A systematic review of comparative studies of CO2 and erbium:YAG lasers in resurfacing facial rhytides (wrinkles)

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.

Resurfacing of atrophic facial acne scars with a multimodality CO2 and 1570 nm laser system

BACKGROUND

Scarring is one of the most prevalent long-term complications of acne vulgaris and has cosmetic, psychological, and social burdens. Contemporary management programs integrate multiple modalities to best address the multiple factors underlying their development and persistence. This work assessed the impact of sequential multimodal laser therapy on acne scar geometrics and texture.

METHODS

Adult patients (n = 16) with Fitzpatrick skin type II-IV and presenting with facial acne scars, underwent three combination ablative (CO2), and nonablative (1570 nm) laser treatment sessions at two-month intervals. Treatment was delivered using a ProScan Hybrid applicator, with each regimen including illumination with both ablative and a nonablative lasers applied in a grid mode sequence. Scar microtopography was assessed at baseline and 6 months after the last treatment session.

RESULTS

At baseline, all patients had both box and rolling scars, while only three had icepick scars. Six months following treatment, mean scar volume improved from 5.7 ± 5.2 mm3 at baseline to 3.1 ± 3.0 mm3 and mean affected area improved from 165.6 ± 134.0 mm2 94.0 ± 80.1 mm2, translating to 47.0 ± 7.9% and 43.2 ± 8.6% reductions from baseline, respectively. Patients were highly satisfied with treatment outcomes, and no serious adverse reactions were documented during the course of treatment or follow-up.

CONCLUSION

Multimodal CO2 and 1570-nm laser treatment improved the surface profilometry of patients with atrophic facial acne scars. Customization of both treatment intervals and laser settings to cosmetic regions, scar profiles and skin phototypes may further enhance treatment outcomes and expand its applicability to additional skin deformities.

Novel 40 µm spot size 3050/3200 nm DFG laser versus CO2 laser for laser-assisted drug delivery

BACKGROUND AND OBJECTIVES

The use of ablative fractional lasers to enhance the delivery of topical drugs through the skin is known as laser-assisted drug delivery. Here, we compare a novel 3050/3200 nm difference frequency generation (DFG) fiber laser (spot size: 40 µm) to a commercially used CO2 laser (spot size: 120 µm). The objective is to determine whether differences in spot size and coagulation zone (CZ) thickness influence drug uptake.

MATERIALS AND METHODS

Fractional ablation was performed on ex-vivo human abdominal skin with the DFG (5 mJ) and CO2 (12 mJ) lasers to generate 680 µm deep lesions. To evaluate drug delivery, 30 kDa encapsulated fluorescent dye was topically applied to the skin and histologically analyzed at skin depths of 100, 140, 200, 400, and 600 µm. Additionally, transcutaneous permeation of encapsulated and 350 Da nonencapsulated dye was assessed using Franz Cells.

RESULTS

The DFG laser generated smaller channels (diameter: 56.5 µm) with thinner CZs (thickness: 22.4 µm) than the CO2 laser (diameter: 75.9 µm, thickness: 66.8 µm). The DFG laser treated group exhibited significantly higher encapsulated dye total fluorescence intensities after 3 h compared to the CO2 laser treated group across all skin depths (p < 0.001). Permeation of nonencapsulated dye was also higher in the DFG laser treated group vs the CO2 laser treated group after 48 h (p < 0.0001), while encapsulated dye was not detected in any group.

CONCLUSION

The DFG laser treated skin exhibited significantly higher total fluorescence uptake compared to the CO2 laser. Additionally, the smaller spot size and thinner CZ of the DFG laser could result in faster wound healing and reduced adverse effects while delivering similar or greater amount of topically applied drugs.

Does Platelet-Rich Plasma Promote Facial Rejuvenation? Revising the Latest Evidence in a Narrative Review

Facial aging is characterized by progressive macroscopic, histological, and molecular changes. Due to its regenerative and rejuvenating properties, the use of platelet-rich plasma (PRP) as a facial antiaging agent has gained popularity over the last decade. In order to gather and evaluate the latest evidence focusing on the effect of PRP on facial skin rejuvenating, a search through MEDLINE (PubMed) using relevant keywords, inclusion, and exclusion criteria was performed. A total of 539 articles were initially retrieved, and from those, 16 were included in the review. Treatment protocols comprised the use of PRP both in monotherapy and in combination with other substances and by means of direct injection or topical application following skin permeation. The selected studies presented high variability regarding PRP preparation methods, administration protocols, and results assessment. In most studies, PRP seemed to improve to some degree the signs of facial aging, such has wrinkles, skin quality, and pigmentation, accompanied by significant histological and molecular responses. Optimizing treatment protocols should be the next step in assessing the full potential of PRP.

Sexual function after energy-based treatments of women with urinary incontinence. A systematic review and meta-analysis

INTRODUCTION AND HYPOTHESIS

Urinary incontinence (UI) affects approximately 50% of adult women worldwide and is associated with declining sexual function (SF). Energy-based devices emerged as a minimally invasive alternative treatment. Nevertheless, their effect on sexuality is uncertain. We hypothesize that the UI energy treatment can lead to sexual function improvement.

METHODS

A search was performed in PubMed, Cochrane Library, Web of Science, Embase, and Scopus for randomized clinical trials (RCTs) and nonrandomized studies of intervention, which treated incontinent women using energy, with UI and sexual function (SF) as outcomes. Severe comorbidities, pelvic organ prolapse (POP)> grade 2, and use of medication to treat UI or that affects SF were excluded. Quality assessment and meta-analysis were performed.

RESULTS

From 322 articles, 11 RCTs were included for qualitative analysis. UI symptoms improved in all studies. Regarding SF, RCT with premenopausal women showed improvement in SF in the Er:Yag group (Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire-12 and Female Sexual Function Index). A prospective study showed improvement in SF independent of the grade of SUI. RF showed benefits for SF but was not superior to pelvic floor muscle training. One nonrandomized study of intervention with a High-Intensity Focused Electromagnetic Field showed significant improvement of SF in the Golombok Rust Inventory of Sexual Satisfaction total score, a decline in pain and dissatisfaction domains. Meta-analysis with 4 RCTs and 2 nonrandomized studies found no difference between groups (0.26 (95% CI -0.67 to 1.20, and -0.74 (95% CI -3.78 to 2.30) respectively).

CONCLUSIONS

This meta-analysis did not confirm that energy equipment improved the SF of women with UI.

Assessment of a 3050/3200 nm fiber laser system for ablative fractional laser treatments in dermatology

Background and Objectives

Mid‐infrared (IR) ablative fractional laser treatments are highly efficacious for improving the appearance of a variety of dermatological conditions such as photo‐aged skin. However, articulated arms are necessary to transmit the mid‐IR light to the skin, which restricts practicality and clinical use. Here, we have assessed and characterized a novel fiber laser‐pumped difference frequency generation (DFG) system that generates ablative fractional lesions and compared it to clinically and commercially available thulium fiber, Erbium:YAG (Er:YAG), and CO₂ lasers.

Materials and Methods

An investigational 20 W, 3050/3200 nm fiber laser pumped DFG system with a focused spot size of 91 µm was used to generate microscopic ablation arrays in ex vivo human skin. Several pulse energies (10–70 mJ) and pulse durations (2–14 ms) were applied and lesion dimensions were assessed histologically using nitro‐blue tetrazolium chloride stain. Ablation depths and coagulative thermal damage zones were analyzed across three additional laser systems.

Results

The investigational DFG system‐generated deep (>2 mm depth) and narrow (<100 µm diameter) ablative lesions surrounded by thermal coagulative zones of at least 20 µm thickness compared to 13, 40, and 320 µm by the Er:YAG, CO₂, and Thulium laser, respectively.

Conclusion

The DFG system is a small footprint device that offers a flexible fiber delivery system for ablative fractional laser treatments, thereby overcoming the requirement of an articulated arm in current commercially available ablative lasers. The depth and width of the ablated microcolumns and the extent of surrounding coagulation can be controlled; this concept can be used to design new treatment procedures for specific indications. Clinical improvements and safety are not the subject of this study and need to be explored with in vivo clinical studies.

Preauricular Aging: A Three-Point Grading System to Guide Treatment in Facial Rejuvenation

BACKGROUND

Aging affects the face in all its dimensions. However, more has been published about the improvement of the periocular, midface, and perioral aging changes. We believe the profile view, particularly the preauricular area, is of great value when assessing the need for facial contouring procedures, as well as their effectiveness.

OBJECTIVE

To develop and evaluate a classification based on the aging changes around the preauricular area, which aims to provide an objective direction to the appropriate treatment method.

METHODS AND MATERIALS

All patients who attended the clinic for different aesthetic procedures between June 2019 and January 2020 were photographed. Two non-treating dermatologists and two non-treating plastic surgeons were asked to evaluate the perceived aging of the preauricular area using a three-point grading system. The assessment of each photograph was made once by each evaluator, and the inter-rater correlation was calculated.

RESULTS

A total of 158 profile pictures of the preauricular area of 158 patients were evaluated by two non-treating dermatologists and two non-treating plastic surgeons. The inter-rater correlation was excellent at 0.942. The mean grading system of the patient samples was 1.42, with a standard deviation of 0.9 and a variance of 0.001.

CONCLUSIONS

The preauricular area is often overlooked and undertreated. Our results demonstrate an excellent inter-rater correlation between plastic surgeons and dermatologists at assessing the degree of aging in the area. This relatively hidden lateral area can serve as a test point, evaluating response to selected treatment before proceeding to full-face intervention. We suggest using a simple three-point scale to help guide treatment of the preauricular area and as part of our holistic approach to facial rejuvenation.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Low-fluence and low-density CO2 laser: histological analysis of collagen fiber changes in skin and its clinical repercussions in photorejuvenation

This study refers to clinical and histologic analysis of effects on photorejuvenation after one single treatment of fractional CO2 laser with low fluence and low density. To analyze histologically the quantitative variation of collagen fibers type I and III, elastic fibers, and epidermal thickness on D84, besides clinical evaluation of amount, length, thickness, and depth of periocular wrinkles during the same period. This is an open, prospective, interventional study. There were 40 healthy female with age between 35 and 65 years. Twenty-six participants were randomly selected for D0 and D84 biopsy. A single session of fractional CO2 laser was done in the hole face, using a 800-µm tip, 5% density, and 10 mJ fluence with a single pass. On D0, D42, and D84, a clinical comparative analysis of amount, length, depth, and thickness of periocular wrinkles has been done. On histological analysis, a comparative quantitative evaluation of collagen fibers type I and III, elastic fibers, and epidermal thickness has been done on D0 and D84. The results of this study denoted a significant clinical improvement of amount (- 32.17%; p < 0.0001), thickness (- 33%; p < 0.0001), lenght (- 35.84%; p < 0.0001), and depth of periocular wrinkles (- 32.46%; p < 0.0001). A significant increase in the amount of collagen fibers type III was observed on D84 (+ 60.67%; p = 0.0013). Collagen fibers type I and elastic fibers did not have the same result, with a nonsignificant increase (+ 8.31%; p = 0.3820) and a decrease (- 12.4%; p = 0.0585) respectively. Epidermal thickness has a tendency to significant variation (p = 0.05553). The results demonstrate that fractional CO2 laser with low fluence and low density is a safe and efficient option for photorejuvenation of the face.

Histological and immunohistochemical changes in facial skin treated with combined ablative and non-ablative laser therapy

Background

Facial skin rejuvenation is a highly sought after procedure. Different materials, energy‐based devices and techniques have been shown to offer good results in facial rejuvenation.

Aims

The aim of this study was to evaluate the macroscopic and histological and immunohistochemical changes in facial skin treated with a combined laser therapy.

Patients/Methods

Fourteen patients aged from 38 to 59 years were included in the study. Two different wavelengths (2940 and 1064 nm) were used in this four‐step procedure.

Results

Significant improvement according to classification for age‐related changes in all areas of the face was achieved. There were also significant structural changes in the epidermis and dermis, confirmed with histology and immunohistochemistry.

Conclusion

The dual‐wavelength protocol has been found to provide excellent results for facial rejuvenation.

Treatment of periorbital and perioral wrinkles with fractional Er:YAG laser: What are the effects of age, smoking, and Glogau stage?

BACKGROUND

Dynamic and static wrinkling are observed on the facial skin as a result of aging. Previously, it was showed that fractional Er:YAG laser was effective in the treatment of facial wrinkles.

AIMS

The aims of this study are to determine the effects of age, Glogau stage, and smoking status on the treatment efficacy of fractional Er:YAG laser; and to compare the success of laser treatment on periorbital wrinkles with perioral wrinkles.

MATERIAL/METHOD

Periorbital and perioral wrinkles of the same patient were treated with fractional Er:YAG laser (2940 nm) for 4 sessions with monthly intervals. Treatment parameters were affluence of 1.5J, a spot size of 7 mm, and a frequency of 5 Hz. Treatment efficacy was evaluated by a blinded physician evaluation scale and patient satisfaction scale 2 months after the final treatment session.

RESULTS

Fifteen patients completed the study. The mean age of the patients was 42.8 years. The blinded physician evaluation of the improvement in the periorbital wrinkles decreased (P =.034) and the patient satisfaction in perioral wrinkles decreased (P =.049) with increasing age. The relationship between smoking and patient satisfaction in the treatment of periorbital wrinkles was also statistically significant (P =.014). No difference in terms of treatment efficacy was found between periorbital and perioral regions.

CONCLUSION

Fractional Er:YAG laser (2940 nm) is equally successful in the treatment of periorbital and perioral wrinkles. The treatment success decreases with smoking and increasing age.

Application of Texture and Fractal Dimension Analysis to Estimate Effectiveness of Oral Leukoplakia Treatment Using an Er:YAG Laser-A Prospective Study

BACKGROUND

Oral leukoplakia (OL) is a potential neoplasmic lesion. The aim of this study was to apply texture analysis (TA) and fractal dimension analysis (FDA) to estimate the effectiveness of OL treatment using an Er:YAG laser.

METHODS

Eighteen patients with 32 lesions were treated. Laser procedures were conducted using the LiteTouch™ Er:YAG Dental Laser. The diameter of the operational tip was 1.3 mm, the power was 50 mJ, the frequency was 50 Hz, and the wavelength was 2940 nm. TA was based on long and short-run emphasis inverse moments, difference entropy, inverse difference moment, and wavelet decomposition for two-dimensional photography. FDA was measured using the box-counting method.

RESULTS

Total response was achieved in 50% of lesions, partial response was observed in 47%, and 3% of lesions did not respond to treatment. Recurrence occurred in 34% of lesions. TA features indicated pathological images depicting leukoplakia and complete reconstruction of the correct mucosal image after laser ablation. The discrete wavelet transformation feature detects much larger structures than the properties derived from the run-length matrix and co-occurrence matrix.

CONCLUSIONS

The Er:YAG laser is an effective treatment method in cases of oral leukoplakia. Leukoplakia treatment by Er:YAG laser is an effective modality, as revealed by the oral mucosa microstructure. TA and FDA are promising methods to estimate the effectiveness of OL treatment.

Effects of non-ablative Er:YAG laser on the skin and the vaginal wall: systematic review of the clinical and experimental literature

INTRODUCTION AND HYPOTHESIS

Er:YAG laser is frequently used in dermatology and gynecology. Clinical studies document high satisfaction rates; however, hard data on the effects at the structural and molecular levels are limited. The aim of this systematic review was to summarize current knowledge about the objective effects of non-ablative Er:YAG laser on the skin and vaginal wall.

METHODS

We searched MEDLINE, Embase, Cochrane, and the Web of Science. Studies investigating objectively measured effects of non-ablative Er:YAG laser on the skin or vaginal wall were included. Studies of any design were included. Owing to the lack of methodological uniformity, no meta-analysis could be performed and therefore results are presented as a narrative review.

RESULTS

We identified in vitro or ex vivo studies on human cells or tissues, studies in rats, and clinical studies. Most studies were on the skin (n = 11); the rest were on the vagina (n = 4). The quality of studies is limited and the settings of the laser were very diverse. Although the methods used were not comparable, there were demonstrable effects in all studies. Immediately after application the increase in superficial temperature, partial preservation of epithelium and subepithelial extracellular matrix coagulation were documented. Later, an increase in epithelial thickness, inflammatory response, fibroblast proliferation, an increase in the amount of collagen, and vascularization were described.

CONCLUSIONS

Er:YAG laser energy may induce changes in the deeper skin or vaginal wall, without causing unwanted epithelial ablation. Laser energy initiates a process of cell activation, production of extracellular matrix, and tissue remodeling.

Efficacy, safety, and guidelines of application of the fractional ablative laser erbium YAG 2940 nm and non-ablative laser erbium glass in rejuvenation, skin spots, and acne in different skin phototypes: a systematic review

Non-ablative and ablative fractional erbium lasers are among the most frequently used resources in dermatology for facial rejuvenation and for treating dermatological disorders. This type of erbium laser can be found at wavelengths of 1540 or 1550 nm, which are classified as non-ablative erbium glass, and at 2940 nm, classified as ablative erbium YAG. Despite the reports of their clinical benefits, few scientific studies have demonstrated the efficacy and safety of these lasers in the short or long term. In order to substantiate the effects, benefits, and safety of applying the erbium glass and erbium YAG lasers, a systematic review was carried out from August to December 2019 about studies published in the last 20 years. Randomized clinical trials in humans were considered that evaluated the efficacy, safety, and benefits of applying the fractional lasers erbium glass and erbium YAG to facial rejuvenation, skin spots, and atrophic acne scars. A total of 338 articles were identified; 76 articles remained after their titles and abstracts were read, and 42 articles were selected after removing the duplicates. After the articles were read in full, 17 of these articles were included in the systematic review (453 patients). The erbium glass and erbium YAG lasers seem promising in the short term, with minimal adverse effects; however, the long-term efficacy and safety still present limitations. Consequently, future research is needed, with better methodological standardization and a follow-up with a longer evaluation period for possible permanent adverse effects to determine the standardization and safety of therapy with erbium glass and erbium YAG lasers.

Development of a combination therapy with silanols complexed with boron citrate and ablative-fractional laser for treatment of wrinkles and stretch marks

OBJECTIVE

The twenty first century's progress in medicine and cosmetology triggered the search for effective and safe new cosmetics and procedures to fight with such problems as wrinkles or stretch marks. The study aimed to use the synergy of silanols with boron compounds and to develop treatment methods supported by a fractional-ablative laser.

METHODS

Sixty-seven Caucasian people were enrolled in this study: 33 patients with facial and neck wrinkles and 34 patients with stretch marks. Preparations containing methylsilanetriol were pressed into the skin by means of oxygen infusion which were followed by the fractional-ablative laser treatments.

RESULTS

The effectiveness of removal of wrinkles was better if combination therapy was used in the form of transdermal delivery of methylsilanetriol combined with laser therapy. The effectiveness of stretch marks removal by combination therapy was comparable to a two laser treatments and more effective than one laser therapy. Moreover, the use of products based on methylsilanetriol stabilized with boric citrate resulted in shortening the period of regeneration after the treatment with fractional-ablative laser by 29-58%.

CONCLUSION

The gel based on methylsilanetriol developed in this study can be successfully used after all laser treatments, but also those related to skin pricking to accelerate regeneration.

Handheld laser devices and laser-induced retinopathy (LIR) in children: an overview of the literature

Handheld laser devices are easily available to purchase through the internet and unregulated marketplaces at a relatively low cost. They are particularly attractive to children as they are seen as 'high tech', brightly coloured, and known to be able to burn holes in objects such as balloons. There is a widespread lack of knowledge about the risks of viewing the beam emanating directly from handheld lasers, and particularly those with high-output powers. The number of reported laser induced retinopathy (LIR) injuries in children is on the increase in the United Kingdom and represents a major public health issue. The number of individuals affected by LIR is likely to be underestimated owing to lack of presentation to health professionals, general poor awareness and non-reporting by children after the incident. The presentation of LIR is highly variable and dependent on many factors including type of laser, length of exposure and how it is administered. In this article, we review the features of retinal damage associated with inadvertent or deliberate laser administration using a handheld laser device. We highlight the importance of educating the wider public about this increasing problem; children who play with these devices are usually completely unaware of the long-term consequences of laser damage to the eye. It is also important that the features of LIR are recognised by health professionals involved in eye care as they can be mistaken for retinal dystrophies, particularly if the history of laser exposure is not volunteered or elicited.

Solvent and Substituent Effects on the Phosphine + CO2 Reaction

A theoretical study of the substituent and solvent effects on the reaction of phosphines with CO2 has been carried out by means of Møller-Plesset (MP2) computational level calculations and continuum polarizable method (PCM) solvent models. Three stationary points along the reaction coordinate have been characterized, a pre-transition state (TS) assembly in which a pnicogen bond or tetrel bond is established between the phosphine and the CO2 molecule, followed by a transition state, and leading finally to the adduct in which the P–C bond has been formed. The solvent effects on the stability and geometry of the stationary points are different. Thus, the pnicogen bonded complexes are destabilized as the dielectric constant of the solvent increases while the opposite happens within the adducts with the P–C bond and the TSs trend. A combination of the substituents and solvents can be used to control the most stable minimum.