Lasers deemed highly effective for excessive scarring

Laser therapy approaches are effective for treating excessive scarring resulting from abnormal wound healing, but not all scars are affected equally, according to a recent review article.

Dr. Qingfeng Li and colleagues at Shanghai Ninth People’s Hospital analyzed 28 well-designed clinical trials that focused on various medical lasers for two types of excessive scarring: hypertrophic scarring and keloids. Both are abnormal tissue responses that lead to raised and thickened areas of scarring, resulting in cosmetic and sometimes functional problems. Hypertrophic scars are limited to the initially injured area; keloids, which are more common in dark-skinned people, can spread beyond the area of the initial wound. Most of the studies evaluated the effects of laser therapy for hypertrophic scarring, with only three reports focusing exclusively on keloids.

Laser therapy has been shown effective in treating hypertrophic scarring (shown here), but better evidence is needed on treating keloids with lasers.

Several different treatment approaches are used for excessive scarring, but there is little guidance from evidence-based research. Modern lasers used for this application are nonablative, so they work by coagulating deep tissues. Compared to older lasers, which worked by destroying abnormal scar tissue at the skin surface, modern nonablative lasers provide more consistent results with a lower risk that excessive scarring will return.

Data from more than 900 patients showed high success rates with laser treatment: about 70 percent for both hypertrophic scarring and keloids. Based on studies targeting scars that were less than a month old, laser therapy had a similar success rate in prevention of excessive scarring. The responses appeared best with two specific lasers: the 585-/595-nm pulsed-dye laser (PDL) and the 532-nm laser. About two-thirds of the studies reviewed examined the former; just three studies evaluated the latter. Some studies provided data on objective responses to laser treatment, reporting improvements on standard rating scales and measures of scar height and redness. Data from the PDL studies suggested that the best interval for repeated laser treatments was five to six weeks; PDL treatment appeared most effective in patients with fairer skin types.

The review paper was published in the American Society of Plastic Surgeons’ Plastic and Reconstructive Surgery (doi: 10.1097/PRS.0b013e3182a97e43). The authors highlighted the need for further research in this and other key areas, including the benefits of different types of lasers and the results of laser treatment for scarring in patients with darker skin. They also highlight the need for better evidence on the effectiveness of lasers for treating keloids.