Skin responses to fractional photothermolysis

Comparing Line-Field Confocal Optical Coherence Tomography and Reflectance Confocal Microscopy on the In Vivo Healing Process of Lesions Induced by Fractional Photothermolysis

BACKGROUND

The advent of ablative fractional photothermolysis has revolutionized laser dermatology by providing a method to produce well-standardized, precise, and repeatable microscopic lesions. These wounds typically heal within 1-3 weeks, depending on the body site, with a minimal risk of permanent scarring. This positions ablative fractional photothermolysis as an exemplary in vivo model for studying the skin's wound healing processes.

OBJECTIVES

This study aims to evaluate and compare the effectiveness of two noninvasive imaging techniques, reflectance confocal microscopy (RCM) and line-field confocal optical coherence tomography (LC-OCT), in assessing skin wound healing following microscopic injuries induced by ablative fractional photothermolysis.

METHODS

The forearms of participating volunteers were treated and ablated with a CO2-Laser in a fractional pattern using varying power settings (2.5-10 mJ/MTZ). In vivo RCM and LC-OCT images were obtained at predefined time intervals post-laser treatment, ranging from 6 h to 14 days.

RESULTS

Vertical visualization of the lesions through both imaging modalities revealed a healing process characterized by the upward and outward movement of microscopic epidermal necrotic debris, thereby reducing the depth of the injury while forming an external crust. LC-OCT imaging demonstrated more comprehensive results with fewer movement artifacts. Conversely, horizontal visualization with both techniques highlighted a gathering of keratinocytes around the wounds, indicating the initiation of the regenerative process. RCM provided superior image clarity in this horizontal plane.

CONCLUSIONS

RCM and LC-OCT offer valuable and complementary noninvasive alternatives to conventional biopsy methods for the assessment and characterization of the skin's wound healing process post-ablative fractional photothermolysis. These findings underscore the potential of such imaging techniques in enhancing our understanding of the wound healing process.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05614557.

Exploring Fractional Pigment Toning: A Novel Approach for Treating Benign Pigmented Lesions in Asian Patients With Fitzpatrick Skin Types III-V

BACKGROUND/OBJECTIVE

Laser therapy has emerged as a widely favored treatment option for solar lentigines (SL). However, a significant challenge associated with this treatment, particularly among individuals with darker skin tones, is the notable risk of postinflammatory hyperpigmentation (PIH) induction. In response to these concerns, the authors conducted a prospective, self-controlled study to comprehensively evaluate the safety and effectiveness of 532-nm picosecond laser, both with and without a microlens array (MLA), for the management of SL in patients with Fitzpatrick skin types (FST) III-V.

METHODS

Twenty-seven patients with FST III-V and bilateral SL on the face underwent randomized treatment. One side of the face was treated with a 532-nm picosecond laser coupled with an MLA, utilizing the fractional pigment toning (FPT) technique, while the other side received treatment without the MLA, following the conventional technique (CT). The FPT technique utilized a 9-mm spot size with a fluence of 0.47 J/cm2 for two passes covering 40% of the area. In contrast, the CT used a 4.5-mm handpiece with fluence ranging from 0.3 to 0.7 J/cm2. Patients received a single treatment and were evaluated for pigment clearance, occurrence of PIH, and other adverse effects at 2 weeks, 1, 3, and 6 months posttreatment.

RESULTS

Twenty-seven participants completed the study protocol. Analysis of pigment clearance, measured via 3D photography, showed significant improvement from 2 weeks to 6 months posttreatment for both the FPT technique (p < 0.001) and CT (p = 0.004). PIH occurred in 64%, 80%, 96%, and 88% of cases on the CT side, compared to 8%, 32%, 36%, and 16% on the FPT technique side at 2 weeks, 1, 3, and 6 months posttreatment, respectively. The incidence of PIH was significantly lower on the FPT technique side compared to the CT side throughout the follow-up periods. Additionally, transient and mild hypopigmentation occurred in one participant (4%) on the FPT technique side and in five participants (20%) on the CT side. No other adverse effects were observed during the study.

CONCLUSIONS

The 532-nm picosecond laser emerges as a safe and efficacious treatment modality for SL in individuals with FST III-V. Particularly noteworthy is the efficacy of the FPT technique, which demonstrates comparable effectiveness while significantly reducing the incidence of PIH compared to the CT.

A comparison of surgical scar treatment using various combinations of autologous fat, hyaluronic acid and resurfacing with the 1540 nm non-ablative Erbium laser - a prospective pilot study

Scars can cause aesthetic or functional disturbance. Several interventions had been described to improve their appearance. We propose that the combination of some of those treatments can synergize their effects on the scar. We designed a prospective pilot study with ten patients using the patient as their own control to compare different interventions. In each patient, the scar was divided into four parts treated differently: 1. No treatment (control), 2. Fat grafting only, 3. Fat grafting and Hyaluronic Acid (HA), 4. Fat grafting, HA and with a non-fractional laser. Each part of the scar was evaluated by the Patient and Observer Scar Assessment Scale (POSAS). Treatment of the scar with the combination of the three modalities showed better results in the observer scale. In addition, a combination of fat injection, HA, and subsequent skin resurfacing with non-ablative laser showed better outcomes for all parameters on the Observer Scale except vascularity, while on the Patient Scale thickness, relief, pliability, surface area, and overall measurement were better. The combination of all three treatments tends to improve scarring results and appears to be safe and effective. However, further studies with larger samples are needed to explore the potential use of this combined treatment.

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.

Interventional and device treatment of the periocular area

Growth in the research, innovation, and development of laser and energy-based technologies over the past few decades has led to dramatic increases in treatment options for dermatologic and cosmetic concerns of the periorbital area. We highlight recent treatment options using laser and energy-based devices for the clearance of periocular pigmented lesions, including solar lentigines and nevus of Ota; vascular lesions, including port-wine birthmarks, infantile hemangiomas, superficial telangiectasias, and reticular veins; laser ablation of benign tumors, such as xanthelasma; cosmetic rejuvenation; treatment of infraorbital dark circles and festoons; laser removal of eyebrow and eyeliner tattoos; and device-based treatment of chronic dry eyes.

A prospective clinical study evaluating the efficacy and safety of a Laminin-5 fragment contained soothing cream in post-laser treatment care

BACKGROUND

Photothermolysis effect, resulting from laser procedures, can cause redness/erythema, skin irritation and burning sensation, these symptoms may persist more than several days after the procedure and leading to discomfort for patients. Proper management is necessary for the better outcome, especially in early period after the laser procedure. Laminin-5 fragment contained soothing cream (CEBELIA Extreme Care®), is believed to have the calming/soothing effect on overheated/irritated skin after undergoing the laser treatment. It is assumed that cream can help alleviate the redness, erythema and burning sensation commonly experienced after laser treatments. This study aimed to assess the effectiveness and safety of Laminin-5 fragment contained soothing cream (CEBELIA Extreme Care®) during the early post-laser care period.

MATERIALS AND METHODS

This prospective split-face study involved 28 patients who underwent CO2 laser procedures and met inclusion criteria. The laser treatment was performed on both sides of the midface, and subsequently, the Laminin-5 fragment contained soothing cream (CEBELIA Extreme Care®) was applied to one side of the midface. The efficacy of the cream was evaluated through objective measures, including photographic evaluation by two independent evaluators and assessment using an automatic skin analysis device. Subjective evaluations were also conducted.

RESULTS

The objective evaluation, based on the erythema score, revealed a statistical significant difference (p < 0.05) between the side treated with Laminin-5 fragment contained soothing cream (CEBELIA Extreme Care®) and the control side. The erythema score was 1.34 ± 2.469 after the laser treatment with subsequent application of the cream for 10 min and 0.7 ± 2.28 on the second day after the procedure. The subjective evaluation showed a statistically significant high of patient satisfaction. No complications were observed during the follow-up period.

CONCLUSION

The application of Laminin-5 fragment contained soothing cream (CEBELIA Extreme Care®) after the CO2 laser treatment was found to be effective, particularly when applied for 10 min after the laser treatment and on the second day after the procedure. Both objective and subjective evaluations yielded significantly different results. Patients reported a high satisfaction rate with the characteristics of the cream during the follow-up period.

Delayed Collagen Production without Myofibroblast Formation Contributes to Reduced Scarring in Adult Skin Microwounds

In adult mammals, wound healing predominantly follows a fibrotic pathway, culminating in scar formation. However, cutaneous microwounds generated through fractional photothermolysis, a modality that produces a constellation of microthermal zones, exhibit a markedly different healing trajectory. Our study delineates the cellular attributes of these microthermal zones, underscoring a temporally limited, subclinical inflammatory milieu concomitant with rapid re-epithelialization within 24 hours. This wound closure is facilitated by the activation of genes associated with keratinocyte migration and differentiation. In contrast to macrothermal wounds, which predominantly heal through a robust myofibroblast-mediated collagen deposition, microthermal zones are characterized by absence of wound contraction and feature delayed collagen remodeling, initiating 5-6 weeks after injury. This distinct wound healing is characterized by a rapid re-epithelialization process and a muted inflammatory response, which collectively serve to mitigate excessive myofibroblast activation. Furthermore, we identify an initial reparative phase characterized by a heterogeneous extracellular matrix protein composition, which precedes the delayed collagen remodeling. These findings extend our understanding of cutaneous wound healing and may have significant implications for the optimization of therapeutic strategies aimed at mitigating scar formation.

Unlocking the Power of Light on the Skin: A Comprehensive Review on Photobiomodulation

Photobiomodulation (PBM) is a procedure that uses light to modulate cellular functions and biological processes. Over the past decades, PBM has gained considerable attention for its potential in various medical applications due to its non-invasive nature and minimal side effects. We conducted a narrative review including articles about photobiomodulation, LED light therapy or low-level laser therapy and their applications on dermatology published over the last 6 years, encompassing research studies, clinical trials, and technological developments. This review highlights the mechanisms of action underlying PBM, including the interaction with cellular chromophores and the activation of intracellular signaling pathways. The evidence from clinical trials and experimental studies to evaluate the efficacy of PBM in clinical practice is summarized with a special emphasis on dermatology. Furthermore, advancements in PBM technology, such as novel light sources and treatment protocols, are discussed in the context of optimizing therapeutic outcomes and improving patient care. This narrative review underscores the promising role of PBM as a non-invasive therapeutic approach with broad clinical applicability. Despite the need for further research to develop standard protocols, PBM holds great potential for addressing a wide range of medical conditions and enhancing patient outcomes in modern healthcare practice.

Use of a fractional 1570-nm diode laser scanner for non-ablative face and neck rejuvenation

BACKGROUND

The use of non-ablative fractionated lasers for skin rejuvenation has been proven to be effective in improving skin texture, and has become popular due to minimal wounding, significantly shorter recovery times and decreased adverse effects.

OBJECTIVE

To retrospectively analyze improvement in skin texture in healthy women aged over 18 years with Fitzpatrick skin types II-IV.

METHODS

Participants received three facial and/or neck treatments with the 1570-nm fractional scanning diode laser at 1-month intervals. Three months after the last treatment session two blinded evaluators assessed skin improvement using before and after photos. Pain and patient satisfaction were recorded.

RESULTS

Sixteen women with a mean age of 45.4 ± 4.1 years (range 35-50 years) and skin type II-IV were included in the analysis. All 16 participants received facial treatments and seven (43.8%) also received neck treatments. Three months follow-up evaluation showed that the majority of participants had a visible change in the treated areas. Mean pain score was low and decreased with each treatment session.

CONCLUSION

Skin treatment using fractional scanning 1570-nm diode laser improves skin laxity in women with skin types II-IV. Larger studies are warranted to further clarify the efficacy and safety of this modality.

Early postoperative interventions in the prevention and management of thyroidectomy scars

Thyroidectomy scars, located on the exposed site, can cause distress in patients. Owing to the cosmetic importance of thyroidectomy scars, many studies have been conducted on its prevention and treatment. Scar formation factors mainly include inflammatory cell infiltration, angiogenesis, fibroblast proliferation, secretion of cytokines such as transforming growth factor (TGF)-β1, and mechanical tension on the wound edges. Anti-scar methods including topical anti-scar agents, skin tension-bearing devices, and local injections of botulinum toxin, as well as lasers and phototherapies, that target these scar formation factors have been developed. However, current studies remain fragmented, and there is a lack of a comprehensive evaluation of the impacts of these anti-scar methods on treating thyroidectomy scars. Early intervention is a crucial but often neglected key to control hyperplastic thyroidectomy scars. Therefore, we review the currently adopted early postoperative strategies for thyroidectomy scar reduction, aiming to illustrate the mechanism of these anti-scar methods and provide flexible and comprehensive treatment selections for clinical physicians to deal with thyroidectomy scars.

Management of Melasma: Laser and Other Therapies-Review Study

Melasma is a commonly occurring pigmented skin condition that can significantly affect one's appearance, described as symmetric hyperpigmentation that presents as irregular brown to gray-brown macules on various facial areas, such as the cheeks, forehead, nasal bridge, and upper lip, along with the mandible and upper arms. Due to its complex pathogenesis and recurrent nature, melasma management is challenging and the outcomes following treatment are not always deemed satisfactory. Solely treating hyperpigmentation may prove ineffective unless paired with regenerative techniques and photoprotection, since one of the main reasons for recurrence is sun exposure. Hence, the treatment protocol starts with addressing risk factors, implementing stringent UV protection, and then treatment using different strategies, like applying topical treatments, employing chemical peels, laser and light therapies, microneedling, and systemic therapy. This review aims to provide a summary of the effectiveness and safety of the frequently employed laser and light therapies for treating melasma, focusing on laser therapy as a treatment for melasma.

Pilot Study to Demonstrate Improvement in Skin Tone and Texture by Treatment with a 1064 nm Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser

BACKGROUND

The 1064 nm Q-switched neodymium-doped yttrium aluminum garnet (QS Nd:YAG) laser was developed to treat unwanted pigmentation in the skin such as lentigines caused by photoaging, and tattoos from dye/ink insertion. This laser has also been used for non-ablative epidermal rejuvenation (skin toning).

OBJECTIVE

To evaluate changes in skin tone, skin texture and overall improvement after a series of treatments with the QS Nd:YAG laser.

METHODS

Participants received seven full-face treatments with M22 or Stellar M22, a 1064 nm QS Nd:YAG laser, at 2-week intervals. The investigators and participants evaluated the improvement in skin tone and texture at 1, 3 and 6 months after the last treatment. Patient satisfaction, patient discomfort, downtime and adverse events were recorded. Histological changes in the treated area were also evaluated.

RESULTS

Thirteen women with a median age of 45 years (range, 34-61 years) were included in the study. The majority of the participants (53.9%) had skin type VI. One month after the last treatment session, 38% of participants reported good to very good improvement. This value increased to 100% participant improvement at both the 3-month and 6-month follow-up visits. The reduction in melanin index and the histological analysis demonstrated that the laser procedure contributed to a reduction in epidermal melanin content. Treatments were not associated with high levels of pain or discomfort. The most common immediate post-treatment response was erythema and edema. Most participants were satisfied with the resulting treatment outcome.

CONCLUSION

Skin treatment with the 1064 nm QS Nd:YAG laser module on the M22 and Stellar M22 devices, using a large spot size, low fluence, moderately high repetition rate, improves skin tone and texture in patients with skin types II-VI.

Large area fractional laser treatment of mouse skin increases energy expenditure

Fractional laser (FL) treatment is a common dermatologic procedure that generates arrays of microscopic treatment zones separated by intact tissue, promoting fast wound healing. Using a mouse model, we introduced a large area fractional laser treatment (LAFLT) method to study metabolic effects. Using two laser modalities, ablative FL (AFL) and non-ablative FL (NAFL), and exposing different percentages of mice's total body surface area (TBSA), we followed changes in metabolic parameters in real time using metabolic cages. Additionally, body composition, markers of inflammation, neurohormonal signaling, and browning of adipocytes were investigated. LAFLT, especially in high TBSA groups, had specific metabolic effects such as significantly increased average daily energy expenditure, increased fat mass loss, systemic browning of adipocytes, and inflammatory states, without compromising other organs. The ability of LAFLT to stimulate metabolism in a controlled way could develop into a promising therapeutic treatment to induce positive metabolic changes that replace or augment systemic drugs.

The efficacy and safety of low- versus high-fluence fractional picosecond Nd:YAG 1064-nm laser in the treatment of acne scars: A randomized split-face comparison study

BACKGROUND

Differences in clinical efficacy based on the fluence of fractional picosecond laser treatment for acne scars are unknown.

OBJECTIVE

To compare the efficacy and safety of low-fluence versus high-fluence fractional picosecond Nd:YAG 1064-nm laser treatment in acne scar patients.

METHODS

In this 12-week, investigator-blinded, randomized, split-face study, 25 patients with moderate-to-severe acne scars received three sessions of high-fluence laser treatment (1.0 J/cm2 ) on one side of their face and low-fluence (0.3 J/cm2 ) on the other side every 4 weeks. Patients were assessed using acne scar counts, the scar global assessment (SGA), and the ECCA scar grading scale every 4 weeks. The histological analysis compared the acne scars obtained before and 4 weeks after treatment.

RESULTS

At their last visit, 88.00% and 92.00% of the subjects achieved >30% reduction in scar counts on the low- and high-fluence sides, respectively, without a significant difference between the two sides. On both sides, the scar counts, SGA, and ECCA score significantly improved 4 weeks after the last treatment. Although the high-fluence side showed a greater reduction in scar counts (-66.73%) than the low-fluence side (-62.13%), the two sides had no significant difference in the grading scores. The high-fluence side showed significantly more severe pain and higher side-effect scores immediately and 4 weeks after treatment. Histological analysis revealed a significantly increased collagen, elastin, and vimentin expression after treatment on the low-fluence side.

CONCLUSIONS

The low-fluence setting demonstrated comparable efficacy and superior safety in treating acne scars compared with the high-fluence setting.

Efficacy and safety of ablative CO2 fractional laser and narrowband intense pulsed light for the treatment of hypertrophic scars: a prospective, randomized controlled trial

BACKGROUND AND OBJECTIVES

Hypertrophic scarring is a complex process, and numerous methods have been introduced to treat scars. This study aims to evaluate the effect of combined CO2 fractional laser and narrowband intense pulsed light (IPL) compared to IPL alone in the treatment of hypertrophic scars.

MATERIALS AND METHODS

This was a prospective, randomized controlled study enrolled 138 patients with hypertrophic scars. The participants were randomly divided into two groups: CO2-IPL and IPL group, and received three sessions at 10-14-week intervals for 3-month follow-up. Two independent plastic surgeons evaluated the treatments using the Patient and Observer Scar Assessment Scales (POSAS). Overall satisfaction was evaluated using the Patient Satisfaction Scale (PSS).

RESULTS

101 subjects completed the study. Compared to single IPL, the combination CO2-IPL group showed a significant improvement in itching, color, stiffness, thickness, and irregularity, except for pain, and an enhancement in vascularization, pigmentation, thickness, relief, and pliability of the scar, assessed by POSAS (p < .01). 100% patients in the combination group were satisfied compared to 84% in IPL alone.

CONCLUSION

The combination of CO2 fractional laser and narrowband IPL efficiently improved the appearance and profile of hypertrophic scars, offering a comprehensive and reliable approach for scar therapy.

Translational Biochemistry of the Skin

Understanding translational biochemistry of the skin is an essential component in mastering non-invasive aesthetic treatments. Collagen is the most abundant protein in the animal kingdom and plays a significant role in maintaining structural function in biologically healthy human skin. Collagen degradation and synthesis occurs throughout human life. Upregulation of collagen synthesis remains the mainstay of non-invasive aesthetic skin treatments. Elastin is a smaller yet significant component in the skin's ability to maintain biologically healthy stretch and recoil. Multi-Omics represents a relatively nascent field in the optimization and development of therapies aimed at the aesthetic improvement of the skin.

Ablative Laser Therapy of Skin

Laser skin rejuvenation was introduced in the mid-1990s. Early ablative laser devices relied on scanner technology that provided significant ablation and longer time on tissue treatments. These early treatments provided significant improvement in the appearance of the skin, but because of the longer treatment times and in some cases excessive treatment, complications such as scarring and hypopigmentation were significant. More recent advances in skin resurfacing technology have now minimized these risks providing certain key principles are observed. These parameters are reviewed in detail to improve the reader's ability to propose and execute proper skin resurfacing treatments.

Full-thickness skin rejuvenation by a novel dual-length microneedle radiofrequency device: A proof-of-concept study using human skin

BACKGROUND

A novel dual-length microneedle radiofrequency (DLMR) device has been developed to achieve full-thickness skin rejuvenation by stimulating the papillary and reticular dermis simultaneously. This device's dual-level targeting concept need to be validated on human skin, although its clinical efficacy has been demonstrated in a previous study.

OBJECTIVES

This study evaluated the dual-depth targeting capability and the ability to induce rejuvenation in each layer of vertical skin anatomy, that is, the epidermis, papillary dermis, and reticular dermis, using full-thickness human facial skin samples.

METHODS

Human facial skin samples were obtained from 13 Asian patients who had facelift surgery. To validate the dual-depth targeting concept, DMLR-treated skin samples were analyzed using a digital microscope, thermal imaging, and hematoloxylin and eosin (H&E) staining immediately after DLMR application. On samples stained with H&E, Masson's tricrome, and Verhoeff-Van Gieson, histological observation and morphometric analysis were performed. Total collagen assay (TCA) and quantitative real-time polymerase chain reaction (qPCR) were used to assess changes in total collagen content and mRNA expression levels of collagen types I/III and vimentin, respectively.

RESULTS

The DLMR device successfully induced thermal stimulation in the papillary and reticular dermis. The thickness, stacks, and dermal-epidermal junction convolution of the epidermis treated with DLMR were significantly increased. Collagen bundles in the dermis treated with DLMR exhibited a notable increase in thickness, density, and horizontal alignment. Dermal collagen levels were significantly higher in the morphometric and TCA data, as well as in the qPCR data for dermal matrix proteins.

CONCLUSIONS

Our DLMR device independently and precisely targeted the papillary and reticular dermis, and it appears to be an effective modality for implementing full-thickness rejuvenation.

Dynamic panoramic presentation of skin function after fractional CO2 laser treatment

Fractional CO2 laser, as a typical ablative laser, has been used to assist in the treatment of many skin diseases, such as photoaging, atrophic scar, hypertrophic scar, superficial pigmentation, vitiligo, and so on. However, the dynamic changes in skin function after fractional CO2 laser treatment are still unclear. This study explored the changes in local skin function and possible regulatory mechanisms after fractional CO2 laser treatment for 1, 3, 5, and 7 days through transcriptome high-throughput sequencing. The results showed that fractional CO2 laser tended to transform the "lesions" into "normal skin", regulate the skin barrier, coordinate the rearrangement of collagen, enhance the local microvascular circulation, activate the immune system to secrete a large number of cytokines, and act as an auxiliary tool to assist drug transport. In conclusion, according to the basic principle of destruction before reconstruction, fractional CO2 laser plays a key role of balancer in skin reconstruction.

Dermal Fibroblasts as the Main Target for Skin Anti-Age Correction Using a Combination of Regenerative Medicine Methods

This article includes the data from current studies regarding the pathophysiological mechanisms of skin aging and the regenerative processes occurring in the epidermis and dermis at the molecular and cellular level, mainly, the key role of dermal fibroblasts in skin regeneration. Analyzing these data, the authors proposed the concept of skin anti-age therapy that is based on the correction of age-related skin changes by stimulating regenerative processes at the molecular and cellular level. The main target of the skin anti-age therapy is dermal fibroblasts (DFs). A variant of the cosmetological anti-age program using the combination of laser and cellular methods of regenerative medicine is presented in the paper. The program includes three stages of implementation and defines the tasks and methods of each stage. Thus, laser technologies allow one to remodel the collagen matrix and create favorable conditions for DFs functions, whereas the cultivated autologous dermal fibroblasts replenish the pool of mature DFs decreasing with age and are responsible for the synthesis of components of the dermal extracellular matrix. Finally, the use of autological platelet-rich plasma (PRP) enables to maintenance of the achieved results by stimulating DF function. It has been shown that growth factors/cytokines contained in α-granules of platelets injected into the skin bind to the corresponding transmembrane receptors on the surface of DFs and stimulate their synthetic activity. Thus, the consecutive, step-by-step application of the described methods of regenerative medicine amplifies the effect on the molecular and cellular aging processes and thereby allows one to optimize and prolong the clinical results of skin rejuvenation.

Microlesion healing dynamics in in vivo porcine skin after treatment with 1064 nm picosecond-domain Nd:YAG laser

The fractionated picosecond laser produces microscopic lesions in the epidermis and dermis due to laser-induced optical breakdown (LIOB). There have been multiple histological reports, but the present literature lacks detailed in vivo studies after treatment with high-power laser systems. Our study aimed to characterize the healing patterns of microlesions induced with 150 ps duration 1064 nm MLA-type picosecond laser. The induced picosecond laser-tissue reactions with pulse energy of 50-250 mJ and different treatment modes were observed in in vivo porcine skin model over 10 days after the laser procedure. A macroscopic evaluation was combined with microscopic histological analysis to observe the healing dynamics of laser-induced microlesions. Superficial, intraepidermal cavitation bubbles were induced using microbeam fluence of 4-20 J/cm² . Skin irritation scores positively correlated with pulse energy and dose. Our findings demonstrate that dose and pulse energy had a direct impact on epidermal thickness and lesions healing dynamics.

Laser Therapy Changes the Expression of Matrix Metalloproteinases in Bleomycin-Induced Skin Fibrosis

Matrix metalloproteinases (MMPs) are often considered biomarkers of skin fibrosis. At the early stages of the pathological process, an elevation of their enzymatic activity causes significant changes in the composition of the extracellular matrix. MMPs secreted by immune cells facilitate their migration to the site of damage. Then, the immune cells eliminate the affected cells and biomolecules. Moreover, bidirectional changes in the activity of proteolytic enzymes, including MMPs, accompany wound healing. This study aimed to assess changes in the expression of Mmp2, Mmp3, and Mmp9 after treating mice with laser therapy using the experimental model of bleomycin-induced skin fibrosis. Using immunohistochemistry, we characterized the histological features of scarred skin. We also analyzed changes in the expression of MMPs using real-time polymerase chain reaction before and after laser irradiation. We showed that treatment of the mice with a CO2 laser partially normalized the histological features of scarred skin. We also noticed a decrease in the expression of Mmp2, Mmp3 (both p < 0.05), and Mmp9 (p = 0.065) during scar healing. The obtained results suggest that normalization of skin homeostasis requires control of MMP activity via induction of genes.

Is Tranexamic Acid Use Effective in Preventing Postinflammatory Hyperpigmentation after Laser Treatment? A Systematic Review and Meta-Analysis

Postinflammatory hyperpigmentation (PIH) is one of the most prevalent complications of laser treatment. However, comprehensive evidence is lacking to confirm the effect of tranexamic acid (TXA) for the prevention of postlaser PIH. We classified laser combined with TXA as the experimental group and laser alone as the control group from the selected studies in order to determine the efficacy of the extra use of TXA. We conducted a comprehensive literature review of randomized controlled trials (RCTs) that matched TXA coupled with laser vs. laser alone. The melanin index (MI) scores were employed as the clinically improved outcomes. Seven RCTs and a total of 222 individuals were evaluated in this meta-analysis. The findings revealed no statistically significant difference between the TXA and control groups in terms of decrease in mean MI scores at the end of the research ( $P=0.45$ ). The subgroup analysis showed that at month 1, extra use of TXA after laser treatment resulting in a statistically significant decrease in MI as opposed to laser alone ( $P=0.04$ ). However, at months 2 ( $P=0.73$ ), 3 ( $P=0.85$ ), and 6 ( $P=0.64$ ), the decrease in MI scores was not statistically significant. In addition, there was no statistically significant difference between topical, oral, and intradermal TXA on the reduction of MI scores after treatment ( $P=0.61$ ). Furthermore, nausea and menorrhagia occurred in the oral TXA group. The current meta-analysis found limited temporary efficacy of TXA in preventing postlaser PIH after 1 month.

Review of Laser Treatments for Post-Inflammatory Hyperpigmentation in Skin of Color

Post-inflammatory hyperpigmentation is an extremely common disorder of pigmentation in skin of color. It most frequently and severely affects phototypes that are rich in melanin and often has a chronic and unpredictable course. It presents significant treatment challenges and often requires a multi-factorial approach. We review the literature available for the optimal use of laser-based devices in the treatment of post-inflammatory hyperpigmentation, particularly for Fitzpatrick skin phototypes III-VI. For the treatment of post-inflammatory hyperpigmentation in skin of color, lasers remain second line to topical agents based on the variable response, cost, and risk of complications with laser use. For post-inflammatory hyperpigmentation resistant to topicals, laser devices, particularly neodymium:yttrium-aluminum-garnet and fractional photothermolysis systems, can provide adjunctive treatment in skin of color patients when appropriate parameters are used. Future studies would benefit from an objective and consistent assessment to assist with a systematic analysis.

Combination of Non-Ablative Fractional Laser with Q-Switched Laser for the Treatment of Becker's Nevus: Efficacy and Limitations

Becker's nevus (BN) is a benign hamartoma that may present as a distressing cosmetic problem. The treatment of BN poses a significant challenge as current therapeutic modalities are suboptimal and have an increased risk of adverse effects, such as scarring and dyspigmentation. We present the use of non-ablative fractional laser therapy combined with Q-switched Nd:YAG laser as a possible therapeutic option for BN treatment and review relevant literature to discuss its efficacy and limitations.

Combination 1550 nm non-ablative fractional resurfacing and laser hair removal for treatment of Becker's nevi in skin types III-VI

OBJECTIVES

Becker's nevus is a cosmetically bothersome benign hamartoma typically associated with basal layer hyperpigmentation and hypertrichosis. We herein present the largest case series characterizing treatment parameters and clinical outcomes of combined 1550 nm non-ablative fractional resurfacing and laser hair removal (long-pulsed neodymium-doped yttrium aluminum garnet or alexandrite) in the treatment of Becker's nevus. This is also the largest case series of laser treatment of Becker's nevus in Fitzpatrick skin types V and VI.

METHODS

We performed a retrospective review of patients treated between 2016 and 2021. Clinical photographs were graded by three independent physicians using a 5-point visual analog scale.

RESULTS

Twelve patients (mean age: 24.8 years, Fitzpatrick skin types III-VI) were treated for Becker's nevus on the face (4) or the trunk and/or extremities (8). Four patients were Fitzpatrick skin types V or VI. On average, patients received 5.3 treatments in 1-4-month intervals. Ten of the 12 patients had concomitant laser hair removal preceding same-day non-ablative fractional resurfacing (n = 7 with long-pulsed 1064 nm neodymium-doped yttrium aluminum garnet and n = 3 with long-pulsed 755 nm alexandrite). The number of treatments with each modality was determined by patient satisfaction with improvement in hyperpigmentation and hypertrichosis. At follow-up, which ranged from 6 to 40 weeks (mean 10.5 weeks), patients were given a mean improvement score of 51%-75%. No long-term adverse events were encountered in either group. Limitations include a small sample size and a lack of long-term follow-up.

CONCLUSION

Combination 1550 nm non-ablative fractional resurfacing and laser hair removal is safe and efficacious in the cosmetic reduction of hyperpigmentation and hypertrichosis associated with Becker's nevus, including those with Fitzpatrick skin types V and VI.

Treatment of Nevus of Ota in Black patients with the 1064 nm QS or picosecond laser and nonablative fractional photothermolysis

OBJECTIVES

Nevus of Ota is a benign melanocytic lesion that presents as a unilateral blue gray to brown facial patch favoring the distribution of the first two branches of the trigeminal nerve. Incidence is highest in Asian and Black populations, however, the overwhelming majority of studies are limited to diagnosis and treatment in Asian patients. We herein present 10 Black patients with Fitzpatrick skin types (FST) V and VI who underwent laser treatment for Nevus of Ota.

METHODS

We performed a retrospective review of Black patients presenting with Nevus of Ota. Race was self-designated by all patients and documented in the medical record at the time of initial consultation. Primary outcomes were based on improvement using before and after photographs which were graded by three independent board-certified dermatologists using a 5-point visual analog scale.

RESULTS

Ten FST V or VI patients with an age range of 9 months to 45 years were treated for Nevus of Ota. All patients were treated with the 1064 nm Q-switched neodymium doped yttrium aluminum garnet (QS Nd:YAG) and on average received 4.7 treatments at 2-10 month intervals. Fluence ranged from 1.8 to 2.3 J/cm² , and total pulse count ranged from 510.9 to 776.6. 2/10 patients were additionally treated with 1550 nm nonablative fractional resurfacing (NAFR), and 1/10 patients underwent combination therapy with both NAFR and 1064 nm picosecond laser therapy. Overall, patients saw a mean improvement of 51%-75% at follow-up 5-254 weeks (mean 51.5 weeks) after treatment. Three patients experienced mild guttate hypopigmentation in treated areas. No other long-term adverse events were encountered.

CONCLUSION

1064 nm QS Nd:YAG laser therapy is a safe and efficacious treatment for Nevus of Ota in patients with FST V and VI. When patient improvement plateaus, combining therapy with 1550 nm NAFR or transitioning to 1064 nm picosecond laser may be of benefit. Patients should be counseled on the risk of guttate hypopigmentation. This is the largest case series to date of Black patients with Nevus of Ota, highlighting the need for further investigation to determine optimal device settings and treatment parameters for this population.

A Single Center, Prospective, Randomized, Blinded Study to Evaluate the Efficacy and Safety of a Topical Tripeptide/Hexapeptide Anhydrous Gel When Used Pre- and Post- Hybrid Fractional Laser for the Treatment of Acne Scars

Background

Acne scarring remains a significant problem. Laser therapy has produced varying results with deeper ablative therapies occasionally associated with side effects including delayed healing, infection, scarring, erythema, acne, milia, edema and dyspigmentation.

Objective

Can adjuvant topical therapy impact the healing process and outcome of patients treated with fractional laser for acne scarring?

Methods and Materials

Ten patients were randomized to receive either Regenerating Skin Nectar with TriHex Technology^®- RSN or a bland moisturizer. Patients underwent two laser procedures one month apart with Hybrid Fractional Laser. The topical was applied twice daily for 2 weeks prior to the first laser procedure, and through completion of the study. Seven study visits occurred over a 90-day period. Measurements were conducted in lesional and non-lesional areas - transepidermal water loss (TEWL), erythema, photography, Goodman and Baron qualitative scale, Global Aesthetic Improvement Scale and patient questionnaires - to assess functional recovery and aesthetic outcomes in the scarred areas. One patient from each cohort consented to biopsy before the procedures and 90 days after the first procedure.

Results

Reduced TEWL scores in the RSN group were evident at all time points with statistically significant reductions occurring 4 days after first and second procedures indicating more efficient fluid conservation at a critical point in the healing trajectory. Erythema index demonstrated a consistent decrease in the RSN cohort over the control from day 4 through day 90 on lesional and non-lesional skin. Acne scar assessment scores improved in the RSN cohort compared with the control at all time points. Biopsy results showed early elastin regeneration in the RSN biopsy with controlled non-hypertrophic collagen formation evident.

Conclusion

The use of RSN pre- and post- laser resurfacing significantly decreased postprocedural TEWL and erythema, and increased aesthetic improvement in acne scars and patient satisfaction, when compared with bland moisturizer.

Research trends and hotspot analysis of fractional carbon dioxide laser: A bibliometric and visualized analysis via Citespace

INTRODUCTION

There is limited basic research on carbon dioxide (CO₂ ) fractional laser, indicating blind spots in CO₂ fractional laser treatment of certain diseases. This study aimed to organize previous literature, summarize the current research, and speculate on possible future development.

METHODS

We searched document data on fractional CO₂ lasers from the Web of Science core collection database and retrieved 928 articles from 2004 to 2021. CiteSpace software was used to analyze the main institutions, authors, subject hotspots, and research frontiers in global CO₂ fractional laser research.

RESULTS

The results revealed that 928 related papers were published in the past 18 years (2004-2021), and the number has increased annually. The publications were written by 3239 authors from 626 institutions in 60 countries/regions. The United States (US) dominates this field (312 documents), followed by Italy (289), and South Korea (88). Lasers in Surgery and Medicine is the journal with the most publications and citations, and Uebelhoer is the central author. The main research hotspots include vulvovaginal atrophy, fractional photothermolysis, keloids, drug delivery, gene expressions, facial acne scarring, resurfacing, vitiligo, and photo damage.

CONCLUSION

Using CiteSpace, this paper draws a map of authors, institutions, and keywords in fractional CO₂ laser from 2004 to 2021; summarizes the main authors, institutions, research hotspots, and cutting-edge topics of global fractional CO₂ laser technology in recent years; and summarizes the current application status of global fractional CO₂ laser in disease treatment. It also provides new ideas for the future application and research of fractional CO₂ lasers.

A Long-Term Follow-up Study for the Treatment of Snoring after Using Patterned Non-Ablative Erbium: YAG 2,940 nm Laser

Introduction  Laser uvulopalatoplasty is an established operation for the treatment of snoring with good results on a short-term basis, while long-term follow-up studies, in addition to their scarcity, had conflicting results regarding recurrence, the change of snoring quality, and complications. Objective  To assess the long-term follow-up results of using nonablative 2,940 nm Erbium: YAG for the treatment of snoring regarding outcomes and recurrence. Methods  This 2-year follow-up study was conducted on 76 patients operated upon by non-ablative 2940 nm Erbium: yttrium-aluminum-garnet (YAG) using a PS01 patterned headpiece. Subjective evaluation of the treatment was performed relying on a smartphone application to record snoring in addition to a questionnaire specially designed to report recurrence and change in the quality of snoring reported by a patient's spouse. The objective evaluation was done by computed tomography (CT) imaging of the soft palate. The patients were evaluated preoperatively, 6 weeks postoperatively and after a 2-year follow-up period. Results  Six week after the procedure, there was a significant improvement in 52 patients (68.4%). Out of the 52 patients, only 43 completed the 2-year follow-up; however, 15 of them complained of recurrence. Nevertheless, the patients who suffered from recurrence showed subjective improvement in snoring quality. Conclusions  The nonablative mode of Erbium: YAG 2,940 nm laser proved to be efficient in soft palate tightening for the management of snoring. However, there was recurrence in 34.8% of the patients who presented objective and subjective improvement of the complaints, 6 weeks postoperatively and after a 2-year follow-up period.

Enhancing Skin Uptake of Topical Antioxidants With 1,440-nm Nonablative Fractional Diode Laser Pretreatment

BACKGROUND

Energy-based devices, such as nonablative lasers, are a promising method to enhance the delivery and absorption of topically applied molecules.

OBJECTIVE

To characterize ex vivo uptake of common antioxidant topicals after pretreatment with a nonablative laser wavelength.

MATERIALS AND METHODS

Using donor human skin tissue, uptake of 3 topical antioxidants was analyzed (C E Ferulic with 15% l-ascorbic acid [15% vitamin C serum], Phloretin CF with ferulic acid [10% vitamin C serum], and Phyto+ [botanical serum]; SkinCeuticals, Dallas, TX; 2010 formulations) after pretreatment with a 1,440-nm nonablative fractional diode laser.

RESULTS

Pretreatment with the 1,440-nm laser enhanced uptake of 15% and 10% vitamin C serums by approximately 10 and 21 times, respectively, compared to controls. Laser pretreatment also enhanced uptake of botanical serum by approximately 6 times relative to controls. Permeation of vitamin C and botanical serums was also enhanced through laser pretreatment.

CONCLUSION

Nonablative laser pretreatment increased uptake and permeation of topical antioxidants. Optimizing treatment requires consideration of the device and treatment parameters as well as the properties of the topical formulation.

Wound Healing After Fractional Skin Harvesting

BACKGROUND

Autologous fractional full-thickness skin grafting is a method of harvesting full-thickness skin with reduced donor site morbidity compared with conventional skin grafting.

OBJECTIVE

To demonstrate that full-thickness skin microbiopsies can be harvested with minimal scarring or complications.

MATERIALS AND METHODS

In a nonrandomized, self-controlled, pilot trial, subjects (n = 8) underwent tissue harvesting of full-thickness skin columns of 200, 400, 500, 600, 800 μm, 1, and 2 mm diameters. The extent of scarring was measured by using the Patient and Observer Scar Assessment Scale and blinded evaluation of photographs at 6 weeks postprocedure. Pain visual analog scale (VAS) and side effects were recorded.

RESULTS

When present, scars were first observed after 2 to 4 weeks, much more often for wounds >400 μm (p < .001). Blinded dermatologists increasingly identified clinical scarring on photographs with larger harvested microcolumn diameters (p < .001). Median VAS pain score was 0 (range 0-4). All subjects rated the procedure safe and tolerable.

CONCLUSION

Harvesting full-thickness skin microcolumns is well-tolerated over a wide range of column diameters. At diameters of less than 500 μm, side effects including scarring are minimal.

Quantifying Skin Uptake of Topicals After 1,927-nm and 1,440-nm Nonablative Fractional Diode Laser Treatment

BACKGROUND

Although the stratum corneum limits transdermal absorption of topicals, laser devices can enhance topical uptake by disrupting the skin barrier. Nonablative lasers are commonly used, but their effects on topical uptake should be quantified to optimize outcomes.

OBJECTIVE

The objective of this study is to analyze transdermal uptake of 4 topicals after nonablative fractional diode laser pretreatment.

METHODS AND MATERIALS

Human donor tissue was pretreated ex vivo with a nonablative fractional diode laser (1,927 nm or 1,440 nm, at varying treatment densities, powers, and peak energies) followed by application of either 2% salicylic acid, 10% ascorbic acid, over-the-counter mineral eye serum, or 4% hydroquinone. Topical uptake was quantified over 24 hours.

RESULTS

Despite lower power settings, pretreatment with the 1,927 nm wavelength was associated with greater uptake of 10% ascorbic acid, mineral eye serum, and 4% hydroquinone than the 1,440 nm wavelength. In addition, 1,440-nm laser pretreatment with higher density (320 microscopic treatment zones [MTZ]/cm2) and peak power (3 W) was associated with similar uptake but greater retention of 2% salicylic acid and greater uptake of 10% ascorbic acid than that with lower density (80 MTZ/cm2) and peak power (1.2 W).

CONCLUSION

When using laser pretreatment, device settings should be adjusted to balance outcomes with potential side effects.

Observation on the efficacy of 1565-nm non-ablative fractional laser combined with compound betamethasone topical application on the treatment of early scar in Chinese patients

The objective of the study was to evaluate the efficacy of combining 1565-nm non-ablative fractional laser with low-dose compound betamethasone topical application in the treatment of immature early red hypertrophic scar. We enrolled 38 cases of patients who had immature red hypertrophic scar due to surgery or trauma which are all less than 6 months old. About 28 patients were assigned to the treatment group, and 10 patients were assigned to the control group. The patients in the treatment group were all treated with 1565-nm non-ablative fractional laser with the following parameters: spot size 10-16 mm, round or square-shaped according to lesional morphology, fluence 20-35 mJ/cm², and density 150-200 microspot/cm². The treated area was then applied immediately with low-dose compound betamethasone through topical application. Treatment cycles were repeated every month for a total 5 months. Photos were taken before the start of the treatment, and then monthly after. Vancouver Scar Scale score was used to evaluate the scar changes; all the patients were followed up for 3 more months after the last treatment. All side effects were documented. The patients in the control group received no treatment at all. All the parameters were recorded as the same as the treatment group. The total VSS score after the combination therapy is 0.96 ± 1.53, which in comparison with prior treatment VSS score 8.86 ± 1.43, showed a significant reduction following the treatments (P < 0.001). The control group without any treatment shows VSS score 7.10 ± 0.99 at the end of the study vs VSS score 7.70 ± 0.82 at the start of the study (P > 0.05). The patient satisfaction rate reaches 89.2% after treatment, The major side effects reported include 3 patients with post-inflammatory hyperpigmentation (10.7% of patients in the treatment group), and other minor discomfort such as transient warmth, erythema, and swelling of treatment sites. The combination approach using 1565-nm non-ablative laser and low dose of local application of compound betamethasone can effectively improve the immature red hypertrophic scar with no significant side effects; this should provide our practitioners with a new weapon in fighting those hard-to-manage early scar formations.

Molecular Features of Hypertrophic Scars After Thermal Injury: Is There a Biologic Basis for Laser Therapy?

Significance: Hypertrophic scars (HTS) and keloids are common after thermal injuries and other trauma to deep regions of dermis of the skin. These abnormal scars can cause contractures and the thick masses of scar tissue that result in functional and cosmetic impairment. Management of these dermal fibrotic conditions includes a wide range of medical and surgical treatments, which can be time consuming, only partially effective, and often uncomfortable for patients. Recent Advances: The molecular pathophysiology of HTS has become more understood over the past two decades, where thermal injury to the reticular dermis results in an inflammatory response, fibrogenic growth factor release, and the formation of a dermal scar with increased collagen and proteoglycan composition in an abnormal morphology. Lasers are becoming a widely used form of treatment for these types of scars; however, the evidence for the beneficial effects of laser treatments and the understanding of their mechanism of action are still evolving. Critical Issues: Paradoxically, laser delivery of thermal energy to the skin is suggested to improve scar remodeling and wound healing, yet HTS is a well-recognized complication of excessive thermal energy delivered by laser treatments. This review aims to examine the current evidence for the use of lasers for HTS, and to investigate the molecular mechanisms where re-injury of a burn scar from laser treatment could result in overall improvements in scar quality. Future Directions: Improved design of clinical trials for the treatment of scarring in the future will evolve from new methodology and models of HTS in animals and humans.

A Prospective Trial: Handsfree Thermoregulated Bipolar Radiofrequency for Face and Neck Contouring

Background:

The use of radiofrequency in aesthetic surgery has evolved significantly since it was first introduced in the early 2000s. Nonexcisional correction of the lower one-third of the face and neck has long been a challenging problem. The purpose of this prospective study was to assess the safety and efficacy of the first handsfree thermoregulated bipolar radiofrequency device for face and neck contouring.

Methods:

This prospective multicenter (New York, Nevada) IRB-approved study evaluated healthy candidates who desired noninvasive correction of their lower face and neck laxity. The primary objective of this study was to evaluate safety and soft tissue remodeling pretreatment and at 1-, 3-, and 6-months post last treatment. Assessment was made using blinded evaluators, 3D photographic analysis (Quantificare, France), and volumetric measurements. Investigator and subject assessments were obtained using a 0-4 point Likert scale.

Results:

A total of 34 patients completed both the cheek and chin applicator treatment series. Average age of patients was 38 (STD 3.4), BMI 27 (STD 2.2), average Baker Face & Neck classification 2.6 (STD 1.1), and average Fitzpatrick type 2.4 (STD 1.2). Mean treatment time was 41 min (STD 3.5) with a temperature of 42°C–43°C. Patient discomfort data were statistically very low based on t-test analysis. Satisfaction metrics measured at 1- and 3-month follow-up demonstrated a significant change in subject skin appearance, subject overall satisfaction, and investigator improvement perception. More patients were satisfied at the 3-month follow-up compared with the 1-month follow-up for all three measures. Volumetric data demonstrated an average change of −3.2 cm³ (STD ±1.2 cm³) per side for the cheek applicator and −4.1 (STD ±2.3) for the submental applicator. Of note there were cases where volume increases were noted that were believed to be related to soft tissue contraction.

Conclusions:

This is the first prospective study to evaluate a handsfree thermoregulated bipolar radiofrequency device for face and neck contouring. This device demonstrates a significant advance in the control and delivery of radiofrequency for aesthetic purposes. With a favorable safety and comfort profile, this device is able to concentrate thermal energy consistently at a depth that allows for fibroseptal network tightening to improve lower third of face and submental soft tissue contraction.

Laser Treatment of Hypopigmentation in Scars: A Review

BACKGROUND

Despite history of multiple treatment modalities, repigmentation of hypopigmented scars remains a difficult clinical problem.

OBJECTIVE

The purpose of this review is to evaluate the literature on laser and combination laser plus adjunct topical therapy for hypopigmented burn and traumatic scars.

MATERIALS AND METHODS

A search on PubMed and on Oxford Academic was conducted with additional relevant literature obtained from reference lists.

RESULTS

Treatment regimens that address hypopigmentation within scars were reviewed. A combination of nonablative fractional or ablative fractional laser treatment with topical prostaglandin analogue with or without topical retinoid were found to result in superior repigmentation.

CONCLUSION

Reliable improvement of hypopigmentation in scars after laser treatment is challenging. Laser can achieve success in some cases. Ultraviolet laser can achieve modest repigmentation; however, results are short-lived and require continued re-treatment. Modest improvement in pigmentation is seen with nonablative fractional laser or ablative fractional laser alone and enhanced repigmentation is demonstrated when combining fractional laser resurfacing with topical application of synthetic prostaglandin analogues and other known modulators of melanogenesis.

Transdermal Delivery of Therapeutic Compounds With Nanotechnological Approaches in Psoriasis

Psoriasis is a chronic, immune-mediated skin disorder involving hyperproliferation of the keratinocytes in the epidermis. As complex as its pathophysiology, the optimal treatment for psoriasis remains unsatisfactorily addressed. Though systemic administration of biological agents has made an impressive stride in moderate-to-severe psoriasis, a considerable portion of psoriatic conditions were left unresolved, mainly due to adverse effects from systemic drug administration or insufficient drug delivery across a highly packed stratum corneum via topical therapies. Along with the advances in nanotechnologies, the incorporation of nanomaterials as topical drug carriers opens an obvious prospect for the development of antipsoriatic topicals. Hence, this review aims to distinguish the benefits and weaknesses of individual nanostructures when applied as topical antipsoriatics in preclinical psoriatic models. In view of specific features of each nanostructure, we propose that a proper combination of distinctive nanomaterials according to the physicochemical properties of loaded drugs and clinical features of psoriatic patients is becoming a promising option that potentially drives the translation of nanomaterials from bench to bedside with improved transdermal drug delivery and consequently therapeutic effects.

Fractional Photothermolysis for Treatment of a Residual Discoid Lupus Erythematosus Lesion: A Case Report

Cutaneous discoid lupus erythematosus (CDLE) is a chronic inflammatory skin disease often resulting in permanent scarring of the affected area. Fractional photothermolysis (FP) is a well-known inducer of tissue regeneration by wounding the skin in a fractional pattern, hence inducing a well defined, wound healing response. It has been used clinically to treat atrophic as well as hypertrophic scars and also fibrotic diseases like morphea since more than a decade. We report a case of a young female patient treated with three sessions of ablative FP for stable atrophic scars due to CDLE affection of the upper left and right cheeks. After the last treatment, no side effects were observed. At the 13-month follow-up visit, the treated atrophic scars showed satisfying improvement for the patient. Skin texture, relief, color, and overall cosmetic appearance were all rated as improved by three independent dermatologists. No signs of unwanted side effects were observed at any time point. This case report should be followed up with a larger case series or ideally a prospective randomized clinical trial to better establish FP as a safe and effective tool to treat reminiscent scars after CDLE.

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.

Effectiveness of a combination therapy using non-ablative fractional laser and intralesional triamcinolone injection for thyroidectomy scar treatment: a prospective, randomized, blinded pilot study

BACKGROUND

The occurrence of thyroid cancer has increased dramatically, and postoperative scars are placed at easily visible locations. Many patients show stronger desire for scar prevention. So far, numerous approaches have been discussed for the treatment of scars; this study is conducted to verify whether the early application of combined therapy contributes to minimal scar formation.

METHODS

Between March 2019 and December 2019, total of 64 patients with thyroidectomy scars of a size greater than 4.5 cm located on the anterior neck were enrolled in this prospective pilot study. Subjective and objective evaluation were carried out using the Patient and Observer Scar Assessment Scale (POSAS) at one, two, and six months after operation. Results were compared between a treatment group and a non-treatment group.

RESULTS

In PSAS score, the mean values of pain, itching sensation, pliability, thickness, and relief were significantly higher in the laser and steroid treatment group (p = 0.009, p = 0.000, p = 0.013, p = 0.002, and p = 0.007). The value of color of the scars showed no significant differences (p = 0.504). In OSAS score, parameter of thickness, relief, and surface area score was significantly higher score in the combination group (p = 0.029, 0.035, and 0.020), while vascularity, pigmentation, and pliability were not significantly different between two groups (p = 0.548, p = 0.983, and p = 0.128).

CONCLUSION

This study demonstrates that early combination therapy contributes to scar improvement to a meaningful extent based on POSAS. We believe that the combined therapy has a synergy effect on scar management, which improves the patients' quality of life in relation to their postoperative scars.

Laser Therapy for the Treatment of Morphea: A Systematic Review of Literature

Morphea, also known as localized scleroderma (LoS), comprises a set of autoimmune sclerotic skin diseases. It is characterized by inflammation and limited thickening and induration of the skin; however, in some cases, deeper tissues might also be involved. Although morphea is not considered a life-threatening disease, the apparent cosmetic disfigurement, functional or psychosocial impairment affects multiple fields of patients’ quality of life. Therapy for LoS is often unsatisfactory with numerous treatments that have only limited effectiveness or considerable side effects. Due to the advances in the application of lasers and their possible beneficial effects, the aim of this study is to review the reported usage of laser in morphea. We present a systematic review of available literature, performed with MEDLINE, Cinahl, Central, Scopus, Web of Science, and Google Scholar databases. We identified a total of twenty relevant studies (MEDLINE n = 10, Cinahl n = 1, Central n = 0, Scopus n = 2, Web of Science n = 5, Google Scholar n = 2) using laser therapy for LoS. Eight studies were focused on the use of PDL, six on fractional lasers (CO₂ and Er:YAG), four on excimer, and two on either alexandrite or Nd:YAG.

Laser in surgical scar clearance: An update review

Scar formation is a consequence of wound healing that developed from damaged tissue either from physical injury or surgical incision. A hypertrophic scar develops due to an abnormal healing response to trauma. It might lead to serious functional and cosmetic disability. There are numerous methods mentioned in the literature to treat such scars but to date, no single method has been known to cure them. In this review, we focused on differences between various types of nonsurgical management of hypertrophic scar focusing on the indication, mechanism of action, and efficacy of the pulsed dye laser (PDL), fractional carbon dioxide laser (fCO2), Er-YAG laser, and intense pulse light (IPL). The literature research included peer-reviewed articles (clinical trials or scientific reviews) which were identified by searching electronic databases like PubMed till January 2021 and reference lists of respective articles. Only articles published in the English language were included.

Addressing Full-Thickness Skin Defects: A Review of Clinically Available Autologous Skin Replacements

Autologous keratinocyte culture, and combinations of scaffolds, different cell types, solutions of macromolecules, or growth factors have contributed to the resurfacing of full-thickness skin defects. Ideally, a treatment for full-thickness skin defects should not merely reestablish continuity of the surface of the skin but should restore its structure to allow skin to function as a dynamic biological factory that can participate in protein synthesis, metabolism, and cell signaling, and form an essential part of the body's immune, nervous, and endocrine systems. This paper provides a review of clinically available autologous skin replacements, highlighting the importance of regenerating an organ that will function physiologically.

Early Treatment Effects of Nonablative Fractional Lasers (NAFL) on Hypertrophic Scars in an Animal Model

BACKGROUND AND OBJECTIVES

Recently, there have been several attempts to apply the laser therapy to hypertrophic scars (HTS). In particular, the fractional laser is in the spotlight for its usefulness in rapid wound healing and dermal remodeling. However, most previous studies have focused on the ablative fractional laser (AFL), and there are no studies on the mechanism of the nonablative fractional laser (NAFL) effect in HTS treatment. In this study, we aimed to evaluate the changes in histology and molecular chemistry to provide scientific evidence for the early treatment of HTS with NAFL.

STUDY DESIGN/MATERIALS AND METHODS

A total of 40 hypertrophic burn scars were made on the abdomens of two female pigs. After epithelialization, the HTS were randomly subdivided into four groups-control, AFL, NAFL (low energy), and NAFL (high energy). Laser treatment was initiated 1 week after the crust fell and the epithelium became covered, and it was repeated for six sessions over an interval of 2 weeks. Five excisional biopsies were obtained for histologic analysis and biomarker assessment.

RESULTS

Histologically, dermal remodeling with thin coil-shaped collagen fibers was observed in the NAFL groups. It also showed a significant increase of matrix metalloproteinase-2 (MMP-2) and Decorin at 16 weeks in an enzyme-linked immunosorbent assay. The reverse-transcription polymerase chain reaction analysis showed a tendency that high-pulse energy of NAFL led to higher messenger RNA expression than did the low-energy group.

CONCLUSION

The NAFL-treated groups showed characteristic collagen re-arrangement and a significant increase in MMP-2 and Decorin. These molecular changes suggest that MMP-2 and Decorin play a significant role in dermal remodeling. Early NAFL treatment for HTS could be supported with both histological and molecular evidence. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Comparison of 1064-nm and Dual-Wavelength (532/1064-nm) Picosecond-Domain Nd:YAG Lasers in the Treatment of Facial Photoaging: A Randomized Controlled Split-Face Study

BACKGROUND AND OBJECTIVES

To compare the efficacy and safety of 1064-nm and dual-wavelength (532/1064 nm) picosecond Nd:YAG lasers with a holographic optic in the treatment of facial photoaging.

STUDY DESIGN/MATERIALS AND METHODS

In this prospective, randomized split-face study, each half of each participant's face was randomly treated with a 1064-nm or 532/1064-nm picosecond laser. All participants underwent five treatment sessions and follow-up visits 1 and 3 months after the final treatment. The primary outcomes were measured as the global photoaging scores, determined by two physicians who were blinded to the treatments. The secondary outcomes were the participant-assessed Global Aesthetic Improvement Scale (GAIS) and satisfaction scores. Histopathological examinations were performed.

RESULTS

Global photoaging scores decreased significantly after treatment with either laser. The global photoaging scores, GAIS scores, and satisfaction scores did not differ significantly between the 1064-nm and 532/1064-nm picosecond laser treatments. Histological changes were similar between the two groups. Intraepidermal vacuoles and dermal hemorrhaging were observed immediately and 24 h after treatment. After five treatments, neocollagenesis was observed in the upper dermis of both groups, and elastic fibers were more elongated and orderly.

CONCLUSIONS

Treatments with 1064-nm and 532/1064-nm picosecond Nd:YAG lasers were comparably effective at improving photodamaged facial skin by remodeling the collagen and elastin network through laser-induced optical degradation and vascular damage.