PALM DESERT, CALIF. The 755-nm alexandrite laser was highly effective in improving lentigines in 18 volunteers treated at Naval Hospital Camp Pendleton, Lt. Cmdr. John Paul Trafeli, USN, said at the annual meeting of the American Society for Dermatologic Surgery.
Independent reviewers judged that the patients had a 60% average improvement in their lentigines after a single treatment with one or two passes of the alexandrite laser, which is more commonly used for hair removal.
Dr. Trafeli said that 18 patients were also treated for facial telangiectasis in the same study, but the results were not quite as good. Those patients had a 30% average improvement.
"For telangiectasis, the alexandrite laser is a ground ball, but for lentigo, it is a definite home run," he said.
After experimenting with several parameters on test areas, the investigators generally settled on a 3-millisecond pulse duration at 34 J/cm
Increasing the pulse duration improved the background epidermal tolerance and did not work as well.
The 755-nm alexandrite laser is an "interesting" wavelength because it appears to be optimal for absorption in areas of dyspigmentation, Dr. Trafeli said.
It has a high absorption by melanin relative to hemoglobin, compared with the 532-nm and 595-nm lasers, and it has three times the melanin absorption of the 1064-nm laser.
"The nicest thing about this alexandrite is that it is very fast and simple," he added.
"I liken it to a lawn mower. You don't need much skill. You just kind of go over the whole face."