The CO2 laser was the first laser that showed a significant clinical response for wrinkle and acne scars removal. The laser type and setting can be adjusted to target a specific lesion according to the tissue type, scattering pattern, and absorption spectrum. Lasers, in general, produce their effect via photothermolysis (the process of light amplification). A specific chromophore in the tissue will rope the light and converts it to heat energy. The primary endogenous chromophore is water, melanin, and oxyhemoglobin. Exogenous chromophores can also be used, such as carbon particle in from the colloidal charchol masked applied before the carbon peel procedure using the Lutronic spectra q-switch laser.
The absorption spectrum of each chromophore determines the degree of the laser absorption and, therefore, the heat produced. Another important factor is the depth of penetration; laser beam will have higher penetration as the wavelength increase. The depth of laser beam penetration is inversely proportional to the light scattering. This is only valid only before the mid-infrared region of the light spectrum. After that region the longer the wavelength, the more water the absorbs the light, the more superficial the laser is.
To medical aesthetician should be comfortable with these fundamental concepts to choose the correct settings for the desired outcomes. In other words, if we are targeting a lesion, such as wrinkles or pigmentation, we need to be as close as possible to the target absorption profile. This will help to deliver the energy to the target tissue and leave the surrounding tissues intact.
Another important concept is the Thermal relaxation time, which is the time takes for the target to heat up and then release the heat to the surrounding tissue. If we deliver the energy to a target for the prolonged period, this energy will be passed to the surrounding tissue, regardless of how specific the laser is. The laser pulse width deals with this concept. The pulse width is the time span through which the laser energy is delivered. This time varies in the range of millisecond, nanosecond and picosecond. This concept is important in all type of treatment special hair removal as the medical professional can control the pulse width (it is not the case with the nano and pico range). The pulse width has to be shorter than the thermal relaxation time, to give a long enough break to the target tissue or cool down enough not to damage the surrounding tissue. On the other hand, very short pulse width means at all the laser energy will be delivered in a very short time, which will be looked at as aggressive treatment.
For wrinkle removal, we have to use resurfacing laser, and they are classified as ablative and non-ablative. Each one of these lasers can be fractional and not-fractional. The ablative lasers, mainly CO2 and ER: YAG laser, target water and vaporize the whole tissue and considered as the most aggressive laser treatment. One way to team the beast is to use the fractional head. These heads will direct the laser beam to create specific treatment areas and leave most of the surrounding tissues intact. Using ablative non-fractional laser will destroy epithelium, the papillary dermis, and occasionally the reticular dermis. This results in collagen synthesis, tissue remodeling, and skin tightening. The Er: Yag Fraxel laser, emits light with a wavelength of 2940 nm and is ready absorbed by water resulting in superficial penetration. It has been demonstrated that Er: YAG and CO2 have the same effect on acne scars with less adverse effect reported on the group treated with ER:YAG. The main adverse effect reported after using the ablative laser is the post-inflammatory pigmentation PIH. Reseach showed that the risk could significantly decrease by using the Hydroquinone 4% and tretinoin 1% for six weeks before the laser treatment. The main indications for the fractional ablative and non-ablative laser treatment are skin tightening, scar removal, pigmentation removal, wrinkle removal and acne treatment. The non-ablative laser has less affinity to water and is associated with great results on skin tightening, acne scar and wrinkle removal with less downtime and adverse events.
Patients with mild to moderate wrinkles such as Glogau types I– III are appropriate candidates for all nonablative lasers. Patients who are willing to accept modest improvements and desire short visits with little to no downtime postprocedure are best suited to treatment with nonfractional lasers. Patients with mild to moderate wrinkles seeking more dramatic reduction of wrinkles, who are willing to accept some procedural discomfort and postprocedure downtime, are good candidates for fractional lasers. Patients with severe wrinkling are better candidates for ablative lasers or surgery, especially if skin laxity is significant. Light Fitzpatrick skin types (I– III) may be treated with all nonablative laser technologies including those with shorter wavelengths (e.g., 532 nm and pulsed dye lasers) as these patients have relatively lower risks of complications such as
hyperpigmentation. Dark Fitzpatrick skin types (IV-VI) can be safely treated with nonfractional lasers that target water. While fractional lasers that target water are also indicated for darker skin types, these technologies have greater risks of pigmentary alterations and may necessitate more conservative settings which can attenuate results. Patient Expectations Skin resurfacing with nonablative lasers requires a series of treatments performed at monthly intervals to demonstrate visible results: 4– 6 for fractional lasers and 6– 8 for nonfractional lasers. Results with nonablative resurfacing treatments (even with a series) are slow and subtle compared to ablative lasers. Assessment of patients’ expectations at the time of consultation and commitment to a series of treatments is essential to ensure success with these treatments. Nonfractional lasers that target water or melanin and oxyhemoglobin result in mild wrinkle reduction. Results are typically seen 2– 3 months after the initial laser treatment, and improvements may continue up to 6 months posttreatment. Relative to fractional nonablative lasers, skin resurfacing effects. are less dramatic. However, these treatments have the advantage of requiring little to no recovery time, lower risks of complications, and are easily incorporated into patients’ daily lives. Fractional lasers that target water have faster results and more significant improvements than nonfractional lasers. Results are usually seen by 1 month posttreatment and, like nonfractional lasers, improvements may continue up to 6 months posttreatment. These laser treatments are more uncomfortable than other nonablative lasers and typically require topical anesthetic preprocedure and forced-air cooling during the procedure for treatment to be tolerable. Some patients require oral analgesics and anxiolytics. Postprocedure erythema and edema typically last for 3– 4 days, and procedures can be associated with complications such as pigmentary alteration, acne exacerbations, and milia formation.
Indications • Mild static rhytids • Rough skin texture • Enlarged pores • Superficial acne scars Additional Indications for Nonablative Fractional Lasers • Moderate static rhytids • Benign pigmented lesions (e.g., lentigines, ephelides) • Melasma • Scarring (atrophic and hypertrophic) • Striae • Actinic keratoses • Hypopigmentation • Poikiloderma of Civatte • Telangiectasias and erythema
Alternative Therapies Ablative lasers (e.g., carbon dioxide and erbium lasers) are the gold standard for skin resurfacing. These more aggressive, deeper skin resurfacing procedures offer greater potential for static wrinkle reduction, but require longer recovery times and have greater risks of complications. Although fractional lasers have reduced recovery time and risk of complications, ablative laser treatments, whether fractional or nonfractional, create an open wound and have risks of scarring and infection. Nonlaser treatment options for wrinkle reduction include superficial skin resurfacing with light chemical peels or microdermabrasion, and topical skin care products such as retinoids and exfoliants (e.g., hydroxy acids). More aggressive skin resurfacing has historically been performed with deeper chemical peels (e.g., phenol) and dermabrasion, which utilizes a motorized rotating wire bristle brush to abrade the skin, but these higher-risk procedures are uncommon today. Other available treatments for facial lines and wrinkles include botulinum toxin for dynamic wrinkles and dermal fillers for static lines, and these treatments are often performed in conjunction with laser procedures. For severe wrinkling with saggy lax skin, surgery is an option. Light-emitting diodes (LEDs) emit a narrow range, or band, of low-intensity wavelengths without inducing epidermal or dermal damage. While these light-based devices have similarities to lasers and other light-based technologies, their results are extremely modest and are briefly discussed here. Red light LED devices (570– 670 nm) have been used for mild wrinkle reduction and blue light LED devices (400– 500 nm) for acne. They do not operate based on the theory of selective photothermolysis, but rather are based on the principle of photomodulation, where cellular activity is modulated through illumination by particular wavelengths of light. The main advantage of LEDs is their ease of use. Radiofrequency technologies are used to reduce skin laxity and skin folds and to treat wrinkles. Reduction of skin laxity and folds to improve skin contour is commonly known as “skin tightening”; however, the term used by the U.S. Food and Drug Administration (FDA) is soft tissue coagulation. Radiofrequency devices (such as Thermage ®, Solta) employ rapidly alternating current that creates heat when applied to the skin due to the skin’s resistance to current flow. Tissue heating with radiofrequency devices is controlled by several factors, including the type of electrodes used (e.g., monopolar or bipolar), fluence, and cooling times. These technologies have been shown to improve laxity in areas such as the periocular region, nasolabial folds, jowls, neck, and abdomen. Newer radiofrequency devices are being used for fractional resurfacing (e.g., Matrix RF ™, Syneron and Infini ™, Lutronic). Fractional RF devices concentrate heat in the mid to deep dermis with limited epidermal disruption and these devices are therefore, referred to as subablative.
Do not hesitate to consult as for your skin care needs; we are Edmonton most advanced cosmetic and laser clinic. We have long lasting experience with skin tightening, wrinkle removal, acne scar removal, acne treatment, scar removal, stretch mark removal, pigmentation removal, melasma treament, frenckles and sun spots treatment, body shaping, fat reduction, body slimming, coolsculpting and sculpsure.
Part of this post is taken from Small, Rebecca. A Practical Guide to Laser Procedures