1,927 nm thulium laser shows promise for melasma treatment

Melasma is one of the most challenging aesthetic conditions we face in our dermatology practices. Driven by both internal (hormonal) and external (sun exposure) factors, melasma can be improved with sunscreen, topical bleaching agents, chemical peels, and laser and light sources, but long-term remission has proven elusive.

When a new laser or light-based device addressing pigment is introduced there is much enthusiasm regarding its potential for this stubborn condition. For instance, the 1,550 nm erbium:glass nonablative fractional laser (NAFL; Fraxel re:store; Solta Medical) was suggested as a potential melasma treatment modality and showed success in initial studies (Rokhsar CK, Fitzpatrick RE. Dermatol Surg. 2005;31(12):1645-1650. Katz TM, Glaich AS, Goldberg LH, et al. Dermatol Surg. 2010;36(8):1273-1280). Subsequent investigations, however, found the laser to be less efficacious.

In 2010, Wind et al studied 29 melasma patients in a split-face fashion and found that four to five sessions of 1,550 nm laser worsened hyperpigmentation and patients preferred the side with triple topical therapy (tretinoin/hydroquinone/triamcinolone; Wind BS, Kroon MW, Meesters AA, et al. Lasers Surg Med. 2010;42(7):607-612).

Investigators from a group in Germany treated 26 melasma patients with four sessions of 1,550 nm fractional laser plus sunscreen versus the 25 melasma patient controls who received sunscreen alone. Both groups improved, but there was no statistically significant difference between subjective or objective measurements of improvement (Karsai S, Fischer T, Pohl L, et al. Eur Acad Dermatol Venereol. 2012;26(4):470-476).

Benefits of 1,927 nm laser

The most recently evaluated nonablative fractional laser for melasma is the 1,927 nm thulium fiber laser (Fraxel re:store DUAL, Solta Medical) first described in the literature in 2011 (Polder KD, Harrison A, Eubanks LE, Bruce S. Dermatol Surg. 2011;37(3):342-348). This wavelength is potentially attractive due to its higher water absorption coefficient than 1,550 nm and subsequent shallow depth of penetration of approximately 200 μm. The investigators treated 14 patients with melisma who had Fitzpatrick skin types II through IV with three to four sessions of the 1,927 nm laser at varied parameters (10 mJ to 20 mJ, 20 to 45 percent density, six to eight passes). A statistically significant reduction in Melasma Area and Severity Index (MASI) score of 51 percent was seen one month after treatment, however at three (33 percent reduction vs. baseline) and six (34 percent) months there was a partial rebound.

Another recent publication of the 1,927 nm laser for melasma comes from a group in San Diego, which includes one of the authors of this column (Massaki ABM, Eimpunth S, Fabi S, et al. Lasers Surg Med. 2013;45(2):95-101). In this study, 20 female patients with Fitzpatrick types II through IV who had recalcitrant melasma underwent a single treatment at the following parameters: 10 mJ to 20 mJ, 60 to 70 percent surface area coverage (treatment level nine through 11). A high potency corticosteroid cream (clobetasol propionate 0.05 percent) was used over the melasma for three days following the procedure. Four independent investigators determined MASI score before, at four weeks, at three to six months, and at six to 12 months after the laser session.

One month after the treatment patients were advised to begin treatment with 4 percent hydroquinone cream to prolong remission. Twelve of 20 subjects (60 percent) had more than 50 percent clearance of their melasma at four-week follow-up. Recurrence was reported in seven of 15 patients who were followed up a mean of 10.2 months, which subsided within three months with topical bleaching creams. Eleven patients completed the three to six month follow-up and eight (40 percent) completed the final visit.

Mean MASI scores continued to decrease for the duration of the study, 13.4 before, to 8.5 (37 percent reduction from baseline) at four weeks, to 6.1 (54 percent reduction from baseline) at the final follow-up. Two of the subjects felt they experienced poor (<25 percent) clearance and two of the nine (22.2 percent) of skin type IV patients, 10 percent of the whole cohort, had worsening of their melasma.

The most recently published data comes from South Korea, where investigators sought to evaluate the effects of the 1,927 nm fractional laser on melasma and photoaging in Asian skin (Lee HM, Haw S, Kim JK, et al. Dermatol Surg. 2013;39(6):879-888). The authors evaluated 25 Asian women with photoaging, eight of whom had melasma in a split-face fashion, treated with the 1,927 nm thulium laser three times at three-week intervals with the following parameters: 10 mJ 30 percent density (treatment level 3, no mention of number of passes) compared to the untreated control side. No topical bleaching agents were permitted two months prior to initial treatment or during the study.

Patients were evaluated at two (8/8) and six months (6/8) following the final treatment. Two subjects had 2 mm punch biopsies taken prior to treatment and at the two-month follow-up. The mean MASI score at baseline was 6.06, at two months, 4.04 (33 percent decrease from baseline), and at six months, 4.34 (28 percent decrease), a slight rebound in contrast to the aforementioned high density single treatment protocol.

Rebound effect

This slight rebound may be attributed to the lack of bleaching agents allowed to be used during the study, compared to the high-density single treatment study. All subjects (photaging and melasma) were satisfied at two and six months, with 80 percent and 57.1 percent stating they were more than moderately satisfied respectively. In the two subjects who underwent biopsy, at two months a marked increase in procollagen 3 and a decrease in basal melanin was observed with immunostaining.

Despite the relative paucity of published data on the 1,927 nm NAFL for melasma treatment, the available results appear encouraging. Whether the most effective approach with this laser is with low density and multiple treatments versus the high density single treatment technique remains to be seen. Furthermore, the impact of topical treatment before and after the laser has not as of yet been delineated.

One of the authors (SGF) and her colleagues recommend high potency topical corticosteroid two days before and three days after the laser session. They theorize that this can be beneficial in the immediate post-treatment period to ameliorate the inflammatory cascade that eventuates in postinflammatory hyperpigmentation. Since their report using a single high density treatment, one of the authors (SGF) and her colleagues now initiate topical bleaching creams as early as one week after the procedure, as tolerated, to maximize the longevity of their results and minimize any rebound.

They also treat type IV skin with a lower density than they initially reported, 50 percent. The authors await additional well-executed studies and long-term follow-up to refine and enhance this potentially beneficially laser intervention for melasma. In the meantime, other modalities that may show promise in ameliorating this condition include the 1,927 nm diode (Perméa handpiece, Clear + Brilliant System, Solta Medical) combined with topical lightening agents, as well as the picosecond 755 nm alexandrite laser (Picosure, Cynosure) with defractive lens, for which clinical trials are currently under way.