A newly modified 595-nm pulsed dye laser with compression handpiece for the treatment of photodamaged skin

A novel treatment for Riehl's melanosis targeting both dermal melanin and vessels

BACKGROUND/PURPOSE

Riehl's melanosis is a difficult-to-treat condition characterized by persisting dermal hyperpigmentation. This study aimed to evaluate the efficacy of a histology-specific targeted therapy for Riehl's melanosis.

METHODS

Skin biopsy samples of Riehl's melanosis were assessed to identify histology-specific targets for treatment. Subsequently, the efficacy of a combination involving a fractional picosecond laser and a pulsed dye laser (PDL) targeting the dermal melanin and vessels, respectively, was evaluated. Clinical improvement was assessed using the dermal pigmentation area and severity index (DPASI). The treatment outcomes were compared to those of a control, in this case a single laser treatment solely targeting pigmentation.

RESULTS

Histological and immunohistochemical analyses identified dermal melanin pigment and dilated vessels as treatment targets for Riehl's melanosis. The combined treatment of the fractional picosecond laser and PDL showed a significant reduction of the DPASI scores, which was significantly better than the control group. Patients who underwent the combined laser treatment indicated high levels of satisfaction with no adverse events except of transient erythema and oedema.

CONCLUSION

The combined treatment of a fractional picosecond laser and a PDL was more effective for Riehl's melanosis compared to single laser treatment. The treatment targets both dermal pigmentation and dilated vessels, offering promising results for those working to manage Riehl's melanosis.

Pr3+-doped CeF3 crystals: Analysis of optical traits and fluorescence from Pr3+: 1D2 level for visible and near-infrared lasers

In this work, four Pr³⁺ -doped CeF₃ crystals with 0.2, 0.4, 0.6, and 0.8 at.% Pr³⁺ ion doping levels nominally in the melt have been successfully grown, and their absorption and emission spectra, including fluorescence decay times were analyzed. Especially, yellow and near-infrared (NIR) emissions originating from Pr³⁺: ¹D₂ level were explored in detail. In comparison, 0.2 at.% Pr³⁺-doped sample showed better spectral parameters in all studied crystals. In such a crystal, at 443 nm wavelength, the derived absorption cross-section (σ_abs) is 0.88 × 10^-20 cm² with full width at half maximum (FWHM) ∼ 10 nm in π polarization direction, whereas σ_abs is 1.32 × 10^-20 cm² with FWHM ∼ 6.7 nm in σ polarization direction at the same wavelength. Likewise, the calculated emission cross-section (σ_em) for 594 nm wavelength is 0.69 × 10^-20 cm² in π direction and 0.46 × 10^-20 cm² in σ direction. Also, acquired σ_em at 790, 755, 1014, and 1432 nm wavelengths is 6.15 × 10^-21 cm², 7.33 × 10^-21 cm², 7.66 × 10^-21 cm², and 6.56 × 10^-21 cm² individually. Here evaluated fluorescence decay time of ¹D₂ level is ∼ 200.6 μs. Obtained higher σ_abs, larger σ_em, and higher luminescence decay rates of 0.2 at.% Pr: CeF₃ crystal specify its potential as a gain medium for orange and NIR lasers.

Long pulsed dye laser with a back-to-back double-pulse technique and compression for the treatment of epidermal pigmented lesions

BACKGROUND

In the recent past, long pulsed dye lasers (LPDL) have been investigated for the treatment of epidermal pigmented lesions (EPLs). Using a pigmented lesion compression headpiece, blood is pushed laterally out of the laser field focusing laser energy on melanin. Recent studies have demonstrated excellent responses using a single-pulse at the following settings: 9-12 J/cm² , 1.5 milliseconds, 7-10 mm spot size with compression. However, the majority of these studies report patients requiring up to four treatments for lesion resolution. Herein, we describe our experiences utilizing a back-to-back double-pulse technique to decrease the total number of treatments needed for EPL clearance.

METHODS

Thirty-six patients (27 females, 9 males; skin types I-IV) with benign facial EPLs were included. Each lesion received two back-to-back pulses (fluence of 9-12 J/cm² , 1.5 milliseconds duration, and 7 mm spot size). If needed, a second treatment was delivered 4-8 weeks later. Pre- and post-photos after the first treatment were evaluated by two independent board-certified dermatologists.

RESULTS

Lesion clearance after the first treatment was graded on a Likert scale as: 1 = poor (<25% clearance); 2 = fair (25-50%); 3 = good (51-75%); and 4 = excellent (>75%). Of the 36 participants, 23 had excellent clearing, 10 with good, 2 with fair and 1 with poor clearance. There was only one case of post-inflammatory hyperpigmentation that subsequently resolved, and no cases or scarring or hypopigmentation.

CONCLUSION

LPDL with compression continues to be a safe and effective modality for treatment of EPLs. Double-pulsing decreases the total number of treatments needed for lesion resolution, while maintaining safety and potentially decreasing cost. Lasers Surg. Med. 51:136-140, 2019. © 2018 Wiley Periodicals, Inc.

TRASER--Total Reflection Amplification of Spontaneous Emission of Radiation

Background and Objective

Light and lasers in medical therapy have made dramatic strides since their invention five decades ago. However, the manufacture of lasers can be complex and expensive which often makes treatments limited and costly. Further, no single laser will provide the correct parameters to treat all things. Hence, laser specialists often need multiple devices to practice their specialty. A new concept is described herein that has the potential to replace many lasers and light sources with a single ‘tunable’ device.

Study Design/Material and Methods

This device amplifies spontaneous emission of radiation by capturing and retaining photons through total internal reflection, hence the acronym Total Reflection Amplification of Spontaneous Emission of Radiation, or TRASER.

Results

Specific peaks of light can be produced in a reproducible manner with high peak powers of variable pulse durations, a large spot size, and high repetition rate.

Conclusion

Considering the characteristics and parameters of Traser technology, it is possible that this one device would likely be able to replace the pulsed dye laser and many other light based systems.

Efficacy and safety of long-pulse pulsed dye laser delivered with compression versus cryotherapy for treatment of solar lentigines

Background:

Although cryotherapy is still the first-line therapy for solar lentigines, because of the side effects such as post-inflammatory hyperpigmentation (PIH), especially in patients with darker skin types, pigment-specific lasers should be considered as a therapy for initial treatment.

Aim:

The aim of this study is to evaluate the efficacy and safety of cryotherapy compared with 595-nm pulsed dye laser (PDL) with cutaneous compression in the treatment of solar lentigines.

Materials and Methods:

Twenty-two patients (skin type II–IV) with facial or hand lentigines participated in this study. Lesions of one side of the face or each hand were randomly assigned and treated with either cryotherapy or PDL. Treatments were performed with radiant exposures of 10 J/cm² , 7-mm spot size and 1.5 ms pulse duration with no epidermal cooling. Photographs were taken before treatment and 1-month later. The response rate and side effects were compared.

Results:

PDL was more likely to produce substantial lightening of the solar lentigines than cryotherapy, especially in skin type III and IV (n = 8, n = 9; P < 0.05), but might be no difference in type II (n = 5; P > 0.05). PIH was seen only in cryotherapy group. PDL group had only minimal erythema. No purpura was observed.

Conclusion:

PDL with compression is superior to cryotherapy in the treatment of solar lentigines in darker skin types.

A pulsed dye laser with a 10-mm beam diameter and a pigmented lesion window for purpura-free photorejuvenation

BACKGROUND AND OBJECTIVES

In traditional pulsed dye lasers (PDLs), power limitations and pulse characteristics have compromised purpura-free procedures. This study evaluated a new PDL with a modified pulse structure and a 10-mm beam diameter for purpura-free photorejuvenation. A compression handpiece was used for targeting lentigines.

MATERIALS AND METHODS

Twenty patients with skin types I to III were treated three times at 3- to 4-week intervals. The first pass was delivered through a 10-mm compression handpiece to target pigment dyschromias using fluences between 6.5 and 8.0 J/cm(2) with a 1.5-ms pulse duration. A second pass was then performed with a 10-mm spot with fluences between 9.5 and 10 J/cm(2), a 20-ms pulse duration, and cryogen spray enabled. Improvement was evaluated by comparing pre- and posttreatment photographs and live subjects 1 month after the third treatment.

RESULTS

In the majority of patients, >90% reduction of fine telangiectasias (<0.6 mm) and dark lentigines was achieved. Pigmented dyschromias improved proportional to the degree of pigment at presentation. Avoidance of purpura with the compression handpiece was dependent on obtaining proper compression before laser emission. Mean textural improvement was 34%.

CONCLUSIONS

The new 595-nm PDL is highly effective for two-pass purpura-free improvement of telangiectases, pigment dyschromias, and texture.