Atlanta - Nonablative treatment with a 1320nm Nd:YAG or 1450nm diode laser offers a viable option for achieving moderate improvement in the appearance of atrophic acne scars with no downtime, according to preliminary results from a randomized study conducted at the Washington Institute of Dermatologic Laser Surgery, Washington.

Atrophic scars before treatment (left) and three months following series of three SmoothBeam laser treatments.

"These nonablative lasers have been proven safe and effective for improving rhytids by stimulating dermal collagen synthesis, and so it seemed rational that they might also be used to treat atrophic acne scars. Our results so far indicate both systems are a good addition to our armamentarium for treating atrophic acne scars, and those observations are consistent with some recent reports describing efficacy during short-term follow-up of patients treated with a 1320nm Nd:YAG laser.

However, we are continuing to observe our patients in order to evaluate the longevity of the effects and if there are any relative efficacy differences between these systems," said Elizabeth L. Tanzi, M.D., a fellow at the Washington practice under the direction of Tina Alster, M.D.

The study used a split-face design and included 20 patients with skin phototypes I to V who received three treatments at monthly intervals to the full cheeks and temple region using a 1320nm Nd:YAG laser (CoolTouch) on one side and a 1450nm diode (Smoothbeam) laser contralaterally. Dr. Tanzi administered all of the laser treatments with the same technique, applying nonoverlapping pulses to produce transient erythema and swelling without blistering.

Atrophic scars before treatment (left) and three months following series of three CoolTouch II laser treatments.

Outcome assessments, including clinical ratings improvement by two independent investigators examining pretreatment and posttreatment digital photographs, patient satisfaction ratings, objective in vivo measurement of surface textural change using three-dimensional microtopography, and histopathologic assessment for dermal fibroplasia in biopsy specimens taken from a subgroup of patients, were planned at study visits over a 12-month period after the last treatment.

Follow-up to six months indicates that there is progressive improvement over time, becoming evident at a follow-up visit three months after the last treatment. Overall, the changes have been mild to moderate - at six months, investigator improvement ratings averaged about 45 percent, with mild to moderate atrophic scars appearing to respond better than more severe "icepick" scars.

So far, the results in all efficacy end points show a modest advantage of the 1450nm diode laser over the 1320nm Nd:YAG laser, although the difference is slight, Dr. Tanzi said.

Both of the laser treatments were very well tolerated. The only side effects recorded included erythema and edema lasting up to six hours after treatment with the 1320nm Nd:YAG laser and up to 24 hours posttreatment with the 1450nm diode laser. Both lasers were associated with development of temporary postinflammatory hyperpigmentation in a small proportion of patients. There were no cases of scarring or any adverse textural changes.

"Ablative laser procedures with the CO2 or erbium:YAG lasers are very effective for treating atrophic acne scars, but postoperative recovery can be significant and they also carry potential risks for more persistent pigmentary changes. These nonablative laser treatments appear to be a possible option for patients who are unwilling or unable to experience downtime and who accept the tradeoff of a less dramatic treatment benefit," Dr. Tanzi said.

The CoolTouch laser is a product of CoolTouch Corp. The SmoothBeam is manufactured by Candela Corp. Dr. Tanzi has no financial interest in either company.