Factors Which Affect The Performance of Individual Lasers
The factors affecting individual lasers used for hair removal are:
Wavelength - individual wavelengths have different effects on the skin tissue and on how the laser light is absorbed. The optimum wavelength for hair removal would be highly absorbed in the concentration of melanin in the hair shaft and transmitted harmlessly through the surrounding tissue.
Pulse Duration -this is the length of time the laser light is in contact with the skin. The heat must be maintained for long enough to destroy the hair growth mechanism, but not too long as to burn the skin. The ideal pulse duration required to generate the correct amount of heat in and around the hair follicle is approx. 1 millisecond. If the pulse duration is too short not enough heat will be generated to destroy the follicle. If the pulse duration is too long heat may dissipate into the surrounding skin increasing the risk of burns.
Energy density- This is the amount of energy required to prevent regrowth and must be between 10-25 joules per sq. cm of skin.
In conclusion Laser hair removal can be the answer to the dreams of many patients providing:
The skin and hair are suitable. That is, not too dark skinned and not grey/red hair. The object of the exercise is to kill the hair follicle without damage to the skin. There is no point in removing one problem and leaving the patient with another. This inevitably means even the best lasers have limitations.
The laser type: This is a vital parameter for successful treatment. Lasers have many purposes - they don’t all remove hair successfully.
Management of the treatment: A laser is not a magic wand and there must be total commitment from both patient and clinician.
