Helping children with facial port wine stains was the first cosmetic usage of laser energy. Since then, our understanding of energy in the skin has grown exponentially.
Today, lasers and other light/energy-based devices have dozens of cosmetic applications. From hair to brown spots to wrinkles and much more, demand for non-invasive (non-surgical) procedures has exploded as the baby boomers have aged.
A laser wavelength targets and destroys a specific chromophore, or colored molecule, and can focus at different levels in the skin to minimize damage. Research into tissue temperature sensitivity has brought new ways to tighten skin and kill fat. Cosmetic market competition is strong, so these devices have to be effective to replace surgery and older technology. This article will provide an overview and act as a primer for the reader.
Vascular Targets
Pulsed dye and KTP lasers are the gold standards for facial veins and redness. Birthmarks, rosacea, angiomas and sun damage respond well to the 532, 585 and 595 nanosecond wavelengths. Multiple manufacturers make devices with these settings, with the differences being the method of cooling the skin, spot sizes and pulse length.
Leg veins are harder to treat with lasers due to thick skin and pressure in the legs from gravity. 1064 NdYag lasers are marketed to help leg veins, but every lecture I go to on leg veins and lasers confirms that the gold standard for leg veins is still sclerotherapy.
Brown Spots
All brown spots are not created equal! Some are sun damage, some are genetic. Some are superficial, some deep. Some are from hormones, some from acne or trauma. But all brown spots are universally despised. Lasers can help some, not all, brown spots. Lasers can darken brown spots from hormones (melasma).
Many different lasers and light-based devices target brown spots. Classically, intense pulsed light (IPL), not a laser but a spectrum of light, is used to treat an area of sun damage, principally on the face, neck, chest and arms. Over a few days, obvious and not-so-obvious brown spots disappear. Remaining brown spots may be cleaned up individually with new picosecond lasers and 810 and 1064 wavelengths lasers.
Hair Reduction
The most common use of cosmetic laser therapy today is hair reduction. Dark hair in light skin can be treated effectively. Unfortunately, light hair does not have a chromophore to attract a laser, and dark hair in dark skin cannot be seen by the laser. Hair reduction wavelengths are commonly 810 in lighter skin, 1064 in darker skin. IPL is used for hair reduction but with a higher risk of hyperpigmentation and blistering due to multiple wavelengths hitting unintended targets.
Skin Texture, Wrinkles and Collagen Refreshment
Aging, primarily sun damage, causes large pores, wrinkles/crinkles and droopy skin. Compare the skin on your lower abdomen or buttocks (which typically has less sun damage) to that of your hands or face. A biopsy of 60-year-old sun-damaged skin compared to young sun-protected skin shows frayed, crinkled collagen and increased elastin. Anyone can tell the difference.
According to The New York Times, collagen production is stimulated by three things. One: laser resurfacing, which gets energy into the dermis where most damaged collagen is found. Two: prolonged use of tretinoin. Three, dermal fillers, which are used to plump thin lips, enhance contours, soften facial creases, remove wrinkles and improve the appearance of recessed scars. Enough said.
In the 1990s, two laser wavelengths were used for full face resurfacing, CO2 and Erbium Yag. They completely removed the epidermis and tightened the dermis. Folks who got a great result were thrilled, but not all got a home run. Poor healing and infection could impair results. It was expensive and usually required general anesthesia. Patients needed to lay low for 3 weeks, keeping the face moist, covered and out of the sun until the epidermis reformed. Scarring and hypopigmentation were not uncommon. Still, the demand for improvement in aged skin motivated research into other options.
In 2005, the fractionated laser was born. It lasered 20 percent, not all of the epidermis and superficial dermis, leaving columns of lasered skin surrounded by normal skin. This assured that the lasered skin was excreted and the damage healed quickly without scarring or hypopigmentation. The original wavelength was 1550; five treatments resurfaced the face for maximum results. Fractionated lasers now include 1550, CO2 and Erbium Yag. Multiple treatments are necessary, with some downtime, but not the risks of non-fractionated lasers.
Skin Tightening
Radiofrequency and ultrasound are now used to tighten skin without surgery. Both go through the epidermis into the dermis without damaging the skin, so they have no downtime. Radiofrequency heat contracts dermal collagen while ultrasound focuses on lower levels of the dermis. Some devices add microneedles to wound the epidermis and deliver focused radiofrequency waves deeper in the skin to tighten both epidermis and dermis.
Fat Destruction and Body Sculpting
Fat is the latest frontier in noninvasive, in-office procedures. Liposuction has been used for decades to remove fat cells in localized fat pockets. Laser-assisted liposuction was developed about 15 years ago to make the process less traumatic and to tighten skin from the inside. Knowledge that fat is temperature sensitive led the developers of the fractionated laser to focus on ways to destroy fat noninvasively. A technique to freeze fat while protecting the overlying skin and underlying muscle was first approved by the FDA in 2010 and is now considered by many to be the gold standard for noninvasive fat destruction. It takes three months to see results; the tradeoff is no cuts, stitches and invasive suction, which is worth it to many.
Cold kills fat, but so do heat and ultrasound! Radiofrequency waves and focused 1064 lasers are used to heat fat. Deep ultrasound is being used to target fat pockets as well.
Tattoo Removal
Tattoo removal is challenging. It involves multiple chromophores (colors), hence multiple wave lengths. The science is that the laser hits the ink and breaks it into smaller pieces, which the body’s macrophages carry away. It typically involves multiple treatments about every 2 months, with eight to 20 total treatments necessary.
A breakthrough in tattoo removal came with the development of a picosecond laser. (All conventional cosmetic lasers are nanoseconds.) This extraordinarily fast laser adds acoustic energy, breaking ink into smaller pieces so it is removed faster, requiring only three to eight treatments.
Obviously, there are many devices and methods that improve the appearance of skin and the body. Young skin reflects light, is smooth and one color. Photo-aging results in dyschromia (multiple colors in the skin: reds and browns of multiples shades), prominent vessels, a rough texture, enlarged oil glands and folds in the skin. The skin is dull with permanent lines from smiling and frowning (motion).
The underlying problems are that collagen and blood vessel walls are damaged by sun and free radicals, and the body’s protective pigmentation eventually cannot be totally removed because the removal processes are tired and worn out.
Not every machine is right for every person. The physician directing treatment must understand the color of the skin. Though operating lasers and other cosmetic devices can be delegated, the devices discussed here require the direction of a physician.
Remember that if one only has a hammer, then everything will look like a nail. Make sure that the physician understands the patient’s goals and that the physician and the patient are sure that the treatment is right for that patient.
