J AM ACAD DERMATOL
The first to mention is the 532-nm KTP laser, which is safe and effective for improvement of acne84 (more so than scar treatment), thus aiding in prevention of acne sequelae such as scarring. The optimal nonablative laser to use for hypertrophic scars or keloids is the 585-nm pulsed dye laser (PDL). Best results and least side effects are obtained on Fitzpatrick skin types I or II because of less competition with melanin.16 This laser focuses on erythema and vascularity so incidental scar improvement is possibly because of decreasing vascularity (the scars are hyperemic because of angiogenesis) and its associated secondary effects in the local field or other cellular alterations, specifically regarding collagen. Improvement after use can be seen up to a year later.
One study of 15 patients with erythematous, hypertrophic scars treated with 510- or 585-nm PDL with the objective of observing pigmentation and/or erythema improvement found incidental improvement in scar texture and elevation. It was suggested that this was most likely a result of the above explanation, which leads to decreased perfusion and nutrition with resultant anoxia, cell death, and enzymatic changes.85 However, the discussion after that article does not completely concur, noting some shortcomings of the article, such as the improvement seen in younger scars that would potentially improve as part of the natural maturation process. The author of that discussion performed her own study, using optical profilometry, to evaluate the 585-nm PDL when used for previous argon laseretreated port wine stains. It was found that there was improvement of hypertrophic and atrophic scar regions as exhibited by flattening and reappearance of skin markings, respectively. The article went on to reason that part of the improvement could possibly be attributed to eradication of enlarged blood vessels trapped within the sclerotic collagen.86 So, to this author, it does seem plausible that, within scars, both the laser’s primary effect on vasculature and the proposed, secondary effect on collagen (because of the nutrition changes and/or heat generation) both have benefit.
The 1064-nm neodymium:YAG (Nd:YAG) laser demonstrates low pigment effect with higher vascular effect causing hemostasis and resultant infarctions within vessels. It could have effect similar to those just discussed for PDLs used on hypertrophic scars or keloids. One small observational study using short-pulsed 1064-nm Nd:YAG lasers showed improvement in 100% of subjects’ scars. Nine patients completed the study of 10 initially enrolled (7 male, 3 female; 15-48 years, mean age 32 years; Fitzpatrick I-V; mild to severe scarring). There were 8 total treatments, each given 2 weeks apart. Physician assessment was performed 1 to 2 months after the final treatment and graded as 29.36% average improvement. Self-assessment revealed 8 of 9 patients thought improvement was 10% to 50%, whereas one patient noted that they were less than 10% better. However, all reported that they were satisfied with the results and would undergo the same treatment again.87 Recent studies have evaluated the effectiveness for atrophic scars as well. For example, 12 subjects (age 18-36 years, average age 27.6 years; Fitzpatrick II-V) with mild to moderate atrophic acne were treated with the 1064-nm Nd:YAG laser every 4 to 6 weeks over 8 months to total 5 sessions. Patients reported continual improvement on satisfaction surveys through the treatments. On completion, the mean satisfaction score was 8.6 of 10, with one patient reporting a grade of 6. Photographs evaluated by independent dermatologists revealed mild to moderate improvement for all patients (with one patient being graded by one physician only as no improvement). Histology revealed a statistically significant increase in dermal collagen.88
A minimal melanin absorption spectrum and deep papillary and midreticular dermal treatment is achieved with the 1320-nm Nd:YAG laser. For 12 patients (10 female, 2 male; 35-59 years, mean age 50 years; Fitzpatrick I-III) with mixed scars, photographs and nontreating physician and patient clinical evaluations at baseline and at 6 months after the last treatment were performed using the 10-point scale of Jacob et al.20 The acne scars were rated as more severe by the subjects than by the physicians at all intervals. Those with a predominance of atrophic scars, defined as greater than 90% of scars present, improved the most with mixed scars next. The trend was not found to be statistically significant. Physicians noted improvement in 100% of the subjects whereas only 67% of subjects believed they had seen improvement themselves. None of those involved reported a worsening of appearance or complications.89
Another laser variant is the 1450-nm diode. One small study evaluating its effectiveness, primarily as an acne treatment, showed improvement in acne scarring in 83% (of 6 who initially presented with scarring, 5 improved; 9 of 11 finished the study proper) of subjects. A split-face bilaterally paired treatment design was used with one half of the face receiving a single pass that was double-stacked and the other a double pass of single pulses. Mean acne scar improvement on a scale of 0 to 3 was ranked as a 1 and there was no difference between the two treatment protocols.90 Even if only an acne treatment, this may carry importance as a measure for scar prevention. Further evaluation will be needed to evaluate this laser specifically for scar treatment.
Acne Scarring Light, Laser, and Energy Therapy page 3
Acne Scarring A review and current treatment modalities BACKGROUND and ACNE SCARS ACNE SCARS page 2 ACNE SCAR TREATMENT and MEDICAL MANAGEMENT SURGICAL MANAGEMENT PROCEDURAL MANAGEMENT PROCEDURAL MANAGEMENT page 2 TISSUE AUGMENTATION TISSUE AUGMENTATION page 2 TISSUE AUGMENTATION page 3 TISSUE AUGMENTATION page 4 Light, laser, and energy therapy Light, laser, and energy therapy page 2 Light, laser, and energy therapy page 3 Light, laser, and energy therapy page 4 Conclusion and REFERENCES Manufacturers of brand name drugs mentioned in this article