(HealthDay)—Fractional CO2 laser treatment is safe and seems effective for atrophic acne scars, with no difference observed for treatment with a one- or three-month interval, according to a study published online Sept. 9 in Lasers in Surgery and Medicine.

Marie Bjørn, M.D., from Aarhus University in Denmark, and colleagues evaluated whether treatment of acne scars with fractional CO2 laser resurfacing at one-month interval achieves better results than treatment at three-month intervals. Participants included 13 patients with symmetrical atrophic acne scars on right and left sides of the mid-face and lower-face, who were randomized to two treatments at one-month or three-month intervals.

The researchers found that at one-month and six-months after treatment, acne scars appeared with less atrophy on both treated sides, with no difference in the improvement of scar atrophy by treatment interval (P = 0.81). The patients were moderately satisfied with the results and the satisfaction was not influenced by the treatment interval (P = 0.93). Treatment interval did not influence postoperative adverse effects, which were minor.

"Fractional CO2 laser resurfacing improves atrophic acne scars and a treatment interval of either one-month or three-months does not seem to influence the improvement of scar nor the occurrence of postoperative adverse effects," the authors conclude.