TUESDAY, July 22 (HealthDay News) -- Carbon dioxide laser resurfacing still seems the best way to erase telltale signs of aging on your face -- and keep them away.

The technique does have a fairly high rate of complications, namely lightening of the skin color, according to authors of a study published in the July/August issue of Archives of Facial Plastic Surgery.

The finding is not entirely new. But, said Dr. Keyvan Nouri, director of dermatologic and laser surgery at the University of Miami Miller School of Medicine, "The point is basically that carbon dioxide is still a very good treatment. It does have a down time and some side effects, but it does cause a dramatic improvement in many patients that we can't achieve with anything else out there now."

Added study co-author Dr. Shan R. Baker, director of the Center for Facial Cosmetic Surgery at the University of Michigan Medical Center: "There's nothing earth-shattering about this paper except the fairly long-term follow-up. It just confirms that carbon dioxide laser resurfacing is very effective for deeper facial wrinkles, and it's long-lasting."

The laser works by absorbing water inside and outside of sells, causing heat damage to nearby tissue. As a result, the skin produces more of the protein collagen, filling in wrinkles.

"It basically causes a controlled burn to the skin," Nouri explained. "Then it removes the epidermis [top layer of the skin] and dermis [middle layer of the skin]. It also causes contraction or tightening of the skin."

The authors of the study described the experiences of 47 patients who underwent full-facial carbon dioxide laser resurfacing at the University of Michigan. Forty-two of the patients were women; the average age was 52.

After more than two years of follow-up, participants' "wrinkle scores" improved 45 percent and were consistent across the face.

The main long-term complication was hypopigmentation (loss of skin color), notably present in 13 percent of patients. One case of hyperpigmentation (patches of skin that become darker) righted itself within two years of treatment.

Some patients also developed milia, small cysts or acne. One participant developed an infection, and one had sagging of the eyelids.

"The biggest problem with CO2 is lightening of the skin. Essentially all of our patients got lightening to some degree, but a certain percentage got marked lightening where you could see quite a bit of difference on photographs," Baker said. "That's the cost of getting rid of wrinkles permanently or near-permanently."

"Part of it has to do with how aggressive you are with peeling," he added. "If there are more wrinkles, you have to do more energy levels, and you often do more than two or three passes, so the patients are going to get more lightening. The deeper you go, the more lightening you are going to get."

According to Nouri, today's treatments tend to be less aggressive than in the past, so healing is faster.

The lightening tended to be consistent across the face, but there was a demarcation between the color of the skin of the face and that of the neck.

"That's why we peel down below the jaw line to try to hide it in the shadow," Baker said.

Related MedlinePlus Pages:

• Plastic and Cosmetic Surgery
• Skin Aging