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

Topical, light-based, and complementary interventions for acne: an overview of systematic reviews

BACKGROUND

Acne is a chronic inflammatory and immune-mediated disease of the pilosebaceous unit (the skin structure consisting of a hair follicle and its associated sebaceous gland). It is characterised by non-inflammatory lesions (open and closed comedones) and inflammatory lesions (papules, pustules, nodules, and cysts). Lesions may be present on the face, thorax, and back, with variable severity. Acne exhibits a global distribution and has a growing prevalence. Acne vulgaris is the most common form. Acne gives rise to complications such as scars and can seriously affect people's mental health, especially those with severe acne. Acne has a huge impact on the quality of life and self-esteem of those affected.

OBJECTIVES

To synthesise the existing evidence on the efficacy and safety of non-systemic pharmacological interventions and non-pharmacological interventions (physical therapy and complementary therapies) in the treatment of acne vulgaris and related skin complications.

METHODS

We searched the Cochrane Database of Systematic Reviews, Epistemonikos, MEDLINE, and Embase to 2 December 2021, and checked the reference lists of included reviews. At least two authors were responsible for screening, data extraction, and critical appraisal. We excluded reviews with high risk of bias as assessed with the ROBIS tool. We evaluated the overall certainty of the evidence according to GRADE (as carried out by the authors of the included reviews or ourselves). We provide comprehensive evidence from the review data, including summary of findings tables, summary of results tables, and evidence maps.

MAIN RESULTS

We retrieved and assessed a total of 733 records; however, only six reviews (five Cochrane reviews and one non-Cochrane review) with low risk of bias met the overview inclusion criteria. The six reviews involved 40,910 people with acne from 275 trials and 1316 people with acne scars from 37 trials. The age of the participants ranged from 10 to 59 years, with an average age range from 9.8 to 30 years. Four reviews included original trials involving only female participants and three reviews included original trials with only male participants. Main results for clinically important comparisons: Benzoyl peroxide versus placebo or no treatment: In two trials involving 1012 participants over 12 weeks, benzoyl peroxide may reduce the total (mean difference (MD) -16.14, 95% confidence interval (CI) -26.51 to -5.78), inflammatory (MD -6.12, 95% CI -11.02 to -1.22), and non-inflammatory lesion counts (MD -9.69, 95% CI -15.08 to -4.29) when compared to placebo (long-term treatment), but the evidence is very uncertain (very low-certainty evidence). Two trials including 1073 participants (time point: 10 and 12 weeks) suggested benzoyl peroxide may have little to no effect in improving participants' global self-assessment compared to placebo (long-term treatment), but the evidence is very uncertain (risk ratio (RR) 1.44, 95% CI 0.94 to 2.22; very low-certainty evidence). Very low-certainty evidence suggested that benzoyl peroxide may improve investigators' global assessment (RR 1.77, 95% CI 1.37 to 2.28; 6 trials, 4110 participants, long-term treatment (12 weeks)) compared to placebo. Thirteen trials including 4287 participants over 10 to 12 weeks suggested benzoyl peroxide may increase the risk of a less serious adverse event compared to placebo (long-term treatment), but the evidence is very uncertain (RR 1.46, 95% CI 1.01 to 2.11; very low-certainty evidence). Benzoyl peroxide versus topical retinoids: Benzoyl peroxide may increase the percentage change in total lesion count compared to adapalene (long-term treatment), but the evidence is very uncertain (MD 10.8, 95% CI 3.38 to 18.22; 1 trial, 205 participants, 12 weeks; very low-certainty evidence). When compared to adapalene, benzoyl peroxide may have little to no effect on the following outcomes (long-term treatment): percentage change in inflammatory lesion counts (MD -7.7, 95% CI -16.46 to 1.06; 1 trial, 142 participants, 11 weeks; very low-certainty evidence), percentage change in non-inflammatory lesion counts (MD -3.9, 95% CI -13.31 to 5.51; 1 trial, 142 participants, 11 weeks; very low-certainty evidence), participant's global self-assessment (RR 0.96, 95% CI 0.86 to 1.06; 4 trials, 1123 participants, 11 to 12 weeks; low-certainty evidence), investigators' global assessment (RR 1.16, 95% CI 0.98 to 1.37; 3 trials, 1965 participants, 12 weeks; low-certainty evidence), and incidence of a less serious adverse event (RR 0.77, 95% CI 0.48 to 1.25, 1573 participants, 5 trials, 11 to 12 weeks; very low-certainty evidence). Benzoyl peroxide versus topical antibiotics: When compared to clindamycin, benzoyl peroxide may have little to no effect on the following outcomes (long-term treatment): total lesion counts (MD -3.50, 95% CI -7.54 to 0.54; 1 trial, 641 participants, 12 weeks; very low-certainty evidence), inflammatory lesion counts (MD -1.20, 95% CI -2.99 to 0.59; 1 trial, 641 participants, 12 weeks; very low-certainty evidence), non-inflammatory lesion counts (MD -2.4, 95% CI -5.3 to 0.5; 1 trial, 641 participants, 12 weeks; very low-certainty evidence), participant's global self-assessment (RR 0.95, 95% CI 0.68 to 1.34; 1 trial, 240 participants, 10 weeks; low-certainty evidence), investigator's global assessment (RR 1.10, 95% CI 0.83 to 1.45; 2 trials, 2277 participants, 12 weeks; very low-certainty evidence), and incidence of a less serious adverse event (RR 1.27, 95% CI 0.98 to 1.64; 5 trials, 2842 participants, 10 to 12 weeks; low-certainty evidence). For these clinically important comparisons, no review collected data for the following outcomes: frequency of participants experiencing at least one serious adverse event or quality of life. No review collected data for the following comparisons: topical antibiotics versus placebo or no treatment, topical retinoids versus placebo or no treatment, or topical retinoids versus topical antibiotics.

AUTHORS' CONCLUSIONS

This overview summarises the evidence for topical therapy, phototherapy, and complementary therapy for acne and acne scars. We found no high-certainty evidence for the effects of any therapy included. Randomised controlled trials and systematic reviews related to acne and acne scars had limitations (low methodological quality). We could not summarise the evidence for topical retinoids and topical antibiotics due to insufficient high-quality systematic reviews. Future research should consider pooled analysis of data on new emerging drugs for acne treatment (e.g. clascoterone) and focus more on acne complications.

Physical Treatments and Therapies for Androgenetic Alopecia

Androgenetic alopecia, the most common cause of hair loss affecting both men and women, is typically treated using pharmaceutical options, such as minoxidil and finasteride. While these medications work for many individuals, they are not suitable options for all. To date, the only non-pharmaceutical option that the United States Food and Drug Administration has cleared as a treatment for androgenetic alopecia is low-level laser therapy (LLLT). Numerous clinical trials utilizing LLLT devices of various types are available. However, a myriad of other physical treatments for this form of hair loss have been reported in the literature. This review evaluated the effectiveness of microneedling, pulsed electromagnetic field (PEMF) therapy, low-level laser therapy (LLLT), fractional laser therapy, and nonablative laser therapy for the treatment of androgenetic alopecia (AGA). It also explores the potential of multimodal treatments combining these physical therapies. The majority of evidence in the literature supports LLLT as a physical therapy for androgenetic alopecia. However, other physical treatments, such as nonablative laser treatments, and multimodal approaches, such as PEMF-LLLT, seem to have the potential to be equally or more promising and merit further exploration.

Effectiveness and Safety of Energy-Based Devices for Acne Scars: A Network Meta-Analysis of Randomized Controlled Trials

Background: Acne vulgaris is an inflammatory disease of the pilosebaceous unit in teenagers. Acne-induced inflammation leads to acne scarring. Scholars have discussed acne scar treatments; however, energy-based devices with satisfactory outcomes remain unidentified. Objective: To measure quartile grading scale and visual analog scale (VAS) to study the difference between energy-based devices. Methods: We included randomized controlled trials that evaluated patients with acne scars. The primary outcomes were the quartile grading scale and VAS scores. We used Confidence in Network Meta-Analysis to evaluate indirectness, imprecision, heterogeneity, and incoherence. Results: A total of 26 studies met the inclusion criteria. The quartile grading scale results revealed that ablative fractional laser was significantly more effective than nonablative fractional laser (standard mean difference [SMD]: 0.516, confidence interval [95% CI]: 0.281-0.750) and radiofrequency treatment (SMD: 0.941, 95% CI: 0.540-1.342). Moreover, nonablative fractional laser was significantly more effective than radiofrequency treatment (SMD: 0.426, 95% CI: 0.049-0.802). No significant difference in VAS score was found among the devices. Conclusion: Ablative fractional laser is an effective treatment for acne scars although it is associated with more pain.

Topical 5% minoxidil versus combined erbium YAG laser and topical 5% minoxidil in androgenetic alopecia: A randomized controlled trial

BACKGROUND

Androgenetic alopecia (AGA) is the most common type of hair loss in men, and several treatment options have been proposed for it. Fractional ablative erbium YAG laser can promote hair growth through trans-epidermal drug delivery and the thermal stimulation of hair follicles; this study therefore aims to evaluate minoxidil alone and in combination with fractional ablative erbium YAG laser in male patients with AGA.

METHODS

This study was performed on 30 male patients with moderate to severe AGA. Patients were equally randomized into two groups, and the intervention group was treated with 1 mL of topical 5% minoxidil twice daily and six sessions of 2940-nm ablative fractional erbium YAG laser, and the control group received topical 5% minoxidil alone. The assessment entailed photography, dermoscopy, and patient satisfaction based on a 7-point grading scale.

RESULTS

Both groups showed statistically significant improvements in terms of patient satisfaction, photography, and dermoscopy scores. The group receiving a combination of laser and minoxidil treatment obtained a higher dermoscopy score than the patients receiving minoxidil alone (p-value = 0.016). Nonetheless, there was no difference between the two groups in terms of the photography score (p-value = 0.13).

CONCLUSION

Laser treatment can stimulate the hair follicles and also enhance the dermal delivery of minoxidil, which was found to be associated with slightly better outcomes in this study.

The safe use of lasers in biomedicine: Principles of laser-matter interaction

Optical radiation sources, and in particular lasers, find an ever-increasing number of applications in the medical field. It is essential that personnel who are in the presence of an optical radiation source, whether operator, patient or researcher, know precisely the risks inherent in the exposure of the human body to radiation. In order to reduce the risk of biological damage, beyond the provisions of the law on safety regulations, the precise information and accurate preparation of personnel are the main guarantee for the correct use of these sources. In all the application fields, the possibility of a biological damage cannot be completely eliminated, assuming the connotation of occupational risks. In order to understand the risks and operate their effective mitigation, the basic knowledge of the fundamental concepts at the basis of laser-matter interaction will be presented and discussed, with a focus on the physical parameters needed to efficiently estimate and mitigate the related occupational risks, in both a laboratory and clinical context.

The quantitative investigation of spark plasma on skin parameters with skin elasticity, thickness, density, and biometric characteristics

Cold atmospheric plasma has been developed and utilized as a novel technique for skin rejuvenation because of its various effects on cells and living things. This study investigated the accuracy of this claim and any possible side effects of using spark plasma to rejuvenate skin. The present work is the first quantitative investigation using animal models. 12 Wistar rats were divided into two groups for this investigation. To compare the skin's natural process with the treated skin, the first group underwent a single session of plasma therapy, while the second group served as the control group. The back of the necks of the samples was shaved for 20 cm. Before beginning treatment, the MPA9 multifunctional skin tester was used to determine the melanin index, erythema index, and transepidermal water loss (TEWL). The skin's thickness and density were assessed using sonography, and its elasticity index was calculated using a Cutometer. The samples were exposed to plasma radiation in the designated area (in a triangular pattern). The abovementioned signs were examined immediately after the following therapy and at the weekly appointment 2-4 weeks later. Optical spectroscopy was also used to demonstrate the presence of active species. In this study, we found that a plasma spark therapy session significantly boosts skin elasticity, and the ultrasound results revealed a significantly increased skin thickness and density. The plasma increased the amount of skin surface evaporation, erythema, and melanin immediately following the treatment. However, 4 weeks later, it recovered to its former state and did not differ significantly from before the therapy.

Comparative efficacy and safety of six photoelectric therapies for the atrophic acne scars: A network meta-analysis

Objectives

This network meta-analysis assessed the relative efficacy and safety of six common photoelectric therapies including 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG), fractional carbon dioxide laser(FSCO2), fractional micro-plasma radiofrequency(Plasma), micro-needling fractional radiofrequency (MRF), 1550nm or 1540nm erbium-glass non-ablative fractional laser (NAFL) fractional erbium-doped yttrium aluminum garnet (Er: YAG).

Methods

A comprehensive search to identify relevant studies was conducted using four electronic databases. Outcome measures were extracted based on subjective and objective indexes, including the dermatologists’ evaluation(DE), the patients’ overall satisfaction(PS), VAS score, and Postinflammatory hyperpigmentation (PIH).

Results

Eleven published clinical research studies, involving 405 patients were included in this study. Ranking of DE from large to small is as follows: Nd: YAG, FSCO2, Er: YAG, Plasma, NAFL, MRF. In terms of PS, the rand from high to low can be described as follows: Er: YAG, Nd: YAG, FSCO2, Plasma, NAFL, MRF. In connection with the sequencing of adverse events, pain severity from slight to severe as follows: Er:YAG, Nd:YAG, FSCO2, NAFL, MRF, Plasma. The probability of having PIH are presented in order from lowest to highest as follows: MRF, Plasma, Nd: YAG, NAFL, Er: YAG, FSCO2.

Conclusion

FSCO2 remains the mainstream of potentially curative treatment, then again Nd: YAG and Er: YAG require greater efforts to prove their superior effectiveness. NAFL might be appropriate for mild and moderate improvement with its strengths of good tolerance while Plasma fits into patients with higher pain thresholds but an expectation of higher results. MRF has not given expression on absolute predominance for the present.

Registration

PROSPERO CRD42021242160

(available from https://www.crd.york.ac.uk/prospero).

Photobiomodulation Reduces Periocular Wrinkle Volume by 30%: A Randomized Controlled Trial

Objective: This study aimed to evaluate red and amber light-emitting diode protocols for facial rejuvenation at the same light dose. Background: The demand for minimally invasive cosmetic procedures to address skin aging has grown throughout the world. In vitro red and amber photobiomodulation (PBM) has been shown to improve collagen synthesis. Meanwhile, red PBM has already been studied in clinical trials; however, a comparison of the use of different wavelengths at the same light dose to reduce periocular wrinkles has not yet been performed. Methods: This split-face, randomized clinical trial recruited 137 women (40-65 years old) presenting with skin phototypes II-IV and Glogau photoaging scale types II-IV. The individuals received 10 sessions for 4 weeks of red (660 nm) and amber (590 nm) PBM (3.8 J/cm²), one at each side of the face. The outcomes, measured before and after the treatments, were the periocular wrinkle volume measured by VisioFace^® RD equipment; hydration measured by the Corneometer CM 825; skin elasticity measured by the Cutometer Dual MPA 580; and quality of life determined by adapted versions of validated questionnaires [Melasma Quality of Life Scale-Brazilian Portuguese (MelasQoL-BP) and Skindex-29]. Results: There was a significant reduction in wrinkle volume after red (31.6%) and amber (29.9%) PBM. None of the treatments improved skin hydration and viscoelasticity. Both questionnaires showed improvements in participants' quality of life. Conclusions: PBM, both at red and amber wavelengths, is an effective tool for rejuvenation, producing a 30% wrinkle volume reduction. The technique has strong potential in patients with diabetes or those presenting with keloids, conditions for which highly inflammatory rejuvenating procedures are not indicated. Clinical trial registration number: REBEC-6YFCBM.

A Review of Laser Therapies for the Treatment of Scarring and Vascular Anomalies

Significance: Laser use has become part of the gold standard of treatment as an effective adjuvant in multimodal therapy for pathologic scarring caused by burns, trauma, acne, and surgery, as well as vascular anomalies. Understanding indications and applications for laser therapy is essential for physicians to improve patient outcomes. Recent Advances: Since the 1980s, the medical use of lasers has continuously evolved with improvements in technology. Novel lasers and fractionated technologies are currently being studied in the hopes to improve treatment efficacy, while reducing complications. Recent advancements include acne treatment with novel picosecond lasers, new hypertrophic scar therapies with simultaneous laser and intense pulsed light use, and novel systems such as lasers with intralesional optical fiber delivery devices. In addition, optimizing the timing of laser therapy and its use in multimodal treatments continue to advance the field of photothermolysis. Critical Issues: Selecting the correct laser for a given indication is the fundamental decision when choosing a laser balancing effective treatment with minimal complications. This article covers the principles of laser therapy, the preferred lasers used for the treatment of scarring and vascular anomalies, and discusses the current evidence behind these laser choices. Future Directions: To optimize laser therapy, larger randomized control trials and split scar studies are needed. Continued advancement through better randomized controlled studies will help to improve patient outcomes on a broader scale.

Synergistic Sequential Emission of Fractional 10.600 and 1540 nm Lasers for Skin Resurfacing: An Ex Vivo Histological Evaluation

Background: Fractional ablative and non-ablative lasers are useful treatments for skin rejuvenation. A procedure that provides the sequential application of fractional ablative followed by non-ablative laser treatment may reduce patients' downtime and deliver better cosmetic results than with either laser alone. Objective: The purpose of the current study was to demonstrate the ameliorative and therapeutic effects in skin remodeling of the synergistic use of the two laser wavelengths (fractional ablative CO₂ and non-ablative 1540 nm) with three different types of pulse shapes, S-Pulse (SP), D-Pulse (DP) and H-Pulse (HP), through which the CO₂ laser can emit, performing an ex vivo histological evaluation. Methods: In this prospective study, ex vivo sheep inner thigh skin was chosen due to its similarity to human skin tissue, and a histological evaluation was performed. Three irradiation conditions, using all of the three CO₂ pulse shapes (alone or averaged), were investigated: (1) 10.600 nm alone, the sequential irradiation of the two wavelengths in the same perfectly controlled energy pulses (DOT) for the entire scan area; ((2) 10.600 nm followed immediately by 1540 nm; and (3) 1540 nm followed immediately by 10.600 nm). Results: When comparing ablative to sequential irradiations, the synergy of the two wavelengths did not alter the typical ablative pulse shape of the 10.600 nm laser alone. With the same CO₂ pulse shape, the lesion depth did not vary with the synergy of the two wavelengths, while thermal lesion width increased compared to CO₂ alone. The ablation rate was achieved, while the total thermal lesion coverage in the scanning area of CO₂ - 1540 lasers was greater than when using CO₂ alone and then the other sequential irradiation. Conclusions: This study provides important preclinical data for new and early uses of the novel 10.600/1540 nm dual-wavelength non-ablative fractional laser. The synergy of the two wavelengths enhanced all the benefits already available when using CO₂ laser systems both in terms of tone strengthening, thanks to a greater shrinking effect, and in terms of stimulation and collagen remodeling thanks to a greater volumetric thermal effect.

Clinical Efficacy and Safety of Pulsed Dye Laser Combined with Pingyangmycin on Hyperplastic Scar after Acne

Background

Acne is the most common chronic inflammatory disease of hair follicles and sebaceous glands in dermatology. Hyperplastic scar (HS), a very common sequelae of acne, is also the most common scar type in clinical practice.

Objective

This research analyzed the clinical effectiveness and safety of pulsed dye laser (PDL) combined with pingyangmycin (PI) in the treatment of post-acne HS.

Methods

One hundred and nine patients with post-acne HS admitted in June 2020 were selected and divided into a research group (n = 52) and a control group (n = 57) according to the difference in treatment methods. The efficacy, incidence of adverse reactions, skin repair, treatment comfort, and satisfaction were compared between groups.

Results

The total effective rate was higher in the research group compared with the control group. No statistical difference was observed between groups in the incidence of adverse reactions. The research group showed better scar repair, skin improvement, and granulation tissue maturity than the control group. And compared with the control group, the growth factor of the research group was lower, while the treatment comfort and satisfaction, psychological state, and prognosis quality of life were higher. The two groups showed no notable difference in the recurrence rate.

Conclusions

PDL combined with PI can effectively improve the clinical efficacy, scar repair effect, overall skin status, and treatment experience of patients and boost the psychological state and prognostic quality of life of patients, which has great clinical application prospect for the treatment of HS.

Comparative appraisal with meta-analysis of erbium vs. CO2 lasers for atrophic acne scars

Recent advances in laser technology allowed the development of systems that improve texture, appearance and pliability of skin in acne scars (AS). Currently, comprehensive comparative studies on the efficacy of the most commonly used fractional systems in AS are lacking. Thus, the aim of this work was to appraise and compare the clinical response to erbium versus CO₂ lasers in AS in the form of a meta-analysis. The databases MEDLINE, EMBASE, Cochrane library were searched. Main clinical outcomes were investigator-reported scar improvement and participant-reported scar improvement. Five studies were included in this meta-analysis. Scar improvement was similar for both types of laser in terms of investigator-reported scar improvement (RR: 0.60 95 % CI: 0.35-1.02) and participant-reported scar improvement (RR: 0.99 95 % CI: 0.79-1.25). A sensitivity analysis that excluded studies with high risk of bias found the CO₂ lasers to be superior to the erbium lasers (RR: 0.47 95 % CI: 0.24-0.93): However, the subgroup analysis showed the CO₂ laser not to be significantly different from either the non-ablative erbium (RR: 0.65 95 % CI: 0.34-1.24) or the ablative erbium laser (RR: 0.60 95 % CI: 0.35-1.02). The CO₂ laser produced a slightly greater clinical response compared to the erbium lasers based on the physician's assessment. Overall, the two devices do not differ largely in terms of efficacy but may be complementary, with each resurfacing laser better suited for different clinical tasks.

Comparison of Pulse Wave Signal Monitoring Techniques with Different Fiber-Optic Interferometric Sensing Elements

Pulse wave (PW) measurement is a highly prominent technique, used in biomedical diagnostics. Development of novel PW sensors with increased accuracy and reduced susceptibility to motion artifacts will pave the way to more advanced healthcare technologies. This paper reports on a comparison of performance of fiber optic pulse wave sensors, based on Fabry–Perot interferometer, fiber Bragg grating, optical coherence tomography (OCT) and singlemode-multimode-singlemode intermodal interferometer. Their performance was tested in terms of signal to noise ratio, repeatability of demodulated signals and suitability of demodulated signals for extraction of information about direct and reflected waves. It was revealed that the OCT approach of PW monitoring provided the best demodulated signal quality and was most robust against motion artifacts. Advantages and drawbacks of all compared PW measurement approaches in terms of practical questions, such as multiplexing capabilities and abilities to be interrogated by portable hardware are discussed.