Melasma Lasers

What is melasma and types of melasma

Melasma is a localized hyperpigmentation problem that is characterized by uneven brown or grey-brown macules and well-defined macules that appear symmetrically on sun-exposed areas of the body, usually the face. This disease most often occurs in women, and the best known etiological factors are exposure to the sun and ultraviolet radiation. Histological and immunohistochemical studies have shown that melasma-affected skin is characterized by pronounced skin damage from the sun. UV radiation is known to increase the synthesis of alpha-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropic hormone (ACTH), which is formed from pro-opiomelanocortin (POMC) in keratinocytes. These peptides lead to the proliferation of melanocytes, and also increase melanin synthesis by stimulating tyrosinase and tyrosinase-related protein-1 (TRP-1) activity.

One study has shown that melasma, in addition to changes in pigmentation, is characterized by changes in the structure of the dermis, suggesting a role for the dermis in the development of melasma. The role of fibroblasts in the development of melasma is also being considered. In fact, an excessive expression of both stem cell factors has been revealed: cytokines of fibroblast origin stimulate the proliferation and melanogenesis of melanocytes in cultivation. Therefore, it is possible that the inflammation of the dermis caused by the accumulation of UV radiation may be associated with the activation of fibroblasts, which leads to an increase in stem cell growth factor in dermal melasma, which in turn causes increased melanogenesis. Recent data have also shown that melasma-affected skin is more vascularized than normal skin. located on the periphery of the pathological focus. Increased expression of vascular endothelial growth factor (VEGF) in keratinocytes has been suggested to be an important angiogenic factor in the altered vessels in melasma. Therefore, the network of cellular interactions between keratinocytes, fmbroblasts, and possibly vasculature and melanocytes during chronic sun exposure may play an important role in the development of melasma by stimulating melanocytes together, resulting in epidermal hyperpigmentation.

vasculature and melanocytes during chronic sun exposure may play an important role in the development of melasma by stimulating melanocytes together resulting in epidermal hyperpigmentation.

vasculature and melanocytes during chronic sun exposure may play an important role in the development of melasma by stimulating melanocytes together resulting in epidermal hyperpigmentation.

Melasma can be classified according to the site of lesions (craniofacial, zygomatic, maxillary), histological depth of pigmentation (epidermal, dermal, mixed), and Wood's lamp appearance (epidermal, dermal, mixed, indeterminate):
2. Epidermal melasma: light brown with increased pigmentation under Wood's lamp. Histologically characterized by an increase in melanin in the basal, suprabasal and stratum corneum of the epidermis.
3. Dermal melasma: gray or grey-blue with no enhancement of pigmentation under Wood's lamp. Histological characteristics: the predominance of melanophages in the superficial and deep layers of the dermis.
4. Mixed melasma: dark brown with increased pigmentation under Wood's lamp in some areas.

Indeterminate melasma: not detectable under Wood's lamp.

Epidermal melasma tends to provide the best results. As a rule, the laser is used when the disease does not respond to conventional treatments.

Q-switched lasers in the treatment of melasma

There have been attempts in the past to treat melasma with melanin-targeting lasers such as Q-switched ruby ​​laser (694 nm), short-pulsed green dye lasers (504-510 nm), Q-switched neodymium lasers (1064 nm) , as well as an argon laser (514 nm). The results were disappointing. Jeong et al. compared the clinical efficacy and side effects of low-density yttrium aluminum garnet (1064 nm) neodymium lasers before and after treatment with topical creams in 13 patients. They used a collimated pulse width of 7 nm, a dot size of 7 mm, and a density of 1.6 – 2.0 J/cm

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. Sessions were held weekly for 8 weeks. The lasers were compared with the cream before and after the treatment.

The authors found that pre-treatment with topical creams was more effective as it reduced melanin production prior to laser action; thus, the risk of post-procedural hyperpigmentation decreased along with melasma. If a topical cream was used after laser exposure, melanin was produced at full capacity, which increased the risk of post-procedural hyperpigmentation and reduced the effectiveness of melasma treatment. The authors therefore recommended medical treatment of hyperpigmentation 8 weeks prior to laser treatment for optimal results.

Kauvar evaluated the safety and efficacy of a procedure combining microdermabrasion, topical treatment and laser treatment with a Q-switched neodymium yttrium garnet low density laser treatment in 27 women. Treatment was carried out with a laser with a density of 1.6 - 2 J / sq. cm with a point of 5 or 6 mm immediately after microdermabrasion. The procedures were repeated with an interval of 4 weeks. In 22 women (81%), 75% elimination of melasma was observed; 11 women (40%) had more than 95% elimination of melasma. Side effects were limited to slight redness after the procedure, which appeared after microdermabrasion and disappeared after 30-60 minutes. CO

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-lasers and IVS for the treatment of melasma Better results can be achieved by using a neodymium yttrium aluminum garnet laser in combination with a pulsed CO₂ laser and a Q-switched alexandrite laser, as the CO

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laser destroys melanocytes, and the alexandrite laser eliminates pigments remaining in the dermis.

The IVS is a non-coherent broad spectrum light source that emits a constant spectrum in the range from 500 to 1200 nm. Therapeutic efficacy is relatively higher in patients with epidermal melasma than in patients with mixed melasma. This phenomenon may be related to the location of melanin. In epidermal melasma, melanosomes in the epidermis quickly move to the surface of the skin and are covered with a microcrust. In mixed melasma, macrophages full of melanin are difficult to damage. In a 2010 study, Zokkali et al. found excellent results with IVS for the treatment of melasma. They treated 38 patients (with Fitzpatrick phototypes III-IV) with IVS in 3-5 sessions spaced 40-45 days apart. They chose the 550nm arm as it provides greater selectivity for melanin and reaches the deep layers of the epidermis. using two pulses of 5-10 ms and a delay of 10-20 ms between pulses, and the density was modulated in accordance with the anatomical zones. For the cheeks and cheekbones, an energy of 12–14 J/sq.m was used. cm, for the forehead - 10-12 J / sq. cm, for the neck and around the eyes - 7-8 J / sq. see Results were very good in 18 patients (47.37%), good in 11 patients (28.95%), moderate in 5 patients (13.16%), and poor in 4 patients (10.52%) who had recurrence of hyperpigmentation observed after 2-4 months. Side effects were minimal and included a burning sensation during the procedure and transient redness. Possible complications included short-term, permanent hyperpigmentation and, in rare cases, scarring.

and the density was modulated in accordance with the anatomical zones. For the cheeks and cheekbones, an energy of 12–14 J/sq.m was used. cm, for the forehead - 10-12 J / sq. cm, for the neck and around the eyes - 7-8 J / sq. see Results were very good in 18 patients (47.37%), good in 11 patients (28.95%), moderate in 5 patients (13.16%), and poor in 4 patients (10.52%) who had recurrence of hyperpigmentation observed after 2-4 months. Side effects were minimal and included a burning sensation during the procedure and transient redness. Possible complications included short-term, permanent hyperpigmentation and, in rare cases, scarring.

and the density was modulated in accordance with the anatomical zones. For the cheeks and cheekbones, an energy of 12–14 J/sq.m was used. cm, for the forehead - 10-12 J / sq. cm, for the neck and around the eyes - 7-8 J / sq. see Results were very good in 18 patients (47.37%), good in 11 patients (28.95%), moderate in 5 patients (13.16%), and poor in 4 patients (10.52%) who had recurrence of hyperpigmentation observed after 2-4 months. Side effects were minimal and included a burning sensation during the procedure and transient redness. Possible complications included short-term, permanent hyperpigmentation and, in rare cases, scarring.

good in 11 patients (28.95%), moderate in 5 patients (13.16%) and poor in 4 patients (10.52%), in whom the reappearance of hyperpigmentation was observed after 2-4 months. Side effects were minimal and included a burning sensation during the procedure and transient redness. Possible complications included short-term, permanent hyperpigmentation and, in rare cases, scarring.

good in 11 patients (28.95%), moderate in 5 patients (13.16%) and poor in 4 patients (10.52%), in whom the reappearance of hyperpigmentation was observed after 2-4 months. Side effects were minimal and included a burning sensation during the procedure and transient redness. Possible complications included short-term, permanent hyperpigmentation and, in rare cases, scarring.

In the authors' opinion, IVS can rightly be considered a viable option for those patients who do not respond to conventional topical agents. However, only temporary results can be achieved in this way, as hyperpigmentation reappears after several weeks or months.

Fractional treatment is a new concept in skin rejuvenation that has the potential to treat a wide range of dermal and epidermal conditions due to its unique thermal injury pattern. Unlike ablative and non-ablative laser exposure, which result in homogeneous thermal damage at a certain depth, fractional exposure creates microscopic thermal damage. During fractional treatment, tissues around microdamages are not damaged, which makes it possible to quickly restore the epidermis due to the small size of the damage and short migration paths for keratinocytes. In a study by Kroon et al., non-ablative 1550 nm fractional laser treatment showed good results in patients with dark skin types, while local brightening was ineffective. <

The biological role of cutaneous blood vessels in the pathogenesis of melasma is an interesting topic that opens up new therapeutic perspectives. The authors recently conducted a prospective study to evaluate pulsed dye laser treatment. After a multi-spectral study to evaluate the components of hemoglobin and melanin, the authors use this low density vascular laser and have obtained some significant improvements. By targeting vascularization of at least some of the elastosis in melasma lesions, it may be possible to reduce the stimulation of melanocytes and thus reduce the likelihood of their return.

Conclusions

All the lasers described in this article open up new horizons for the treatment of hyperpigmentation, especially in patients with dark skin (Fitzpatrick skin types IV - VI). The use of lasers and intense light pulses to treat moderate pigmentation lesions has opened up new possibilities for dermatologists.

Physical laser treatment is generally reserved for patients who do not respond to initial local and cosmetic treatments. However, according to the authors, in particular with regard to the treatment of melasma, only temporary results can be achieved with lasers. > The role of vascularization in the pigmentation process needs further study. This research field may provide new therapeutic options such as vascular lasers or angiogenic agents. It is essential to conduct an accurate clinical, dermoscopic and multispectral assessment of hyperpigmentation in order to select the most appropriate treatment, as well as to ensure proper post-procedure care (photoprotection), follow-up, and the quality and retention of results. According to Prime magazine.