absorbing chromophores within the multi-cellular hair unit include melanin, hemoglobin and water. Among these, melanin is considered to be the most attainable target for selective photothermolysis. The hair unit is destroyed by heat diffusion from the eumelanin-rich hair structures. Prolonged hair growth delay is attained by causing either damage to matrix cells of anagen hair follicles or coagulating blood vessels of the papilla or possibly by destroying part of the outer root sheath (ORS).2
Based on the physiological skin and hair properties, various laser and light-based devices have been introduced to the market over the past two decades encompassing various wavelengths. Different wavelengths have been shown to specifically induce hair reduction emphasizing the complexity of the process underlying laser hair reduction.3-7 Failure to tailor treatment parameters to a patient’s characteristics, such as skin type, hair color or treatment area could lead to unsatisfactory results and side effects (dyschromia, scarring, burns, etc.). In terms of safety, darker skin types pose the greatest challenge, as the higher melanin concentration can lead to epidermal heating, with limited light reaching the dermal pigmented hair follicle. To overcome this obstacle, longer wavelengths, such as 810nm and 1064nm, longer pulse duration, and conjoint epidermal cooling devices are used.8
Many comparative studies have tested the efficacy, treatment outcome, and treatment related pain between different wave lengths laser devices as well as laser versus intense pulsed
Photoepilation utilizes light to cause photo-thermal or photo-mechanical damage to the hair follicles. Selective photothermolysis of the hair unit is aimed to achieve a permanent damage of the hair follicle, specifically to the follicle stem cells within the hair bulge, with the surrounding tissue held intact. Light absorbing chromophores within the multi-cellular hair unit include melanin, hemoglobin and water. Among these, melanin is considered to be the most attainable target for selective photothermolysis. The hair unit is destroyed by heat diffusion from the eumelanin-rich hair structures. Prolonged hair growth delay is attained by causing either damage to matrix cells of anagen hair follicles or coagulating blood vessels of the papilla or possibly by destroying part of the outer root sheath (ORS).2
Based on the physiological skin and hair properties, various laser and light-based devices have been introduced to the market over the past two decades encompassing various wavelengths. Different wavelengths have been shown to specifically induce hair reduction emphasizing the complexity of the process underlying laser hair reduction.3-7 Failure to tailor treatment parameters to a patient’s characteristics, such as skin type, hair color or treatment area could lead to unsatisfactory results and side effects (dyschromia, scarring, burns, etc.). In terms of safety, darker skin types pose the greatest challenge, as the higher melanin concentration can lead to epidermal heating, with limited light reaching the dermal pigmented hair follicle. To overcome this obstacle, longer wavelengths, such as 810nm and 1064nm, longer pulse duration, and conjoint epidermal cooling devices are used.8
Many comparative studies have tested the efficacy, treatment outcome, and treatment related pain between different wave lengths laser devices as well as laser versus intense pulsed
