Fractional photothermolysis improves photodamaged skin

March 1, 2008

A nonablative 1,550 nm erbium-doped fiber laser effectively treats facial and non-facial photodamage, rhytids and dyspigmentation with a favorable side effect and recovery profile, according to a recent study.

Key Points

The study was the first to analyze a large cohort - 50 patients - and follow them for a year after initiation of treatment, says Tina S. Alster, M.D., director, Washington Institute of Dermatologic Laser Surgery and clinical professor of dermatology, Georgetown University Medical Center, Washington.

"So it was a bit more complete than any of the other studies that had been published to that time," Dr. Alster tells Dermatology Times.

Researchers enrolled 30 patients with mild to moderate facial photodamage, rhytids and dyspigmentation, plus 20 with similar mild to moderate nonfacial concerns.

They excluded patients who were undergoing concomitant treatments in these skin areas and those with histories of keloid scarring, isotretinoin use within one year and ablative resurfacing procedures within three years of the study's start.

To prepare skin for treatment, investigators applied alcohol, followed by a water-soluble tracking dye (OptiGuide Blue, Reliant Technologies) and 30 percent lidocaine ointment unoccluded for 60 minutes.

They gave patients a total of three treatments with a 1,550 nm erbium-doped fiber laser (Reliant) spaced three to four weeks apart using a 15 mm handpiece.

Each facial treatment consisted of eight passes at a fluence of 8 mJ/cm2 and a density of 250 microthermal zones (MTZ)/cm2. Energy delivered per session totaled approximately 3 kJ or 2,000 MTZ/cm2.

To treat chest and neck skin, Dr. Alster says investigators treated more conservatively (because these areas contain fewer pilosebaceous units), using six to eight passes at the same fluence and density as above for a total of 1,500 to 2,000 MTZ/cm2 or about 2 to 3 kJ.

To analyze results, researchers took standardized clinical photos at baseline and three, six and nine months after the final treatment.

Independent evaluators assessed clinical improvement in areas including dyspigmentation, degree of wrinkling and other surface irregularities, using a quartile grading scale.

Investigators also tracked side effects, complications and patient satisfaction at each treatment and follow-up visit.

Three months after treatment, mean facial clinical improvement topped out at 2.3, which corresponded with 51 percent to 75 percent improvement.

Mean scores for nonfacial improvement (1.85, or 25 percent to 50 percent) also peaked at this point. At six months, mean facial and nonfacial improvement scores were 2.1 and 1.81, and at nine months 1.96 and 1.7, respectively.

Altogether, at least 73 percent of facial treated areas and 55 percent of nonfacial treated areas achieved at least 51percent to 75 percent improvement in photodamage at nine months (Alster TS, et al. Dermatol Surg. 2007;33:23-28).

"What I like about this treatment for nonfacial areas is that it's one of the most viable treatments, certainly on the neck area," where no suitable options to treat crepeyness exist, Dr. Alster says.

The fact that clinical improvements peaked three months after treatment contrasts with results achieved by purely nonablative, midinfrared lasers, which show optimal efficacy six months after treatment, Dr. Alster says.

"The nonablative lasers really do not address the epidermal dyspigmentation that is often part of the clinical situation - it's not just wrinkling or scarring," she says.

If one uses entirely nonablative technologies that heat tissue without creating any microscopic peeling of the type that occurs with the Fraxel, Dr. Alster says, "No improvement of epidermal discoloration can be achieved."

Side effects

Side effects - including post-treatment erythema observed in all patients and lasting a mean of 2.9 days - were limited and transient, Dr. Alster says.

Furthermore, Dr. Alster says the Fraxel technology itself makes the entire experience easier on patients, during both treatment sessions and recovery.

In patients she's seen since the study concluded, Dr. Alster adds, "The improvements have been long-standing. It's not like they had this procedure done and then reverted to where they were before."

Fewer than half of these patients have elected to undergo maintenance procedures, which Dr. Alster says she generally advises having performed on an annual basis after the initial treatment series.

Disclosure: Dr. Alster reports no relevant financial interests.

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