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Low-fluence Q-switched laser shows efficacy in treating melasma, solar lentigo

Low-fluence Q-switched 1,064-nm neodymium:yttrium-aluminum-garnet laser achieved efficacy in treating melasma and small–plaque-type solar lentigo in Asian women, according to study results published in Dermatologic Surgery.

Researchers in the dermatology department at Wakayama Medical University, Wakayama, Japan, conducted a randomized clinical study on 22 women (mean age, 48.1 year) with melasma (n = 13) or solar lentigo (n = 9) with pigmented lesions on both cheeks.

The patients received low-fluence Q-switched 1,064-nm neodymium:yttrium-aluminum-garnet laser (QSNYL) treatment weekly for 10 sessions on one cheek, with a 1-month rest after the fifth treatment. The Medlite C7 (Hoya ConBio) with 1,064-nm QSNYL was used. Mexameter (Courage and Khazaka), physician and patient assessment and evaluation of histological changes were used to measure efficacy.

Twenty patients completed the study. There was statistically significant reduction in melanin and erythema indices in the treated sides of the cheek, with 50% of patients with melasma; 62.5% of patients with solar lentigo had greater than 50% or good clearance after their final treatment.

There were no improvements in increased erythema index, vascularity and mast cell activity in patients with melasma and large-sized solar lentigo.

Patients with melasma had a recurrence rate of 16.7%, whereas patients with solar lentigo had a recurrence rate of 12.7%.

One patient developed postinflammatory hyperpigmentation. Slight, transient post-treatment erythema, swelling and mild pain were reported by most patients. Other adverse events included skin dryness in three patients and pruritus in one patient.

“Reduction of epidermal and dermal pigmentation, vascularity, and activated melanocyte count could predict the efficacy of low-fluence QSNYL treatment for melasma and small–plaque-type solar lentigo,” the researchers concluded. “Moreover, these findings suggest that assessment of the lentigo size, epidermal hyperplasia, horny cell thickness, vascularity and mast cell activity can be used to track the effectiveness of treatment for melasma and solar lentigo.”

The researchers noted that low-fluence QSNYL treatment was limited in treating large–plaque-type solar lentigo and that other therapeutic options would be better suited. – by Bruce Thiel

Disclosure: The study was supported by JMEC Co., LTD. The researchers report no relevant financial disclosures.