Evolution of Laser Skin Resurfacing: From Scanning to Fractional Technology

Histopathological Evaluation of Bipolar and Microneedle Radiofrequency Energy on the Skin and Fat of the Abdominal Region of the Rat

BACKGROUND

Radiofrequency-based devices are used frequently in plastic surgery procedures. In the current literature, no comparative experimental study has demonstrated the histologic and immunologic effects of these devices, which are used frequently in the facial area. In this study, the authors investigated the histologic and immunologic effects of bipolar radiofrequency (BodyTite) and microneedle radiofrequency (Morpheus 8) devices in the rat abdominal region.

METHODS

A total of 24 rats were used in this study. The rats were divided into 4 groups: controls (group 1), BodyTite applied to the abdominal region (group 2), Morpheus 8 applied to the abdominal region (group 3), and both Morpheus 8 and BodyTite applied to the abdominal region (group 4). The histologic and immunologic features of the tissues, collagen formation, and desmosome structures were examined using light microscopy.

RESULTS

Collagens in group 2 were thinner than those in the other groups. In addition, there were fewer vessels in group 3. The collagen scores were as follows: group 2, 1.5; group 3, 2; and group 4, 3. Vascular endothelial growth factor scores were 2.5 in group 2, 2 in group 3, and 3 in group 4. The collagen score in group 2 and vascular endothelial growth factor score in group 3 were significantly lower than in the other groups. In addition, the bonds between desmosomes in group 3 were found to be looser using electron microscopy. Collagen morphology in groups 3 and 4 was found to be similar to that in group 1.

CONCLUSION

Radiofrequency-based devices increased tissue regeneration and healing.

CLINICAL RELEVANCE STATEMENT

The use of radiofrequency devices has increased in plastic surgery practice over the past 2 decades, particularly emerging as a unique alternative for nonsurgical candidates. There is a lack of experimental studies concerning these devices, which are commonly used in clinical practice.

Repeated exposure to fractional CO2 laser delays squamous cell carcinoma formation and prevents clinical and subclinical photodamage visualized by line-field confocal optical coherence tomography and histology

OBJECTIVES

Ablative fractional laser (AFL) is a well-established modality for treating ultraviolet radiation (UVR)-induced skin photodamage. We aimed to investigate the potential of AFL to delay squamous cell carcinoma (SCC) formation and prevent photodamage in a preclinical UVR-induced SCC model.

MATERIALS AND METHODS

Hairless C3.Cg-Hrhr /TifBomTac mice (n = 50) were exposed to UVR three times weekly throughout the study. UV-exposed mice were randomized to two groups that received dorsal CO2 AFL (10 mJ/mb, 10% density) or no treatment. AFL was performed every other week for a total of 16 weeks (nine treatments in total). The primary outcome was time to tumor occurrence. In a subset of mice on Day 150, prevention of clinical photodamage was assessed by examination of skin tightness and dyspigmentation. Concomitantly, assessment of subclinical photoprevention based on normalization of keratinocyte dysplasia, dermo-fiber morphology (collagen and elastin fibers), and skin thickness, was performed using line-field confocal optical coherence tomography (LC-OCT) and histology.

RESULTS

Repeated AFL treatments delayed SCC tumor development compared to UVR control mice by 12, 19, and 30 days for first, second, and third tumors, respectively (p ≤ 0.0017). Compared to UVR controls, AFL prevented photodamage both clinically and subclinically, based on LC-OCT and histology. In the epidermal layer, AFL imparted photopreventative effects including reduced dyspigmentation and keratinocyte dysplasia (1 vs. 2.5, p = 0.0079) and partial normalization of the epidermal thickness (p < 0.0001). In the dermis, AFL led to twofold greater skin tightness (p = 0.0079), improved dermo-fiber structure, and dermal thickness (p = 0.0011).

CONCLUSION

In conclusion, repeated AFL treatments of UVR-exposed skin significantly delayed SCC tumor formation and prevented clinical and imaging-assessed subclinical signs of photodamage, indicating a potential for AFL in prevention strategies for SCC and photodamage in high-risk populations.

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.

CO2 Laser Treatment of Multiple Oral Hamartomas in Cowden's Syndrome: A Review and Case Study

Background

Cowden’s syndrome is a genetic disorder characterized by multiple oral hamartomas and an increased risk of internal malignancy. These mucocutaneous lesions can be physically disfiguring and psychologically distressing. As a result, patients frequently seek treatment for their destruction. Removal of oral hamartomas is often a challenge due to their sensitive location and high risk of recurrence.

Objective

To review the clinical use, effectiveness, and safety of a fractional ablative laser to treat multiple oral hamartomas in a patient with Cowden’s syndrome.

Materials and Methods

A thorough literature review pertaining to treatment of oral hamartomas and a discussion of an illustrative case showcasing successful lesional destruction with a fractional ablative carbon dioxide (CO₂) laser in a 33-year-old man with Cowden’s syndrome.

Results

Multiple oral hamartomas were effectively removed with fractional CO₂ laser vaporization. No infection, scarring, dermatitis, nor lesional recurrence were observed 6 months post-treatment.

Conclusion

Fractional CO₂ laser vaporization can be used effectively to treat multiple oral hamartomas associated with Cowden’s syndrome.

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.

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.

Wounding Therapies for Prevention of Photocarcinogenesis

The occurrence of non-melanoma skin cancer (NMSC) is closely linked with advanced age and ultraviolet-B (UVB) exposure. More specifically, the development of NMSC is linked to diminished insulin-like growth factor-1 (IGF-1) signaling from senescent dermal fibroblasts in geriatric skin. Consequently, keratinocyte IGF-1 receptor (IGF-1R) remains inactive, resulting in failure to induce appropriate protective responses including DNA repair and cell cycle checkpoint signaling. This allows UVB-induced DNA damage to proliferate unchecked, which increases the likelihood of malignant transformation. NMSC is estimated to occur in 3.3 million individuals annually. The rising incidence results in increased morbidity and significant healthcare costs, which necessitate identification of effective treatment modalities. In this review, we highlight the pathogenesis of NMSC and discuss the potential of novel preventative therapies. In particular, wounding therapies such as dermabrasion, microneedling, chemical peeling, and fractionated laser resurfacing have been shown to restore IGF-1/IGF-1R signaling in geriatric skin and suppress the propagation of UVB-damaged keratinocytes. This wounding response effectively rejuvenates geriatric skin and decreases the incidence of age-associated NMSC.

Applications of microneedling for various dermatologic indications with a special focus on pigmentary disorders: A comprehensive review study

Microneedling can accelerate skin repair through numerous complex processes triggered by micro-injuries it produces on the skin surface with very thin needles. The current growth in the application of microneedling in the treatment of cutaneous diseases can be explained by its numerous effects on the skin as reported in the literature. Despite the numerous studies conducted on the application of microneedling in the treatment of skin lesions, its effects on pigmented skin lesions have remained relatively unexplored. The present review comprises an examination of the evidence for the application of microneedling in skin diseases in general and a comprehensive review of the applications of microneedling in pigmentation disorders. The review involved a search of all clinical studies, including trials, case reports, and case series, in the databases MEDLINE/PubMed and Google Scholar using the following keywords: "microneedling," "dermal needling," "percutaneous collagen induction," "skin needling," "dermaroller," and "dermatology disorder." Pertinent data were extracted from all relevant articles published from 1990 to April 2021, and focused on the application of microneedling in the treatment of pigmented skin lesions. Despite the limited number of available studies, evidence suggests the effectiveness and safety of microneedling in treating vitiligo, melasma, and periorbital hypermelanosis. It is noteworthy that the combination of any type of non-aggressive needing technique with other effective therapies (especially topical agents and mesotherapy) yields more promising therapeutic results than single therapy for melasma, dark cycles, and vitiligo as the prototype of pigmentary disorders. However, single needling therapy is significantly effective, too.

Plume Effect of Fractional Radiofrequency Verus Laser Resurfacing: Considerations in the COVID-19 Pandemic

INTRODUCTION

The COVID-19 pandemic requires us all to re-evaluate aesthetic practices to ensure optimal patient safety during elective procedures. Specifically, energy-based devices and lasers require special consideration, as they may emit plume which has been shown to contain tissue debris and aerosolized biological materials. Prior studies have shown transmission of viruses and bacteria via plume (i.e., HIV and papillomavirus). The purpose of this study was to evaluate plume characteristics of the Er:YAG resurfacing laser (Sciton; Palo Alto, CA) and compare it to the Morpheus8 fractional radiofrequency device (InMode; Lake Forest, CA).

METHODS

Five patients who underwent aesthetic resurfacing and/or skin tightening of the face and neck were treated with the Er:YAG (Sciton Joule, Palo Alto, CA) and/or fractional radiofrequency (Morpheus8, Lake Forest, CA) between April 1 and May 11, 2020. Data collected included patient demographics, past medical history, treatment parameters, adverse events, particle counter data, as well as high magnification video equiptment. Patients were evaluated during treatment with a calibrated particle meter (PCE; Jupiter, FL). The particle meter was used at a consistent focal distance (6-12 inches) to sample the surrounding environment during treatment at 2.83 L/min to a counting efficiency of 50% at 0.3 µm and 100% at >0.45 µm. Recordings were obtained with and without a smoke evacuator.

RESULTS

Of our cohort (n = 5), average age was 58 years old (STD ±7.2). Average Fitzpatrick type was between 2 and 3. Two patients received Er:YAG fractional resurfacing in addition to fractional radiofrequency during the same treatment session. Two patients had fractional radiofrequency only, and one patient had laser treatment with the Er:YAG only. There were no adverse events recorded. The particle counter demonstrated ambient baseline particles/second (pps) at 8 (STD ±6). During fractional radiofrequency treatment at 1-mm depth, the mean recording was 8 pps (STD ±8). At the more superficial depth of 0.5 mm, recordings showed 10 pps (STD ±6). The Er:YAG laser resurfacing laser had mean readings of 44 pps (STD ±11). When the particle sizes were broken down by size, the fractional radiofrequency device had overall smaller particle sizes with a count of 251 for 0.3 µm (STD ±147) compared with Er:YAG laser with a count of 112 for 0.3 µm (STD ±84). The fractional radiofrequency did not appear to emit particles >5 µm throughout the treatment, however, the Er:YAG laser consistently recorded majority of particles in the range of 5-10 µm. The addition of the smoke evacuator demonstrated a 50% reduction in both particles per second recorded as well as all particle sizes.

CONCLUSION

Re-evaluation of the plume effect from aesthetic devices has become important during the COVID-19 pandemic. Further studies are required to characterize viability of COVID-19 viability and transmissibility in plume specimens. Based on this pilot study, we recommend that devices that generate little to no plume such as fractional radiofrequency devices be used in Phase I reopening of practice while devices that generate a visible plume such as Er:YAG laser resurfacing devices be avoided and only used with appropriate personal protective equipment in addition to a smoke evacuator in Phase IV reopening.

Dermatologic Laser Side Effects and Complications: Prevention and Management

The evolution of modern laser and light-based systems has mirrored the demand for clinically effective treatments and the need for safer technologies with reduced postoperative recovery, side effects, and complications. With each new generation of lasers, more selective tissue destruction can be achieved with reduced unwanted sequelae. Patient selection and preparation, operator technique, and expeditious recognition and management of post-treatment side effects are paramount in avoiding complications and patient dissatisfaction. An overview of important variables to consider for dermatologic laser treatments are presented in order to provide a framework to reduce the severity and duration of possible post-treatment side effects and complications.

Fractional CO2 laser ablation of porcine burn scars after grafting: Is deeper better?

INTRODUCTION

Fractional CO₂ lasers have been used in clinical settings to improve scarring following burn injury. Though used with increasing frequency, the appropriate laser settings are not well defined and overall efficacy of this therapy has not been definitively established. As it has been proposed that for thick hypertrophic scars proportionally greater fluence and thus deeper ablation into the scar tissue would be most effective, the goal of this study was to examine the role of ablation depth on scar outcomes in a highly-controlled porcine model for burn scars-after grafting.

METHODS

Properties of laser ablated wells were quantified on ex vivo pig skin as a function of laser energy (20, 70 or 150mJ). Full-thickness burn wounds were created on the dorsum of red Duroc pigs with the eschar excised and grafted with a split-thickness autograft meshed and expanded 1.5:1. After four weeks of healing, sites were treated with either 20, 70, or 150mJ pulse energy from a fractional CO₂ laser at 5% density or left untreated as a control. Sites were treated every four weeks with three total sessions. Scar area, pigmentation, erythema, roughness, histology, and biomechanics were evaluated prior to each laser treatment at day 28, 56, and 83, as well as four weeks after the final laser treatment, day 112. Additional biopsies were collected at day 112 for gene expression analysis.

RESULTS

The depth of the laser ablated wells increased with increasing pulse energy while the width of the wells was smaller in the 20mJ group and not significantly different in the 70 and 150mJ groups. Scar properties (area, color, biomechanics) were not significantly altered by laser therapy at any of the laser energies tested versus controls. Average scar roughness was improved by laser therapy in a dose dependent manner with scars treated with 150mJ of energy having the smoothest surface; however, these changes were not statistically significant. Assessment of matrix metalloproteinase 9 gene expression showed a slight upregulation in scars treated with 70 or 150mJ versus control scars and scars treated with 20mJ pulse energy.

CONCLUSION

The current study demonstrated that the properties of the ablative well (depth and width) are not linearly correlated with laser pulse energy, with only a small increase in well depth at energies between 70 and 150mJ. Overall, the study suggests that there is little difference in outcomes as a function of laser energy. Fractional CO₂ laser therapy did not result in any statistically significant benefit to scar properties assessed by quantitative, objective measures, thus highlighting the need for additional clinical investigation of laser therapy efficacy with non-treated controls and objective measures of outcome.

Will Repeated Ablative Er:YAG Laser Treatment Sessions Cause Facial Skin Sensitivity? Results of a 12-Month, Prospective, Randomized Split-Face Study

Whether multiple laser irradiations affect skin sensitivity is still elusive. We aimed to investigate if repeated ablative erbium:yttrium-aluminum-garnet (Er:YAG) laser therapy could cause or increase skin sensitivity in the treatment areas. Nineteen healthy females received three sessions of a randomized, split-face, Er:YAG laser treatment in a scanning ablative mode (MicroLaserPeel™), with a 6-mm spot size, 8-μm ablative depths, and 30% of pulse overlap first. The next round was conducted in the fractional mode (ProFractional™) at depths ranging from 100 to 150 μm, with one pass by at coverage of 11% in the coagulation mode. Objective biophysical parameters, including transepidermal water loss (TEWL), skin glossiness, epidermal and dermal thickness and density, sensory nerve current perception threshold (CPT), and local blood flow, were measured before and after treatment. Quantitative evaluation of the Er:YAG laser treatment's effect on skin sensitivity is presented. Seventeen volunteers completed a follow-up of 12 months. On days 1 and 3, skin TEWL and epidermal thickness increased, while glossiness decreased. On day 7, there was no significant difference in the skin barrier function between the treated and the control side. Similarly, there was no significant difference in CPT values or local microvascular blood flow between sides at any time point before or after treatment, except that the local microvascular blood flow on the treated side was higher on the first day post-treatment. Er:YAG laser treatment does not influence skin sensitivity in healthy subjects in a long-term follow-up.

Concomitant Use of 1,550-nm Nonablative Fractional Laser With Low-Dose Isotretinoin for the Treatment of Acne Vulgaris in Asian Patients: A Randomized Split-Face Controlled Study

BACKGROUND

Nonablative fractional laser (NAFL) has been shown to improve the appearance of inflammatory acne and acne scars. Isotretinoin is effective for the treatment of moderate-to-severe cases of recalcitrant acne. However, the recommended dose of isotretinoin can have profound effects.

OBJECTIVE

To investigate the clinical efficacy and safety of performing NAFL treatment in patients with moderate-to-severe acne vulgaris under treatment with low-dose oral isotretinoin.

METHODS AND MATERIALS

Eighteen patients who received 10-mg oral isotretinoin per day completed 3 sessions of NAFL treatment on one half of the face and presented for each scheduled follow-up appointment.

RESULTS

Low-dose isotretinoin was effective in managing papules and nodule lesions (p < .001). Comedo lesions were significantly improved on NAFL-treated half-faces, compared with untreated half-faces (p < .05) as well as on the appearance of atrophic boxcar scars (superficial boxcar scar, p < .05; deep boxcar scar, p < .01). The most common side effects of oral isotretinoin were xerostomia and cheilitis. The most common discomforts associated with NAFL treatment were mild transient erythema and edema in the treated area.

CONCLUSION

The combination of NAFL with low-dose isotretinoin is a safe and effective treatment for moderate-to-severe acne.

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.

Laser applications in surgery

In modern medicine, lasers are increasingly utilized for treatment of a variety of pathologies as interest in less invasive treatment modalities intensifies. The physics behind lasers allows the same basic principles to be applied to a multitude of tissue types using slight modifications of the system. Multiple laser systems have been studied within each field of medicine. The term "laser" was combined with "surgery," "ablation," "lithotripsy," "cancer treatment," "tumor ablation," "dermatology," "skin rejuvenation," "lipolysis," "cardiology," "atrial fibrillation (AF)," and "epilepsy" during separate searches in the PubMed database. Original articles that studied the application of laser energy for these conditions were reviewed and included. A review of laser therapy is presented. Laser energy can be safely and effectively used for lithotripsy, for the treatment of various types of cancer, for a multitude of cosmetic and reconstructive procedures, and for the ablation of abnormal conductive pathways. For each of these conditions, management with lasers is comparable to, and potentially superior to, management with more traditional methods.

The effect of pre-operative topical anaesthetic cream on the ablative width and coagulative depth of ablative fractional resurfacing laser

Topical anaesthetic cream (TAC) is commonly used as a pre-treatment of ablative fractional resurfacing (AFR) laser. Most of anaesthetic cream contains distilled water as major component. Therefore, pre-operative TAC may interfere the photothermal reaction in the skin treated with fractional carbon-dioxide (FCO₂) laser and fractional erbium-doped yttrium aluminium garnet (FEr:YAG) laser. The objective of the study was to compare the ablative width (AW) and coagulative depth (CD) of AFR laser with and without pre-treatment with TAC. Four Thai females who underwent abdominoplasty were included in the study. The excised skin of each subject was divided into four areas. TAC (eutectic mixture of local anaesthesia; EMLA) with 1-h occlusion was applied only on the first and second areas. The first and third areas were treated with FCO₂ at 15 mj and 5% density. The second and fourth areas were treated with FEr:YAG at 28 J/cm² and 5% density. Six biopsied specimens were obtained from each area. A total of 96 specimens (24 specimens from each area) were collected from four patients and examined randomly by two dermatopathologists. The ablative width and coagulative depth from each specimen were determined. In FCO₂-treated specimens, the mean AW of the specimens that were pre-treated with TAC and control was 174.86 ± 24.57 and 188.52 ± 41.32 μm. The mean CD of the specimens that were pre-treated with TAC and control was 594.96 ± 111.72 and 520.03 ± 147.40 μm. There were no significant differences in AW and CD between both groups (p = 0.53 and p = 0.15). In FEr:YAG-treated specimens, the mean AW of the specimens that were pre-treated with TAC and control was 381.11 ± 48.02 and 423.65 ± 60.16 μm. The mean CD of the specimens that were pre-treated with TAC and control was 86.03 ± 29.44 and 71.59 ± 18.99 μm. There were no significant differences in AW and CD between both groups (p = 0.16 and p = 0.24). The pre-treatment with TAC provided no statistically difference from the control group on AW and CD of both FCO₂ and FEr:YAG laser irradiation. However, there was a tendency to have narrower AW and deeper CD of the areas that were pre-treated with TAC when comparing to that of the control.

Application of reflectance confocal microscopy to evaluate skin damage after irradiation with an yttrium-scandium-gallium-garnet (YSGG) laser

The objective of this study was to observe the characteristics of the skin after irradiation with a 2790-nm yttrium-scandium-gallium-garnet (YSGG) laser using reflectance confocal microscopy (RCM). A 2790-nm YSGG laser was used to irradiate fresh foreskin (four doses, at spot density 3) in vitro. The characteristics of microscopic ablative columns (MAC), thermal coagulation zone (TCZ), and microscopic treatment zones (MTZ) were observed immediately after irradiation using digital microscope and RCM. The characteristics of MAC, TCZ, and MTZ with variations in pulse energy were comparatively analyzed. After irradiation, MAC, TCZ, and MTZ characteristics and undamaged skin between MTZs can be observed by RCM. The depth and width of MTZ obviously increased with the increase in pulse energy. At 80, 120, and 160 mJ/microbeam (MB), the MTZ actual area and proportion were about two times that of the theoretical value and three times at 200 mJ/MB. With increases in depth, the single MAC gradually decreased in a fingertip-shaped model, with TCZ slowly increasing, and MTZ slightly decreasing in a columnar shape. RCM was able to determine the characteristics of thermal injury on the skin after the 2790-nm YSGG laser irradiation with different pulse energies. Pulse energy higher than 200 mJ/MB may have much larger thermal injury and side effect. RCM could be used in the clinic in future.

Retinoids: Literature Review and Suggested Algorithm for Use Prior to Facial Resurfacing Procedures

Vitamin A-containing products have been used topically since the early 1940s to treat various skin conditions. To date, there are four generations of retinoids, a family of Vitamin A-containing compounds. Tretinoin, all-trans-retinoic acid, is a first-generation, naturally occurring, retinoid. It is available, commercially, as a gel or cream. The authors conducted a complete review of all studies, clinical- and basic science-based studies, within the literature involving tretinoin treatment recommendations for impending facial procedures. The literature currently lacks definitive recommendations for the use of tretinoin-containing products prior to undergoing facial procedures. Tretinoin pretreatment regimens vary greatly in terms of the strength of retinoid used, the length of the pre-procedure treatment, and the ideal time to stop treatment before the procedure. Based on the current literature and personal experience, the authors set forth a set of guidelines for the use of tretinoin prior to various facial procedures.

Minimally Invasive Radiofrequency Devices

This article reviews minimally invasive radiofrequency options for skin tightening, focusing on describing their mechanism of action and clinical profile in terms of safety and efficacy and presenting peer-reviewed articles associated with the specific technologies. Treatments offered by minimally invasive radiofrequency devices (fractional, microneedling, temperature-controlled) are increasing in popularity due to the dramatic effects they can have without requiring skin excision, downtime, or even extreme financial burden from the patient's perspective. Clinical applications thus far have yielded impressive results in treating signs of the aging face and neck, either as stand-alone or as postoperative maintenance treatments.

Photoaging and the clinical utility of fractional laser

The description of atomic structure by Niels Bohr set the basis for the emergence of quantum physics. Based on these fundamentals, Einstein published in 1917 a paper on the amplification of energy by Stimulated Emission of Radiation as part of his quantum theories. In 1955, Townes and Gordon turned Einstein’s theories into practice, creating a coherent and amplified microwave device using ammonia gas in an optical medium. But it was at the beginning of the 1980s, that Anderson and Parrish published an article about the selective photothermolysis model which revolutionized clinical practice. The use of laser in photoaging began with CO₂ (10,600 nm). In 1989, it was first used for resurfacing of a face with prominent photoaging. Ablative lasers have therefore had great popularity in the 1980s and 1990s, but prolonged postoperative time and significant risk of side effects have lowered the acceptance by patients. In 2004, the description of the fractionated radiation for the treatment of photoaging, by Mainstein, represented a great event. The stimulation of collagen occurred through fractional laser beams, which would reach the selected area while saving islands of sound skin. These islands accelerated the process of cicatrization of the treated tissue and shortened the postprocedure time. Furthermore, the fractionated radiation presented a smaller range of side effects, increasing the safety of the procedure. As mentioned earlier, as fractional lasers incise on the skin, they leave islands of healthy skin that accelerate recovery, while generating necrosis columns. Such necrosis columns remove damaged extracellular matrix material, allowing resettlement of fibroblasts. Such resettled fibroblasts, under the influence of a new tensile strength, restart to produce structures for extracellular matrix, such as collagen, elastin, and proteoglycans, in a more physiological way. Fractional lasers are considered by many dermatologists as the best choice in laser therapy for the treatment of photoaging.

The role of lasers and intense pulsed light technology in dermatology

The role of light-based technologies in dermatology has expanded dramatically in recent years. Lasers and intense pulsed light have been used to safely and effectively treat a diverse array of cutaneous conditions, including vascular and pigmented lesions, tattoos, scars, and undesired hair, while also providing extensive therapeutic options for cosmetic rejuvenation and other dermatologic conditions. Dermatologic laser procedures are becoming increasingly popular worldwide, and demand for them has fueled new innovations and clinical applications. These systems continue to evolve and provide enhanced therapeutic outcomes with improved safety profiles. This review highlights the important roles and varied clinical applications that lasers and intense pulsed light play in the dermatologic practice.