The microsecond 1064 nm Nd:YAG laser as an adjunct to improving surgical scars following Mohs micrographic surgery

Laser Applications in Wound and Scar Management Post-Mohs Micrographic Surgery: A Systematic Review

Mohs micrographic surgery (MMS) can lead to complications such as scarring and delayed wound healing, particularly in sensitive areas such as the face, neck, and chest. This study aims to assess the evidence regarding the use of lasers post-MMS for wound healing and scar revision. A comprehensive systematic review of the literature was performed using databases including MEDLINE, PubMed, EMBASE, Web of Science, Cochrane Library, and CINAHL from inception until July 25, 2022. A total of 2147 unique studies were identified, from which 17 were included in the analysis. A total of 17 studies reported applications of lasers with favourable efficacy including wound healing (n = 1), resurfacing of full-thickness skin grafts and split-thickness skin grafts (n = 4), periscar telangiectasias (n = 1), functional scar contractures (n = 2), and scar texture (n = 9). Minimal adverse effects were reported with the use of lasers post-MMS. Overall, the use of lasers post-MMS is a safe and well-tolerated option for scar revision with high patient satisfaction and is less invasive than surgical interventions.

Wound Healing and Cell Dynamics Including Mesenchymal and Dental Pulp Stem Cells Induced by Photobiomodulation Therapy: An Example of Socket-Preserving Effects after Tooth Extraction in Rats and a Literature Review

High-intensity laser therapy (HILT) and photobiomodulation therapy (PBMT) are two types of laser treatment. According to recent clinical reports, PBMT promotes wound healing after trauma or surgery. In addition, basic research has revealed that cell differentiation, proliferation, and activity and subsequent tissue activation and wound healing can be promoted. However, many points remain unclear regarding the mechanisms for wound healing induced by PBMT. Therefore, in this review, we present an example from our study of HILT and PBMT irradiation of tooth extraction wounds using two types of lasers with different characteristics (diode laser and carbon dioxide laser). Then, the effects of PBMT on the wound healing of bone tissues are reviewed from histological, biochemical, and cytological perspectives on the basis of our own study of the extraction socket as well as studies by other researchers. Furthermore, we consider the feasibility of treatment in which PBMT irradiation is applied to stem cells including dental pulp stem cells, the theme of this Special Issue, and we discuss research that has been reported on its effect.

Near-Infrared Laser-Annealed IZO Flexible Device as a Sensitive H2S Sensor at Room Temperature

A metal-oxide material (indium zinc oxide [IZO]) device with near-infrared (NIR) laser annealing was demonstrated on both glass and bendable plastic substrates (polycarbonate, polyethylene, and polyethylene terephthalate). After only 60 s, the sheet resistance of IZO films annealed with a laser was comparable to that of thermal-annealed devices at temperatures in the range of 200-300 °C (1 h). XPS, ATR, and AFM were used to investigate the changes in the sheet resistance and correlate them to the composition and morphology of the thin film. Finally, the NIR-laser-annealed IZO films were demonstrated to be capable of detecting changes in humidity and serving as a highly sensitive gas sensor of hydrogen sulfide (in ppb concentration), with room-temperature operation on a bendable substrate.

Modeling and Analysis of High-Power Ti:sapphire Laser Amplifiers–A Review

We have introduced several factors that can be useful for the modeling and analysis of high-power Ti:sapphire laser amplifiers. The amplification model includes the phase distortion effect caused by the atomic phase shift (APS) in gain medium and the thermal-induced phase distortion effect caused by the high-average-power amplification. We have provided an accurate amplification model for the development of ultra-high-intensity and high-average-power lasers.

Correction of cicatricial ectropion using non-ablative fractional laser resurfacing

Lower eyelid malposition is the most frequent and severe complication after blepharoplasty and ectropion is observed in 1% of patients after surgery. This article describes a non-surgical method to treat lower eyelid cicatricial ectropion using a non-ablative laser as an alternative to surgery. Twelve patients with unilateral or bilateral lower lid cicatricial ectropion, following surgery or trauma, underwent laser therapy from 2012 to 2016. Laser therapy was performed with a fractional non-ablative laser emitting at a wavelength of 1540 nm. Ten patients had a full correction of their ectropion and two patients had a partial recovery after laser therapy at 6-month follow-up visit. No serious adverse events were reported. Non-ablative fractional laser resurfacing can successfully treat cicatricial ectropion by remodeling the periocular scar tissue and improving the scar texture, and as such may be considered as a valuable alternative to surgery in selected patients.

A Single-Center, Randomized, Double-Blind, Placebo-Controlled Clinical Trial of the Effectiveness of ANT1 Soybean Extract Cream on Skin Recovery After Nd: YAG Laser Treatment

Nd:YAG laser has been used extensively for its versatility in treating many common aesthetic problems, but numerous adverse effects are often complained by recipients of Nd:YAG laser. This study introduces the ANT1 soybean extract cream, which was formulated to alleviate adverse effects after laser therapy. This study explores whether ANT1 enhances the repair mechanism of the postlaser skin, decreases laser-induced complication, and shortens recovery time. The study also aims to pinpoint the ANT1 concentration that is most effective in improving the skin condition after Nd-YAG laser therapy.

MATERIALS AND METHODS

This study was a single-center, randomized, double-blind, placebo-controlled trial. Patients eligible for the study were Asian women, aged 25 to 40 years, who were free of dermatological diseases and allergic reaction. There were a total of 45 subjects. Each subject received a session of Nd-YAG laser therapy every 2 weeks, totaling 3 sessions. Facial skin assessment was achieved via VISIA complexion analysis. VISIA complexion analysis quantitatively assessed the skin condition and tracked the recovery progress of each subject at baseline, immediately after all 3 laser sessions, and a week after the final laser treatment.

RESULTS

Skin condition was evaluated by VISIA complexion analysis. Skin condition was recorded in aspects of pigmented spots, wrinkles, texture, pores, and red area. After Nd-YAG laser therapy, postlaser inflammation was observed in all subjects. Throughout the laser sessions and the outpatient follow-up clinic, the adverse effects of laser therapy, such as redness, spots, wrinkles, pores, and textures, decreased with the use of ANT1 cream. There has been a marked effect in wrinkle reduction in the patients who received a higher concentration of ANT1 cream (P ≤ 0.05). Statistically significant improvement in spots and pores is also seen (P ≤ 0.05).

CONCLUSIONS

Through this study, the results suggest that the application of ANT1 soybean extract cream ameliorates the complications and enhances the cosmetic effects of Nd-YAG laser therapy. A higher concentration of the ANT1 cream significantly reduces wrinkles and redness after laser. All in all, this study proves that the ANT1 soy extract cream may be a useful addition to postlaser care for an overall enhancement in skin condition and recovery.

[Mechanism of lipolytic and smooth effects of D980-nm laser treatment on skin tissue in rats]

Objective

To determine the efficacy of D980-nm laser in dissolving fat and renewing skin, and to explore the clinical application of D980-nm laser in reconstruction of photodamaged skin.

Methods

Eighteen 12-14 month-old male Sprague-Dawley rats, weighing 400-450 g, were randomly divided into 3 groups ( n=6). The rat skin at the left side was exposed to D980-nm laser irradiation at a density of 20 J/cm ², a power of 8 W, a pulse width of 20 ms, and a pulse frequency of 40 Hz for 1 time (group A), 2 times of 5-minute interval (group B), and 3 times of 5-minute interval (group C) as a treatment course, for 4 treatment courses with an interval of 1 week; the other side of the skin was not treated as the control groups (groups A1, B1, and C1, respectively). After 8 weeks, the skin was harvested for HE staining and immunohistochemical staining to observe the structure changes of skin, to measure the dermal thickness, to count the number of fibroblasts, and detect the expressions of transforming growth factor β ₁ (TGF-β ₁) and basic fibroblast growth factor (bFGF).

Results

Compared with groups A1, B1, and C1, the skin structure was significantly improved in groups A, B, and C. After D980-nm laser irradiation, the number of fat cells decreased; local angiogenesis was observed; the total number of fibroblasts and fibers increased; the collagen fiber had large diameter, and arranged closely and regularly; the dermal thickness and the number of the fibroblasts increased; and the expressions of TGF-β ₁ and bFGF were significantly enhanced, showing significant differences ( P<0.05). With increased D980-nm laser irradiation times, the above indexes increased, showing significant differences between group C and groups A, B ( P<0.05).

Conclusion

D980-nm laser treatment has lipolytic and tender effect on the skin, and the frequency of the treatment is an important factor in skin renewal.