Application of reflectance confocal microscopy to investigate the non-ablative, micro-ablative, and ablative effects of CO2 fractional laser irradiation on skin

Study of different pre-treatments in the comparison of the efficacy of photodynamic therapy for moderate to severe acne vulgaris

OBJECTIVE

To evaluate the efficacy of CO2 fractional laser and microneedling pretreatment combined with ALA-PDT for moderate-to-severe acne, aiming to optimize clinical treatment.

METHODS

Patients were randomly divided into three groups: Group A (CO2 fractional laser + ALA-PDT), Group B (microneedling + ALA-PDT), and Group C (ALA-PDT). Each group underwent photodynamic therapy once a week for 3 weeks. Efficacy was assessed at the end of the 4th week, and recurrence was assessed at the end of the 12th week.

RESULTS

A total of 150 patients with moderate to severe acne were included in this study, with 50 patients in each group. Four weeks after the end of treatment, the effective rates were 88 % for Group A, 62 % for Group B, and 36 % for Group C. Statistically significant differences were found between the groups (P < 0.05), with Group A showing superior efficacy compared to Group B (P < 0.05). No serious systemic or local adverse reactions were observed in any group. No recurrence was seen in any group 12 weeks after the end of treatment, and some patients continued to show improvement in skin lesions over time.

CONCLUSION

Both the CO2 fractional laser group and the microneedling group improved the efficacy of photodynamic therapy for moderate to severe acne compared to the control group, with the CO2 fractional laser group demonstrating better efficacy and fewer adverse effects.

Laser-Induced Blood Coagulation for Surgical Application: A Scoping Review

There is a lack of evidence-based reviews on the effects of laser irradiation on blood coagulation in the literature, despite a large number of clinical trials. We therefore evaluated the available evidence on laser irradiation parameters used in coagulation of blood to optimize physical parameters. We performed a literature search for recent scientific studies indexed between 2017 and 2023 using the databases of PubMed and ScienceDirect. Articles were selected based on defined inclusion and exclusion criteria, and 78 publications in total were eventually included in this scoping review. The following were found to produce significant benefits in blood coagulation for surgical application: (1) dentistry and oral surgeries: 980 nm, 27 s, 2 W, 1502.7 W/cm2, 26.5 J, 622 J/cm2, 400 μm; (2) urogenital disorders: 532 nm, 4 s, 40 W, 10600 W/cm2, 1.3 J, 424 J/cm2, 600 μm; (3) ophthalmic disorders: 810 nm, 1 s, 1 W, 3540 W/cm2, 0.75 J, 1326 J/cm2, 100 μm; (4) embryological surgeries: 1064 nm, 10 s, 25 W, 35400 W/cm2, 262.5 J, 371000 J/cm2, 332.5 μm; (5) dermatological disorders: 1064 nm, 20 W, 2440 W/cm2, 0.1 J, 24 J/cm2, 670 μm; (6) gastrointestinal disorders: 532 nm, 3 s, 20 W, 1051 W/cm2, 120 J, 26500 J/cm2, 760 μm; (7) neurological surgeries: 2.5 s, 1.5 W, 1035 W/cm2, 2 J, 1584 J/cm2, 385 μm; (8) pulmonary disorders: 1320 nm, 5s, 35 W, 12450 W/cm2, 250 J, 65000 J/cm2, 700 μm (9) cardiovascular disorders: 1064 nm, 16.5 s, 5 W, 1980.5 W/cm2, 900 J, 760 J/cm2, 400 μm. In conclusion, our scoping review identifies that combining data from all clinically heterogeneous studies suggests that laser irradiation reflects an effective method for inducing blood coagulation in several medical fields.

Investigation of the efficiency and stability of a novel visualized lattice CO2 laser-based gynecological therapeutic apparatus for the treatment of cervical diseases in rhesus monkeys

The fractional CO₂ laser is a type of ablative laser. In this study, a novel fractional CO₂ laser therapeutic apparatus was developed for cervical diseases. To compare the depth and diameter of penetration as well as the stability of a novel laser against a control laser emitting at the same wavelength, we tested this using a rhesus monkey model. The cervixes of rhesus monkeys were irradiated with the novel CO₂ laser. The effects of irradiation were assessed by measuring the depths and diameters of the holes created by the laser. In addition, the depths and diameters of the holes were compared between the novel CO₂ laser-based gynecological therapeutic apparatus and the conventional CO₂ laser-based therapeutic apparatus. When operated under the single spot mode and at the same energy level, the novel CO₂ laser-based gynecological therapeutic apparatus created holes that could reach the greater depth. In addition, the laser spot size of the new apparatus was more constant. Moreover, there were no significant differences in the side effects between the new apparatus and the conventional apparatus. The results indicate that the novel CO₂ laser-based gynecological therapeutic apparatus exhibits better stability in comparison to the conventional CO₂ laser-based therapeutic apparatus.