Five parameters you must understand to master control of your laser/light-based devices

Nonablative Fractional Diode Laser Resurfacing (1440 nm and 1927 nm) for Photoaged Skin

BACKGROUND

Nonablative lasers treat photoaged skin and stimulate new collagen formation while sparing epidermal damage.

OBJECTIVE

To evaluate the effectiveness and safety of nonablative fractional diode combination laser skin resurfacing treatment (1440 and 1927 nm) in mild-to-moderate photoaged skin.

MATERIALS AND METHODS

The entire face was treated with both 1440-nm and 1927-nm wavelengths per treatment, with a total of 4 treatments spaced 1 month apart. Follow-up occurred at 1 and 3 months post-treatment. Outcomes were improvement in the appearance of ≥1 measure of photodamage (rhytides, skin texture, dyschromia/pigment, skin radiance, pore size, and overall appearance) at the 3-month (primary) and 1-month (secondary) follow-up visits. Safety was monitored throughout the study.

RESULTS

Participants ( N = 28; 89% female; mean age, 40 years) experienced significant mean improvement from baseline in all measures of photodamage with combination laser treatment at 1 and 3 months post-treatment (all p < .001). No serious adverse events occurred. Post-treatment erythema and edema were minimal, and pain levels remained consistent throughout treatment. Most participants (96.4%) considered their overall appearance as improved and expressed satisfaction with treatment outcomes.

CONCLUSION

Nonablative combination laser skin resurfacing treatment was well tolerated and significantly improved measures of photodamage in photoaged skin across diverse skin types.

Current trends and available evidence on low-level laser therapy for osteoradionecrosis: A scoping review

BACKGROUND

This scoping review explored current trends and available evidence in Low-Level Laser Therapy (LLLT) in the treatment and prevention of osteoradionecrosis.

METHODS

The search strategy was conducted in MEDLINE/PubMed, EMBASE, Web of Science, and grey literature on January 15, 2024, without language or time restrictions.

RESULTS

19 studies were included. The application of LLLT protocols was 58 % for therapeutic use, 21 % for preventive use, and 21 % for a combination of both. Regarding the use of antimicrobial photodynamic therapy (aPDT), 41 % of the studies employed this technique, which utilized methylene blue as the photosensitizer. For treatments associated with photobiomodulation, 57 % reported pharmacological treatment, 29 % surgical treatment, 11 % prescribed chlorhexidine mouthwashes, and 4 % other therapies. In vivo studies used diode lasers emitting low incident power densities in the near-infrared wavelength (67 %) at 780 to 904 nm. In comparison, case reports also used diode lasers emitting low incident power densities in the red and near-infrared wavelength (64 %) at 660 to 904 nm. The continuous emission mode was utilized in 83 % of in vivo studies and 17 % of the case reports. None of the studies included in this review reported all laser parameters.

CONCLUSIONS

In general, studies suggested that LLLT can be used for therapeutic and preventive applications in the management of osteoradionecrosis. However, clinical studies are case reports and the variability in laser parameters across the included studies poses challenges for establishing standardized treatment protocols. The lack of comprehensive data on laser parameters underscores the need for future research to focus on standardizing LLLT protocols and conducting well-designed, large-scale clinical trials. This approach will help to better evaluate the effectiveness of LLLT and potentially integrate it more reliably into clinical practice.

Use of a fractional 1570-nm diode laser scanner for nonablative face and neck rejuvenation

BACKGROUND

The use of non-ablative fractionated lasers for skin rejuvenation has been proven to be effective in improving skin texture, and has become popular due to minimal wounding, significantly shorter recovery times and decreased adverse effects.

OBJECTIVE

To retrospectively analyze improvement in skin texture in healthy women aged over 18 years with Fitzpatrick skin type II-IV.

METHODS

Participants received 3 facial and/or neck treatments with the 1570-nm fractional scanning diode laser at one-month intervals. Three months after the last treatment session two blinded evaluators assessed skin improvement using before and after photos. Pain and patient satisfaction were recorded.

RESULTS

Sixteen women with a mean age of 45.4 ± 4.1 years (range 35-50 years) and skin type II-IV were included in the analysis. All 16 participants received facial treatments and seven (43.8%) also received neck treatments. Three months follow-up evaluation showed that the majority of participants had at least a visible change in the treated areas. Mean pain score was low and decreased with each treatment session.

CONCLUSION

Skin treatment using fractional scanning 1570-nm diode laser improves skin laxity in women with skin types II-IV. Larger studies are warranted to further clarify the efficacy and safety of this modality.

Theoretical Model for In Vivo Induction of Chemotherapy Sensitization Using miRNA Packaged in Distinct Layered Liposomes

Resistance to chemotherapy is a problem of major social and economic importance, when looking at factors like the decrease in life expectancy, the associated therapeutic costs, and a significant number of cancers that resist current chemotherapy. The development of chemotherapeutics for all theoretically possible tumor variants is an approach that requires unreasonable resources. We propose a theoretical model that serves the purpose of overcoming resistance to chemotherapeutic agents used in cancer therapy. The model describes a gene delivery system based on liposomes, which are optically guided to the tumor's location. The main aim of the gene delivery system is inhibiting the activity of enzymes involved in drug metabolism, hence offering the opportunity to use inexpensive chemotherapeutics that are already on the market. This model will reduce the costs of chemotherapy and will assure a positive outcome for patients.

A Comprehensive Review on Finite Element Analysis of Laser Shock Peening

Laser shock peening (LSP) is a formidable cold working surface treatment that provides high-energy precision to enhance the mechanical properties of materials. This paper delves into the intricacies of the LSP process, offering insights into its methodology and the simulation thereof through the finite element method. This review critically examines various points, such as laser energy, overlapping of shots, effect of LSP on residual stress, effect of LSP on grain refinement, and algorithms for simulation extrapolated from finite element analyses conducted by researchers, shedding light on the nuanced considerations integral to this technique. As the significance of LSP continues to grow, the collective findings underscore its potential as a transformative technology for fortifying materials against mechanical stress and improving their overall performance and longevity. The discourse encapsulates the evolving landscape of the LSP, emphasizing the pivotal role played by finite element analysis in advancing our understanding and application of this innovative surface treatment.

Laser tattoo removal strategies: Part II: A review of the methods, techniques, and complications involved in tattoo removal

The rising global popularity of cosmetic and corrective tattoos has concurrently led to an increased demand for their removal. While in the past, methods like surgical excision, chemical destruction, and dermabrasion were employed, lasers have emerged as a reliable and effective tool for tattoo removal. Increasing technological options and combination treatment strategies have raised the importance of understanding the various approaches to laser tattoo removal along with their respective clinical impact. This CME aims to describe the multifaceted aspects of laser tattoo removal, including the method selection, application principles, and safety considerations. Furthermore, it addresses the factors considered when selecting the most suitable laser to achieve optimal treatment outcomes.

Use of a fractional 1570-nm diode laser scanner for non-ablative face and neck rejuvenation

BACKGROUND

The use of non-ablative fractionated lasers for skin rejuvenation has been proven to be effective in improving skin texture, and has become popular due to minimal wounding, significantly shorter recovery times and decreased adverse effects.

OBJECTIVE

To retrospectively analyze improvement in skin texture in healthy women aged over 18 years with Fitzpatrick skin types II-IV.

METHODS

Participants received three facial and/or neck treatments with the 1570-nm fractional scanning diode laser at 1-month intervals. Three months after the last treatment session two blinded evaluators assessed skin improvement using before and after photos. Pain and patient satisfaction were recorded.

RESULTS

Sixteen women with a mean age of 45.4 ± 4.1 years (range 35-50 years) and skin type II-IV were included in the analysis. All 16 participants received facial treatments and seven (43.8%) also received neck treatments. Three months follow-up evaluation showed that the majority of participants had a visible change in the treated areas. Mean pain score was low and decreased with each treatment session.

CONCLUSION

Skin treatment using fractional scanning 1570-nm diode laser improves skin laxity in women with skin types II-IV. Larger studies are warranted to further clarify the efficacy and safety of this modality.

Utility of devices for onychomycosis: a review

Onychomycosis is difficult to treat due to long treatment durations, poor efficacy rates of treatments, high relapse rates, and safety issues when using systemic antifungal agents. Device-based treatments are targeted to specific regions of the nail, have favorable safely profiles, and do not interfere with systemic agents. They may be an effective alternative therapy for onychomycosis especially with increasing reports of squalene epoxidase gene mutations and potential resistance to terbinafine therapy. In this review, we discuss four devices used as antifungal treatments and three devices used as penetration enhancers for topical agents. Lasers, photodynamic therapy, microwaves, and non-thermal plasma have the capacity to inactivate fungal pathogens demonstrated through in vivo studies. Efficacy rates for these devices, however, remain relatively low pointing toward the need to further optimize device or usage parameters. Ultrasound, nail drilling, and iontophoresis aid in improving the permeability of topical agents through the nail and have been investigated as adjunctive therapies. Due to the paucity in clinical data, their efficacy in treating onychomycosis has not yet been established. While the results of clinical studies point toward the potential utility of devices for onychomycosis, further large-scale randomized clinical trials following regulatory guidelines are required to confirm current results.

The effect of bone remodeling with photobiomodulation in dentistry: a review study

Photobiomodulation (PBM) has been emerging as a promising alternative therapy in dentistry. However, various parameters of PBM are used in different studies, and there is limited cumulative data on PBM for improving bone formation in clinical trials. The aim of this review was to evaluate the effectiveness of PBM in the process of bone remodeling in dentistry using randomized controlled trials. Initially, a total of 1,011 articles published from January 2008 to December 2021 were retrieved from five electronic databases (PubMed, Scopus, Cochrane Library, EMBASE, and CINAHL). After a two-step review, nine articles met the inclusion criteria. The parameter of PBM, group, treatment sessions, assessment times and outcomes of the included studies were reviewed. Eighty-nine percent of the studies revealed positive effects on bone formation between the laser group and the control group. Only one article reported that light-emitting diode did not significantly enhance osteogenesis. Additionally, the present study shows that Gallium aluminum arsenide of near infrared (NIR) laser with continuous mode is the most commonly used form of PBM. The biostimulatory effects are dependent on several parameters, with wavelength and dose being more important than others. Based on this review, it is suggested that the NIR range and an appropriate dose of PBM could be used to increase the efficiency of stimulating bone healing and remodeling. However, standardization of treatment protocols is needed to clarify therapeutic strategies in dentistry.

Developing Consensus-Based Guidelines for Case Reporting in Aesthetic Medicine: Enhancing Transparency and Standardization

Clinical case reporting plays a vital role in sharing detailed patient narratives, providing insights into rare conditions, innovative treatments, and unexpected outcomes. However, existing reporting guidelines in aesthetic medicine fail to capture the specific nuances of procedures and outcomes in this field. The authors' objectives were to develop comprehensive guidelines for Case REporting in Aesthetic Medicine (CREAM). The study employed a 3-phase consensus process, including a literature review, expert interviews, and a consensus meeting. A diverse group of 10 expert participants (plastic surgeons, dermatologists, noncore specialists, evidence-based medicine expert, and research scientist) in Phase I and 30 experienced aesthetic practitioners in Phase II contributed to the research. Statistical analysis was conducted to assess agreement levels among participants and explore associations and variations within the data. The participants represented various specialties, genders, LGBTQ+ identities, and ethnic backgrounds. The research resulted in the development of the CREAM guidelines, consisting of a 16-item checklist. The guidelines covered essential aspects of case reporting, such as patient and practice information, procedure details, clinical assessment and outcomes, adverse events, and ethical considerations. Statistical analysis indicated a high level of consensus among participants, as well as significant associations between checklist items. CREAM guidelines represent a step toward enhancing transparency and standardization in case reporting in aesthetic medicine. Adhering to these guidelines will allow authors to contribute to a robust evidence base, prioritize patient safety, and drive advancements aesthetic medicine.

Near Infrared Illumination Optimization for Vein Detection: Hardware and Software Approaches

Venepuncture is one of the most crucial processes in many medical procedures. However, finding a real-time and vibrant visualization of the vein structures faces many difficulties. Several devices were introduced to solve this problem, yet, these devices shared common drawbacks, primarily when visualizing deep veins or veins in a thicker tissue of the human body. This study proposes a novel method for visualizing vein structures using a near-infrared (NIR) imaging technique enhanced with Hessian ridge detection. Several factors, including the wavelength of NIR light, square LED and ring LED arrangement and the effect of the diffuser and number of LEDs, were evaluated in the study. This study improves the overall quality of the acquired vein images and highlights the vein-morphological structure through image processing techniques. The study’s main aim is to achieve the highest number of visible veins. Based on the optical window, the maximum absorption range in the NIR spectrum was found from 700 to 950 nm. The NIR light absorption of human deoxygenated blood in the vein was highest at 850 nm peak of wavelength. The image processing further enhances the vein image by highlighting the extracted vein. The study also suggests that the square LED arrangements of NIR illumination are much more robust than the ring LED arrangement in ensuring excellent light penetration. The light diffuser further adds promising effects to the NIR illumination process. In terms of the square LED arrangement, increasing the square LED for enlarging the illumination area did not show any degradation effects in the visualization process. Overall, this paper presents an integrated hardware and software solution for the NIR image acquisition of a vein visualization system to cope with the image visualization of the vein for a thicker part of the human tissue, particularly on the arm and palm area.

Characterization of the Workspace and Limits of Operation of Laser Treatments for Vascular Lesions of the Lower Limbs

The increase of the aging population brings numerous challenges to health and aesthetic segments. Here, the use of laser therapy for dermatology is expected to increase since it allows for non-invasive and infection-free treatments. However, existing laser devices require doctors' manually handling and visually inspecting the skin. As such, the treatment outcome is dependent on the user's expertise, which frequently results in ineffective treatments and side effects. This study aims to determine the workspace and limits of operation of laser treatments for vascular lesions of the lower limbs. The results of this study can be used to develop a robotic-guided technology to help address the aforementioned problems. Specifically, workspace and limits of operation were studied in eight vascular laser treatments. For it, an electromagnetic tracking system was used to collect the real-time positioning of the laser during the treatments. The computed average workspace length, height, and width were 0.84 ± 0.15, 0.41 ± 0.06, and 0.78 ± 0.16 m, respectively. This corresponds to an average volume of treatment of 0.277 ± 0.093 m³. The average treatment time was 23.2 ± 10.2 min, with an average laser orientation of 40.6 ± 5.6 degrees. Additionally, the average velocities of 0.124 ± 0.103 m/s and 31.5 + 25.4 deg/s were measured. This knowledge characterizes the vascular laser treatment workspace and limits of operation, which may ease the understanding for future robotic system development.

A Unique Case of Facial Hypervascularity Responding to Pulsed-Dye Laser

Facial hypervascularity is a condition that manifests as erythema and edema caused by aberrant blood vessels. Often, the cause of these abnormal blood vessels can be attributed to previous trauma or vascular conditions such as rosacea, although sometimes the cause is unknown. Pulsed dye laser (PDL) can be an effective treatment even when the cause is unknown.

We present a case of a 24-year-old male presenting with intermittent swelling, redness, and throbbing sensations of the nose and cheeks for the past five years. Physical examination was notable for prominent erythema and swelling of the nasal skin and mild erythema on the cheeks. He underwent treatment with PDL and achieved complete resolution of his symptoms. This case illustrates the effectiveness of PDL in the treatment of facial hypervascularity.

Enhancing Skin Uptake of Topical Antioxidants With 1,440-nm Nonablative Fractional Diode Laser Pretreatment

BACKGROUND

Energy-based devices, such as nonablative lasers, are a promising method to enhance the delivery and absorption of topically applied molecules.

OBJECTIVE

To characterize ex vivo uptake of common antioxidant topicals after pretreatment with a nonablative laser wavelength.

MATERIALS AND METHODS

Using donor human skin tissue, uptake of 3 topical antioxidants was analyzed (C E Ferulic with 15% l-ascorbic acid [15% vitamin C serum], Phloretin CF with ferulic acid [10% vitamin C serum], and Phyto+ [botanical serum]; SkinCeuticals, Dallas, TX; 2010 formulations) after pretreatment with a 1,440-nm nonablative fractional diode laser.

RESULTS

Pretreatment with the 1,440-nm laser enhanced uptake of 15% and 10% vitamin C serums by approximately 10 and 21 times, respectively, compared to controls. Laser pretreatment also enhanced uptake of botanical serum by approximately 6 times relative to controls. Permeation of vitamin C and botanical serums was also enhanced through laser pretreatment.

CONCLUSION

Nonablative laser pretreatment increased uptake and permeation of topical antioxidants. Optimizing treatment requires consideration of the device and treatment parameters as well as the properties of the topical formulation.

Key Parameters of Non-ablative Fractional Laser Pretreatments for Enhanced Topical Uptake

BACKGROUND

The uptake of topical formulations can be enhanced through laser pretreatments. Newer technologies, such as non-ablative fractional lasers (NAFLs), can target dermal tissues and spare the stratum corneum (SC), which can mitigate common side effects associated with ablative laser treatment.

OBJECTIVE

To discuss parameters of 2 NAFL pretreatment systems (1440-nm/1927-nm diode system or 1550-nm erbium-doped glass/1927-nm thulium system), which can be paired with topicals to improve their cutaneous uptake.

METHODS & MATERIALS

The parameters of the 1440-nm/1927-nm diode system and 1550-nm erbium-doped glass/1927-nm thulium system were reviewed, as well as in-vivo experiments using both laser systems.

RESULTS

Multiple parameters should be optimized to enhance the uptake of various topical formulations and minimize side effects, including wavelength, spot size, density, pulse duration, thermal properties, and topical formulation. Chosen therapeutic parameters must account for patient-specific factors, such as treatment indication, therapeutic area, and Fitzpatrick skin type. In-vivo experiments have demonstrated that both laser systems are effective in enhancing the uptake of various topical therapies relative to untreated controls.

CONCLUSION

Individualization of laser system parameters increases efficiency and minimizes risk.

A randomized controlled trial evaluating the effect of two low-level laser irradiation protocols on the rate of canine retraction

The objective of this study was to evaluate the canine retraction rate with two low-level laser therapy (LLLT) irradiation protocols, involving both a high and a low application frequency. Twenty patients were randomly divided into two equal groups. In Group A, one side of the maxillary arch randomly received LLLT on days 0, 3, 7, 14, and every 2 weeks thereafter, whereas in Group B, one side received LLLT every 3 weeks. Tooth movement was checked every three weeks since the onset of canine retraction, over the 12-week study period. Moreover, Interleukin-1β (IL-1β) levels in the gingival crevicular fluid were assessed. Results revealed a significant increase in the canine retraction rate on the laser sides of groups A and B, in comparison with the control sides (p < 0.05), with no significant differences reported between the laser sides in both groups (p = 0.08–0.55). Also, IL-1β levels were significantly higher on the laser sides of both groups, in comparison with the control sides (p < 0.05). Therefore, LLLT can effectively accelerate tooth movement, with both frequent and less frequent applications, which is attributed to an enhanced biological response as reflected by the elevated IL-1β levels on the compression sides.

The influence of two photobiomodulation protocols on orthodontically induced inflammatory root resorption (a randomized controlled clinical trial)

Background

Controversial results have been reported regarding the impact of photobiomodulation (PBM) on orthodontically induced inflammatory root resorption (OIIRR). The aim of this study was to evaluate the influence of two PBM protocols, one of them requiring a high application frequency (on days 0, 3, 7, 14, then every 2 weeks), while the second requires less frequent applications (every 3 weeks), on OIIRR accompanying orthodontic treatment.

Methods

Twenty female patients were recruited for this randomized controlled trial, requiring the therapeutic extraction of maxillary first premolars, and they were randomly divided into 2 equal groups. In Group A, one side of the maxillary arch randomly received PBM on days 0, 3, 7, 14, and every 2 weeks thereafter, while in Group B, one side was randomly chosen to receive PBM every 3 weeks. The laser applied was a Diode laser with a wavelength of 980 nm, in a continuous mode. Canine retraction in both groups was carried out using closed-coil springs, delivering 150 g of force, and the force level was checked every 3 weeks, over a 12-week study period. Pre-retraction and post-retraction cone-beam computed tomography (CBCT) was done for the evaluation of OIIRR.

Results

No significant differences in the amount of OIIRR have been reported between the laser and control sides in both groups A and B. Also, no significant differences have been reported between the laser sides in both groups.

Conclusions

Photobiomodulation does not affect OIIRR, whether by increasing or decreasing its occurrence, with both laser application protocols. Therefore, it can be stated that PBM does not result in root resorption less than the commonly observed range elicited with conventional orthodontic treatment, and that it has no effect on OIIRR.

Trial registration Two Low-level Laser Irradiation Protocols on the Rate of Canine Retraction (NCT04926389), 15/06/2021—retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT04926389.

Quantifying Skin Uptake of Topicals After 1,927-nm and 1,440-nm Nonablative Fractional Diode Laser Treatment

BACKGROUND

Although the stratum corneum limits transdermal absorption of topicals, laser devices can enhance topical uptake by disrupting the skin barrier. Nonablative lasers are commonly used, but their effects on topical uptake should be quantified to optimize outcomes.

OBJECTIVE

The objective of this study is to analyze transdermal uptake of 4 topicals after nonablative fractional diode laser pretreatment.

METHODS AND MATERIALS

Human donor tissue was pretreated ex vivo with a nonablative fractional diode laser (1,927 nm or 1,440 nm, at varying treatment densities, powers, and peak energies) followed by application of either 2% salicylic acid, 10% ascorbic acid, over-the-counter mineral eye serum, or 4% hydroquinone. Topical uptake was quantified over 24 hours.

RESULTS

Despite lower power settings, pretreatment with the 1,927 nm wavelength was associated with greater uptake of 10% ascorbic acid, mineral eye serum, and 4% hydroquinone than the 1,440 nm wavelength. In addition, 1,440-nm laser pretreatment with higher density (320 microscopic treatment zones [MTZ]/cm2) and peak power (3 W) was associated with similar uptake but greater retention of 2% salicylic acid and greater uptake of 10% ascorbic acid than that with lower density (80 MTZ/cm2) and peak power (1.2 W).

CONCLUSION

When using laser pretreatment, device settings should be adjusted to balance outcomes with potential side effects.

Development of a numerical multi-layer model of skin subjected to pulsed laser irradiation to optimise thermal stimulation in photorejuvenation procedure

BACKGROUND AND OBJECTIVE

This paper presents the development of a 3D physics-based numerical model of skin capable of representing the laser-skin photo-thermal interactions occurring in skin photorejuvenation treatment procedures. The aim of this model was to provide a rational and quantitative basis to control and predict temperature distribution within the layered structure of skin. Ultimately, this mathematical and numerical modelling platform will guide the design of an automatic robotic controller to precisely regulate skin temperature at desired depths and for specific durations.

METHODS

The Pennes bioheat equation was used to account for heat transfer in a 3D multi-layer model of skin. The effects of blood perfusion, skin pigmentation and various convection conditions are also incorporated in the proposed model. The photo-thermal effect due to pulsed laser light on skin is computed using light diffusion theory. The physics-based constitutive model was numerically implemented using a combination of finite volume and finite difference techniques. Direct sensitivity routines were also implemented to assess the influence of constitutive parameters on temperature. A stability analysis of the numerical model was conducted.

RESULTS

Finally, the numerical model was exploited to assess its ability to predict temperature distribution and thermal damage via a multi-parametric study which accounted for a wide array of biophysical parameters such as light coefficients of absorption for individual skin layers and melanin levels (correlated with ethnicity). It was shown how critical is the link between melanin content, laser light characteristics and potential thermal damage to skin.

CONCLUSIONS

The developed photo-thermal model of skin-laser interactions paves the way for the design of an automated simulation-driven photorejuvenation robot, thus alleviating the need for inconsistent and error-prone human operators.

Treatment Effect and Pain During Treatment With Intense Pulsed-Light Therapy According to the Light Guide in Patients With Meibomian Gland Dysfunction

PURPOSE

We investigated whether there is a difference in the treatment effect and pain during the treatment of meibomian gland dysfunction (MGD) with intense pulsed-light (IPL) between new light guide and conventional light guide.

METHODS

We retrospectively reviewed medical records of 85 patients (170 eyes) who underwent IPL treatment of the upper and lower eyelids 3 times, at 3-week intervals, for MGD. Patients treated with the 6-mm or 8 × 15-mm cylindrical light guide were designated as group A or group B, respectively. The ocular surface disease index (OSDI), dry eye (DE), and MGD parameters were obtained before the first and after the third IPL treatments. Visual analog scale (VAS) scores were obtained at every IPL treatment. OSDI, DE, and MGD parameters and VAS scores were compared between the groups.

RESULTS

VAS scores at the first, second, and third IPL treatments were lower in group A than in group B. OSDI, DE, and MGD parameters were improved after 3 IPL treatments in both groups. There were no significant differences in OSDI, DE symptoms, and MGD parameters between before the first IPL treatment and after the third IPL treatment between the groups.

CONCLUSIONS

Using the new 6-mm cylindrical light guide for IPL treatment in patients with MGD induced less pain during treatment and had similar treatment effects to the conventional 8 × 15-mm light guide. The new 6-mm cylindrical light guide can be useful when treating patients with dark or hyperpigmented skin and for pediatric patients with low compliance.

The review of the light parameters and mechanisms of Photobiomodulation on melanoma cells

Photobiomodulation (PBM) uses low-intensity visible or near-infrared light to produce beneficial effects on cells or tissues, such as brain therapy, wound healing. Still there is no consistent recommendation on the parameters (dose, light mode, wavelength, irradiance) and protocols (repetition, treatment duration) for its clinical application. Herein, we summarize the current PBM parameters for the treatment of melanoma, and we also discuss the potential photoreceptors and downstream signaling mechanisms in the PBM treatment of melanoma cells. It is hypothesized that PBM may inhibit the melanoma cells by activating mitochondria, OPNs, and other receptors. Regardless of the underlying mechanisms, PBM has been shown to be beneficial in treating melanoma. Through further in-depth studies of the underlying potential mechanisms, it can strengthen the applications of PBM for the therapy of melanoma.

Laser and Light-Based Device Education in a Plastic Surgery Residency Program: A Continuing Medical Education Overview

The increasing prevalence of laser use, particularly in plastic surgery, demands education of both practitioners and trainees to ensure efficacy and patient safety. The purpose of this continuing medical education module is to provide the learner with a detailed outline for laser training education for plastic surgery trainees. In this overview, a discussion of the characteristics of light, an introduction to fundamental laser principles, a comparison of lasers and pulsed light systems, and examples of several therapeutic applications for light-based devices in the clinical setting will be presented. Additionally, the 5 parameters necessary for operation of light-based devices, as well as the importance of laser safety education, will be reviewed. We hope this continuing medical education will provide both practicing plastic surgeons and trainees with the proper education on the lasers and pulsed light devices they will use in their clinical practices.

Potential surgical therapies for drug-resistant focal epilepsy

Drug-resistant focal epilepsy (DRFE), defined by failure of two antiepileptic drugs, affects 30% of epileptic patients. Epilepsy surgeries are alternative options for this population. Preoperative evaluation is critical to include potential candidates, and to choose the most appropriate procedure to maximize efficacy and simultaneously minimize side effects. Traditional procedures involve open skull surgeries and epileptic focus resection. Alternatively, neuromodulation surgeries use peripheral nerve or deep brain stimulation to reduce the activities of epileptogenic focus. With the advanced improvement of laser-induced thermal therapy (LITT) technique and its utilization in neurosurgery, magnetic resonance-guided LITT (MRgLITT) emerges as a minimal invasive approach for drug-resistant focal epilepsy. In the present review, we first introduce drug-resistant focal epilepsy and summarize the indications, pros and cons of traditional surgical procedures and neuromodulation procedures. And then, focusing on MRgLITT, we thoroughly discuss its history, its technical details, its safety issues, and current evidence on its clinical applications. A case report on MRgLITT is also included to illustrate the preoperational evaluation. We believe that MRgLITT is a promising approach in selected patients with drug-resistant focal epilepsy, although large prospective studies are required to evaluate its efficacy and side effects, as well as to implement a standardized protocol for its application.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Laser Resurfacing for the Management of Periorbital Scarring

Laser (light amplification by the stimulated emission of radiation) skin resurfacing is currently one of the most widely adopted technologies in facial rejuvenation. While most often used for aesthetic purposes, lasers also have applications in the management of scars. Since the introduction of the CO₂ laser for skin rejuvenation in the 1990s, the last three decades have seen significant growth in the number of laser devices available to the physician. More recently, promising alternatives to light-based resurfacing technologies have emerged that include radiofrequency and intense focused ultrasound. To help the physician navigate the most current laser technologies as they apply to periocular scars, this review discusses the available treatment modalities, pre-treatment assessment of periorbital scars, treatment selection, and reported outcomes and complications. The recommendations described herein are based on published literature and the authors' experience in an academic oculoplastics practice.

Laser tattoo removal: Fundamental principles and practical approach

Tattoos have long become a part of human civilization. However, as the number of people who get tattoos increases, so is the number of people who wish to have their tattoos removed. Compared to other methods, laser-based devices are associated with the best efficacy and least side effects in tattoo removal. Lack of understanding of the fundamental principles of laser and managing its parameters may result in suboptimal result and increased risk of side effects. Recognizing and mastering multiple factors including skin types, nature and color of tattoos, and proper selection of laser parameters such as wavelength, fluence, and pulse, are central in achieving an optimal tattoo removal outcome. This review provides a comprehensive overview on the fundamental principle of laser and practical approaches in tattoo removal.

Laser Resurfacing at the Time of Rhytidectomy

BACKGROUND

Laser resurfacing with simultaneous rhytidectomy has been used to augment aesthetic results and decrease overall patient recuperative time, yet presents a potential dual insult to the microvasculature supply of facial skin flaps. This study describes the authors' experience with rhytidectomy and simultaneous laser resurfacing.

METHODS

Between May of 1999 and January of 2013, 85 face lifts with concomitant erbium laser resurfacing were reviewed retrospectively. Seven procedures were excluded for incomplete charting. Patient demographics, treatment zone, concomitant procedures, and secondary/tertiary face lifts were analyzed for associations with postoperative complications attributable to laser resurfacing.

RESULTS

No complications were reported in the perioral resurfacing group. There was one instance of delayed wound healing and prolonged erythema in the full face group, and one instance of moderate hyperpigmentation in the central face group. No instances of hypopigmentation or flap necrosis attributable to laser resurfacing were noted. The overall complication rate was 3.8 percent. There was a statistically significant difference when comparing the number of complications between the facial laser resurfacing zones (p = 0.037). When analyzing zone of laser resurfacing as an independent risk factor for complications, no significant association was derived, but full face zone resurfacing approached statistical significance (p = 0.063).

CONCLUSIONS

Although a significant difference in the number of complications between treatment groups existed, the authors were not able to definitively attribute this solely to the extent of laser resurfacing. Simultaneous laser resurfacing and rhytidectomy can be performed safely in select patients using ablative mode only over the undermined flap.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.