The ruby laser, early developed for use in medicine, showed a side effect of stopping hair growth in the area treated. This was explored further and the early hair removal lasers were produced.
The earliest was the ruby. It was effective, but had limitations in the depth it could penetrate in the skin and hence its effectiveness in deeper hairs (the aim is to destroy the growing centres of the hair follicles, which are near the bases of the hair roots). The length of each treatment pulse was limited too, which again affected its effectiveness.
With the smaller beams the early versions produced, a lot of the active energy of the laser beam was lost in scattering of the light. Ruby lasers are quite inefficient in effective laser energy production.
The red light of the ruby was also strongly absorbed by the brown melanin skin pigment. Therefore those best treated were fair skinned people. And darker skinned people that were treated tended to get areas of altered pigmentation that could be more distracting than the original hair problem.
Further lasers were developed in an attempt to overcome this problem. Hence there has been the alexandrite and more lately diode lasers that sought to overcome the ruby’s limitations. Each one had its problems.
All were exploring longer wavelengths than the ruby (i.e. tending to the red end of the spectrum). Even white light non-lasers have been tried, with certain filters put in the light path to select out the more unwanted wavelengths of the spectrum.
The NdYag laser had been around for many years. But only recently was it explored for effectiveness in hair removal. It showed promise once the appropriate power and length of the pulse had been chosen. All the aforementioned lasers had shown that they could treat some hair.
The NdYag had the advantage that it was the longest wavelength laser around. This meant it could penetrate deeply into the skin and get to the hair roots. Some of the diode lasers had sought to overcome this by pressing firmly on the skin, in an attempt to bring the skin surface closer to the hair bulge.
Initial NdYag lasers had quite a narrow beam, meaning it took more pulses to treat a given area. But even more importantly, this caused them to suffer from the fact that narrow light beams tend to get strongly scattered at the skin surface leaving relatively little energy to get through the skin and to the hair follicle root.
The Cool Glide Laser System
The Cool Glide Laser
The Cool Glide laser had a wide beam at one square centimetre causing less scattering and more effective skin penetration, as well as allowing it to cover the treated area more quickly. It had an effective cooling head. This is vital in a laser as it allows the skin to be protected. Because the lasers target the black/brown melanin pigment in the hair shaft, problems can arise for the skin – particularly brown to black skins – their colour being produced by the same melanin pigment that occurs in hair deposited in the skin. If the area that is not wanted to be treated can be cooled enough, it will not allow the laser energy to heat it up enough to cause permanent damage (death) of this tissue. However the deeper hair shaft does not get cooled too much and hence the laser energy kills the tissue about the hair shaft, including the hair follicle’s growth centres.
As hair grows in different cycles, and hair that is effectively in contact with the growing areas of the follicle will only occur where it is actively growing, only those growing hairs will be affected. Dormant ones will not. Hence the need for repeated treatments to get all hair follicles over time.
It is also vital that the laser used has enough power to deliver the appropriate amount to the target: in this case the hair follicle’s growth centre. Cool Glide is a powerful laser.
The Cool Glide laser is an infrared spectrum laser that allows deep penetration of the laser into the skin to get to the deepest hairs. It’s special cooling head, that remains in contact with the skin, cools the skin in advance of the laser beam (and can be used after it too) to protect the skin from damage.
Consequently most or all of the sensation of the treatment is from the very cool head. Some of the pulses can be felt as a small needle-like prick at times.
Special blackout eyewear is worn by the patient to protect his/her eyes from stray laser light that does arise from reflection off the skin and other surfaces.
The operator wears a specially graded pair of laser spectacles to protect his/her own sight. Likewise the treatment room is off limits to others (including children) unless they are wearing special protective eyewear. Medical lasers can be very dangerous if not operated correctly.
The Prowave 770TM Head
This addition to the versatile Xeo Cool Glide platform has offered another option in its hair removal technology. Essentially an intelligent light source in the infra-red range beginning at 770nm, it allows for rapid treatments with its larger head of some difficult hair removal cases. Cooling is not as potent as with the Cool Glide itself.
It has three programmes to allow for the variation in hair type and skin colour encountered. We have found it effective as a second option in our methodologies.
How is it done?
The area to be treated is identified. A cool gel is applied to the surface usually. This allows the head to slide readily across the skin. Eyewear is checked. The laser is put off standby. A test dose or so is fired to determine the appropriate laser settings for comfort and effectiveness. Once this established, the session begins in earnest at a rate that is suitable for the area and patient comfort. Areas about the teeth, such as about the lips and cheeks often have a moist gauze placed underneath in the mouth between the teeth and the overlying area to stop laser energy warming the teeth pulp.
Does it hurt?
The Cool Glide laser is very comfortable. Mostly the patient is aware of the cold tip only. Sometimes some heat or a sharp-feeling sensation occurs. The treatment levels can be adjusted for any locally more sensitive areas.
How many treatments are required?
For dark hairs usually six treatment sessions are required. Lighter coloured hairs usually need around eight sessions (assuming they are sensitive to the laser light – that is that the absorbing melanin pigment is well represented). A very few (usually less than 5%) might need more. The sessions are based about every two months or at such time as there is sufficient growth of new hair to make the treatment worthwhile. Facial hair usually is done every six weeks.
How long lasting is it?
Studies so far have been done with Cool Glide showing no regrowth in treated areas after two years. People who have had this laser since it was first produced about 1998 say they tend not to see people returning for the same areas. However, the body can grow new hair areas over time with changing hormonal levels.
Who does it?
It done by the doctor or a laser trained technician. A very good understanding of lasers and laser safety factors is required of the operators.
What skin colours can treated?
All skin colours can be operated on by the Cool Glide laser. This is not so of other types of lasers. Also even tanned skin can be treated. Some of the laser energy will be diverted to and wasted by the skin pigment in this case. And a lesser power might need to be used to stop unnecessary discomfort. But it will still work.
What hair colours can be treated?
As long as there is some pigment in the hair shaft to bulb, the hair can be treated. White hairs, not having pigment, can not be treated. Very blonde and red hairs tend to be slower to respond. We can test fire individual hairs in these lighter colours to judge how sensitive they will be to the laser treatment. If there is little reaction this way there is no point in pursuing a course.
What happens to the hairs?
Some hairs will be forcibly expelled from the hair follicle at the time of the treatment. A number fall out in the next 24 hours. Most tend to gradually work their way up, appearing to still be growing, until about week two to three when suddenly they all seem to disappear. Due to related swelling within the hair follicle, in the first week the hairs will appear firmly attached. Usually by the second week they slide out readily.
Is laser energy safe?
Laser light is non-ionising radiation. Apart from some ultraviolet lasers (and the Cool Glide is infrared) there is no risk of damage to the skin that could result in later cancer etc. Care with the energy levels needs to be taken to avoid burns.