Treatment of acne scars with fractional CO2 laser at 1-month versus 3-month intervals: An intra-individual randomized controlled trial


  • Role of the sponsor: The sponsor had no role in design and conduction of the study, in the collection, analysis, and interpretation of data, or in the preparation, review, or approval of the manuscript.
  • Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.



Treatment of acne scars with ablative fractional CO2 laser appears to be an effective and well-tolerated treatment. However, so far the influence of treatment interval has not been evaluated.


To evaluate whether treatment of acne scars with fractional CO2 laser resurfacing at 1-month interval achieves better results with no difference in the occurrence of adverse effects, than treatment given at 3-months interval.


Patients (n = 13) with symmetrical atrophic acne scars on right and left sides of the mid-face and lower-face were randomized to two fractional CO2 laser treatments at 1-month versus 3-month intervals. Blinded on-site evaluations were performed 1 and 6 months after the last treatment on 10-point scales. Endpoints were scar atrophy, patient satisfaction, and adverse effects.


Pre-operatively, acne scars were moderately atrophic (5.86 ± 1.87). After treatment acne scars appeared with less atrophy on both treated sides 1 month postoperatively (1-month interval 1.96 ± 1.23, P < 0.0001; 3-months interval 1.82 ± 1.08, P = 0.0006) and 6 months postoperatively (1-month interval 1.56 ± 1.24, P = 0.0021; 3-months interval 1.33 ± 1.66, P = 0.0002). The treatment interval did not influence the improvement of scar atrophy at any time postoperatively (P = 0.81). Patients were moderately and equally satisfied with the treatment result on facial sides (P = 0.93). Postoperative adverse effects were minor and not influenced by the treatment interval.


Fractional CO2 laser resurfacing improves atrophic acne scars and a treatment interval of either 1-month or 3-months does not seem to influence the improvement of scar atrophy nor the occurrence of postoperative adverse effects. Lasers Surg. Med. 46:89–93, 2014. © 2013 Wiley Periodicals, Inc.