P. Petrovska, Corrective Dermatology, Prague, CZ

P. Fryda, MediCom a.s. Laser, Prague, CZ

E-mail: fryda@medicom.cz

 

ABSTRACT

The use of laser is a very widespread method in skin treatment. In dermatology and related specialties, invasive high-power lasers represent a top tool which can be hardly be substituted by other means. Furthermore, this paper evaluates also the position of a therapeutic laser (LLLT) in dermatology where these lasers can often be indicated as the method of first choice, or at least as a more advantageous alternative in treatment of many dermatologic pathologies. Statistics have revealed that in the Czech Republic almost three fourths of all private dermatologic offices are equipped with a therapeutic low-power laser, and it can only be assumed that, in view of its therapeutic results, this proportion will grow up.

 

INTRODUCTION

Laser and dermatology are ideally suited together. No wonder that dermatology had been one of the first medical specialties which lasers started to be utilized in. At first it was Goldmann with an invasive Ruby laser in 1963, whilst for the development of LLLT trials of Endre Mester since 1964 (Ruby) and especially since 1974 (Helium-Neon) have been of the main importance. Dermatology is a very suitable application field for a laser and, in common, laser is able to provide this medical discipline with a very potent tool with many new possibilities. It should be also mentioned that, apart from medical contributions, laser brings in skin treatment, dermatology, corrective dermatology, cosmetology, esthetic and plastic surgery, undisputable commercial potential.

 

INVASIVE HIGH-POWER LASERS

Invasive dermatologic high-power lasers represent a perfect touch between traditional human desire for beauty on one hand, and the most sophisticated medical technology on the other hand. Laser is able to perform such surgeries, the extent, efficacy, speed, result and easy healing of which can hardly be achieved using other methods. However, it should also be mentioned that although a high-power laser in dermatology is an example of top technology, no universal device has been developed yet, and each type of dermatological laser is usually suitable for a limited range of operations only.

Sclerotizations of vessel lesions, spider veins and little varices is widespread. Here mainly dye sclero-lasers with the possibility of tuning their wavelength, so that the best results may be reached, will play the main role (up to 95 per cent success). Thinner veins are treated usually with KTP lasers, veins with a larger diameter can be sclerotized with diode, Alexandrite or Nd:YAG lasers, sometimes even in combination with dye lasers (see Clinixperience No. 17/2000). Furthermore, dye lasers are used to remove verrucas, haemangiomas incl. naevus flameus, and recently they have been tested for treatment of manifestations of psoriasis.

Pigmented lesions (age spots, café-au-lait, sun spots) represent another large sphere of typical laser treatments, laser tattoo removal is also very successful. In these cases Q-switched Alexandrite laser is mainly utilized, sometimes also Q-switched Nd:YAG or Ruby laser. The action lies in huge amount of energy of a laser beam penetrating through tissue in a super-quick pulse, being selectively absorbed in dark pigments which are shattered in negligible particles and later on washed away in a natural way.

 

Amateur tatoo on the arm - before

Same arm after laser tatoo removal

Pictures courtesy: Asklepion Lasercenter, Prague.

 

Removal of wrinkles, smooth away of scars, removal of little skin defects (verrucas, fibromas), as well as full-face skin resurfacing are domaines of Er:YAG laser. Modern types of super-pulsed or ultra-pulsed CO₂ lasers can also be used, otherwise deeper zone of necrosis and therefore longer regeneration time should be expected. During therapy superficial layers of skin in the order of thousands of a milimetre are peeled off. Diode and Nd:YAG lasers, acting through selective warming up collagen fibres, have been tested recently. Here we rather talk about rejuvenalization of skin.

So far laser hair removal has been proven the most perfect method of permanent removal of unwanted hairs. Ruby laser (non suitable for darker skin types), Alexandrite, or Nd:YAG lasers have proved to be most successful. The therapy is based on selective thermolysis of hair follicles, which have to be repeatedly liquidated in exact intervals in their anagen stage with the energy of a laser beam. During the therapy cooling of the skin in treatment area plays the key role. Best results have been obtained with the system of dynamic cooling, when several hundreths of a second before the laser shot dermis adjacent to hair is locally frozen with a cryogen.

Above mentioned laser operations are being regarded as standard ones, and numbers of such surgeries in individual renowned laser centers count hundreds and thousands. Laser invasive dermatology ranks among relatively young and fastest developing medical specialties. New methods are being tested, new sophisticated devices are being developed. Laser hair transplantations or laser welding of tissue are being tried out, photodynamic therapy (PDT) develops further on, new types of lasers (combined, diode-pumped, Nd:YAP, superfast scanners etc.) are emerging.

 

THERAPEUTIC LASERS (LLLT)

The use of therapeutic lasers (LLLT) in treatment of adverse skin manifestations has been holding a firm position in dermatology for a number of years. Furthermore, these devices are much more widespread in dermatology thanks to their easy availability, low price, and simple operation. However, the main reason is that LLLT broadens therapeutic range as well as holds a significant share in accelerated healing of all superficial skin affections. Especially the following applications can be stressed:

Herpes simplex and herpes zoster. In case of an early application of LLLT (within 24 hrs.) visible virustatic effect can be ascertained. Patients feel subjective relief, for soreness and sensitivity of manifestations decrease. Objectively, anti-inflammatory and virustatic effects lead to discontinuation in the spread of herpetic vesicles, oedema and erythema, resulting in their quick drying with healing time being cut down to one half at least. If we succeed in starting therapy at the very beginning, in the prodrome phasis (herpes simplex), herpes does not appear at all. Simultaneously, in further course of the disease future relapses can be reduced, or time intervals between individual onsets can be prolonged. In case of herpes zoster secondary infection can be often prevented due to improved activity of macrophages. Caution - LLLT is contra-indicated in case of affection of cornea! Recommended dosage is 1 - 2 J/cm², daily sessions, 5 - 15 times in total.

Aphtous stomatitis. Falling rather within dentistry, however dermatologists can often encounter it. It is a very rewarding indication since LLLT brings a quick and visible effect. Quick healing and significant relief of soreness and sensitivity, similar to herpetic eruptions, can be noticed. Aphtae usually heal up within several hours, the worst cases in less than in two days. Dosage 0.4 - 0.6 J/cm² , 1 - 2 applications per day recommended.

Laser therapy of wounds and ulcers ranks among most frequent indications, no matter if speaking about operation wounds or traumatic injuries, healing per primam or per secundam. Dermatologists` experience affirmed quick cleansing of base, improved blood supply, anti-inflammatory effect, rapid induction of epithelisation. Necrotic or purulent tissue causes worse penetration of laser beam, and principles of wound treatment techniques should be therefore maintained accordingly. Individual dosages are 2 - 8 J/cm² according to appearance and condition of a wound, with superficial wounds dosages can be lower. Sessions once a day, or every other day, till total recovery. It is very advantageous to use a scanner.

LLLT of burns. Biostimulation effect speeds up regeneration and epithelisation of I - III grade burns. We proceed along the same lines as in wounds and ulcers management. Subjectively, quick relief of pain and sensitivity is achieved. Daily irradiation is necessary. Applied dosages range between 3 - 8 J/cm², according to burns grade. In cases of larger areas laser scanners are recommended.

LLLT of cicatricial tissue. Cicatricial tissue is not only a cosmetic visual complaint, but it can also cause unpleasant ador, paresthesia, itching, tingling, palpation pain, espacially in case of hypertrophic and keloid scars. LLLT reduces these subjective complaints in active scars, even after a few applications. The success of LLLT appears in lightening and gradual flattening of a scar, thanks to improved activity of macrophages, and due to stimulated function of fibroblasts. Early application is very important, the sooner LLLT is applied, the quicker is the effect. With active scars we proceed once a day for the first 10 sessions, followed by 1 - 2 applications per week, for several weeks or months till satisfactory cosmetic effect is reached. For larger scars  also the use of a scanner appears advantageous.

Acne vulgaris - LLLT brings double improvement here - anti-inflammatory effect in case of acute eruption contributes to phlogistic papules heal up earlier, and positive effect in the course of creation of painful hypertrophic scars (especially in acne conglobata). Recommended dosage is reported in the range of 1 - 2 J/cm². In case of larger extent (for example on the back) a scanner is usually better than a point probe.

 

 

Acne before LLLT

Acne after 10 LLLT sessions

Pictures courtesy: Asklepion Lasercenter, Prague.

 

Treatment of diffuse and focal alopecias. LLLT is applied twice a week, usually 10 - 15 sessions is enough. In the first step the hair loss is limited thanks to better supply of hair follicles with blood, followed by improved growth within a month`s time. The effect of treatment depends on correct diagnosis with determination of the cause of alopecia. Recommended dosage is 0.05 - 0.1 J/cm².

Other dermatological indications. In general, positive biostimulation effect of LLLT can be applied on all superficial dermatoses, ranging from eczema and psoriasis vulgaris to seborrhoic or perioral dermatitis. In all cases check of further diffusion of the disease, faster healing, and limitation of possible cicatrization tendency can be achieved. Caution - LLLT is contra-indicated with photosensitive patients! It is always necessary that LLLT in dermatology be considered by a dermatologist. Correct diagnosis, dosage and irradiation time are crucial for proper application of LLLT.

 

STATISTICS

In order to be able to ascertain to what extent therapeutic low-power lasers are spread among dermatologists a statistic survey has been carried out. According to the official membership database of the Dermatovenerological Society of the Czech Medical Society 450 private dermatologists were contacted. The dermatologists were addressed in three phases, two letters were followed by a telephone contact, and the results obtained were compared with a commercial database. Seven of the 450 letters were returned (addressee died, closed his/her medical practice ...). Altogether 111 answers out of the total number of 443 active members of the Society were received, representing a rather good response ratio of almost 25 per cent. Given numbers are summarized in the following table:

Included in Statistics	Number of Dermatologists	Per Cent of Dermatologists
Active respondent	111	100
Not having a therapeutic laser	32	28.8
Working with a therapeutic laser	79	71.2

Dermatologists have also been questioned the type of laser they worked with. Overwhelming majority (more than 90 per cent) uses a laser emitting in the red part of spectrum. It stemms from depth of penetration of laser beam, which is rather lower with red laser than with infrared types (see Clinixperience No. 15/2000). Red laser penetrates to tissue in the order of several milimetres (up to 15 mm according to the type of tissue), which is quite satisfactory for most of dermatological disorders. Using infrared lasers with higher output bring to superficial layers of tissue only a part of emitted energy, whilst major portion of the light pass through deeper with no direct impact, if not speaking about systemic effect of LLLT in general. Thus it can be more or less simply said that, to a certain extent, in dermatology therapeutic effect of stronger infrared lasers compares to results of red light emitting lasers with less power output. The following table brings comparison of dermatologists according to type of laser they work with:

Type of Laser	Number of Dermatologists	Per Cent of Dermatologists
Working with a therapeutic laser	79	100
He-Ne laser	30	38
Diode laser - Red	44	55.7
Diode laser - IR	5	6.3

Average reported number of LLLT patients varies between 20 to 50 patients per month. Average number of LLLT therapies per patient reaches from 2 up to 20 sessions, depending on particular diagnosis and condition of a case.

 

CONCLUSIONS

The use of laser in dermatology appears a very advantageous method for both surgery and therapy. In many indications invasive high-power lasers are unbeatable ang highly efficient modern devices. Therapeutic lasers (LLLT) can be indicated in many cases as the method of first choice. Furthermore, this method is a very effective one, its results being quite satisfactory and in some cases even better than those of so called conservative care (minor surgeries, medication). It can also be stated that the use of laser eliminates potential risks of drug contra-indications, post-op complications, and does not burden patients, especially their gastrointestinal tract, with possible negative side effects. In view of extension of therapeutic lasers in dermatology, and of their good therapeutic results, there is no wonder that a laser becomes quite a natural and standard piece of equipment.