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Laser hair removal

Laser hair removal

Dr Rahul Pillai discusses the various treatment options for ethnic skin

laser_squareWhen it comes to hair removal in ethnic skin, there’s a very narrow spectrum of treatment options. Few laser industry giants in the aesthetic field have developed laser technologies for hair reduction, and over the years these technologies have been modified to treat ethnic skin with more specificity.

Principles of removal

The principle behind hair removal is selective photothermolysis—heat is being absorbed by melanin, which eventually heats up the hair shaft, the hair follicle, the surrounding area and the germinating layers in such a way that the melanin helps in destroying the hair. The chromophore here is melanin, which is competing with other chromophores that are oxyhemoglobin and water.

The spectrum of 600 nm to 1,100 nm wavelength is useful in destroying the hair follicle, but the more specific we are, the lesser chance of complications. This brings us down to a few technologies utilising different wavelength, such as Pulsed Diode, Nd-Yag, Alexandrite and Ruby, which are a little more specific when it comes to heating the melanin which helps in destroying the hair.

The latest statistics on population from the US show that by 2020 ethnic skin will become a far more significant demographic proportion. European trends are similar—the ethnic skin majority is increasing in number – and that’s one reason why understanding how to treat an ethnic skin will become important in order to maintain a good practice.

Patient selection

Different areas of the body respond differently to lasers. A place like upper lip requires multiple numbers of sittings. Promising that you’ll be able to do a permanent hair reduction in six to nine sittings is risky—you’ll probably require more. The rest of the cheeks, or the arms or legs respond better and the back of the body also responds differently.

Ideally, when we look at ethnic skin, we are looking at a patient who comes with realistic expectations, somebody who’s got normal endocrine activities—so not with polycystic ovarian syndrome, hirsutism or hyperandrogenism. This factors are very important because that will influence the number of sittings that we are going to do, no matter what technology is used.

An ideal patient has thick, dark hair, but light skin tone. However, this is challenging when it comes to Indian skin because there are huge variations between different people across the states.

The differences from one Indian state to another are probably greater than between Czech and Slovak—yet India is one country. You may have a patient who’s fair in skin, with dark hair and light-brown eyes and expect that using a high energy will be safe, but she gets a burn. On the other hand you might have to treat a darker skin tone, which doesn’t respond the same. It’s challenging because you can’t judge an Indian patient or a darker skin Indian simply by looking at them. It’s with experience repeatedly treating such patients that we get an idea of how such skin tones react. Of course we have the option of doing a test dose and deciding our fluence and pulse width—or to be on safer side, always starting with a higher pulse width and lesser fluence.

Considerations

Three important parameters to consider when treating are pulse width, the spot size, and fluence.

Pulse Width

We all talk about thermal relaxation time, although I’m not convinced this is actually the right term to be used. Thermal containment time is more relevant and more importantly thermal destruction time, because a specific amount of energy is needed within the hair shaft so that it heats up the tissue and the melanin, in such a way that the hair gets destroyed. That should be ideally with a pulse width not less than 10 ms. In fact a 10 ms would burn the patient and something of 100ms won’t give good results, so we’re looking for something between 10 to 90 ms pulse width and optimal between 15-30 ms.

Thermal destruction time should give a heat sufficient to destroy the primary as well as the secondary germinating layers. The main reason hair returns, is not because the primary germinating layer is not getting destroyed, but that the secondary germinating layer is not getting destroyed—which is located near the arrector pili muscle. So ideally enough energy should be present to heat up and destroy this layer too, this is why different variations of same technology  work, such diode laser which produces single shots of high energy, or in motion technology which gradually heats up the tissue. No particular technology can be called the best technology—all of them can work, provided you know to make them work.

Technologies provided from Alma and Lumenis are contrasting machines, but they both work and give differing explanations for their efficacy, but as a doctor, the physics is an important consideration. Both machines gradually create heat within the hair shaft, which increases and destroys the primary and secondary germinating layers. So, it doesn’t matter what technology you use, if you understand the physics, you can make it work.

Spot size

A larger spot size creates more dispersion or scattering of energy. A large hand-piece, for example from Lumenis (22mmx35mm), can do an entire back in 15 minutes, or the entire body in one hour, without any complications and give good results. It is because a large spot size requires smaller fluence, and hence lesser complications and also gives the same results, because the dispersion is more than a small spot size.

Fluence

Understanding the implications of this isn’t entirely simple. One should not confuse the terms of fluence, energy, power, or peak intensity of a laser—they’re all different terms.

I have myself used them as synonyms and been corrected, and that’s when I went back to my books and realised that we’re looking at different terms. Fluence is the amount of energy that we are delivering per treated area, in joules per square cm. So fluence is the same as energy density.

A burn happens when the dermal-epidermal junction is being destroyed—so epidermal cooling is important. A burn will never occur if the dermal-epidermal junction remains intact. There are  cooling devices, but most lasers have inbuilt cooling systems in the hand piece itself, so that theoretically, if you are cooling the area well enough, using any energy level is safe. That’s true in theory, but must be implemented practically.

Types of technology

IPL: IPL’s broad spectrum Intense Pulse Light is very useful when it comes to fine vellus hair. Since it targets a broad spectrum between 600 -1100nm it is not very specific for hair reduction and never the first go-to machine, but an optional one to have as IPL has high versatility although not much specificity.

Ruby: Ruby, 694 nm, was the first such laser for hair reduction. It was quite effective, but had many complications such as burns and pigmentary changes, so I wouldn’t favour its use in treating ethnic skin.

Alexandrite: Alexandrite was initially very popular because it gave great results, but because of the complications the diode took over. Alexandrite is now back in fashion again, but I’m not convinced that alexandrite use is the right decision when it comes to ethnic skin. I won’t favour it, because I think I would rather see a patient for a few more sittings rather than having less with alexandrite and expecting some kind of complications such as pigmentations or burns. Because laser is a voluntary procedure, if it burns, patients simply aren’t going to come back to you. One has to note companies which promote Alexandrite laser are not actually selling an Alexandrite laser but a Diode laser with a wavelength of Alexandrite, 755nm.

Nd:YAG: The Nd:YAG has the longest wavelength, but the melanin absorption is less, making it very safe on darker skin types. Low melanin absorption means it can be used safely with high energy and the penetration is comparatively less, but more energy can be used. It is safer, but I still prefer the diode when it comes to ethnic skin and I still believe it’s the gold standard when treating this skin type.

Diode: The diode absorption is probably not as good as alexandrite, the penetration is not as much as an Nd:YAG, but somewhere in between, and that makes it ideal for treating ethnic skin. Somewhere between 800 nm to 810 nm would be ideal for treating, and the various lasers that have come into the market right now are modifications of a Diode laser, because that’s what is ideal in darker skin type and selling more in the emerging Asian aesthetic market. The Lumenis Infinity with a 1060nm is a Diode laser with wavelength similar to Nd-Yag, hence safer to treat in darker skin types, even Fitzpatrick type 6 skin.

Problems and solutions 

I don’t believe in applying local anaesthesia. I would want my patient to react and tell me if it burns. If it hurts, I want to know so that I know that I have to increase my pulse width or or reduce my fluence.

Cooling is a must. For example Lumenis lasers are have Sapphire Chilltip, which cools the skin adequately before firing. Even the temperature of a room is very important when it comes to treating ethnic skin and also for the maintenance of laser equipment. Lower energy can be used if patients are feeling any pain, or pulse width can be increased so that the patient feels more comfort—however this may lead to a higher number of sittings being required.

Vacuum suction technology is unique. It’s pretty effective because the skin is pulled closer to the hand-piece, in such a way that lesser energy is going to give better results hence less painful. Using a 5.5 or 6 fluence larger hand piece (22×35 mm) will give the same results as something like 20 or 30 fluence in a smaller hand-piece (9×9 mm). When vacuum technology pulls the skin up, the competing chromophores and the oxyhemoglobin move apart. Even the chromophores on the skin are reduced. Also the unique vacuum mechanism activates tactile and pressure skin receptors to inhibit the transmission of pain sensation, hence is less painful. It’s also a mechanism that creates pain in one area to reduce pain in another. Initially when this technology came in, I was a little concerned that the suction would create more pain, but the truth is it’s ideal for a patient who thinks they can’t bear even minimal pain.

For treating thin hair there’s no particular solution, except repeated number of sittings. An IPL is a good option if you have the finest, thin-haired patients or lighter-haired patients. It’s inexpensive, but low-efficiency. Or you can use a Diode laser with very short pulse width and high energy, has its own risk of burning, but is effective. Here an Alexandrite like wavelength maybe useful and many users feel its pretty safe, although risk of burning a darker skin type exists.

When it comes to the hand-pieces, the large hand-piece can be used for greater body surface areas with low fluence and smaller areas like upper lip with small hand piece and higher fluence.

I’ve noticed that patients generally don’t see the results in the first or the second sitting with a large handpiece as compared to small hand piece, but by the third or the fourth sitting they find that the results are the same. Hence it doesn’t matter if you are using large piece for larger for larger body areas and small hand piece for lets say facial hair, eventually on a whole body treatments results are the same if you combine both for 6-9 sittings. So, this is one option you can look into when you’re treating ethnic skin.

Lumenis have recently launched the Infinity device which is a diode laser with a 1060 wavelength hand piece making it safe for use in even very dark skin yet with the benefit of a Diode laser. This is a good option as there are various wavelength and handpiece options making it truly versatile. For very dark skin a 1060nm wavelength can be used and after a couple of sittings, once we understand how the skin reacts, shift to a diode laser, 805nm wavelength. Also this gives us a gold standard results for both light and dark skin types.

Using a Diode laser with a Nd-YAG like wavelength (1060nm) the results are not the same as a Nd-YAG laser (1064 nm) but after a follow-up of six months, 75% reduction was noted in most of the studies as an average.

Alma IN-Motion technology gives good results. Both these companies Lumenis and Alma are good, and again, these are both what sell maximally in Asian countries.

The alexandrite has been reintroduced by Alma in a new platform called Soprano platinum Ice which combines three wavelengths (755, 810 & 1064nm) but coming from the same Diode platform. The results are yet to be understood as its a recent launch but it’s effective when it comes to thin-hairs which last at the end, so you treat them with the diode laser, and finally when it comes to the last thin hair, you can treat that with the alexandrite. These are additional luxuries you can have in your clinic if you have the financial capacity and the right kind of patients walking in. I approached Alma with plans to compare both the new Soprano Ice Platinum and Lumenis Infinity, so that we could come to a conclusion about the efficacy, speed and so on but Alma declined, so I have to be rather one sided when talking about an Alex since my experience is with the previous Soprano XL platform. When it comes to speed the Lumenis Duet or Desire or Infinity beats any other competitor lasers.

I am a little sceptical about the fact that Alex is popular again, as it didn’t work before, and I see no reason why it should now. The physics is the same, so is the Chromophore, besides its a Diode laser with a Alexandrite like wavelength—for me Diode is still the gold standard and it has been so for more than a decade now.

Summary

You can make any technology work as long as you understand the physics behind it. No technology is a bad technology. But understanding the skin is more important and also understanding the technology behind a laser, because you know how this skin is going to react, and you know what to do with the laser. Of course it would be a privilege to have all types of lasers in your clinic if its financially viable and that would make any practise versatile. When it comes to treating darker skin types, Diode laser has been the gold standard and it still remains so.

Dr Rahul Pillai completed his MD in General Medicine from Moscow Medical Academy Russia, and his MD in Dermatology, Venereology and Leprosy, from Pondicherry University, India,where he was the rank holder and gold medallist. Now he is Medical Director of KKRIS Skin Care Centre and Laser Llinic, Kochi. He is a speaker, trainer and course conductor at various International conferences and workshops and specialises in laser technologies.

Author: bodylanguage

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