1999


From: Massachusetts General Hospital

Er:YAG Laser Has Advantages Over CO2 Laser For Wrinkle Removal

BOSTON -- The erbium:YAG (Er:YAG) laser can be as effective as the standard CO2 laser for the removal of wrinkles with fewer side effects, according to a study from the Wellman Laboratories of Photomedicine at the Massachusetts General Hospital (MGH). The report in the April Archives of Dermatology demonstrated that, while the Er:YAG required more "passes" of the laser to achieve the same result achieved with the CO2 laser, patients experienced less reddening of the skin and significantly faster recovery time with Er:YAG treatment.

"It is not unusual for people to take two weeks or more to recover from CO2 laser resurfacing, which makes the procedure inconvenient for many working people who cannot stay out of work that long," says Khalil Khatri, MD, of the Wellman Labs, the paper's first author. "The shorter recovery time needed for Er:YAG treatment means it might be a better option for many people, especially those with relatively superficial wrinkling."

The CO2 laser has been used for laser resurfacing -- removal of wrinkles and other signs of sun damage by removing the skin's outer layer -- since the early 1990s and is considered the "gold standard" of treatment. The Er:YAG laser was first used for treatment of wrinkles and other skin blemishes at the MGH Wellman Labs and was approved by the FDA for laser resurfacing in 1997. This study is the first to directly compare the effectiveness and long-term effects of the two treatment modalities.

In 21 volunteer patients, laser resurfacing was carried out using the CO2 laser on one side of the face and the Er:YAG laser on the other side. At intervals of one week, two weeks, two months and six months after the treatment, the participants met with the physicians who treated them to evaluate the overall results. Physicians reviewed such factors as improvement in wrinkles and the presence of redness, infection, scarring or discoloration. In addition, a panel of five dermato-logists not involved in treating study participants reviewed photographs taken at each follow-up visit. This panel did not know which laser had been used on which side of any participant's face.

The early participants in the study showed that equal "dosage" of the CO2 and Er:YAG lasers (two or three passes of the laser) resulted in noticeably greater wrinkle improvement with CO2 laser treatment. As a result, these early participants had additional treatment to the Er:YAG side to produce an equal effect on both sides of their faces, and subsequent participants had five or more laser passes on the Er:YAG laser side.

Evaluation of the overall results found that levels of treatment removing equal depth of skin layers (two to three passes of the CO2 laser, compared with five or more passes of the Er:YAG laser) resulted in similar improvement in wrinkles. Even at the higher level, Er:YAG treatment resulted in fewer side effects and quicker recovery times. Redness was consistently greater on the CO2-laser treated side: at two months, redness was observed in 62 percent of CO2-laser treated sides versus 24 percent of Er:YAG-treated sides. Even at six months, 10 percent of the CO2-laser sides had mild redness, compared with none of the Er:YAG-treated sides.

Areas of lightened skin, with a visible line of demarcation between treated and untreated areas, were significantly more common with CO2-laser treatment. Such areas were seen on 43 percent of CO2-laser treated sides compared with 5 percent of Er:YAG laser treated sides at six months after treatment. There was no signficant difference in levels of swelling or darkening of skin -- both of which disappeared without treatment -- between the two treatment modalities. None of the participants experienced infection or scarring.

"It's clear that the two types of laser treatment have their own advantages," says Khatri. "The Er:YAG laser might be a better choice for those who cannot take as much time to recover. For an older person with deeper wrinkling who might not be as concerned about recovery time, the CO2 laser could be a better choice. I describe the overall effects of both to my patients and let them choose which is best for their particular needs."

Most of the fundamental research underlying today's many uses of lasers in medicine was conducted at the MGH Wellman Labs. Using slightly different technical approaches, the CO2 and the ER:YAG lasers produce beams of concentrated light that are absorbed by water molecules and converted to heat that can ablate or destroy unwanted tissues. They also are used to treat scars, warts and some superficial cancers. Another type of YAG laser called the Nd:YAG laser is used to treat moles and other pigmented lesions.

The paper's coauthors are R. Rox Anderson, MD, senior author; and Joop Grevelink, MD, PhD, of the MGH Wellman Labs; Victor Ross, MD, now at the US Navy Hospital in San Diego; and Cynthia Magro, MD; of Beth Israel Deaconess Medical Center in Boston. The study was supported by a grant from Continuum Biomedical, Inc.

The Massachusetts General Hospital, established in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $200 million and major research centers in AIDS, the neuro-sciences, cardio-vascular research, cancer, cutaneous biology, trans-plantation biology and photo-medicine. In 1994, the MGH joined with Brigham and Women's Hospital to form Partners HealthCare System, an integrated health care delivery system comprising the two academic medical centers, specialty and community hospitals, a network of physician groups and nonacute and home health services.




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