CARLSBAD, CALIF.Some acne patients may respond to various light-based treatments, but most of the time the improvement is modest and short-lived, Dr. E. Victor Ross Jr. said at a symposium on laser and cosmetic surgery sponsored by SkinCare Physicians.
Most light-based therapies for acne "don't work as well as they should," said Dr. Ross, director of the Scripps Clinic Skin and Cosmetic Center in La Jolla, Calif. "The bar should be pretty high. If we're having patients sit under these lights and have these therapies, I think that means long remission periods with one treatment, not five treatments every 2 or 3 weeks, and evidence that there's some robust compromise of the sebaceous gland."
Most patients who seek light-based treatments for their acne have been on isotretinoin in the past yet are unwilling to be on systemic retinoids again. "They don't have severe acne, but they have cyclical moderate acne, and they're tired and frustrated with the typical" therapies, Dr. Ross said.
Light therapies don't work well for acne because a photochemical effect should prevail over any photothermal effect to excite endogenous porphyrins produced by Propionibacterium acnes. In addition, the only studies to show microscopic damage to the sebaceous gland have been those with long incubation times, continuous-wave light sources, and red light only. This regimen caused epidermal damage in every case, he noted.
"It's unlikely that one will achieve long-term and profound sebaceous gland compromise with short aminolevulinic acid times, either with pulsed light sources or with continuous-wave light sources," he said. "Right now we have to be honest with ourselves and say the prescription pad is still pretty darned good. … I've tried these [light] therapies, but I'm not ready to say these are a home run or even a triple or double right now."
He added that many patients who undergo light treatment for their acne fail what he calls the "come back" test. "They don't come back. If they don't come back, [we assume] they're probably better, but I suspect that most of them are not better, they're worse," he said.
Dr. Ross disclosed that he has research relationships with Palomar, Cutera, and Laserscope.