Ablative Non-fractional Lasers

* Laser resurfacing  works best for boxcar and rolling scars.

Laser resurfacing is a non-invasive procedure (does not involve cutting or inserting tools into the skin) that consists of shining an intense beam of light onto the skin. Because the light is concentrated and intense, it causes controlled damage to the skin. The type and extent of the skin damage depends on the type of laser. This controlled damage aims to stimulate skin healing and/or regrowth, which results in a smoother and more even skin surface–in other words, the skin is “resurfaced.”

Lasers can be ablative or non-ablative. Ablative lasers completely ablate (remove) the surface of the skin, whereas non-ablative lasers create a controlled injury deep in the skin, but do not ablate the surface of the skin.

Lasers can also be non-fractional or fractional. Non-fractional lasers, also known as non-fractionated lasers, treat the whole skin surface in a particular area without leaving any gaps. Because an entire section of skin is damaged, healing time is longer than with fractional lasers. Fractional lasers deliver many small pinpoints of laser light in a grid-like pattern, so that areas of skin in-between the pinpoints are left untouched. ¹

Ablative (skin-removing) non-fractional lasers: “Ablative” means “removing”- in this case, removing the skin. Ablative non-fractional lasers work by quickly heating up water molecules in the epidermis (the upper layer of the skin), which essentially “vaporizes” this skin layer. Because ablative non-fractional lasers completely remove the epidermis and trigger it to regrow, they can achieve dramatic results, but they also come with a long recovery time and a relatively high risk of side effects.

Ablative non-fractional lasers:

• How they work: Strip the epidermis from an entire section of skin
• # of treatments: Usually 1 treatment. Doctor performs an evaluation 6-12 months after treatment to determine whether a second treatment is necessary
• Advantages: Most dramatic results, single treatment is usually enough
• Disadvantages: Longest recovery time and highest risk of side effects
  • *Raised scarring is a potential side effect of ablative laser resurfacing, although it’s relatively rare when the procedure is performed correctly. The neck may be more prone to scarring.² 
  • To minimize the risk of scarring, it’s crucial to choose an experienced and qualified practitioner for the procedure. If you’re considering ablative laser resurfacing, it’s important to discuss all potential risks and benefits with a dermatologist or a cosmetic skin care specialist. They can provide guidance based on your skin type, medical history, and the specific concerns you’re looking to address with the treatment.

There are two main subtypes of ablative non-fractional lasers, each named after the material used inside the laser device, and your doctor can discuss with you about which is better for your particular raised scar(s). Lasers can be created using glass, crystals, or gasses, and the specific material determines the color of the laser light.¹

The materials in lasers used for ablative fractional skin resurfacing include:

• Er:YAG (erbium-doped yttrium-aluminum-garnet) laser
• CO₂ (carbon dioxide) laser

Each laser subtype penetrates the skin to a different depth. In general, ablative lasers do not penetrate deep into the dermis:¹

• Er:YAG (erbium-doped yttrium-aluminum-garnet) fractional laser: Does not go as deep into the epidermis as the CO₂ (carbon dioxide) laser
• CO₂ (carbon dioxide) fractional laser: Goes deeper into the epidermis than the Er:YAG (erbium-doped yttrium-aluminum-garnet) laser

As with all scar revision treatments, laser resurfacing is sometimes combined with other scar revision procedures to attain desired results.

People with active acne should not undergo acne scar repair of any kind, including laser resurfacing. Make sure your skin is completely clear of acne before beginning scar treatment.

Laser resurfacing cannot be performed while there is an active skin infection or skin condition such as a bacterial infection, eczema, or psoriasis. Ensure your skin is clear before seeking laser resurfacing.³

Doctors do not recommend undergoing laser scar treatment for 6 months after taking oral isotretinoin (Accutane®), because during this time, the skin may respond unpredictably to laser treatment.³

If you have a history of keloid scarring, approach laser resurfacing with caution, as you may have a higher chance of developing keloid scars as a side effect of laser resurfacing.¹

Patients with darker skin are at increased risk of pigmentation (skin coloring) due to laser treatment, especially hyperpigmentation (skin darkening).

Before agreeing to undergo laser resurfacing, discuss your treatment options, expected outcomes, and treatment prices with multiple doctors.

Procedure details:

Before booking your treatment, your doctor should first schedule a session to discuss the procedure, expected results, and possible complications with you and to answer your questions.

If you are planning to undergo treatment with an ablative laser, your doctor may prescribe antiviral medications for you to take before the procedure in order to prevent a viral skin infection from developing after treatment.

Laser resurfacing is usually performed in an outpatient setting. During the treatment, the doctor will give you protective eyewear to prevent the laser from damaging your eyes.

No matter which type of laser your doctor uses, she will have to fine-tune the laser settings in order to get the best results while minimizing recovery time and side effects. Once the settings are dialed in, she will make several passes over your scar with the laser, which produces mild pain.

In general, ablative lasers cause more skin damage than non-ablative lasers. Still, how much skin damage any given laser produces can vary significantly depending on several variables.

One of these variables is the wavelength that the laser material creates:

• Wavelength: Each type of material creates a laser with a specific wavelength. The wavelength of a laser is a number in nm (nanometers) corresponding to a specific color of light. Most lasers used for skin resurfacing emit colors of light that are invisible to the human eye, so you will not be able to see the laser beam during your treatment. For example, a diode laser emits infrared light with a wavelength of about 800 nm, which you cannot see, but may feel as heat during treatment.

Other settings that determine how much damage a laser causes can be controlled by the doctor:

• Delivered fluence,also known as energy density: Fluence or energy density is a measure of how much energy the laser delivers per unit area of the skin–in other words, how intense the laser is. It is important for the doctor to set the fluence high enough to cause a controlled injury to the skin, but not so high as to create unnecessary damage. The doctor may need to set the fluence higher to target a particularly strong or large structure, like a severe or wide scar. Delivered fluence only depends on the doctor’s settings, not on the type of laser.⁴
• Pulse duration: Normally, the light from a laser is delivered in a series of short bursts, called pulses, with short breaks in-between. Pulse duration is a measure of how long each pulse lasts. The longer the pulse, the more skin damage it causes, so this is another setting that the doctor needs to carefully fine-tune in order to obtain the best results and minimize the side effects. Just like delivered fluence, pulse duration only depends on the doctor’s settings, not on the type of laser.⁴

Anesthesia:

Laser scar treatment can be uncomfortable and even painful. To numb your skin before the procedure, your doctor may:

• Inject a local anesthetic into your skin before beginning treatment.
• Apply a topical anesthetic to your skin 30-60 minutes before the treatment.
• Provide you with a topical anesthetic to apply to your skin before you arrive at the doctor’s office for your treatment^5-8

Before-and-after:

Acne scars before (left) and 8 weeks after (right) treatment with CO2 non-fractional laser.