The Treatment of Melasma with Laser Toning Q Switched ND:Yag 1064nm

What is Melasma?

The clinical definition of melasma is known as bilateral brown patches or macules, generally observed in the centrofacial, malar or mandibular regions. It is an acquired chronic pigmentary disorder of the skin. The prevalence of melasma predominantly occurs in women from a childbearing age, and is seen less frequent in men. It is also more common in darker skin types with fitzpatrick phototypes from III-IV, and is more susceptible to people living closer to the equator, hence having more impact on racial skin types including Asians, Hispanics, Latinos, and African-Americans. The etiopathogenesis of melasma is also linked to racial and genetic factors. Exposure to ultra violet (UV) radiation is seen as the most significant contributing factor to the development of melasma due to its severity in showing solar elastosis. Melanogenesis is increased when UV irradiation is induced causing inflammation. Activation of fibroblasts occurs as well as an upregulation of melanocyte stimulating cytokines and stem cell factor in dermal melasma.

Other triggering factors that can lead to the onset of melasma includes: sex hormones (estrogen and progesterone), paracrine factors, pregnancy and the use of contraceptive pills. In addition to this studies have also found hormonal therapies, autoimmune thyroid disease, stress, endocrine dysfunction, overian dysfuncation/cancer, nutritional disorders, hepatic disease, stress, cosmetic products, phototoxic medications, photoallergic and antiepileptic medications to also be causative agents of this disorder. Melasma that develops post pregnancy is often referred to as cholasma or the pregnancy mask. In some instances cholasma can resolve within months post delivery. Although these factors are caused from endogenous or exogenous influences there is a common similarity between all of these factors. They will all appear as hyperactive melanocytes.

Determining the depth of Melasma

Proper skin analysis and consultations must be performed prior to any treatment to prevent complications from occurring following treatment. By using a Wood’s lamp skin diagnostic tool, it can help to identify the disposition of the melasma to determine if the lesion is epidermal, dermal or combined. There will also be high levels of melanin in the dermis associated with epidermal melasma. Whereas, in dermal melasma the appearance of epidermal pigmentation is less prominent, and superficial and deep perivascular melanophages are found in the dermis. The importance in understanding the exact location of the melasma is for proper treatment diagnosis and to minimize the risk of complications.

Treatment of Melasma with a low fluence laser toning method using QSwitched Nd:YAG 1064nm Laser

A proven and effective modality is by using a low fluence Q-Switched 1064nm Neodymium:yttrium aluminium garnet (QSNY) laser. Using a well-researched technique called ‘laser toning’, it has been known and proven for its capabilities to create minimal thermal damage to the tissue to treat melasma. The use of a longer wavelength (1064nm) reduces absorption of melanin coefficient, but also is able to penetrate deeper into the dermis. The technique uses multiple passes with low energy to promote favourable changes in the skin. Laser toning with a QSNY laser uses nanosecond pulse duration ranges. It creates a shattering effect on the tissue by sufficient kinetic energy delivered from the acoustic waves. Therefore it produces both photothermal and photoacoustic effects on tissue. The laser toning approach uses a similar concept known as subcellular selective photothermolysis. However, this concept is more based on non-specific dermal heating. The application of ultra short pulses allows for minimal heating to the cells thus the pigmented cells remained alive. During this process the destruction of keratinocytes, melanocytes and dermal melanophores takes place. A reduction of the activity of melanocytes and dermal melanophages are seen. Concurrently, it is able to encourage neocollagensis by contraction of collagen fibres. 

Post Laser Toning

Following a laser toning procedure the wound healing phases will start to take place. The heat induced to the shock proteins results in reduced proinflammatory interleukin (IL)8 to the wound healing mediator. This transforms into growth factor (TGF)-B resulting in collagenesis. Type I collagen will be replaced with new collagen type III and therefore, wound romedelling phase will take place. Laser toning is therefore not only beneficial for treating melasma, but also in its dual effects for toning and rejuvenating the skin. Laser toning can also improve in evening out skintone as well as rhytids. Therefore, laser toning is a minimal invasive approach whereby, reducing inflammation and the risks of PIH from occurring post treatment, as well as providing little to no downtime for the patient. Cooling post treatment is important to reduce the risk of PIH and topical application of a physical sunscreen minimum SPF of 30 is mandatory for all patients. 

Combination Treatment

Adjunctive conventional treatments often effective for epidermal melasma and can also include: topical therapies including bleaching agents like hydrquinone, Kligman-Willis Formula (5% hydroquinone, 0.1% tretinoin and 0.1% dexamethasone), topical steroids, retinoids, Azelaic acid, Kojic acid, Ascorbic acid and a variety of chemical peels (e.g. Gycolic, Lactic, Tricholoracetic acid and salicylic peels). However, dermal and mixed types of melasma are found resistant to these treatments. Hence the results can be temporary and have significant risk of pigmentary changes.

My conclusion 

Unfortunately, there is no single modality found in current literature for the treatment of melasma. It seems that a single modality can only yield temporary results. Patients must be diligent with photoprotection and remain out of direct sun exposure, as UV radiation has been found to be one of the leading causes of its onset. Topical treatments have been found satisfactory with treating epidermal melasma. Whereas laser toning with a QSNY laser has been found an effective and popular modality for treating dermal and mixed melasma. However, the limitations and complications from all interventions mentioned has only proven how difficult it is in finding the most appropriate solution for melasma. There needs to be more studies and researched performed in treating melasma.