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From Cosmetic Surgery Times, July 01 2001 by Coriene Hannapel

Author/s: Coriene Hannapel
Issue: July, 2001

New York -- A long-pulse Nd:YAG laser system with a wavelength of 1064 nm may be superior to the previously used shorter wavelength alexandrite or diode lasers for hair removal in tanned patients.

Clinical results of two prospective, controlled hair removal studies were recently discussed by Melanie Grossman, M.D., who reported the studies suggest tanned patients may now be treated safely and effectively with the CoolGlide system (Altus Medical, Burlingame, Calif.).

"We were not able to previously treat suntanned patients," said Dr. Grossman, New York City dermatologist, and assistant clinical attending in dermatology, Columbia University Medical Center.

With previous shorter wavelength lasers, tanned patients were subject to the increased risk of undesirable side effects, such as pigmentary changes and blistering, Dr. Grossman reported.

What differentiates the 1064-nm CoolGlide system from previous systems is the use of high-power, long-pulse Nd:YAG technology.

The system combines a longer wavelength, a longer pulse width, and an integrated cooling system.

"It is the combination of all of these elements that contributes to the overall safety and efficacy of the procedure for tanned patients. It appears that no one element is more significant than the other," Dr. Grossman said. "This combination makes it possible to treat sun tanned skin."

Although laser-based solutions for hair removal have been available in the United States since the mid-1990s, the short wave alexandrite and the diode were not well suited for suntanned individuals.

The CoolGlide system, based on using longer laser wavelength and integrated epidermal cooling, received clearance from the FDA for removing unwanted hair.

The studies were undertaken to determine the safety and efficacy of the CoolGlide aesthetic laser for the removal of unwanted hair in suntanned patients with brown or black hair.

For the initial study, 20 tanned subjects, skin types I to IV, were enrolled. A single treatment on three test areas and an untreated control site was delivered to each patient. Treatment sites were 3 cm x 5 cm.

Follow-up visits to evaluate epidermal response and hair counts were scheduled at intervals of one, three, and six months.

Study findings indicated that hair reduction equal to that achieved with untanned patients could be reached without the undesirable side effects normally associated with the treatment of tanned patients, Dr. Grossman explained.

A second study was undertaken to further confirm the safety results. Using larger treatment areas, up to 15 cm x 15 cm, 38 tanned subjects were followed for one month.

Treatment areas for both studies included arms, legs, backs, shoulders, abdomens, and bikini lines. Skin types represented in the combined studies include 31 percent of skin type II, 24 percent of skin type III, and 45 percent of skin type IV.

Transient erythema and edema were seen immediately posttreatment, however there was no blistering or purpura. Mild hyper- and hypopigmentation seen in two sites was clear by three months.

For the first study, treatments were performed at 15 ms, 20 ms, and 30 ms pulse widths using the 10-mm spot size and the precooling handpiece that comes with the laser. The fluence for each patient was determined by the investigator, with an average fluence of 63 J/[cm.sup.2], with a range of 50 to 70 J/[cm.sup.2].

At six months, there was a hair count reduction of an estimated 30 percent. "Results were measured by counting hairs," Dr. Grossman said, "and photographs were taken to look at side effects."

A study is underway to determine the safety and efficacy of the CoolGlide on darker skin types.

Dr. Grossman has no financial interest in the CoolGlide laser system.