LED Photomodulation: "Light" Way To Skin Renewal

content provided by the Faculty of the Harvard Medical School

LED photomodulation: "Light" way to skin renewal

Acquiring a more youthful look often involves sanding, peeling, or heating the skin. A new painless technique relies only on low light.

At one time, women could get a lasting younger look only by a surgical facelift. Then came skin-rejuvenation techniques that produced more natural-looking results: dermabrasion, chemical peels, and ablative laser resurfacing. In these procedures, the outer layers of skin are removed (ablated) to spur wound healing and the growth of new collagen and skin cells (see "Skin structure and skin aging"). But the process hurts, and recovery can take days or weeks.

Skin structure and skin aging On the skin's outermost layer - the paper-thin epidermis - old cells continually die, flake away, and are replaced by younger cells that rise up from the lower epidermis. This process renews the skin about once a month. Beneath the epidermis is a thicker layer called the dermis, which contains substances such as collagen and elastin, and structures such as blood vessels, oil glands, and nerves. Collagen, a structural protein, is arranged in layers of fiber called fibrils, forming a matrix that holds the skin together. Elastin, a protein similar to collagen, gives skin its elasticity. Beneath the dermis is a layer of fat. As we age, the dead cells don't slough off as easily, so the surface of the skin becomes rougher. Less moisture is retained and less collagen and elastin are produced, so the fibril layers loosen and become less organized, causing skin to sag. Losing collagen and elastin, the skin becomes thinner, so fine lines appear around the eyes, and deeper lines occur at the mouth and across the forehead. All these changes are accelerated by exposure to sun. In fact, damage from sun exposure, also called photoaging or photodamage, is the source of most facial lines and wrinkles. Smoking also prematurely ages the face by damaging collagen and elastin and impairing blood circulation to the skin.

There are several newer ways to tighten skin and improve its tone and texture with less recovery time and usually less discomfort: non-ablative laser treatments, intense pulsed light, and radiofrequency resurfacing. These techniques work below the skin surface, on the dermal level, usually without injuring the outer layers of the skin. But most of them rely on some degree of heat damage to deeper skin layers for their rejuvenating effects. One, Thermage, uses radiofrequency waves to heat collagen deep in the dermis, causing the strands to contract and tighten the skin surface. It causes some pain, but recovery time is less than a day.

There's also a technique that doesn't heat or damage deep skin layers. Called light-emitting diode (LED) photomodulation, it involves the use of low-level light to treat photoaged (sun-damaged) skin. It has less dramatic effects than many other skin-rejuvenation approaches, but it's painless, and requires no recovery time. LED photomodulation appears to work best on skin with mild to moderate sun damage. Patients report tighter pores, fewer wrinkles around the eyes and mouth, and overall improvement in skin quality and texture. Clinicians are also using LED photomodulation in combination with other skin-improvement techniques, although it's unclear how effective this is.

How does it work?

The truth is, we don't know exactly. It uses the same kind of light-emitting diodes that you see on many phones and VCR/DVD players. The diodes deliver short pulses of a narrow band of low-intensity yellow light to skin cells. But the process doesn't heat the dermis. Instead, scientists theorize, the light (which uses less energy than a low-wattage household light bulb) may stimulate mitochondria, the power plants of the cells, causing them to increase production of collagen and elastin, the substances that keep young skin plump. The technique is also being evaluated as a way to speed wound healing and stimulate hair growth in men with male-pattern baldness and women with hair loss.

In two clinical trials involving a total of 183 patients, LED photomodulation has produced improvements in skin texture, skin discoloration, redness, and fine lines around the eyes in most patients. A 2005 study in the journal Lasers in Surgery and Medicine followed 90 patients with mild to moderate photoaging for a year after two months of twice-weekly treatments. Results were evaluated with digital photographs, skin surface measurements, and - in a few cases - skin biopsies.

The researchers reported some improvement in 90% of the participants. Results were best four months after the treatment. By month 12, there was some decline, although the skin's condition was still better than before treatment. All biopsies showed improved collagen production. A caution: This study and most other clinical research on LED photomodulation has been led by dermatology experts in academic medical centers who are also affiliated with LightBioScience, LLC, the manufacturer of GentleWaves, the only photomodulation device approved by the FDA for treating sun-damaged skin.

What's involved?

Before treatment, makeup is removed and the skin's surface may be gently exfoliated to take away dead cells. Then, you sit in front of two LED panels and close your eyes while a bright yellow light flashes onto your face for less than a minute. The process has been tested on all skin types; it is painless and causes no redness or sensation of heat. You can return to normal activities right away. Typically, patients start with a series of 8-10 treatments over about two months, at a cost ranging from $50 to $150 per session. To maintain results, you may need three or four follow-up sessions per year.

At this point, experts aren't sure whether LED photomodulation is any more effective than topical tretinoin creams, such as Retin-A and Renova, which are less expensive and don't require office visits. We'll need studies comparing the two approaches to see how well the newer technique lives up to its claims.

Thinking about a cosmetic procedure?

Even if we still feel "among the very young at heart," our skin can give our age away with lines, wrinkles, unevenness, and discolorations. Some women view these changes with equanimity, although they may apply lotions or creams to soften the effects of age and sun damage. Others seek more active means of resistance through various cosmetic procedures. In 2004, women underwent more than eight million cosmetic procedures, and at least half of them were aimed at reversing facial aging.

If you're thinking about a cosmetic procedure, it's important to spend some time carefully considering why you want a change and what you expect from it. This could make a big difference to your satisfaction with the results. You'll also want to learn about which procedures are available, who should perform them, what's involved, and the possible risks.

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Last updated:	August 21, 2006