Evaluation of the clinical efficacy of the 1450 nm laser in acne vulgaris: a randomized split-face, investigator-blinded clinical trial

Background The 1450 nm laser shrinks sebaceous glands histologically, reduces seborrhoea and has been shown in numerous small uncontrolled studies to improve inflammatory acne. Objectives To assess objectively the clinical efficacy and long-term outcome of the 1450 nm laser for inflammatory acne vulgaris. Methods Participants over 16 years of age with moderate to severe acne vulgaris were recruited from a secondary care dermatology department. A split-face format was used: the side of the face to be treated was randomized with the other side serving as a within-patient control. Treatment was delivered with the Candela 1450 nm Smoothbeam laser (Candela, Cwmbran, U. K.) using a double-pass technique, 6 mm spot size, 210 ms pulse duration and fluence of 8 or 9 J cm) 2. Three treatments were performed monthly. The primary outcome was the change in inflammatory lesion count and grading (using the Leeds Revised Acne Grading Scale) between baseline and 4 weeks after the third treatment on the treated side as compared with the change in the control side. Participants were followed up every 3 months for 12 months after the last treatment. The single assessor was blinded as to the side treated. Results Thirty-eight participants entered the study and 32 completed the study at the primary outcome measure. Within participants, on average, the lesion count reduced by the same amount on both sides of the face [ median 0, 95% confidence interval (CI)) 4 to 2]. On average, acne grade reduced by the same amount on both sides (median 0, 95% CI) 1 to 0). Twelve months after the last treatment (n = 23) the change in lesion count and grade between the treated and control sides of the face remained similar. Treatment was well tolerated. Conclusions Treatment with the 1450 nm laser does not reduce inflammatory lesion count or acne grade when compared with a control side, using a split-face format in participants recruited from secondary care. Both sides of the face improved and a systemic effect of the laser is possible.