New lasers and light sources - old and new risks?

A retrospective study of the efficacy of intense pulsed light delivered by the Lacrystim® for meibomian gland dysfunction therapy

Background

Meibomian gland dysfunction is the most common etiology of dry eye disease worldwide and intense pulsed light appears to be a promising treatment with encouraging results. Lacrystim® is a new IPL device (CE marking in 2019) and no studies have yet been published on it. We propose the first study on this device with an objective assessment of its efficacy and an extended follow-up over 6 months.

Methods

Patients presenting with a dry eye disease (DED) with stable mild to moderate MGD and having received Lacrystim® treatment between june 2019 and june 2020 were included. 3 IPL sessions were performed at D0, D15 and D45 with 4 shots per side at a fluence of 8 mJ/cm2. DED clinical evaluation was performed at D0, D15, D45, 3rd month and 6th month: Oxford scale and break up time, Schirmer test and Ocular Surface Disease Index (OSDI) questionnaire. Lacrydiag® imaging device carried out an objective examination of tear film: interferometry, meibography, tear meniscus height and non-invasive break up time (NIBUT). The primary endpoint was the evolution in NIBUT between the first visit D0 and 3rd month. Data collection was done retrospectively. Statistical analysis was done using a linear mixed-effects model and a non-parametric linear mixed-effects model (R software).

Results

Forthy five consecutive patients were included. NIBUT significantly increased between D0 and 3rd month: mean difference of 1.63 seconds, IC95% [0.51; 2.62], (p = 0.002) with a prolonged effect at 6th month. OSDI and OXFORD scores and interferometry were also significantly improved at 3rd month and 6th month. There was no significant change in BUT, Schirmer test and tear meniscus height. No adverse event was noted.

Conclusions

IPL delivered by Lacrystim® appears effective and safe to treat MGD although a randomized controlled trial is needed to validate its results.

Trial registration

This work was approved by a local ethics committee “Terre d’éthique” (institutional review board number: IRBN672019/CHUSTE) and registered on the clinicaltrial.gov website (NCT04147962, 01/11/2019).

Lipidomics Profiles Revealed Alterations in Patients With Meibomian Gland Dysfunction After Exposure to Intense Pulsed Light

So far, intense pulsed light (IPL) has been widely used in the treatment of meibomian gland dysfunction (MGD), but there was still a lack of research on its specific mechanism. Determining whether there was a correlation between liposome changes and remission of clinical signs in patients with MGD treated with IPL was of great significance in the clinical evaluation of efficacy in patients with MGD. Our study enrolled the 10 healthy subjects and 26 adult patients, who were diagnosed with MGD and had not received any alternative treatments for at least 3 months. Each patient received a series of three treatments at 3-week intervals. The meibum was collected before the first treatment (T0) and the third treatment (T2). The significant changes in ocular surface parameters before and after IPL treatment were analyzed. The results showed that IPL significantly improved the symptoms of MGD, including ocular surface disease index (OSDI), tear breakup time (TBUT), redness of conjunctival (CR), corneal fluorescein staining (CF), the meibomian gland expressibility (MGE), and meibum quality (all p < 0.05). Lipidomics analysis of the meibum characterized the changes in lipid profiles induced by IPL. A total of 323 lipid species compounds were identified in the spectrum. A total of 41 lipid species were significantly different in patients with MGD (T0) vs. healthy controls. Following IPL treatment (T2), 24 lipid species were significantly different compared with T0: TG (10 lipid species), LPC (6 lipid species), OAHFA (4 lipid species), Cer (2 lipid species), SM (1 lipid species), and PE (1 lipid specie). Among these lipids, 4 of the lipids was a high correlation with TBUT, 5 was TH, 6 was CR, and 11 was meibum quality. In a ward, IPL treatment can achieve the therapeutic effect by changing the alternations of tear film lipids in patients with MGD. The changes in lipid expression profiles are potential indexes to evaluate the therapeutic effectiveness of IPL treatment or other treatments on MGD.

Intended Human Exposure to Non-ionizing Radiation for Cosmetic Purposes

Cosmetic devices using non-ionizing radiation (NIR) are increasingly available for people who wish to modify their appearance for aesthetic purposes. There are a wide range of NIR modalities used for cosmetic procedures, including devices that use optical radiation (laser, intense pulsed light, and light-emitting diode), electromagnetic fields, and ultrasound. Common procedures involving the application of NIR include epilation, skin rejuvenation, body sculpting and contouring, treatment of vascular and skin lesions, tattoo removal, and scar reduction. The majority of research on the use of NIR cosmetic devices has focused on the efficacy of the treatment rather than adverse effects or complications. Studies that assessed safety consisted mostly of case reports and small case series. Common adverse effects on the skin reported include mild and transient pain, erythema, swelling, and changes in pigmentation. Less common, more severe side effects include burns, blisters, scarring, persisting erythema, altered pigmentation, and eye damage. Some of the latter may have resulted from treatment errors. Particular groups of people that may be at greater risk from optical radiation include people with dark skin, with high sun exposure, and taking photosensitizing medications or supplements. There is lack of evidence for the safety profile of cosmetic NIR procedures during pregnancy. Reports of injuries to workers administering treatments with cosmetic NIR devices are rare, but inadvertent damage to the eye from optical devices may occur. Randomized controlled trials are required to fully assess potential adverse effects from the use of NIR cosmetic devices. Regulation varies worldwide and some regions apply the same safety classification and guidance as for medical devices. In order to reduce harm associated with the use of cosmetic devices, ICNIRP considers it important that regulations that cover all types and frequencies of cosmetic NIR devices are adopted worldwide and that there is greater oversight regarding their use.

Laser Treatment of Accidental Tattoos: Experience at a Tertiary Referral Center

BACKGROUND

To date, information on laser treatment of accidental tattoos is limited.

OBJECTIVES

This study analyzes the efficacy and safety of quality-switched ruby, quality-switched Nd:YAG and picosecond lasers in the treatment of accidental hyperpigmentation in a larger patient cohort. To date, there is limited information on laser therapy of accidental hyperpigmentation.

METHODS

We conducted a retrospective systematic single-center analysis on 70 patients, which presented with accidental hyperpigmentation at the Dermatology Department of the University Hospital of Zurich between 2008 and 2017. Patients with accidental tattoos due to road injuries, explosives or other traumas and iatrogenic measures were included. We analyzed the data including laser parameters such as wavelength, energy density, spot size and intervals between the sessions. Also, the number of sessions performed and the overall success were registered.

RESULTS

We treated 38 patients by quality-switched nano- and/or picosecond laser therapy and completed the treatment in 28 cases within a mean number of 3-5 laser sessions. No complications occurred.

CONCLUSION

We demonstrate the validity and safety of quality-switched and picosecond lasers in the treatment of accidental hyperpigmentation. Using a combination of different wavelengths and pulse lengths on the same lesion and gradually increasing the fluence in the course of the laser treatment is recommendable to increase efficacy. We observed a tendency towards faster elimination of facial accidental tattoos and/or originating from road injuries compared to tattoos located on the extremities and those caused by explosions, piercings or iatrogenic measures or consisting of metal pigment particles.

In vivo reflectance confocal microscopy for evaluating common facial hyperpigmentation

BACKGROUND

In clinical settings, atypical facial hyperpigmentation such as nevus of Ota, acquired bilateral nevus of Ota-like macules (ABNOM), melasma, and café-au-lait spots are often missed and misdiagnosed. Summarizing in vivo reflectance confocal microscopy (RCM) features of the hyperpigmentation is helpful in the diagnosis of ambiguous lesions.

METHODS

We recruited 196 patients referred for unequivocal facial hyperpigmentation, including 55 patients with nevus of Ota, 45 patients with ABNOM, 62 patients with melasma, and 34 patients with café-au-lait spots. The RCM images were evaluated at the epidermis, the dermis-epidermis junction (DEJ), and the upper papillary dermis from both hyperpigmented patches and normal skin.

RESULTS

In the superficial and middle dermis, 41 of 55 patients (74.5%) with nevus of Ota were characterized by a cord-like or lumpy structure between the collagen fibers. And there was no melanin deposition detected in the dermis in 14 of 55 (25.5%) patients. In ABNOM, 37 of 45 (82.2%) patients were characterized by a cord-like or lumpy structure in the superficial dermis and 8 of 45 patients (17.8%) was no melanin deposition detected in the dermis. The epidermis was no difference between nevus of Ota, ABNOM, and the normal skin. Melasma was detected increased cobblestone pattern in the epidermis of all patients, branching architecture in 21 of 62 patients (33.9%), and focally aggregated round to triangular cells in the upper dermis of 18 of 62 patients (29.0%). In all patients with afé-au-lait spots, increased cobblestone pattern in the epidermis and regular and increased density of ringed pattern in the DEJ were visualized.

CONCLUSIONS

Our findings indicate that RCM may be useful in the auxiliary diagnosis of nevus of Ota, ABNOM, melasma, and café-au-lait spots.

Acne Treatment With Light Absorbing Gold Microparticles and Optical Pulses: An Open-Label European Multi-Centered Study in Moderate to Moderately Severe Acne Vulgaris Patients

BACKGROUND AND OBJECTIVE

Recently, a novel acne treatment based on selective photothermolysis of pilosebaceous units with follicular delivery of inert gold microparticles as an exogenous chromophore and diode laser pulses has been developed. To evaluate the efficacy and safety of a single monotherapy treatment regimen with gold microparticles and diode laser exposure in patients with moderate and moderately severe acne. Further, to evaluate the added benefit of a second treatment regimen combined with pharmaceutical acne treatment in patients with inadequate initial response.

MATERIALS AND METHODS

Patients with moderate and moderately severe facial acne were recruited in this open-label, pilot study. A single treatment regimen consisted of three weekly facial treatments with topically applied gold microparticles and diode laser pulses. Outcome measures were the proportion of patients with ≥40% improvement in number of acne lesions (weighted lesion count [WLC]) at 12 weeks (single treatment regimen, primary outcome measure), 24, and 36 weeks from baseline (two treatment regimens), safety, and patient satisfaction.

RESULTS

A total of 28 patients were enrolled in the study (18 males, 10 females, 19 patients with moderate acne severity, 9 with moderately severe, mean age: 19.8 years). Twenty-five patients underwent analysis for outcome measures. After a single monotherapy treatment regimen, 76% patients (19/25) achieved ≥40% reduction in WLC (mean WLC reduction: 63%; SD: 13%). Of the patients undergoing two treatment regimens (n = 9 patients), 56% experienced a reduction in acne lesion burden (WLC) ≥40% at 24 weeks and 89% 36 weeks post-baseline. Mean pain score was 4.0 (SD: 1.3), and transient erythema and perifollicular edema were commonly noted after treatment. Most patients (81%) were either "satisfied" or "very satisfied" with the treatment.

CONCLUSION

Acne therapy based on selective photothermolysis with gold microparticles shows promise and may be used in treatment of moderate to moderately severe acne. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

2018 update on dermatologic laser therapy: Part 1 - epilation, vascular lesions and pigments

Technical advances in recent years have led to new dermatologic laser systems, light sources, and treatment concepts. Commonly used wavelengths - generated today with LED-based devices - allow for the combination of various tissue effects and are associated with improved outcomes. Laser hair removal has become more efficient with the use of diode lasers that emit multiple wavelengths simultaneously. In the near future, novel LED-based lasers will also be introduced for the treatment of vascular lesions. Here, too, the combination of different wavelengths promises to be beneficial. Picosecond lasers have led to advances in the field of pigment removal (tattoos).