Pulsed Dye Lasers (PDL)

Pulsed Dye Laser Treatment and Acne

Pulsed Dye Lasers (PDL) are occasionally used for the treatment of both active acne symptoms and acne scars. Although they can be used for multiple applications, Pulsed Dye Lasers are not usually not first-choice for the treatment of active acne or acne scars.

Dye Lasers get their name from the fact that they use a specialized liquid dye suspension, instead of a crystal, as the source of the laser beam. Pulsed Dye Lasers (PDLs) are designed to deliver short bursts of light that last only a fraction of a second. Many Pulsed Dye Lasers can be adjusted (tuned) to create lasers of several different wavelengths (colors). For dermatology purposes, Pulsed Dye Lasers that produce laser beams at ~495 nm (green/yellow) are the most common.

The most popular dermatology application for Pulsed Dye Lasers is for the removal of birthmarks and other hyper-pigmented marks on the skin. Low-power Pulsed Dye lasers are also used to improve the appearance of wrinkles by stimulating regrowth of the tissue immediately underneath the skin.

Pulsed Dye Lasers can be used for two ablative and non-ablative treatments. Ablative treatments (ablative means to be removed or vaporized at very high temperature) utilize longer laser pulses and/or high light intensity to thermally damage or destroy the target tissue. Certain molecules, like oxyhemoglobin (found in red blood cells), preferentially absorb energy from Pulsed Dye Lasers. This feature makes Pulsed Dye Lasers a viable treatment for spider veins, erythematous acne scars and other skin discolorations caused by damaged or dilated blood vessels.

Ablative laser treatments destroy the target tissue, which is then replaced by new, healthier tissue. Researchers are experimenting with using ablative laser treatment to target and destroy the sebaceous glands, whose hyperactivity can contribute to acne symptoms. However, longer wavelength laser sources, like diode and CO2 lasers are generally preferred over Pulsed Dye Lasers for many dermatology applications.

The more common application of Pulsed Dye Lasers is for non-ablative treatments. These treatments are intended to stimulate tissue growth or to target specific molecules like porphyrins. Although most commonly used to improve skin tone and correct small wrinkles, Pulsed Dye Lasers are also used to improve the appearance of mild acne scars.

There are a handful of clinical research studies that found Pulsed Dye Lasers may be effective for treating active acne infections. There are also a few studies that found PDLs were not effective treatments for active acne. This disagreement is likely because there are several different kinds of PDLs, and the treatments being researched are not all the same for every study.

Pulsed Dye Lasers can be used as part of Photodynamic Therapy (PDT), which is a treatment that targets sebaceous glands and acne-causing P. acnes bacteria. Photodynamic Therapy works better with adjustable PDLs that are capable of producing a laser with a wavelength near 415 nm (ultraviolet), instead of the more common 595 nm (green/yellow). However, PDLs are rarely used for PDT because there are easier-to-use (and less expensive) light sources available for this treatment.

PDLs are also being studied as a way to selectively ablate the sebaceous gland, which then inhibits sebum production and reduces acne symptoms. While the research indicates using PDLs is a a viable approach, there are alternative lasers (eg. Diode Lasers) with longer wavelengths that are better suited for this application.

Pulsed Dye Lasers can also be used to directly kill acne-causing bacteria. The acne-causing Propionibacterium acnes bacterium produces a special molecule called porphyrin. When porphyrin is exposed to high intensity light at a wavelength around 420 nm (ultraviolet/blue) it generates free radical molecules which can kill the bacterium. This process is called Blue Light Phototherapy. Pulsed Dye Lasers are available that can generate high intensity light in this spectrum. However, other high-intensity sources of blue light (eg. LEDs) are substantially less expensive than PDL and are generally used for this type of acne treatment.

The most common application of Pulsed Dye Lasers is for the treatment of acne scars. Both ablative and non-ablative PDL treatments are available for treating acne scars. Pulsed Dye Lasers are generally only used for the treatment of mild acne scars. Improvements in acne scars following PDL treatment are usually modest and superficial. The Pulsed Dye Laser platform is not well suited to correct severe acne scarring. This is because most PDL systems do not penetrate deeply enough into the skin tissue to correct significant acne scar damage.

On average, Pulsed Dye Laser treatment of acne and acne scars is reviewed as poor to moderate by patients after treatment. It is likely that PDLs are popular because they are a relatively inexpensive, versatile and common platform and not because they are highly efficacious for acne treatment.

Pulsed Dye Laser treatment is usually administered at a dermatology or cosmetic surgery clinic. PDL systems can also be found at some spas specializing in light and laser therapy. As with almost all laser-based treatments, there is the potential to cause permanent damage and PDL treatment should only be administered by a trained and certified professional.

Research studies on the use of PDL systems for the treatment of active acne for acne found that optimum results required at least four treatments. In addition, PDL-based treatment of active acne usually only provides temporary relief, and acne symptoms eventually return.

Popular Pulsed dye laser (PDL) Systems

C-Beam, Cobra, Cynergy, Navigator, N-Lite, PhotoGenica, Regenlite, Vbeam.

References

Laser Treatment of Acne Vulgaris. Jih, et al. 2007.
Investigation of the Mechanism of Action of Nonablative Pulsed Dye Laser Therapy in Photorejuvenation and Inflammatory Acne Vulgaris. Seaton, et al. 2006.
Treatment of Acne Vulgaris With a Pulsed Dye Laser: A Randomized Controlled Trial. Orringer, et al. 2004.
Improvement of Facial Acne Scars by the 585 nm Flashlamp-Pumped Pulsed Dye Laser. Alster, et al. 1996.
Comparison of a 585-nm pulsed dye laser and a 1064-nm Nd:YAG laser for the treatment of acne scars: A randomized split-face clinical study. Lee, et al. 2008.

Nd:YAG Lasers

Nd:YAG Laser Acne Scar Treatment

Nd:YAG lasers are among the most common and widely used class of laser for medical applications.  Nd:YAG lasers are frequently used for the treatment of acne scars. In addition acne scar treatment and other cosmetic applications, Nd:YAG lasers are also routinely employed in eye surgeries, dentistry, cancer treatment and a variety of industrial uses. Nd:YAG lasers are not generally used for treatment of active acne.

There are numerous clinical research studies on the utility of Nd:YAG Lasers for the treatment of acne scars. Overall, the scientific research indicates that Nd:YAG Lasers can help improve the appearance of acne scars. Along with CO2 and Er:YAG lasers, Nd:YAG lasers are one of the most popular and efficacious systems for treating acne scars.

There is also a small amount of research that indicates that Nd:YAG Laser treatment may be a helpful treatment for active acne for some people.
However, improvements in acne symptoms following Nd:YAG treatment tend to be mild and temporary. Achieving good results requires frequent treatments, which can quickly get very expensive. In spite of this challenge, Nd:YAG treatment of active acne is positively reviewed by some patients.

Nd:YAG Lasers are named for the crystal used as the lasing medium, Neodymium-doped Yttrium Aluminium Garnet (Nd:YAG). Nd:YAG Lasers generally produce an infra-red laser (1064 nm), but most systems are adjustable, allowing the system to produce additional colors of laser beam (532, 940, 1120, 1230, 1320, and 1440 nm). Many dermatology clinics use tunable or Q-switched Nd: YAG laser platforms that allow the production of laser wavelengths down to 530 nm.

Like other infra-red lasers (e.g. CO2 Lasers) the Nd:YAG Laser works primarily by heating the water molecules in the treatment area. When used at low power, infra-red lasers are used to stimulate cells by heating them up, but not enough to kill them. When used at high power, infra-red lasers can destroy (ablate) the target tissue very quickly. Ablative laser therapy with Nd:YAG Lasers is a popular technique to resurface the skin and treat acne scars by removing scar tissue.

Laser beams with longer wavelengths are generally capable of penetrating deeper into skin and tissue. Infra-red lasers like Nd:YAG can be quite effective at repairing deep acne scars. Many dermatology laser systems combine an automated coolant spray that is administered simultaneously with the laser treatment. The coolant spray prevents the surface of the skin, the epidermis, from overheating and being damaged. When combined with an infra-red laser like Nd:YAG, this system allows the physician to treat the underlying tissue, while leaving the surface of the skin undamaged.

Nd:YAG laser treatments are almost exclusively performed in a dermatology and cosmetic surgery clinics, along with hospitals. Ablative laser therapy is somewhat invasive and can cause serious damage if done improperly. It is therefore very important to undergo any high-power or ablative laser treatment in a safe, licensed and professional environment.

Common Nd:YAG Laser Systems

Affinity QS, CoolTouch, DermaLase, Excel, Gemini, Genesis, GentleYAG, PhotoSilk, RevLite.

References

A randomized, controlled, split-face clinical trial of 1320-nm Nd:YAG laser therapy in the treatment of acne vulgaris. Orringer, et al. 2007.
Fractional 1320 nm Nd : YAG laser in the treatment of acne vulgaris: a pilot study. Deng, et al. 2009.
Laser resurfacing of the skin for the improvement of facial acne scarring: a systematic review of the evidence. Jordan, et al. 2000.
A Preliminary Study of Utilization of the 1320-nm Nd:YAG Laser for the Treatment of Acne Scarring. Sadick, et al. 2004.
Atrophic and a Mixed Pattern of Acne Scars Improved With a 1320-nm Nd:YAG Laser. Rogachefsky, et al. 2003.
Comparison of a 585-nm pulsed dye laser and a 1064-nm Nd:YAG laser for the treatment of acne scars: A randomized split-face clinical study. Lee. et al. 2006.
Comparison of a Long-Pulse Nd:YAG Laser and a Combined 585/1,064-nm Laser for the Treatment of Acne Scars: A Randomized Split-Face Clinical Study. Min, et al. 2009.
Comparison of a Pulsed Dye Laser and a Combined 585/1,064-nm Laser in the Treatment of Acne Vulgaris. Jung, et al. 2009.
Nonablative 1,064-nm Nd:YAG Laser for Treating Atrophic Facial Acne Scars: Histologic and Clinical Analysis. Keller, et al. 2007.
Nonablative Acne Scar Reduction after a Series of Treatments with a Short-Pulsed 1,064-nm Neodymium:YAG Laser. Lipper, et al. 2006.
Patient Satisfaction and Reported Long-Term Therapeutic Efficacy Associated with 1,320 nm Nd:YAG Laser Treatment of Acne Scarring and Photoaging. Bhatia, et al. 2006.
Subcision and 1320-nm Nd:YAG Nonablative Laser Resurfacing for the Treatment of Acne Scars: A Simultaneous Split-Face Single Patient Trial. Fulchiero, et al. 2004.
Treatment of Atrophic Facial Acne Scars With the 1064-nm Q-Switched Nd:YAG Laser. Friedman, et al. 2004.

KTP Lasers

KTP Laser Treatment

KTP lasers are commonly used for minimally invasive ablation and coagulation treatments. KTP lasers have also been used to treat rosacea, spider veins, hyper-pigmented spots and acne, although it is an uncommon acne treatment.

When used for the treatment of acne scars, lower-power KTP lasers that are non-ablative or partially ablative are most commonly used. KTP Lasers are also occassionaly used for Photodynamic Therapy (PDT) of active acne.

KTP lasers are modified Nd:YAG lasers that produce a laser beams with a wavelength near 532 nm (green). In a KTP laser, an Nd:YAG laser beam (infra-red) is used to illuminate a crystal of potassium titanyl phosphate (KTP), to generate another laser (green).

The green light produced by the KTP laser is readily absorbed by skin pigments (eg. melanin) and blood (eg. oxyhemoglobin). This selectivity, allows KTP lasers to efficiently targeting of pigmented lesions and spider veins.

KTP Lasers are occassionally used to treat minor skin discoloration associated with acne scars (eg. hyper-pigmented and erythematous acne scars). KTP Lasers are generally ineffective treatments for most types of acne scarring. For the treatment of moderate to severe acne scars, laser resurfacing technologies that use CO2, Er:YAG and Nd:YAG Lasers are the most common platforms.

Low power KTP Lasers can theoretically be used for the treatment of active acne. In these application, KTP lasers can be used as a form of light therapy and/or Photodynamic Therapy (PDT) to directly target acne-causing Propionibacterium acnes bacteria living in follicles. The green light generated by KTP lasers can activate molecules in P. acnes bacteria called porphyrins. Activation of the bacterial porphyrin releases free radical molecules, which can kill the bacteria. This mechanism of action is the same as that for Blue Light Phototherapy acne treatment. Although green light is less effective at activating porphyrins then blue light, it is able to penetrate more deeply into the skin tissue.

Blue Light Therapy is more popular than KTP Lasers for the treatment of active acne because it has less risk and a lower cost. KTP lasers are not used to treat active acne by most dermatologists. However, there have been scientific research studies that have reported KTP lasers are moderately effective at improving acne symptoms, with results similar to blue light therapy.

The published research indicates that KTP laser treatment does lead to a moderate decrease in the number and severity of acne lesions. In addition, KTP lasers also apparently lead to a moderate decrease in the sebum production in treated areas, although the mechanism is not understood and those results need to be independently validated.

Popular KTP Laser Systems

Aura, DioLite, VariLite

References

Nonablative Phototherapy for Acne Vulgaris Using the KTP 532 nm Laser. Baugh, et al. 2005.
Effects of 532 nm KTP Laser Exposure on Acne and Sebaceous Glands. Bowes, et al. 2003.
Use of the KTP Laser in the Treatment of Rosacea and Solar Lentigines. Bassichis, et al. 2004.

Intense Pulsed Light (IPL)

Intense Pulsed Light IPL Treatment

Intense Pulsed Light (IPL) therapy uses short bursts of high intensity light to treat a variety of skin conditions. It is most commonly used for photo-rejuvenation procedures and to treat mild skin discolorations caused by hyper-pigmentation. Intense Pulsed Light (IPL) therapy is also occasionally used to treat active acne symptoms and certain types of mild acne scars.

Intense Pulsed Light (IPL) systems are one of the most commonly administered forms of light therapy for dermatology applications. IPL systems are designed to administer many rapid, high intensity pulses of light. The rapid pulsing prevents thermal damage to the skin and minimizes discomfort of the patient.

IPL is not a common treatment for active acne or acne scars. IPL can be used to improve the appearance of hyper-pigmented acne scars, but other laser systems (eg. C02, Nd:YAG, Er:YAG) are much more effective treatments for acne scars.

IPL has been tested as a treatment for active acne symptoms. For the treatment of active acne, IPL is commonly used as the light source for Photodynamic Therapy (PDT), which uses a topical photo-sensitizer to increase the effectiveness of the treatment. Several clinical research studies have been conducted to evaluate the efficacy of IPL as an active acne treatment. Overall, these studies have found that IPL alone was partially effective at improving acne symptoms. Very few patients experienced dramatic improvement of their acne symptoms in response to IPL treatment.

The light produced by IPL treatment is absorbed more by pigmented tissue than non-pigmented tissue causing thermal damage to pigmented cells. Because hair and hair follicles generally have a higher density of melanin (pigment), IPL can be used to damage those structures. IPL is a common procedure for treating areas of hyper-pigmented skin (eg. melasma).

IPL treatments generally use a broad spectrum and non-coherent light source, much like standard white light. In many cases a special optical filter is used that limits the light to a specific range of wavelengths (colors). One of the most common IPL filters is designed to limit the light to orange and red wavelengths.

IPL is usually administered in a spa or clinical environment. IPL is a non-ablative treatment with a good safety record. The incidence of serious complications and side effects is lower for IPL than with more invasive types of laser treatment. Therefore, IPL can be safely administered in many settings.

There are numerous types of IPL treatment systems, each with its own advantages and disadvantages. Some IPL systems include special filter sets to control the wavelengths of light being used, while others include automated cooling systems to prevent damage to the outer surface of the skin during treatment. Because of the variability in the treatment itself, there is a wide range of efficacy with IPL procedures.

Common Intense Pulsed Light (IPL) Systems

AccelaWave, Chromolite, IPL Quantum SR, LimeLight, StarLux.

References

The use of a novel intense pulsed light and heat source and ALA-PDT in the treatment of moderate to severe inflammatory acne vulgaris. Gold, et al. 2000.
Treatment of Inflammatory Facial Acne Vulgaris with Intense Pulsed Light and Short Contact of Topical 5-Aminolevulinic Acid: A Pilot Study. ROJANAMATIN, et al. 2006.
Effectiveness of Photodynamic Therapy with Topical 5-Aminolevulinic Acid and Intense Pulsed Light versus Intense Pulsed Light Alone in the Treatment of Acne Vulgaris: Comparative Study. Arianee, et al. 2005.
A comparative study of intense pulsed light alone and its combination with photodynamic therapy for the treatment of facial acne in Asian skin. Yeung, et al. 2007.
Treatment of Facial Acne Papules and Pustules in Korean Patients Using an Intense Pulsed Light Device Equipped with a 530 to 750 nm Filter. Chang, et al. 2007.
A comparison of intense pulsed light, combination radiofrequency and intense pulsed light, and blue light in photodynamic therapy for acne vulgaris. Taub, et al. 2007.
Treatment of hypertrophic scars and keloids using intense pulsed light (IPL). Erol, et al. 2008.
Intense pulsed light (IPL): a review. Babilas, et al. 2010.
Intense pulsed light vs. pulsed-dye laser in the treatment of facial acne: a randomized split-face trial. Choi, et al. 2010.
A Comparative Study of Topical 5-Aminolevulinic Acid Incubation Times in Photodynamic Therapy with Intense Pulsed Light for the Treatment of Inflammatory Acne. Oh, et al. 2009.

Er:YAG Lasers

Er:YAG and CO2 Lasers are the systems of choice for ablative laser skin resurfacing. Er:YAG Lasers are commonly used to repair skin damage, including acne scars and melasma (excess pigmentation). Er:YAG lasers are also routinely used to cut bone and tissue. They are used in laser dentistry and other surgical applications.

Er:YAG Lasers work by ablating (vaporizing) the surface layer of the skin. Each pass with the Er:YAG laser removes approximately 10 micrometers of skin tissue (1/100th of a millimeter). This type of technology is the basis for the procedure known as a “laser peel”. Some ER:YAG laser systems can be tuned to produce laser peels of varying depth.

Er:YAG Lasers primarily target the surface of the skin, and are not as effective as CO2 lasers at remodeling the collagen matrix underneath the skin. As a result, Er:YAG lasers are excellent options for repairing minor to moderate scarring and other superficial skin damage, but are less effective for severe scarring, especially pitted acne scars. Because Er:YAG lasers primarily affect the surface of the skin, the recovery times are faster and the side effects are generally milder than more invasive laser resurfacing techniques, such as CO2 Laser resurfacing.

Er:YAG Lasers are primarily used as a treatment for acne scars. They are rarely used for the treatment of active acne. Er:YAG Lasers have a good efficacy profile against mild to moderate acne scarring. Er:YAG Lasers are generally considered to be more effective for the treatment of acne scars purposes than many other light and laser treatment modalities, including as Nd:YAG, Pulsed Dye Lasers (PDL) and Intense Pulsed Light (IPL).

The (relatively) mild side effects of Er:YAG Lasers, combined with decent efficacy and generally positive patient response has made Er:YAG lasers a popular treatment option for superficial acne scars. The biggest limitation of Er:YAg lasers is their inability to effectively treat the extensive and deep scarring that is common in those who have suffered from severe inflammatory and cystic acne. For the treatment of moderate to severe acne scars, C02 Lasers generally provide better improvement. However, CO2 Lasers tend to generate more severe side effects and the recovery period can be significantly longer.

Er:YAG Lasers utilize Erbium-doped Yttrium Aluminium Garnet as the lasing medium. Er:YAG Lasers generate a laser beam with a very long wavelength (~2940 nm). This wavelength is in the infra-red spectrum and is strongly absorbed by water. The longer wavelength of the Er:YAG laser beam helps it to penetrate deeply into the skin tissue.

Er:YAG treatment is administered in cosmetic surgery clinics, dermatology offices and hospitals. Er:YAG Laser treatment can be done as a complete or fractional ablation technique. Complete ablation treats all of the skin in a given region, but fractional treatment leaves small areas of untreated skin in between (like a checkerboard). Recovery times from fractional treatment tend to be substantially shorter than from complete ablation treatments.

Common Er:YAG Laser Systems

Alma Pixel, Contour TRL, Fotona, FRAXEL RE:STORE (fractional Er:YAG laser system), Sciton Profractional, Venus .

References

Resurfacing of Pitted Acne Facial Scars with a Long Pulsed Er:YAG Laser. Jeong, et al. 2001.
Resurfacing of Pitted Facial Acne Scars Using Er:YAG Laser with Ablation and Coagulation Mode. Jeong, et al. 2003.
Treatment of Atrophic Acne Scars with a Dual Mode Er:YAG Laser. Tanzi, et al. 2002.
Minimally Ablative Erbium:YAG Laser Resurfacing of Facial Atrophic Acne Scars in Asian Skin: A Pilot Study. Tay, et al. 2008.

C02 Lasers

Carbon Dioxide (C02) Laser systems are ablative laser systems that are commonly used for laser resurfacing procedures.

CO2 Lasers are popular treatments for moderate to severe acne scars. C02 Lasers are capable of penetrating deep into the skin and underlying tissue. C02 Lasers are available at higher fluences (power) than many other laser systems used in dermatology and cosmetic surgery.

Carbon Dioxide (CO2) Lasers use a gas mixture that contains about 20% carbon dioxide as the lasing medium. C02 lasers generate an intense laser beam in the far infra-red spectrum (~10,000 nm). Energy from a CO2 Laser beam is strongly absorbed by water. Because cells are composed mainly of water, they are quickly heated or ablated (vaporized) by CO2 laser treatment.

The ability to penetrate into the supportive tissue underneath the skin surface makes CO2 Lasers a preferred choice for ablative laser resurfacing treatments, such as the repair of skin damage associated with moderate to severe acne scars. The C02 laser penetrates more deeply than the Er:YAG laser (which is another popular laser system for acne scar treatment), and CO2 Lasers are the preferred modality for deep-seated acne scars. CO2 Lasers directly destroy (ablate) scar tissue, which allows new healthy tissue to regrow in the treated area. The process of laser ablation of tissue is called photothermolysis.

Carbon Dioxide (CO2) lasers can be an effective treatment for many types of facial acne scars. In general, both physician and patient satisfaction with the results of CO2 Laser resurfacing are good. For patients with moderate to severe acne scarring, multiple treatments are often necessary to achieve maximum improvement in the appearance of the skin. This is especially true for acne scars around the temple and the middle of the cheeks because these regions tend to respond less favorably to laser resurfacing than other areas of the face.

Ablative CO2 Laser resurfacing treatments are among the most popular and effective methods for repairing acne scars. Treatment is applied to the entire scarred area.

In addition to ablating scar tissue and encouraging the regrowth of healthy skin tissue, CO2 Lasers can be used to shape large acne scars in order to reduce their appearance. CO2 Lasers can be used to ablate the edges and ridges of large scars, which creates a gentler slope and minimizes the apparent depth of the scar. CO2 Laser systems allow for more precise control of the treated area than many other skin resurfacing technologies (eg. Microdermabrasion and Chemical Peels). CO2 Laser resurfacing can also tighten the skin by inducing the contraction of the dermal collagen, which causes scars to appear flatter and less noticeable.

CO2 Lasers can be used for either complete resurfacing or fractional resurfacing. Complete resurfacing treats all of the tissue in a given area, while fractional resurfacing pixelates the laser beam and leaves small regions of untreated skin between the regions of treated skin.

Fractional CO2 laser treatments (eg. Fraxel) are very popular because they tend to have fewer side effects and require shorter healing times than complete resurfacing. Possible side effects of CO2 Laser resurfacing include complications such as edema, prolonged erythema, scarring and hyperpigmentation. Both complete and fractional CO2 treatments have risks of these side effects, although they are substantially higher with complete resurfacing. Patients with darker skin tones appear to be at higher risk of certain types of of side effects (eg. hyper- and hypo- pigmentation) after CO2 resurfacing.

Another advantage of fractional CO2 treatment is that it is safer for higher-power (more aggressive) treatment protocols that ablate tissue to greater depths. This can be helpful for the treatment of deep-seated acne scars.

According to many clinical research studies, the effectiveness of fractional CO2 laser resurfacing for acne scar treatment is comparable to traditional complete resurfacing. Many fractional CO2 Laser systems are now commercially available, and complete CO2 resurfacing is no longer a common procedure in most places. Although they are safer, fractional CO2 systems generally require significantly more treatment sessions than complete CO2 resurfacing to achieve the same level of improvement.

CO2 Lasers are agressive laser resurfacing technologies that can cause significant and permament skin damage if used improperly. They may also require the use of anesthetics. Because of this, CO2 resurfacing procedures are generally only available in a specialized clinical settings.

CO2 Laser treatment of acne scars is a complicated procedure that tends to be substantially more expensive than many other types of Light and Laser Treatments used for acne or acne scars. Effective fractional CO2 treatment of acne scars generally requires 2-6 sessions depending on the specific treatment area, types of acne scars and their severity.

Popular CO2 Laser Systems

Active FX, Affirm CO2, Deep FX, Fraxel Re:pair, Juvia CO2 Fractional, Mixto SX, Mosaic, Pixel CO2 OMNIFIT, Sharplan, SmartXide, Ultra-30 Plus, Ultrapulse.

References

CO2 Laser Resurfacing Patient Reviews @ RealSelf
A clinical and histologic comparison of electrosurgical and carbon dioxide laser peels. Acland, et al. 2001.
A Prospective Survey of Patient Experiences After Laser Skin Resurfacing. Batra, et al. 2003.
Ablative Skin Resurfacing With a Novel Microablative CO2 Laser. Gotkin, et al. 2009.
Carbon Dioxide Laser Abrasion. Trimas, et al. 2000.
Clinical trial of a pinpoint irradiation technique with the CO2 laser for the treatment of atrophic acne scars. Kim. 2008.
CO2 Laser Physics and Tissue Interactions in Skin. Fulton, et al. 1999.
Complications of Fractional CO2 Laser Resurfacing: Four Cases. Fife, et al. 2009.
Efficacy and safety of a carbon-dioxide ablative fractional resurfacing device for treatment of atrophic acne scars in Asians. Manuskiatti, et al. 2009.
Evaluation of a Novel Fractional Resurfacing Device for Treatment of Acne Scarring. Walgrave, et al. 2009.
Fractional photothermolysis: an update. Allemann, et al. 2010.
Laser Punch-Out for Acne Scars. Koo, et al. 2001.
Laser Resurfacing: Usual and Unusual Complications. Rendon-Pellerano, et al. 1999.
Laser resurfacing of the skin for the improvement of facial acne scarring: a systematic review of the evidence. Jordan, et al. 2000.
Long-Term Efficacy of a Fractional Resurfacing Device. Ortiz, et al. 2010.
Successful Treatment of Acneiform Scarring With CO2 Ablative Fractional Resurfacing. Chapas, et al. 2008.
The Efficacy and Safety of 10,600-nm Carbon Dioxide Fractional Laser for Acne Scars in Asian Patients. Cho, et al. 2009.
The principle of a three-staged operation in the surgery of acne scars. Whang, et al. 1999.
The Use of Fractional Laser Photothermolysis for the Treatment of Atrophic Scars. Alster, et al. 2007.

Alexandrite Lasers

Alexandrite Lasers are commonly used for laser hair removal and to treat areas of hyper-pigmentation on the skin (eg. melasma). Except for the treatment of hyper-pigmentation problems associated with acne scarring, Alexandrite Lasers are rarely used to treat active acne or acne scars.

Alexandrite Gemstone

Alexandrite Lasers make use of the gemstone Alexandrite as the lasing medium. Alexandrite is a unique gemstone in that it changes color depending on the type of light that is illuminating it.

Alexandrite Lasers produce light with a wavelength of approximately 755 nm (Red/Infrared). Melanin, the primary pigment in skin and hair, absorbs energy strongly at this wavelength. As a result, the energy from Alexandrite Lasers is strongly absorbed by areas of tissue with high concentrations of melanin, such as the hair bulb and hyper-pigmented areas of skin. The absorption of the laser beam by the melanin damages the melanin-containing cells. This process is the basis of laser hair removal, which can damage the hair producing cells near the base of the hair shaft, and prevents future hair growth.

There is very little clinical research on the effectiveness of Alexandrite lasers in the treatment of active acne or acne scars. At the current time, Alexandrite Lasers are not considered to be an effective treatment for acne or most acne scarring.

Alexandrite Laser treatments are offered at many dermatology offices, cosmetic surgery clinics and laser hair removal clinics.

Popular Alexandrite Laser Systems

Accolade, Apogee, DEKA MOTUS AX, Epilare, GentleLase, Noblex, Songic.

References

Laser Treatment of Pigmented Lesions. Goldberg. 1997.
Combined Ultrapulse CO2 Laser and Q-Switched Alexandrite Laser Compared with Q-Switched Alexandrite Laser Alone for Refractory Melasma: Split-Face Design. Angsuwarangsee, et al. 2003.
Minocycline-Induced Hyperpigmentation Treated with a 755-nm Q-Switched Alexandrite Laser. Alster, et al. 2004.
A Retrospective Study on the Efficacy and Complications of Q-Switched Alexandrite Laser in the Treatment of Acquired Bilateral Nevus of Ota-Like Macules. Ying-Ming, et al. 2001.