Several light-based treatments have been successful in improving acne, but how they do this has not been clear. Dr. Niels Krejci-Papa and his colleagues from Boston University School of Medicine evaluated whether the 1,450-nm diode laser reduces sebum production.The researchers tested four females and four males who had a history of acne, as reported in the February issue of Lasers in Surgery and Medicine. Each patient received treatment on the right side of his or her nose every two weeks over a six-week period. The left side of the nose was left untreated for comparison.A 6-mm circular area on each patient was treated with a 1450-nm laser from Candela Corp. of Wayland, Mass., with a fluence of 12.5 J/cm2 at six pulses per treatment. The researchers used Sebutape, a lipid-absorbing film that shows the amount of oil excreted from the skin, to measure the amount of sebum before and after each treatment.After the six-week period, the number of sebum-producing follicles had been reduced by 18 percent as compared with the untreated skin.The researchers conclude that the laser’s success with improving acne may be partly the result of its effects on sebaceous glands. However, they note that further studies will be needed to evaluate the effects over longer time periods.