The use of the fractional CO2 laser resurfacing in the treatment of photoaging in Asians: Five years long-term results

Advancements in laser technologies for skin rejuvenation: A comprehensive review of efficacy and safety

INTRODUCTION

Laser technology has fundamentally transformed the landscape of dermatology, offering nuanced solutions for skin rejuvenation and resurfacing. This paper aims to explore the spectrum of laser technologies, from ablative to non-ablative and fractional lasers, their mechanisms, benefits, and tailored applications for diverse skin conditions. As we delve into the intricacies of each technology, we also consider the scientific advancements that have made these treatments safer and more effective, promising a new horizon in skin rejuvenation.

OBJECTIVE

This comprehensive analysis seeks to evaluate recent advancements in laser technology for skin rejuvenation, focusing on efficacy, safety, and patient satisfaction.

METHODS

The selection criteria for studies in this publication focused on recent, peer-reviewed articles from the last 20 years, emphasizing advancements in laser technologies for skin rejuvenation. Our comprehensive review involved searches in PubMed, Cochrane, Scopus and Google Scholar using keywords like "skin rejuvenation," "laser technology," "efficacy," "safety," and "dermatology." This approach focused on inclusion of recent research and perspectives on the efficacy and safety of laser treatments in the field of dermatology.

RESULTS

Our literature review reveals advancements in laser skin resurfacing technologies, notably fractional lasers for minimal downtime rejuvenation, ablative lasers for precise tissue vaporization, and non-ablative lasers for coagulation effect promoting collagen with reduced recovery. Hybrid and picosecond lasers are highlighted for their versatility and effectiveness in addressing a wide array of skin concerns. The findings also emphasize the development of safer treatment protocols for ethnic skin, significantly reducing risks like hyperpigmentation and scarring, thus broadening the scope of effective dermatological solutions.

CONCLUSION

This extensive review of advancements in laser technologies for skin rejuvenation underscores a remarkable evolution in dermatological treatments, offering an expansive overview of the efficacy, safety, and patient satisfaction associated with these interventions. Furthermore, the exploration of combination treatments and laser-assisted drug delivery represents a frontier in dermatological practice, offering synergistic effects that could amplify the therapeutic benefits of laser treatments.

Experimental comparative study of the effect of fractional CO2 laser combined with pulsed dye laser versus each laser alone on the treatment of hypertrophic scar of rabbit ears

BACKGROUND AND OBJECTIVE

The use of fractional CO2  laser and pulsed dye laser (PDL) therapy to treat and/or prevent scarring following burn injury is becoming more widespread with a number of studies reporting reduction in scar erythema and pruritus following treatment with lasers. The objective of this study was to directly compare the efficacy of PDL, fractional CO2 , and PDL and fractional CO2  laser therapy in immature red hypertrophic scars in a standardized animal model.

METHODS

Ten New Zealand big-eared rabbits were used to make rabbit ear hypertrophic scar models. A total of 80 hypertrophic scar models were obtained and randomly divided into groups: control (Group A), Fractional CO2  laser (Group B), pulse dye laser (Group C), combined (Group D), 20 in each group. Wound sites were treated with PDL, Fractional CO2  laser, or both at 28 days post-grafting. Grafts receiving no laser therapy served as controls. Hypertrophic scar appearance, morphology, size, and erythema were assessed, and punch biopsies were collected. At days 7 and 28, additional tissue was collected for biomechanical analyses and markers for HE staining, Masson staining, immunohistochemical method to determine the CD31 content in the scar; Western blot to detect the expression of VEGF protein in scars. After the day 7 and 28, the scars were collected. Histomorphological change in scars was observed by hematoxylin-eosin staining, Masson staining. The expression of CD31, VEGF protein, and the cell apoptosis rate was detected by immunohistochemical method.

RESULTS

(i) In morphological observation, HE staining and Masson staining, both the number of fibroblasts and amount of collagen fibrils in the experimental group were significantly reduced compared with those in control group. (ii) Micro-vessel Density (MVD) value can be found much smaller in the experimental groups than the control (p < 0.05). Among the four experimental groups, there was a significant difference among 14d, 21d, and 28d groups (p < 0.05). (iii) On days 7 and 28 after treatment, expression of VEGF could be regulated in experimental group (p < 0.05). Among the three experimental groups, the decrease of VEGF in the combined group was significantly stronger than that of the other two.

CONCLUSION

The effect of Fractional CO2  laser combined with pulsed dye laser treatment was shown to be better than that of Fractional CO2  laser or pulsed dye laser alone and inhibits the early hypertrophic scar in rabbit ears.

Transcriptomic analysis of human skin wound healing and rejuvenation following ablative fractional laser treatment

Ablative fractional laser treatment is considered the gold standard for skin rejuvenation. In order to understand how fractional laser works to rejuvenate skin, we performed microarray profiling on skin biopsies to identify temporal and dose-response changes in gene expression following fractional laser treatment. The backs of 14 women were treated with ablative fractional laser (Fraxel®) and 4 mm punch biopsies were collected from an untreated site and at the treated sites 1, 3, 7, 14, 21 and 28 days after the single treatment. In addition, in order to understand the effect that multiple fractional laser treatments have on skin rejuvenation, several sites were treated sequentially with either 1, 2, 3, or 4 treatments (with 28 days between treatments) followed by the collection of 4 mm punch biopsies. RNA was extracted from the biopsies, analyzed using Affymetrix U219 chips and gene expression was compared between untreated and treated sites. We observed dramatic changes in gene expression as early as 1 day after fractional laser treatment with changes remaining elevated even after 1 month. Analysis of individual genes demonstrated significant and time related changes in inflammatory, epidermal, and dermal genes, with dermal genes linked to extracellular matrix formation changing at later time points following fractional laser treatment. When comparing the age-related changes in skin gene expression to those induced by fractional laser, it was observed that fractional laser treatment reverses many of the changes in the aging gene expression. Finally, multiple fractional laser treatments, which cover different regions of a treatment area, resulted in a sustained or increased dermal remodeling response, with many genes either differentially regulated or continuously upregulated, supporting previous observations that maximal skin rejuvenation requires multiple fractional laser treatments. In conclusion, fractional laser treatment of human skin activates a number of biological processes involved in wound healing and tissue regeneration.

Laser therapy in the treatment of cicatricial ectropion

INTRODUCTION

The objective of this study was to investigate the clinical effects of laser therapy in treating cicatricial ectropion.

METHODS

Seven patients with cicatricial ectropion were entered into this clinical study. The ectropions were pretreated with the 595-nm pulsed dye laser if the scar color was red. If there was no red, the UltraPulse fractional CO₂ laser was used and parameters were adapted according to the height of scar. MEBT/MEBO was used after laser treatment for wound healing. The degree of ectropion was measured for changes before and after treatment, and the scars were evaluated for changes in melanin, height, vascularity, and pliability using the Vancouver Scar Scale (VSS) before and after treatment.

RESULTS

All seven patients with cicatricial ectropion entered into this protocol were completely corrected after 1-2 treatment sessions. The total VSS score, as well as the score for melanin and pliability in 7 patients, showed a decrease following the treatments, and this was statistically significant (P < 0.05). The scores for height and vascularity showed a decrease following the treatments, but there was no significant difference by statistical analysis (P ≥ 0.05). There were no adverse reactions reported.

CONCLUSIONS

The treatment of cicatricial ectropion with laser therapy can not only correct the ectropion, but also improve the scars in the treatment area. Compared with the traditional repair of cicatricial ectropion, the use of fractional CO₂ laser provides surgical precision and the advantage of a timely treatment without the need to wait for the scar to stabilize.

CO2 lattice laser reverses skin aging caused by UVB

The carbon dioxide (CO₂) lattice laser has been successfully used to treat facial skin photoaging induced by UV light. In this study, we analyzed the effect of CO₂ lattice laser irradiation on skin photoaging, and investigated the underlying mechanisms. Our results demonstrate that the laser promoted collagen synthesis and proliferation of primary human skin fibroblasts, inhibited cell senescence, and induced expression of superoxide dismutase (SOD) and the signaling protein SMAD3. In addition, this laser reversed cell cycle arrest and fibroblast apoptosis induced by UVB irradiation, and restored fibroblast proliferation inhibited by SMAD3 silencing. Using a rat model of photoaging, our results show that the laser increased collagen expression and dermal thickness, demonstrating that the CO₂ lattice laser has a profound therapeutic effect on photoaged skin. Together, our in vitro and in vivo data show that the CO₂ lattice laser can reverse the skin aging caused by UVB, and indicate that this effect is mediated through SMAD3.

A novel technique for treating atrophic facial scars in Asians using ultra-pulse CO2 laser

BACKGROUND AND AIMS

Fractional lasers have become increasingly popular for treating atrophic scars, but their effectiveness is limited for deeper scars. We developed a novel technique (manual fractional thermal contraction technology, MFTCT) using an ultra-pulse CO₂ laser and evaluated its efficacy and safety for treating atrophic facial scars.

METHODS

A total of 44 patients with atrophic facial scars were treated with MFTCT every 8 weeks for 1-4 times. Overall scar improvement was assessed by photographs taken at baseline and 3 months after the last treatment according to the 4-point global assessment scale (GAS) and ECCA grading scale. Improvements in color, distortion, and texture were assessed by the modified Manchester Scar Scale and scored individually from 1 to 4. Pain degrees and adverse reactions during and after treatment were recorded.

RESULTS

A total of 44 patients completed the treatment and follow-ups; of them, 89% reported at least 50% overall improvement after the last treatment. The mean ECCA scores fell from 67.50 ± 23.98 to 45.68 ± 18.57 (a 32% improvement), and the change was significant (P = .000). The average score for overall improvement was 3.48. The average scores for color, distortion, and texture were 3.07 ± 0.62, 3.27 ± 0.50, and 3.52 ± 0.51, respectively. Mean pain degree score was 4.27 ± 1.04, and mean erythema duration was 28.43 ± 6.58 days. Some patients developed pigmentation for a few months that resolved with topical treatment.

CONCLUSION

Manual fractional thermal contraction technology has definite clinical efficacy in the treatment of atrophic facial scars with fewer adverse reactions and is worth using in the clinical setting.

A randomized, single-blind, study evaluating a 755-nm picosecond pulsed Alexandrite laser vs. a non-ablative 1927-nm fractionated thulium laser for the treatment of facial photopigmentation and aging

Background: Laser toning is one of the most popular strategies to treat facial photopigmentation and aging. Several laser modalities, including fractional non-ablative, Q-switched (QS) lasers and new generation picosecond lasers have been used for this indication. However, there is paucity of head to head comparisons of older generation of lasers with new ones. Objective: To compare a 755 nm picosecond pulsed alexandrite laser with a non-ablative 1927 nm fractionated thulium laser for the treatment of facial photopigmentation and aging through a randomized, single-blind study. Materials and methods: 20 subjects (skin types I-IV) were randomized to receive either four 755-nm picosecond alexandrite laser treatments, spaced 3 weeks apart, or two dual wavelength thulium fiber fractionated 1550/1927 nm laser treatments, spaced 6 weeks apart. Follow-up assessment visits occurred 4 and 12 weeks after the last study treatment. Results: At the 4- and 12-week follow-up, both groups showed significant improvement of photoaging, pigmentation, skin quality according to the investigator and subjects assessments. When comparing the two groups, subjects in 755 nm group had statistically significant greater improvement in investigator assessments of photoaging/skin quality and subject satisfaction than those in the 1927 nm group. Conclusion: Both the non-ablative 1927 and 755 nm picosecond laser can improve facial photopigmentation, but the latter can yield superior results with less pain and side effects according to patient and investigator assessments.

OnabotulinumtoxinA treatment of moderate to severe glabellar lines in Chinese subjects after laser therapy: A prospective, open-label, noncomparative study

INTRODUCTION

This study evaluated safety and efficacy of onabotulinumtoxinA for moderate to severe glabellar lines (GL) following laser therapy in Chinese subjects.

MATERIALS AND METHODS

Subjects (n = 173) were followed for 120 days following a single onabotulinumtoxinA (20 U) treatment for GL after recent laser therapy. Subjects completed validated patient-reported outcomes, including Facial Lines Outcome 11-item (FLO-11) Questionnaire and Facial Lines Satisfaction Questionnaire (FLSQ). Physicians and subjects assessed GL severity at maximum frown and at rest using the Facial Wrinkle Scale with Asian Photonumeric Guide (FWS-A).

RESULTS

Mean total FLO-11 scores increased from 47.7 (baseline) to 75.9 (day 120) (p < 0.0001), with mean improvement of at least two grades for most items maintained to day 120. Most subjects were mostly or very satisfied, per the FLSQ. Percentages of subjects with at least one-grade improvement in FWS-A (responders) at maximum frown per subjects and physicians were 93.1% and 97.1%, respectively, at day 30, and 72.3% and 81.5% at day 120 (all, p < 0.0001). More than 70% were FWS-A responders at day 120. All adverse events were mild or moderate; none were related to onabotulinumtoxinA.

CONCLUSIONS

A single onabotulinumtoxinA (20 U) treatment following laser therapy was safe and effective in correcting GL for up to 120 days.

Clinical efficacy of utilizing Ultrapulse CO2 combined with fractional CO2 laser for the treatment of hypertrophic scars in Asians-A prospective clinical evaluation

BACKGROUND AND OBJECTIVE

Hypertrophic scarring is seen regularly. Tissue penetration of laser energy into hypertrophic scars using computer defaults from some lasers may be insufficient and penetration not enough. We have developed a treatment with an interrupted laser "drilling" by the Ultrapulse CO₂ (Manual Fractional Technology, MFT) and, a second pass, with fractional CO₂ . The MFT with fractional CO₂ lasers to treat hypertrophic scars is evaluated.

STUDY DESIGN/MATERIALS AND METHODS

A total of 158 patients with hypertrophic scars had three sessions of MFT with fractional CO₂ laser at 3-month intervals. Evaluations made before and 6 months after the 3rd treatment: (1) the Vancouver Scar Scale (VSS), (2) the University of North Carolina (UNC) Scar Scale, and (3) a survey of patient satisfaction.

RESULTS

All data were analyzed using a t-test before and after treatment. The VSS score decreased from 9.35 to 3.12 (P<.0001), and the UNC Scar Scale score decreased from 8.03 to 1.62 (P<.0001). The overall satisfaction rate was 92%. No long-term complications occurred in the clinical trial.

CONCLUSION

The interrupted laser drilling by MFT and a fractional CO2 laser had profound effects on the hypertrophic scars treated. It works by increasing the penetration depth of the CO₂ laser in the scar tissue, exerting more precise effects on the hypertrophic scars. MFT combined with fractional CO₂ laser has the potential to be a major advance in the treatment of hypertrophic scars.

Ablative fractional carbon dioxide laser combined with intense pulsed light for the treatment of photoaging skin in Chinese population: A split-face study

Intense pulsed light (IPL) is effective for the treatment of lentigines, telangiectasia, and generalized erythema, but is less effective in the removal of skin wrinkles. Fractional laser is effective on skin wrinkles and textural irregularities, but can induce postinflammatory hyperpigmentation (PIH), especially in Asians. This study evaluated the safety and efficacy of ablative fractional laser (AFL) in combination with IPL in the treatment of photoaging skin in Asians.This study included 28 Chinese women with Fitzpatrick skin type III and IV. The side of the face to be treated with IPL alone (3 times) or AFL in combination with IPL (2 IPL treatments and 1 AFL treatment) was randomly selected. Skin conditions including hydration, transepidermal water loss, elasticity, spots, ultraviolet spots, brown spots, wrinkle, texture, pore size and red areas, as well as adverse effects were evaluated before the treatment and at 30 days after the treatment.Compared with IPL treatment alone, AFL in combination with IPL significantly increased elasticity, decreased pore size, reduced skin wrinkles, and improved skin texture (P = .004, P = .039, P = .015, and P = .035, respectively). Both treatment protocols produced similar effects in relation to the improvement of photoaging-induced pigmentation. The combined therapy did not impair epidermal barrier function. No postoperative infection, hypopigmentation, or scarring occurred after IPL and AFL treatments. PIH occurred at 1 month after AFL treatment and disappeared at 30 days after completion of the combined therapy.AFL in combination with IPL is safe and effective for photoaging skin in Asians.

Fractional resurfacing in the Asian patient: Current state of the art

BACKGROUND AND OBJECTIVE

Fractionated photothermolysis (FP) has revolutionized modern laser technology. By creating selective columns of microthermal damage, fractionated devices allows for greater treatment depths to be achieved without the prolonged downtime and risk of complications seen in traditional fully ablative laser resurfacing. Fractional resurfacing is a proven method to treat a variety of cutaneous conditions. In the Caucasian patient, a wide range of devices and treatment settings can be utilized safely and effectively. However, ethnic skin requires special consideration due to its unique pigmentary characteristics and clinical presentations. In this review article, we detail the current indications and strategies to optimize results and mitigate complications when utilizing fractional resurfacing for the Asian patient.

METHODS

A review of the MEDLINE English literature was conducted on fractionated laser devices studied in the Asian population. Articles included describe non-ablative devices including fractionated erbium glass, thulium fiber, diode, and radiofrequency devices; and ablative devices including fractionated carbon dioxide (CO₂ ) laser, erbium yttrium aluminum garnet and yttrium scandium gallium garnet (YSGG) laser. These data were integrated with the expert opinion of the authors.

CONCLUSION

Taking into account the unique characteristics and cosmetic concerns of the Asian population, fractional resurfacing can be considered a safe and effective option for the treatment of atrophic and hypertrophic scarring, and photorejuvenation in ethnic skin types. Select cases of melasma may be treated with fractionated non-ablative devices, but utilized with caution. The predominant complication associated with fractional resurfacing for these conditions is post-inflammatory hyperpigmentation (PIH) and rebound worsening of melasma. A greater number of treatments at lower density settings and wider treatment intervals typically produce the lowest risks of PIH without compromising treatment efficacy. Lasers Surg. Med. 49:45-59, 2017. © 2016 Wiley Periodicals, Inc.