As we discussed in the first part of this series, Laser Therapy 101: Ablative Lasers and Skin Resurfacing, laser therapy describes a treatment that uses precise beams of light to heat, cut, burn, or destroy precise tissue targets. Ablative lasers (lasers that cut or burn more deeply) are more aggressive for skin resurfacing or lesion removal purposes (and thus require more true wound healing). Nonablative lasers (lasers that heat, but less aggressively) have less wound care and downtime, making them a valuable option for those with busier lifestyles. Below, we’ll discuss the differences and purposes of nonablative lasers.
Pulsed Dye Laser
A pulsed dye laser uses a concentrated but gentle beam of light to target specific blood vessels or red pigments. Once the light hits your skin, it is converted into heat energy that damages the lining of the targeted blood vessel, which is then safely absorbed by your body as it redirects blood flow into deeper vessels. Pulsed dye lasers are typically used to treat vascular birthmarks (like port wine stains and hemangiomas), rosacea, broken blood vessels, facial redness, and newer, red scars and stretch marks.
Pulsed dye lasers often only require one to three treatments, but more complex conditions, such as rosacea or hemangiomas, may need more. Anesthesia typically isn’t necessary, but many devices contain a built-in skin cooling system. You won’t see the type of side effects like crusting and scarring common with ablative lasers, though a small percentage will experience bruising that disappears within 3-10 days. Post-procedure, wound care is simple.
Nd:YAG Laser
The Neodymium-doped Yttrium Aluminum Garnet laser, or Nd:YAG for short, uses infrared light to remove brown pigmented spots like freckles and sun spots, orange-red tattoos (under certain conditions), birthmarks, and hair in darker-skinned patients. During treatment, the laser pinpoints the contrasting pigment and uses photothermolysis (the principle behind all lasers) to heat the pigment and break it down into microscopic particles which are then absorbed into the bloodstream and removed from your body.
Many conditions only require one treatment with the Nd:YAG laser, depending on the lesion, the patient’s skin type, and the condition being treated. Side effects are minimal as most patients only experience mild skin irritation for up to a week after treatment, the severity of which depends on the pigment targeted. Patients with melasma, post-inflammatory hyperpigmentation, or diffuse hyperpigmentation are not good candidates for this procedure.
The Nd:YAG laser is also used with special settings for a “laser facial” that has no downtime and can, over several sessions, smooth texture, reduce redness, improve breakouts, and temporarily shrink pores. We have seen excellent results with this in our practice. Over many sessions, it may also help to improve acne scarring, though not as quickly as ablative laser treatments.
Alexandrite Laser
The alexandrite laser uses infrared light (755 nm) for the treatment of vascular and pigmented lesions as well as hair and tattoo removal in lighter skinned patients. Its shorter wavelength allows for easier absorption by the targeted area, which minimizes damage to the surrounding tissue. Like the Nd:YAG laser, it uses selective photothermolysis to heat pigmented targets while protecting the surrounding non-pigmented tissue. Because the laser absorbs melanin easily, it’s especially effective for tattoo removal, particularly green or black inks since the laser itself ranges from red to yellow colors.
In my practice, I use the PicoSure alexandrite laser for tattoo removal, which is the newest alexandrite laser introduced to the market in 2013. It features ultra-short picosecond pulse durations – each pulse lasts a trillionth of a second —  that enable the laser to break down ink molecules into even smaller particles than the standard “nanosecond pulse” alexandrite laser. The PicoSure leaves less residual pigment, doesn’t require as many treatments, and can even remove the trickier green/blue inks, though like all tattoo lasers, it has trouble with reddish inks.
Bottom Line
One of the pros of using a non-ablative laser is that the transformation happens under the surface of your skin with much less risk of burning and scarring, allowing for minimal pain and healing time. Discuss your options with a well-trained, board-certified dermatologist to figure out what is appropriate for your situation.