NATIONAL HARBOR, MD. Improvement in melasma severity achieved by fractional photothermolysis lasted for a mean 13 months in five of eight patients, while the other three had recurrences in the first-ever study to follow these patients beyond 6 months.
"For refractory melasma, nonablative fractional photothermolysis is a good treatment option with long-term remission," Dr. Tracy M. Katz said at the annual meeting of the American Society for Laser Medicine and Surgery.
The device used in the study was a 1,550-nm erbium-doped Fraxel laser. Treatments were performed at 640 mJ (starting low in all patients and increasing in some), with eight passes per treatment at levels of 410; this corresponded to surface area coverage of 14%-29%. The laser settings were chosen based on the patients' skin type, with a maximum level of 7 for darker skin and up to 10 for lighter skin, said Dr. Katz of DermSurgery Associates, Houston.
A forced-air cooling device was set at low settings of 23 to decrease inflammation and reduce the risk of postinflammatory hyperpigmentation.
The eight women had a mean age of 44 years (range 2757), with skin types II-IV, and they had melasma on the face that was refractory to hydroquinone and other traditional treatments. The mean duration of disease was 6 years. Each patient underwent two to seven treatments, at intervals of 46 weeks for lighter skin and 68 weeks for darker skin. Topical triple anesthetic was applied 1 hour prior to treatment.
Patients were instructed to use hydroquinone until 23 days prior to each treatment and then to restart it after their skin had healed and continue it for 26 months after the last laser treatment. They were seen for follow-up anywhere from 7 to 36 months after their last laser treatment, with a mean follow-up of 13 months.
Assessments were determined via side-by-side photo analysis by the treating physician (Dr. Paul Friedman) and a nontreating physician (Dr. Katz), based on a well-established quartile grading system of 1%-25%, 26%-50%, 51%-75%, and greater than 75%. At the last treatment session, two patients achieved more than 75% improvement, four had 51%-75% improvement, one had 26%-50%, and one had 1%-25% improvement.
During 736 months' follow-up, five patients had maintained their initial level of improvement and three had recurrence of their melasma. Two of those three patients had the lowest initial improvement (1%-25% and 26%-50%), Dr. Katz reported. Energy settings correlate with an increased depth of thermal injury, and pigment in dermal melasma is usually found up to the papillary/reticular dermal junction around 500 micrometers, with pigment being rare beyond 700 micrometers. Knowing this, energies up to 30 mJ should target most pigment, she noted.
Dr. Katz stated that there were no financial disclosures associated with her presentation.