Retrospective Analysis of Non-Ablative Scar Treatment in Dark Skin Types Using the Sub-Millisecond Nd:YAG 1,064 nm Laser

Background: The use of lasers to treat atrophic scarring conditions in darker skin types presents a significant challenge to laser practitioners. Current treatment modalities, including deep dermal peels; ablative; non-ablative; and fractional laser resurfacing and surgical techniques, are limited in skin types IV through VI due to increased risks of hyper- and hypo-pigmentation. This is especially true when attempting to treat large areas of acne scarring. This study investigates the treatment of atrophic scarring with a non-ablative sub-millisecond-pulsed 1,064 nm Nd:YAG laser in darker skin types. Objective: To evaluate the safety and efficacy of a sub-millisecond 1,064 nm Nd:YAG laser for the treatment of atrophic scarring in Fitzpatrick skin types III-VI through retrospective photographic analysis. Methods: A retrospective analysis was conducted of all patients (n = 22) who received sub-millisecond Nd:YAG laser treatments for atrophic scarring over a 6-month period. Patients had Fitzpatrick skin types III-VI and were treated for the indication of atrophic scarring using the fluence of 14-16 J/cm(2), pulse duration of 300-500 microseconds and repetition rate of 5-7 Hz. An average of six treatments was performed on each patient approximately 3 weeks apart and the mean follow-up time after the final treatment was 9 months (range of 3-10 months). Blinded photographic assessments were performed by three independent physicians using photos unlabeled for before and after and arranged in non-chronological order. Reviewers were asked to determine before and after photos and the degree of improvement in scarring, textural change, and post-inflammatory hyper-pigmentation (PIH) secondary to the acne or scarring condition. Degree of improvement was graded using a four-point scale: 0 = < 25%, 1 = 25-50%, 2 = 51-75%, 3 = 76-100%. Results: Based on blinded photo assessments by three independent reviewers, clinically and statistically significant median improvement of 2 in scarring, 2.3 in texture, and 2 in pigment were observed (one-sample Wilcoxon signed rank test, P < 0.001). Reviewers were highly consistent (inter-reviewer reliability) in identification of before and after photos (kappa of 0.88). Conclusions: Preliminary data collected in this retrospective study suggest that sub-millisecond 1,064 nm Nd: YAG laser treatment is a safe and effective treatment for atrophic scarring in patients with darker skin types, delivering clinically and statistically significant results with reduced risk of pigment complications and patient discomfort. Lasers Surg. Med. 43:130-136, 2011. (C) 2011 Wiley-Liss, Inc.