Efficacy and safety of a carbon-dioxide ablative fractional resurfacing device for treatment of atrophic acne scars in Asians

Treatment of acne scars with fractional CO2 laser at 1-month versus 3-month intervals: an intra-individual randomized controlled trial

BACKGROUND

Treatment of acne scars with ablative fractional CO2 laser appears to be an effective and well-tolerated treatment. However, so far the influence of treatment interval has not been evaluated.

OBJECTIVE

To evaluate whether treatment of acne scars with fractional CO2 laser resurfacing at 1-month interval achieves better results with no difference in the occurrence of adverse effects, than treatment given at 3-months interval.

METHODS

Patients (n = 13) with symmetrical atrophic acne scars on right and left sides of the mid-face and lower-face were randomized to two fractional CO2 laser treatments at 1-month versus 3-month intervals. Blinded on-site evaluations were performed 1 and 6 months after the last treatment on 10-point scales. Endpoints were scar atrophy, patient satisfaction, and adverse effects.

RESULTS

Pre-operatively, acne scars were moderately atrophic (5.86 ± 1.87). After treatment acne scars appeared with less atrophy on both treated sides 1 month postoperatively (1-month interval 1.96 ± 1.23, P < 0.0001; 3-months interval 1.82 ± 1.08, P = 0.0006) and 6 months postoperatively (1-month interval 1.56 ± 1.24, P = 0.0021; 3-months interval 1.33 ± 1.66, P = 0.0002). The treatment interval did not influence the improvement of scar atrophy at any time postoperatively (P = 0.81). Patients were moderately and equally satisfied with the treatment result on facial sides (P = 0.93). Postoperative adverse effects were minor and not influenced by the treatment interval.

CONCLUSIONS

Fractional CO2 laser resurfacing improves atrophic acne scars and a treatment interval of either 1-month or 3-months does not seem to influence the improvement of scar atrophy nor the occurrence of postoperative adverse effects.

Laser resurfacing pearls

Ablative skin resurfacing using the carbon dioxide laser was long considered the gold standard for treatment of photoaging, acne scars, and rhytids. However, conventional full-face carbon dioxide resurfacing is associated with significant risk of side effects and a prolonged postoperative recovery period. Fractional resurfacing has recently revolutionized laser surgery by offering close to comparable results with minimal side effects and a more rapid recovery. Although fractional devices have grown in popularity, and have essentially replaced traditional resurfacing, fractional resurfacing can still be a challenging modality to control precisely due to hardware variations across comparable devices, the range of settings that can be used, and patient-specific considerations. Certain precautions and rules of thumb can reduce the risk associated with fractional resurfacing, and increase the likelihood of a good outcome.

Image analysis and processing methods in verifying the correctness of performing low-invasive esthetic medical procedures

Background

Efficacy and safety of various treatments using fractional laser or radiofrequency depend, to a large extent, on precise movement of equipment head across the patient’s skin. In addition, they both depend on uniform distribution of emitted pulses throughout the treated skin area. The pulses should be closely adjacent but they should not overlap. Pulse overlapping results in amplification of irradiation dose and carries the danger of unwanted effects.

Methods

Images obtained in infrared mode (Flir SC5200 thermovision camera equipped with photon detector) were entered into Matlab environment. Thermal changes in the skin were forced by CO₂RE laser. Proposed image analysis and processing methods enable automatic recognition of CO₂RE laser sites of action, making possible to assess the correctness of performed cosmetic procedures.

Results

80 images were acquired and analyzed. Regions of interest (ROI) for the entire treatment field were determined automatically. In accordance with the proposed algorithm, laser-irradiated L_i areas (ROI) were determined for the treatment area. On this basis, error values were calculated and expressed as percentage of area not covered by any irradiation dose (δ_o) and as percentage area which received double dose (δ_z). The respective values for the analyzed images were δ_o=17.87±10.5% and δ_z=1.97±1.5%, respectively.

Conclusions

The presented method of verifying the correctness of performing low-invasive esthetic medical (cosmetic) procedures has proved itself numerous times in practice. Advantages of the method include: automatic determination of coverage error values δ_o and δ_z, non-invasive, sterile and remote-controlled thermovisual mode of measurements, and possibility of assessing dynamics of patient’s skin temperature changes.

Histological validity and clinical evidence for use of fractional lasers for acne scars

Though fractional lasers are widely used for acne scars, very little clinical or histological data based on the objective clinical assessment or the depth of penetration of lasers on in vivo facial tissue are available. The depth probably is the most important aspect that predicts the improvement in acne scars but the studies on histology have little uniformity in terms of substrate (tissue) used, processing and stains used. The variability of the laser setting (dose, pulses and density) makes comparison of the studies difficult. It is easier to compare the end results, histological depth and clinical results. We analysed all the published clinical and histological studies on fractional lasers in acne scars and analysed the data, both clinical and histological, by statistical software to decipher their significance. On statistical analysis, the depth was found to be variable with the 1550-nm lasers achieving a depth of 679 μm versus 10,600 nm (895 μm) and 2940 nm (837 μm) lasers. The mean depth of penetration (in μm) in relation to the energy used, in millijoules (mj), varies depending on the laser studied. This was statistically found to be 12.9–28.5 for Er:glass, 3–54.38 for Er:YAG and 6.28–53.66 for CO₂. The subjective clinical improvement was a modest 46%. The lack of objective evaluation of clinical improvement and scar-specific assessment with the lack of appropriate in vivo studies is a case for combining conventional modalities like subcision, punch excision and needling with fractional lasers to achieve optimal results.

Management of acne scarring, part I: a comparative review of laser surgical approaches

Acne scarring is the result of a deviation in the orderly pattern of healing and can have profound psychosocial implications for patients. While the most effective means of addressing acne scarring is to prevent its formation through good acne control, there are a number of therapeutic interventions that improve the appearance of acne scars. Many of these procedural modalities have flaws and are limited by operator skill and experience. Laser scar revision, on the other hand, is a precise, well tolerated procedure with clinically demonstrable efficacy and minimal adverse effects that may be used alone or in combination with other scar treatments. The last 20 years has seen a dramatic evolution in laser treatment of acne scars, spanning ablative and nonablative technologies, to the current popularity of fractional laser scar revision. Determining which laser system to use depends upon the type and severity of acne scarring, the amount of recovery a patient can tolerate, and the ultimate goals and expectations of each patient. The importance of proper acne scar classification, laser scar revision techniques, and the evidence that addresses each laser system is reviewed in this article.

Highlights of thirty-year experience of CO2 laser use at the Florence (Italy) department of dermatology

The CO₂ laser has been used extensively in dermatological surgery over the past 30 years and is now recognised as the gold standard for soft tissue vaporization. Considering that the continuous wave CO₂ laser delivery system and the newer “superpulsed” and scanned CO₂ systems have progressively changed our practice and patient satisfaction, a long range documentation can be useful. Our experience has demonstrated that the use of CO₂ laser involves a reduced healing time, an infrequent need for anaesthesia, reduced thermal damage, less bleeding, less inflammation, the possibility of intra-operative histologic and/or cytologic examination, and easy access to anatomically difficult areas. Immediate side effects have been pain, erythema, edema, typically see with older methods, using higher power. The percentage of after-treatment keloids and hypertrophic scars observed was very low (~1%) especially upon the usage of lower parameters. The recurrence of viral lesions (condylomas and warts) have been not more frequent than those due to other techniques. Tumor recurrence is minor compared with radiotherapy or surgery. This method is a valid alternative to surgery and/or diathermocoagulation for microsurgery of soft tissues. Our results are at times not consistent with those published in the literature, stressing the concept that multicentric studies that harmonization methodology and the patient selection are vital.

Minimally invasive aesthetic procedures in young adults

Age is a significant factor in modifying specific needs when it comes to medical aesthetic procedures. In this review we will focus on young adults in their third decade of life and review minimally invasive aesthetic procedures other than cosmetics and cosmeceuticals. Correction of asymmetries, correction after body modifying procedures, and facial sculpturing are important issues for young adults. The implication of aesthetic medicine as part of preventive medicine is a major ethical challenge that differentiates aesthetic medicine from fashion.