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Q-switched 660-nm Nd:YAG laser effectively reduced melanin levels in facial lentigines

A Q-switched 660-nm Nd:YAG laser significantly reduced the objective melanin average when treating facial lentigines in Asian women compared with the 532-nm laser, according to study results.

Researchers treated half of each face of eight Korean women with Fitzpatrick skin type 3-4 and facial solar lentigines with either 660-nm or 532-nm Q-switched nd:YAG lasers. A profilometric skin analysis tool measured pigmentation objectively while pigmentation area and severity index (PSI) score, global assessment of the aesthetic improvement scale (GAIS) and patient satisfaction score at weeks 4 and 8 were used to subjectively measure pigmentation.

Seven women (mean age, 49.4 years) completed the study, due to one patient not returning for the 8-week follow-up visit.

There were no significant differences found between the laser treatments in the PSI, GAIS, patient satisfaction score and melanin average score. The 660-nm treatment group tended have a slightly higher improvement rate at week 8 compared with the 532-nm treatment group.

There was a significant reduction in the melanin average at week 8 in the 660-nm treatment when compared with baseline (P < .05).

Serious or adverse events, such as scarring, were not reported.

“Both 660-nm and 532-nm lasers effectively treat lentigines in patients with darker skin types,” the researchers concluded. “The treatment efficacy is not significantly different between these two devices, but the objective melanin average was significantly reduced by the 660-nm but not the 532-nm treatment at week 8 compared with baseline. This difference could be related to the occurrence of PIH at 8 weeks of treatment. Although there are many factors related to the occurrence of PIH, the laser wavelength may be one of the most important.” – by Bruce Thiel

Disclosure: The researchers report no relevant financial disclosures.