Three-Year Results of Facial Photoaging in Asian Patients After Alexandrite 755 nm Picosecond Laser With Diffractive Lens Array: A Split-Face, Single-Blinded, Randomized Controlled Comparison

Activated melanocytes and senescent collagen fibers predict laser-treated melasma outcomes: An optical biopsy-based prospective cohort study

BACKGROUND

Melasma Area and Severity Index (MASI) score only assesses the pigmentation rather than photoaging. Picosecond alexandrite laser (PAL) with diffractive lens array (DLA) can improve photoaging and has been approved for melasma treatment. Prediction for post-laser outcome is limited.

OBJECTIVE

To in vivo compare the photoaging milieu altered by a PAL with DLA in melasma lesions and adjacent perilesions, and to delineate the predictive factors for outcomes.

METHODS

An optical biopsy with cellular resolution full-field optical coherence tomography (CRFF-OCT) was set up to evaluate the dynamic changes. Quantification was performed with the computer-aided detection (CADe) system.

RESULTS

The mean MASI score decreased significantly (p<0.001) in 12 of 15 patients but increased in the other three. An optical biopsy of 74,340 images showed the numbers of activated melanocytes and melanophages were significantly reduced post laser, and the basement membrane (BM) was repaired in melasma lesions, while basal lightening was noted in perilesions. The pre-treatment presence of activated melanocytes was associated with a high regional MASI score (p=0.013), while the senescent collagen fibers and activated melanocyte patterns were associated with less MASI score improvement (p=0.005). Senescent collagen fibers (p=0.002) and baseline BM damage(p=0.001) were strongly correlated to post-treatment melanophages. The baseline MASI score was not associated with activated melanocyte status or treatment outcomes.

CONCLUSION

Optical biopsy using CRFF-OCT revealed that patterns of activated melanocytes and senescent collagen fibers can serve as predictive markers for post-laser treatment outcomes. The photoaging characteristics of melasma were improved through the reduction of activated melanocytes and the repair of the BM.

Comparison of Intense Pulsed Light With Nonablative Fractional Laser and Picosecond Alexandrite Laser With Diffractive Lens Array for Noninvasive Facial Rejuvenation

BACKGROUND

Both nonablative fractional (NAFL) laser combined with intense pulsed light (IPL) and picosecond alexandrite laser (PSAL) with diffractive lens array (DLA) have been documented for their efficacy in facial rejuvenation.

OBJECTIVE

To observe the safety and efficacy of PSAL-DLA and IPL-NAFL in the rejuvenation of Chinese individuals.

METHODS

Each subject (n = 18) received three treatments on half of their face, with 1-month interval between treatments. One side of the face was randomly treated with PSAL-DLA, and the other side with IPL-NAFL. Quantitative data of wrinkles, pores, brown spots, and red areas were calculated using the VISIA-CR imaging system 3 months after the final treatment. Secondary outcomes included a 10-point VAS for patient-rated pain sensation, incidence of post-inflammatory hyperpigmentation (PIH), erythema and edema, and overall satisfaction. Adverse events were recorded after each treatment and at each follow-up.

RESULTS

A total of 17 Chinese female patients aged 28.2 ± 4.3 years completed the study and the 3-month follow-up. The IPL-NAFL side showed a statistically significant improvement in pores compared to baseline (p < 0.05); the PSAL-DLA side showed a statistically significant improvement in brown spots compared to baseline (p < 0.01). Compared to PSAL-DLA, the improvement in enlarged pores was better for IPL-NAFL (81.8 ± 128.1 vs. 20.8 ± 132.4, p < 0.01). In terms of pain, IPL-NAFL was more painful than PSAL-DLA (6 ± 1 vs. 4 ± 1, p < 0.01), a longer recovery time for erythema and edema (5 ± 1 vs. 2 ± 1, p < 0.001), and a higher incidence of PIH (58.8% vs. 23.5%, p < 0.05). Patient satisfaction was higher for PSAL-DLA than for IPL-NAFL (3 ± 1 vs. 4 ± 0.5, p < 0.01).

CONCLUSION

Our study results indicated that both IPL-NAFL and PSAL-DLA could improve the photoaging, but within the same number of treatments, IPL-NAFL was slightly more effective for enlarged pores than PSAL-DLA, while PSAL-DLA was more effective for brown spots than IPL-NAFL. Patients were more satisfied with PSAL-DLA, with a shorter postoperative recovery period and a lower incidence of PIH.

Paired Treatment Using Radiofrequency Microneedling and 755-nm Picosecond Laser With Fractionated Lens Array for Facial Rejuvenation

BACKGROUND

Patients frequently complain about fine lines, wrinkles, dyschromia, and photoaging, for which lasers and energy-based devices can treat each of these. Pairing various devices in a single treatment session can be safe and effective, but different technologies, mechanisms, histologies, parameters, and techniques must be considered.

OBJECTIVE

To examine the utility of a paired treatment regimen using radiofrequency microneedling and 755-nm picosecond laser with fractionated lens array to improve the clinical appearance of facial wrinkles and photoaging.

MATERIALS AND METHODS

A prospective clinical study investigated this paired treatment regimen using 4 monthly sessions.

RESULTS

Twenty-five subjects were enrolled, while 18 subjects completed 3-month follow-up. The mean age was 54 years, and 92% were women. Fitzpatrick Skin Types I to IV were represented. Assessments compared baseline with the 3-month follow-up. Two of 3 blinded reviewers agreed in identifying pretreatment and post-treatment photographs for 94.4% of cases. For physician Global Aesthetic Improvement Scale, 100% of subjects had clinical improvement. Overall, 88.9% of subjects were considered to be satisfied with their treatment. No serious or unanticipated adverse events occurred.

CONCLUSION

Paired treatment using radiofrequency microneedling and 755-nm picosecond laser with fractionated lens array can safely and effectively improve facial wrinkles and photoaging.

Evaluation of 755-nm Picosecond Alexandrite Laser With a Focus Lens Array for the Treatment of Enlarged Facial Pores

OBJECTIVES

This study aims to evaluate the use of 755-nm picosecond alexandrite laser with a focus lens array to treat facial pores.

METHODS

Laser treatment was performed on 129 patients between January 2021 and October 2022. VISIA imaging system was used for photographic assessments, the total average number and pore index was calculated, the physicians' assessment score and patient satisfaction score were collected, and the incidence of disadvantage effects was also documented.

RESULTS

The mean patient age was 35.2±6.4 years (21-45 y). The total average number of facial pores was 1614.1±412.8, and the total average number decreased to 1262.6±356.2 three months after the last treatment. The pretreatment baseline of pore index was 26.1±4.5, while the pore index was 21.3±3.7 three months after the last treatment. The physicians' assessment score was 2.7 on the 0-to-4 scale, and patient satisfaction score was 3.5 on the 1-to-5 scale. There were no adverse events, such as hyperkeratosis, scarring, and hypo-or hyperpigmentation.

CONCLUSIONS

755-nm picosecond alexandrite laser with a focus lens array was safe and effective in the treatment of facial pores with relatively few unanticipated adverse events.

LEVEL OF EVIDENCE

Level IV-observational study without controls.

A novel chlorin e6 derivative-mediated photodynamic therapy STBF-PDT reverses photoaging via the TGF-β pathway

OBJECTIVE

Photoaging is characterized by wrinkles in the skin and the deterioration of the skin barrier function, mainly caused by long-term exposure to ultraviolet (UV) radiation. Photodynamic therapy (PDT) has been shown to treat photoaging. The novel photosensitizer ShengTaiBuFen(STBF) is a derived substance of Chlorin e6(Ce6) that can exert photodynamic effects directly. In this study, we investigated the availability and the mechanism of STBF-PDT in the treatment of photoaging.

METHODS

Fluorophotometer was used to determine therapeutic parameters for in vivo experiments. Camera photographs, dermoscopy, HE and Masson staining, skin pH, trans epidermal water loss (TEWL), epidermal water content, and sebum testing were used together to evaluate the results of the treatment. Dark toxicity and therapeutic parameters for in vitro experiments were determined by CCK8 analysis. Scratch assay was used to identify the cell migration of STBF-PDT on HaCaT cells. qPCR and Western blot were used to evaluate the TGF-β/Smad signaling pathway in human dermal fibroblast (HDF) cells.

RESULTS

We investigated the optimal STBF concentration and time of incubation in vivo and in vitro experiments. STBF-PDT improved the skin phenotype of photoaged mice. The skin of photoaged mice treated with 80 J/cm² STBF-PDT became smooth, while skin flakes were reduced. The epidermis of STBF-PDT-treated mice was thinner, and the cells were neatly arranged, with increased dermal collagen. In vitro, STBF-PDT promoted the migration of HaCaT cells below a light dose of 0.1 J/cm². HDF cells co-cultured with HaCaT cells treated with low-dose STBF-PDT showed activation of the TGF-β pathway.

CONCLUSION

As a novel photosensitizer, STBF-mediated low-dose PDT could reverse photoaging via the TGF-β pathway.

A Randomized, Prospective, Split-Face Pilot Study to Evaluate the Safety and Efficacy of 532-nm and 1,064-nm Picosecond-Domain Neodymium:Yttrium-Aluminum-Garnet Lasers Using a Diffractive Optical Element for Non-Ablative Skin Rejuvenation: Clinical and Histological Evaluation

BACKGROUND

The advent of fractionated picosecond (ps) lasers has provided an opportunity to explore new ways of creating microinjuries in the skin to induce skin rejuvenation.

OBJECTIVE

To compare the efficacy and safety of diffractive optical element (DOE)-assisted ps neodymium: yttrium-aluminum-garnet (Nd:YAG) lasers with 532-nm and 1,064-nm wavelengths (532-nm and 1,064-nm Nd:YAG P-DOE) using a novel fractional handpiece for the treatment of photoaged skin.

METHODS

An ex vivo guinea pig skin experiment was performed by evaluating the histology of the skin after 532-nm Nd:YAG P-DOE irradiation. A randomized, prospective, split-face study was performed on eight subjects with 532-nm and 1,064-nm Nd:YAG P-DOE.

RESULTS

Based on the histological evaluation using ex vivo guinea pig skin, a reasonable safety profile and the potential to generate effective skin rejuvenation was observed using the 532-nm Nd:YAG P-DOE. Results demonstrated that both 532- and 1,064-nm Nd:YAG P-DOE were similarly effective in improving skin texture and skin pores; however, 532-nm Nd:YAG P-DOE was more effective in treating dyspigmentation.

CONCLUSION

At a preliminary level, this study revealed that 532-nm and 1,064-nm ps Nd:YAG lasers using DOE fractional technology may improve photoaged skin. In conclusion, 532-nm Nd:YAG P-DOE may be especially beneficial for skin with epidermal pigmentary lesions.

An update on fractional picosecond laser treatment: histology and clinical applications

Picosecond lasers have a very short pulse duration and a high peak power density. When fractional optical delivery systems are attached to picosecond lasers, they generate an array of concentrated microspots with a high fluence surrounded by areas with a low fluence. This article discusses the histologic characteristics and clinical applications of fractional picosecond laser treatment. Fractional picosecond laser produces laser-induced optical breakdown (LIOB) and laser-induced cavitation (LIC) in the epidermis and dermis respectively, and can encourage skin regeneration and dermal remodeling. It has been shown that fractional picosecond laser has a positive effect on facial photoaging, enlarged facial pores, dyspigmentation, wrinkles, and atrophic scars. Further research is still needed to confirm the benefits of fractional picosecond lasers.

Efficacy and safety of 755-nm picosecond alexandrite laser with topical tranexamic acid versus laser monotherapy for melasma and facial rejuvenation: a multicenter, randomized, double-blinded, split-face study in Chinese patients

To compare the efficacy and safety of 755-nm picosecond alexandrite laser and topical tranexamic acid (TTA) combination therapy with laser monotherapy, for the treatment of melasma and facial rejuvenation. This multicenter, randomized, double-blinded, split-face study enrolled 37 patients who presented with melasma and photoaging. Facial halves were randomized to receive either laser and TTA combination therapy or laser monotherapy. Three treatments were delivered at 4-5 weeks intervals. Patients were followed up for 1, 3, and 6 months post-final treatment and evaluated by blinded investigators for hemi-Melasma Area and Severity Index (hemi-MASI), facial dyschromia, skin texture, laxity, and rhytids. Daily diaries rating healing progress for 7 days posttreatment and satisfaction grading were performed by all patients. Adverse events were recorded. Thirty-six patients completed the follow-up. Compared with the baseline, hemi-MASI, dyschromia, and skin texture on both halves improved significantly through the follow-up (p = 0.000). A significant difference in hemi-MASI and dyschromia between combination therapy halves and monotherapy halves was noticed at 1- and 3-month follow-ups (p < 0.05). The laser monotherapy halves displayed significantly less redness and sensitivity during the 7-day posttreatment recovery period (p < 0.05). Patients' satisfaction ratings for the combination therapy halves were higher than the monotherapy halves at 1-month follow-up (p < 0.05). No severe adverse events were observed. The picosecond alexandrite laser and TTA combination therapy demonstrated synergistic efficacy for hemi-MASI and dyschromia improvements over laser monotherapy. The optimization of the picosecond laser and TTA combination regimen needs further investigation.

Cavity-dumped mode-locked Alexandrite laser oscillator with 100 mJ pulses stabilized by using a double trigger system

We report a mode-locked Alexandrite single pulse laser with cavity dumping. Mode locking was achieved by using an AOM and an EOM was used for Q-switching and cavity dumping. The instability of the single pulse laser energy output was reduced down to a tenth of that of the conventional single trigger system by introducing a novel double trigger system. The single pulse laser energy and pulse width were 100 mJ and 475 ps in multiple mode and 12.5 mJ and 275 ps in single mode, obtained without a laser amplifier.