Acne Laser Treatment

Acne Laser Treatment

LASER, LIGHT SOURCE, AND RADIOFREQUENCY TREATMENT OF ACNE532-nm Potassium Titanyl Phosphate LaserThe potassium titanyl phosphate (KTP) vascular laser has generally been used for the treatment of telangiectases and rosacea but has also recently been shown to be effective for the treatment of acne. Although the exact mechanism of action is unclear, selective photothermolysis of blood vessels or a photodynamic effect of the laser on P. acnes and/or sebaceous glands have all been postulated. In a split face study of 26 patients with a KTP laser (Aura; Laserscope, San Jose, CA), a 34.9% and 20.7% reduction in acne severity was achieved at 1 week and 4 weeks after four treatments.2 In another study, 25 patients who were treated with the KTP laser (Aura) at fluences ranging from 6 to 12 J/cm2 achieved 60 to 70% clearing after six treatments.3585-nm and 595-nm Pulsed Dye LaserAs with the KTP laser, the pulsed dye laser has been used mainly for the selective photothermolysis of vascular disorders, as well as other inflammatory disorders such as psoriasis and telangiectatic rosacea. In addition, the pulsed dye laser is widely known to stimulate dermal remodeling and collagen production. Thus, it has been used for the treatment of hypertrophic scar, keloids, as well as, acne scarring.4 Recent studies have shown that when used at low, nonpurpuric fluences, this laser can also reduce inflammatory acne. The effect of this laser on acne improvement was believed to be mediated by decreasing P. acnes or sebaceous gland activity; however, a recent study found the pulsed dye laser to have no effect on the degree of P. acnes colonization or sebum production as measured by the standardized application of absorptive tape.5 Rather, this study found a significant upregulation of transforming growth factor β, which is a potent stimulator of neocollagenesis and a potent inhibitor of inflammation. Thus, the efficacy of this laser on inflammatory acne is likely through its local anti-inflammatory effects.There have been several studies on the clinical efficacy of this laser for inflammatory acne. In a randomized controlled trial, 41 adults were assigned to receive either a single low-fluence (1.5 or 3.0 J/cm2, 350-microsecond pulse duration) treatment with the 585-nm pulsed dye laser (n = 31) or a placebo sham treatment (n = 10). Patients were followed for 12 weeks, at which point the average total lesion count fell by 53% in patients treated with the laser compared with 9% in the controls. Similarly, the inflammatory lesion counts fell by 49% in pulsed dye laser patients compared with 10% in controls.6 However, a separate split-face study of 40 patients failed to show any statistically significant reductions in acne lesions after one or two treatments with the 585-nm pulsed dye laser at a fluence of 3 J/cm2 and 350-microsecond pulse duration.7The 595-nm pulsed dye laser (VBeam; Candela Corp.) has also been used in conjunction with the 1450-nm diode laser (Smoothbeam; Candela Corp., Wayland, MA) to treat both acne vulgaris and post-inflammatory erythema resulting from acne. In one noncontrolled study of 15 patients conducted in our practice, the lesions counts dropped by a mean of 52%, 63%, and 84% after 1, 2, and 3 treatments, respectively (p < 0.01).8 In addition to improvements in acne and acne scarring, significant improvement in post-inflammatory erythema was also noted and may be attributed to the selective photothermolysis of vessels by the pulsed dye laser. Although the combination of the two lasers may provide better targeting of different pathophysiologic contributors to acne, it is difficult to know whether the improvement is greater than that achieved with either the pulsed dye laser or the 1450-nm diode laser alone.1450-nm Diode LaserTreatment with the infrared 1450-nm diode laser (Smoothbeam; Candela Corp., Wayland, MA) with a dynamic cooling device has been shown to safely and effectively reduce inflammatory acne lesions of the face with fluences as high as 14 J/cm2. Because of its efficacy, this laser has become a common clinical modality in the laser treatment of acne.At a high fluence of 24 J/cm2 in a rabbit ear model, this device has been shown to cause thermal coagulation of the sebaceous lobule and associated hair follicle through peak thermal heating of the upper to mid dermis up to a depth of 500 μm.9 Although such a high degree of thermal injury and coagulation has not been observed at fluences lower than or equaling 14 J/cm2 as used in clinical practice, the presumed mechanism of acne improvement is through heating of the sebaceous gland and associated structures. It is believed that this heating of the sebaceous gland results in reduced sebaceous gland activity that subsequently leads to a reduction in inflammatory acne lesions. The initial study of the clinical efficacy of this laser on acne was performed by treating acne on the back. A significant reduction in lesion count was found in the treated side compared with the control side.9The first report of the efficacy of this laser in the treatment of facial acne was an uncontrolled pilot study conducted by our practice. Nineteen patients with inflammatory acne, many of whom were refractory to traditional medical treatment, underwent three treatments at 4- to 6-week intervals using a fluence of 14 J/cm2. The decrease in lesion counts from baseline was 37% after the first treatment, 58% after the second treatment, and 83% after the third treatment. Pain was well tolerated, and adverse effects were limited to transient erythema and edema at treatment sites.10A subsequent study conducted by our practice on 20 patients who had received treatment with this laser found that increasing the fluence to 16 J/cm2 using a prototype unit capable of achieving higher fluences did not provide improved results compared with 14 J/cm2.11 More importantly, this study was the first to evaluate long-term improvement in inflammatory acne after cessation of laser treatments, as one of the significant criticisms of laser treatment prior to this study was that the sustained long-term efficacy of laser treatments had not been established. In this study, a reduction of 76.1% from baseline was sustained 12 months after the third and final laser treatment (Fig. 1). Thus, this study helped demonstrate that the 1450-nm diode laser provides a long-term remission in acne, a property not commonly seen with either topical medications or oral antibiotics but which is more commonly associated with oral isotretinoin. This study also demonstrated a significant improvement in acne scarring (Fig. 1). Most of the improvement in acne scarring developed over the 1-year period after the last laser treatment, indicating that collagen remodeling occurs over a protracted period of time after laser treatments are performed. Sebum production, as measured by Sebutape scores, was also significantly reduced by the laser treatments, corroborating the hypothesis that the mechanism of this laser involves reduced sebaceous gland activity.Figure 1 The 1450-nm diode laser provides long-term remission of acne as well as improvement in acne scarring. Comparisons are shown between baseline (A, C) and 12 months after the third and final laser treatment (B, D).1540-nm Erbium Glass LaserA single study has also shown efficacy of the 1540-nm erbium glass laser for treatment of acne. After four treatments at 4-week intervals, a 78% reduction in acne lesions and decreased skin oiliness was noted in 25 patients.12Intense Pulsed LightUnlike a laser, an intense pulsed light source provide a noncoherent (500 to 1200 nm) source of intense light that can be modified by filters to provide irradiation with specific wavelengths of light. The use of intense pulsed light for the treatment of acne has been theoretically based on the production of singlet oxygen after photoactivation of porphyrins synthesized and stored by P. acnes.13 Several studies have utilized intense pulse light sources after topical application of porphyrins, a process discussed later in this article. However, in one study of intense pulsed light, 19 patients with mild to moderate acne were treated using wavelengths between 430 and 1100 nm at an energy density of 3.5 J/cm2 and a pulse width of 35 milliseconds. Reductions of 79% and 74% were noted in noninflammatory and inflammatory lesions, respectively, 1 month after the final treatment.13RadiofrequencyA combined radiofrequency and pulsed light device (Aurora AC; Syneron Medical Ltd., Richmond Hill, Ontario, Canada) has recently been used to treat acne. Twice-weekly treatments for 4 weeks resulted in reduction of mean acne lesion counts by 47% in 32 patients.14 The clinical improvement in acne was associated with both reductions in perifollicular inflammation and sebaceous gland areas, and this is presumed to be the mechanism of action whereby this device improves acne. Adverse effects were limited to temporary erythema, tingling, and burning. Another study of 22 patients using a monopolar radiofrequency device (ThermaCool; Thermage, Hayward, CA) showed greater than 75% reduction in inflammatory acne lesions in more than 90% of patients after one treatment session.15Low-Intensity Light Treatment and Photodynamic TherapyEndogenous coproporphyrins and protoporphyrins produced by P. acnes metabolism form the basis of photochemical interactions that result in the destruction of the bacteria. Upon exposure to visible blue, red, or green light, the endogenous porphyrins are excited and in the presence of oxygen generate reactive singlet oxygen species that damage the cell membranes of the bacteria.16,17 A recent study of narrowband blue light–emitting diode (409 to 419 nm) at 40 mW/cm2 in 30 patients found significant reduction in inflammatory acne lesion after eight 10- or 20-minute treatments provided over a 4-week period.18 In another study of 30 patients, a blue light source (ClearLight; Lumenis Inc., Santa Clara, CA) with a peak emission of 407 and 420 nm was used. Two treatments at 90 mW/cm2 performed up to 5 weeks apart provided an overall 55% reduction in acne lesions.19However, the degree of bacterial killing produced by the interaction of endogenous porphyrins with an exogenous light source is limited as only moderate amounts of porphyrins are produced naturally by the bacteria. Enhanced bactericidal activity can be achieved through photodynamic therapy, which involves the addition of the exogenous 5-aminolevulinic acid, a porphyrin precursor that is converted intracellularly to the photoreactive species protoporphyrin IX.20 In addition to enhancing bactericidal activity, 5-aminolevulinic acid has also been shown to preferentially accumulate in sebaceous glands and can result in selective damage to sebaceous glands.21 Because sebum is actively metabolized into proinflammatory fatty acids by P. acnes, the reduction in P. acnes combined with reduced sebum production after sebaceous gland damage appears to be the mechanism by which photodynamic therapy utilizing exogenous 5-aminolevulinic acid leads to significant improvement in inflammatory acne.Typically, 5-aminolevulinic acid is applied to cleaned skin for 3 hours prior to irradiation with blue or red light sources; however, recently, shorter incubation times with 5-aminolevulinic acid followed by irradiation with intense pulsed light or laser have also been shown to be effective and to have significantly reduced adverse effects.22,23 In a study of 14 patients treated with aminolevulinic acid and low-fluence pulsed dye laser, aminolevulinic acid was applied for a short 45-minute incubation followed by treatment with the long-pulse pulsed dye laser (595 nm, 7.0 to 7.5 J/cm2 fluence).23 Complete clearance was achieved in 100% of patients with a mean of 2.9 treatments required. Moreover, reduction in erythema in acne scars was also seen.Indocyanine green has also been used for photodynamic therapy of acne. Indocyanine green is a dye that binds albumin and has been shown to be selectively absorbed by sebaceous glands.24 After irradiation with a long-pulse diode laser (Cynosure Inc., Westford, MA), a decrease in acne lesions was noted in the treatment area up to 10 months after the last treatment.24 In another study, three patients were provided eight treatments utilizing 5-minute topical applications of indocyanine green followed by near-infrared 803-nm diode laser phototherapy at 50 mW/cm2 for 5 to 10 minutes. Improvements of 80% were seen 1 month after the last laser treatment.25Although photodynamic therapy has been shown in several studies to be effective for the treatment of inflammatory acne, it has been associated with significant pain and posttreatment erythema, severe phototoxicity, pustular eruptions, and epithelial exfoliation.16,17,18,20,21 The more recent use of methyl aminolevulinate, a methyl ester of 5-aminolevulinic acid, has been shown to be associated with a reduction in both pain and posttreatment adverse effects.26

Acne Laser Treatment

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Acne Laser Treatment
Acne Laser Treatment
Acne Laser Treatment
Acne Laser Treatment
Acne Laser Treatment

Acne Laser Treatment