Prospective clinical evaluation of 1440-nm laser delivered by microarray for treatment of photoaging and scars.

Background And Objectives: The use of thermal heating in microscopic zones is generically termed "microrejuvenation." The objective of this study was to evaluate the benefits of using a novel 1440-nm Nd:YAG laser (Affirm, Cynosure, Westford, MA) with a novel approach for microscopic heating. This device utilizes a microarray of lenses delivering a 10-mm beam as hundreds of high-fluence beamlets interspersed with a relatively uniform low-fluence background irradiation.

Study Design: Forty subjects (N = 40) at 2 study sites presenting with superficial rhytides and other symptoms of photoaging or scars received 3 treatments at 4-week intervals using a T-250 lens array. Total fluence ranged from 3.0 to 7.0 J/cm2. Zimmer air cooling was used for all treatments. No topical anesthetic was required.

Results: The most common immediate and expected clinical effects were erythema and edema lasting less than 24 hours, although 6 patients reported edema lasting for up to 1 week. There were no permanent side effects. In total, 2.7% of treatments resulted in temporary side effects, the most significant of which was a slight depression on the cheek (n = 1), which completely resolved within 3.5 months. Other side effects included localized areas of acneiform subcutaneous erythematous papules (n = 4) and a linear superficial crust (n = 1) with the original tip, all of which resolved within 1 week. One patient reported small erythematous subcutaneous nodules resolving in 17 days. Tenderness of the neck lasting from 2 weeks (n = 2) to 3 weeks (n = 1) was also reported.

Results: In all, 92% of the patients completed 3 treatments. Of these, 85% completed the 1-month follow-up. At the follow-up, 94% of subjects exhibited improvement in one or more categories, 82% exhibited mild to moderate improvement, and 12% exhibited good improvement. Side effects were minimal and included mild posttreatment erythema and edema resolving within 24 hours. Pain during treatment was judged minimal to moderate. Postauricular histology showed areas of thermal injury up to 250 microm deep and 150 microm wide.

Conclusions: A 1440-nm beam split by a microlens array is a promising new approach for inducing nonablative neocollagenesis in the remodeling of scars and rhytids. Histologic evidence confirms the microcolumnar nature of collagen heating using this microarray.