Cosmetic Laser Procedures: The Basics

Written by Paul M. Graham, DO

Lasers treatments are one of the fastest growing cosmetic procedures performed by dermatologists worldwide. In this article we will touch on the fundamental concepts of laser devices and outline the specific indications for this popular procedure.

In 1963, Dr. Leon Goldman pioneered the use of lasers in the treatment of various skin conditions, initiating further research in this innovative technology at that time. The theory of selective photothermolysis was introduced by Parrish and Anderson in the early 1980’s further increasing the popularity of these devices. Selective photothermolysis allows for the destruction of a specific target molecule within the skin (melanin pigment & blood) without the risk of surrounding tissue injury caused by lateral heat spread. This concept revolutionized cutaneous laser surgery and has since been characterized as the gold standard for laser treatment. Over the past several decades, there has been a surge in the advancements with laser technology, allowing for the design of more individualized treatment parameters.

What is a Laser?

The word laser represents an acronym for light amplification by stimulated emission of radiation. Lasers are devices that posses a specific color/wavelength and energy that are specifically focused onto the desired target, transmitting a very brief, high energy pulse of light. This laser light is transformed into heat, causing destruction of the specific target. Targets for laser treatment are called chromophores and these include melanin pigment, tattoo ink, and red blood cells. When the laser beam hits these chromophores, the energy is rapidly concentrated and absorbed, leading to target elimination.

Laser Categorization 

The two broad categories of lasers used in dermatology are ablative and nonablative devices. Ablative lasers vaporize the top layers of the skin to stimulate controlled wound healing, whereas nonablative lasers penetrate deeper into the skin, leaving the top layers intact. Nonablative lasers offer significantly less downtime in comparison to ablative devices, but the results are often less impressive in comparison.

Many different types of laser devices currently exist, but they all essentially work in the same way. The main difference between each device brand is the wavelength of light that is produced. Each laser device contains a specific medium (gas, liquid, or solid) that is used to generate a specific wavelength. The wavelength of light produced determines the specific treatment target of the laser. For example, if your physician is treating visible blood vessels or redness on the skin, the wavelength of the laser will correspond to the absorption peak of blood: a wavelength of 532-595 nanometers. Laser physics is very complex so I hope that the above simplified explanation serves to increase your understanding and awareness of these devices.

Types of Laser and Light Devices

• Intense pulsed light [IPL] (515 – 1200 nm)
  • Not actually a laser, but a flashlamp device that emits a broad spectrum of wavelengths
  • Remember, a laser is defined as a device with one specific wavelength
  • Good for diffuse redness, dark spots, sun damage, and skin tightening
• Nd:YAG (1064 nm)
  • A long wavelength laser with the deepest skin penetration
  • Good for hair removal and deep blood vessels
• KTP (532 nm)
  • A short wavelength laser that is good for superficial dark spots and blood vessels
  • Only used in lighter skin types due to the risk of skin lightening (hypopigmentation) in darker skin types
• Pulsed-dye laser [PDL] (585-595 nm)
  • The gold standard device for the treatment of blood vessels and redness
  • Ideal for lighter skin types due to the risk of skin lightening (hypopigmentation) in darker skin types
• Carbon dioxide [CO2] (10,600 nm) and Erbium:YAG [2940 nm] resurfacing lasers
  • Very high affinity for water in the skin, allowing it to be used as both a resurfacing and skin tightening laser
  • Good for fine lines and wrinkles, scars, tattoo pigment, dark spots, elevated skin lesions, skin resurfacing, and skin tightening
• Alexandrite (755 nm)
  • A medium to long wavelength laser with deeper skin penetration
  • Good for hair removal and tattoo pigment
• Diode (800-810)
  • A longer wavelength device that is ideal for hair removal in darker skin types

Skin Conditions Treated with Lasers

The application of lasers in dermatology has significantly expanded over the past decade as a result of increased research and growing technology in the treatment of various skin conditions. Although this article is meant to introduce the concept of lasers, your physician will determine the best device to be used in the treatment of your specific skin condition.

1. Pigmented skin lesions
   • For generalized dark spots, the IPL device is ideal due to the increased laser spot size
   • Devices: IPL, KTP, Nd:YAG, Alexandrite, and ablative CO2 and Erbium:YAG
2. Tattoo ink
   • For treatment of tattoo ink, the wavelength must match the color of the tattoo pigment
   • Q-switch and picosecond lasers work by concentrating the laser energy over a very short period of time to prevent surrounding tissue damage
   • Long-pulsed lasers are not suitable for tattoo removal due to increased risk of scarring
   • Devices: Nd:YAG, Alexandrite, Pulsed-dye, KTP, Ablative CO2 and Erbium:YAG
3. Hair removal
   • Best suited for lighter skin types with dark, course hair
   • Blond, white, and gray hair responds poorly due to decreased pigment and energy absorption
   • For darker skin types, the Nd:YAG laser is ideal
   • Devices: Nd:YAG, Diode, Alexandrite, IPL
4. Diffuse facial redness
   • The IPL is best suited for diffuse redness due to the increase in laser spot size
   • Devices: IPL, Pulsed-dye, KTP
5. Blood vessels
   • Superficial blood vessels are easily treated with the KTP or pulsed-dye laser
   • Devices: KTP, Pulsed-dye, Nd:YAG
6. Wrinkles, fine lines, and skin tightening
   • Ablative lasers offer the best results in skin resurfacing but require longer healing times
   • Devices: Ablative Erbium:YAG and CO2, Nonablative Erbium and Thulium, IPL
7. Acne scars
   • Ablative and nonablative laser resurfacing has emerged as an effective treatment option of acne scarring
   • Devices: Ablative CO2 and Erbium:YAG, Nonablative Erbium and Thulium
8. Precancerous skin lesions
   • Although not first line, laser treatment of precancerous skin lesions is gaining popularity
   • Devices: Ablative CO2 and Erbium:YAG

Lasers have revolutionized the field of cosmetic dermatology and with the vast treatment applications, patients are experiencing better results with less downtime. Laser technology continues to evolve, providing safer and more reliable devices. Schedule an appointment with you dermatologist today to learn more about how lasers can benefit you!

Photo Credit: Huffpost.com, Bolognia, Cutera

References: 

1. Tanzi, Elizabeth L. et al. Lasers in dermatology: Four decades of progress. J Am Acad Dermatol. 2003;49(1):1-34
2. https://www.verywell.com/cosmetic-laser-procedures-decoding-2710211

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