Pilot investigation of the correlation between histological and clinical effects of infrared fractional resurfacing lasers.

METHODS: Yucatan Black pig skin was treated with a 1,540-nm erbium (Er):glass laser (Lux1540, 15 and 30 mJ) and two 1,550-nm Er-doped fiber lasers (Fraxel SR750 and SR1500, 8, 10, and 12 mJ). Histologic sections were examined to determine the depth of damage and to correlate subjects' clinical response. Concurrently, six subjects with photodamaged skin received three split-face and ipsilateral dorsal hand treatments with the 1,540-nm Er:glass laser on one side and one of the 1,550-nm Er-doped lasers (Fraxel SR750) on the other. RESULTS: The 1,550-nm Er-doped lasers, using lower fluences and higher densities, produced shallower micro-columns than the 1,540-nm Er:glass device at higher fluences and lower densities (mean depths 250-275 microm vs 425-525 microm, respectively). Blinded assessors found greater overall improvement in pigmentation with the 1,550-nm Er-doped laser and better overall improvement in texture with the 1,540-nm Er:glass laser. CONCLUSIONS: Greater densities of shallower damage columns at lower energies may better improve pigmentation, whereas deeper injuries, using higher energies and moderate densities, may better improve texture. This pilot study did not compare similar fluences and histologic damage between the two systems, and newer available systems allow for greater depth of penetration.

Ultrastructural effects of an infrared handpiece on forehead and abdominal skin.

BACKGROUND: Collagen fibril contraction has been shown to be associated with tissue tightening by nonablative skin rejuvenation. Transmission electron microscopy has proven to be an effective method for characterizing collagen contraction delivered by ablative and nonablative devices used on human skin. OBJECTIVE: The purpose of this two-part study was to evaluate ultrastructural changes in cadaveric forehead skin and live abdominal skin by transmission electron microscopy for different fluence levels using the Titan infrared handpiece (Cutera, Inc., Brisbane, CA). This device is a noncoherent selectively filtered infrared device operating in the 1,100- to 1,800-nm bandwidth, intended to provide dermal heating. METHODS AND MATERIALS: Cadaveric forehead skin at 37 degrees C was treated with a 1x1.5-cm spot at fluences of 50 and 100 J/cm2. Informed consent was obtained and abdominal skin of one patient (before abdominoplasty) was treated in vivo with a 1x1.5-cm spot at fluences of 30, 45, and 65 J/cm2. Punch biopsies of the treatment areas and a control area were obtained immediately after treatment. Transmission electron microscopy at depths of 0 to 1 and 1 to 2 mm was performed for each biopsy to evaluate morphologic alterations of collagen fibrils in treated areas compared to the control area. RESULTS: In the cadaveric forehead skin samples, the collagen fibril alteration was greatest in the depth range of 1 to 2 mm for both fluence settings. In the abdominal skin samples, collagen fibril alteration was not seen in the control site but was observed at all treatment levels at both the 0 to 1 and the 1 to 2-mm depths, with the least alteration seen at the shallow depth and the lowest fluence. CONCLUSIONS: Our findings suggest that collagen fibril denaturation, consistent with fibril thermocontraction, occurs immediately after infrared tissue tightening. Collagen denaturation occurs at a depth range appropriate for deep dermal treatments. The peak in collagen fibril alteration at 1 to 2 mm is consistent with contact cooling protecting the more superficial layers of the skin.

Ultrastructural evaluation of multiple pass low energy versus single pass high energy radio-frequency treatment.

BACKGROUND AND OBJECTIVE: The radio-frequency (RF) device is a system capable of volumetric heating of the mid to deep dermis and selective heating of the fibrous septa strands and fascia layer. Clinically, these effects promote dermal collagen production, and tightening of these deep subcutaneous structures. A new technique of using multiple low energy passes has been described which results in lower patient discomfort and fewer side effects. This technique has also been anecdotally described as giving more reproducible and reliable clinical results of tissue tightening and contouring. This study will compare ultrastructural changes in collagen between a single pass high energy versus up to five passes of a multiple pass lower energy treatment. STUDY DESIGN/MATERIALS AND METHODS: Three subjects were consented and treated in the preauricular region with the RF device using single or multiple passes (three or five) in the same 1.5 cm(2) treatment area with a slight delay between passes to allow tissue cooling. Biopsies from each treatment region and a control biopsy were taken immediately, 24 hours or 6 months post treatment for electron microscopic examination of the 0-1 mm and 1-2 mm levels. Sections of tissue 1 mm x 1 mm x 80 nm were examined with an RCA EMU-4 Transmission Electron Microscope. Twenty sections from 6 blocks from each 1 mm depth were examined by 2 blinded observers. The morphology and degree of collagen change in relation to area examined was compared to the control tissue, and estimated using a quantitative scale. RESULTS: Ultrastructural examination of tissue showed that an increased amount of collagen fibril changes with increasing passes at energies of 97 J (three passes) and 122 J (five passes), respectively. The changes seen after five multiple passes were similar to those detected after much more painful single pass high-energy treatments. CONCLUSIONS: This ultrastructural study shows changes in collagen fibril morphology with an increased effect demonstrated at greater depths of the skin with multiple low-fluence passes and at lesser depths with single pass higher fluence settings. Findings suggest that similar collagen fibril alteration can occur with multiple pass low-energy treatments and single pulse high-energy treatments. The lower fluence multiple pass approach is associated with less patient discomfort, less side effects, and more consistent clinical results.

Treatment of inflammatory facial acne with the 1,450 nm diode laser alone versus microdermabrasion plus the 1,450 nm laser: a randomized, split-face trial.

BACKGROUND: The 1,450 nm laser has been effective in treating acne. Microdermabrasion may help treat acne and reduce skin barriers to increase the delivery rate of topical anesthetics. OBJECTIVES: To evaluate the efficacy, safety, and pain associated with the treatment of inflammatory facial acne with the 1,450 nm laser alone versus microdermabrasion plus the 1,450 nm laser. METHODS: Twenty patients with facial acne were treated with the 1,450 nm laser alone and microdermabrasion plus the 1,450 nm laser in a randomized, split-face trial. RESULTS: Laser alone and microdermabrasion plus laser significantly reduced the total number of acne lesions. Mean reductions of 53.5% and 55.6% were found after three treatments for laser alone and microdermabrasion plus laser, respectively. Clinical improvement was maintained 12 weeks after the last treatment. Mean pain scores were 5.3 6 1.5 for microdermabrasion plus laser and 5.2 6 1.5 for laser alone. There was no statistical difference between treatment levels for efficacy or pain. There was an average 10% increase in sequential pain as the laser treatment progressed. CONCLUSION: The 1,450 nm laser is effective, well tolerated, and safe for treating facial acne. This small pilot study did not demonstrate increased clinical efficacy or decreased associated pain with the addition of microdermabrasion to treatment with the 1,450 nm laser. A larger study may be needed to demonstrate any additional benefit.

Light patch: preliminary report of a novel form of blue light delivery for the treatment of actinic keratosis.

OBJECTIVE: To evaluate a novel light patch formulated for blue light delivery and topical activation of gamma-aminolevulinic acid (ALA) during photodynamic therapy for the treatment of actinic keratosis (AK). MATERIALS AND METHODS: Ten volunteers with past unsuccessful treatment of AK were enrolled. Areas with AK lesions were treated with 20% ALA (Levulan) for an incubation period of 1 hour. Half of the area was treated with blue light patches (the patch emits 431 to 515 nm wavelength, 55.6 mJ/cm2 over 20 minutes), and the other half was left uncovered (control). The percentage of visible AK lesions cleared at the 3-month follow-up determined therapeutic efficacy. RESULTS: The mean lesion count for all treatment areas was decreased from 7.60 to 2.40 (p<.01). The subjects had slight burning or itching and mild to moderate erythema. One subject developed a blister at the treatment site. Controls had clearance of 30%, 17%, and 20% for the face, scalp, and hands, respectively. Patients were satisfied with the results and noticed an improvement in skin texture. CONCLUSION: Preliminary results show that the blue light patch is a potentially safe, effective, and alternative method for light delivery and topical ALA activation during photodynamic therapy of AK.

Radiofrequency treatment for middle and lower face laxity.

OBJECTIVE: To compare the effectiveness of 1 and 2 radiofrequency (RF) treatments with the ThermaCool TC system (Thermage Inc, Hayward, Calif) on middle and lower face laxity. METHODS: Twenty patients with mild to moderate laxity of the middle and lower face were randomly assigned to receive either a single RF treatment or 2 treatments spaced 1 month apart. Treatment energy levels were titrated to patient tolerance and ranged from 85 to 135 J/cm(2). Acute clinical response was recorded after each session. Standardized photographs were taken before treatment and at 1 and 4 months after the last treatment. Using a percentage scale, 4 blinded physicians experienced in dermatologic laser therapy independently rated improvement in nasolabial folds, marionette lines, jowls, laxity under the chin, and overall appearance. In addition, subjects completed quality-of-life surveys 1 and 4 months after treatment. Each patient paid the same fee for involvement in the study. RESULTS: Eleven patients received a single RF treatment, and 9 patients underwent 2 treatments. All subjects experienced mild edema and mild to moderate erythema as an acute clinical response; no patients experienced burns, skin breakdown, or scarring. At 4-month follow-up, patients in the 2-treatment group received higher scores in all categories of photographic analysis; the difference in improvement in the nasolabial folds was statistically significant (P = .04). In self-assessment ratings, individuals receiving 2 treatments reported more improvement than subjects in the single-treatment group 4 months after treatment (P = .03). In both treatment groups, physician photographic assessment demonstrated continued improvement in all subsites between the 1-month and 4-month assessments (P<.05). Although the overall change noted by both patients and physicians was modest in most patients, 75% of subjects (n = 15) stated they would consider paying for additional treatments. CONCLUSIONS: Two RF treatments yielded significantly better improvement than a single treatment in the nasolabial folds. Significant improvement in laxity after treatment was seen between the 1- and 4-month follow-up visits in both single- and 2-treatment groups. Although overall improvements were modest in both groups, patient satisfaction was relatively high.