Lasers In Dermatology Research Articles

The Role of the CO2 Laser and Fractional CO2 Laser in Dermatology.

Tremendous advances have been made in the medical application of the laser in the past few decades. Many diseases in the dermatological field are now indications for laser treatment that qualify for reimbursement by many national health insurance systems. Among laser types, the carbon dioxide (CO2) laser remains an important system for the dermatologist. The lasers used in photosurgery have wavelengths that differ according to their intended use and are of various types, but the CO2 laser is one of the most widely used lasers in the dermatology field. With its wavelength in the mid-infrared at 10,600 nm, CO2 laser energy is wellabsorbed in water. As skin contains a very high water percentage, this makes the CO2 laser ideal for precise, safe ablation with good hemostasis. In addition to its efficacy in ablating benign raised lesions, the CO2 laser has been reported to be effective in the field of esthetic dermatology in the revision of acne scars as well as in photorejuvenation. With the addition of fractionation of the beam of energy into myriad microbeams, the fractional CO2 laser has offered a bridge between the frankly full ablative indications and the nonablative skin rejuvenation systems of the 2000s in the rejuvenation of photoaged skin on and off the face. The CO2 laser remains an efficient, precise and safe system for the dermatologist. Technological advances in CO2 laser construction have meant smaller spot sizes and greater precision for laser surgery, and more flexibility in tip sizes and protocols for fractional CO2 laser treatment. The range of dermatological applications of the CO2 laser is expected to continue to increase in the future.

Fractional Q-Switched 1,064-nm laser for the treatment of photoaged-photodamaged skin

Introduction: The Q-switched 1064-nm laser is associated with rapid vaporization and thermal expansion stresses leading to skin mechanical damage and is typically used for correction of exogenous and endogenous deep pigmentation. Giving the common place of fractional, infrared-domain milliseconds non-ablative lasers in aesthetic dermatology, a novel non-ablative fractional Q-switched 1,064-nm laser was studied for photoaged skin concerns. Materials and methods: Ten healthy female subjects (Age range: 35–53 years, mean: 44.3) and skin types I–IV were diagnosed with mild-to-moderate facial photo-damage, hyper-pigmentation, telangiectasia, laxity, skin roughness, and actinic keratosis. Subjects were treated with a new non-ablative fractional Q-Switched 1,064-nm Nd: YAG laser (Harmony XL, Alma Lasers Ltd.). Treatments consisted of four sessions at 2–4 week intervals. Follow-up (FU) visits were 1 and 3 months following the final treatment. Results: Utilizing the Glogau scale, six Subjects were graded Type II (means wrinkles in motion), and four Subjects were graded Type III (means wrinkles at rest) at Baseline. At the FU2, 3-month post final treatment, 60% of the subjects were graded with at least a one-point improvement in the overall Glogau global assessment. Between baseline and FU2, Investigator assessments showed the following improvements: Hyperpigmentation 70%, Telangiectasias 80%, Laxity 80%, Tactile Roughness 60%, and actinic keratoses 60%. Pain assessment was reported between 0 and 2 in all treatments (scale 0–10). Of expected side effects, erythema was most common, occasionally being reported as high as a 2(scale 0–10). No unexpected adverse effects were reported. Conclusion: The non-ablative fractional Q-Switched 1,064-nm Nd: YAG laser is safe and effective in improving signs of mild-to-moderate photodamage skin irregularities with no downtime, no pain to only minimal pain, and without any adverse side effects.

LASERS and the LAW: what the dermatologist needs to know.

Dermatologic laser surgery is a continuously evolving field of medicine. According to the American Society for Dermatologic Surgery, over 100 million laser and light source cosmetic procedures were performed by its members in 2003. Procedures, which include hair removal, nonablative treatments, as well as removal of pigmented lesions, tattoos, and unwanted vascular lesions, have revolutionized this field. With an increasing number of physicians and nonphysicians performing these procedures and with the availability of increasingly powerful laser technologies, the potential for problems and their legal consequences continue to increase. This article will address the concept of negligence and the potential for a resultant medical malpractice lawsuit that may arise in such a setting. Inherent in this issue are the associated problems that arise when these procedures are performed by physician extenders. An understanding of the basic principals of a cause of action in medical malpractice will likely protect a physician from losing such a case in a court of law.

A continuously variable beam‐diameter, high‐fluence, Q‐switched Nd:YAG laser for tattoo removal: Comparison of the maximum beam diameter to a standard 4‐mm‐diameter treatment beam

Laser beam diameter affects the depth of laser penetration. Q-switched lasers tend to have smaller maximum spot sizes than other dermatologic lasers, making beam diameter a potentially more significant factor in treatment outcomes. To compare the clinical effect of using the maximum-size treatment beam available for each delivered fluence during laser tattoo removal to a standard 4-mm-diameter treatment beam. Thirteen tattoos were treated in 12 subjects using a Q-switched Nd:YAG laser equipped with a treatment beam diameter that was adjustable in 1 mm increments and a setting that would enable the maximally achievable diameter ("MAX-ON" setting) with any fluence. Tattoos were randomly bisected and treated on one side with the MAX-ON setting and on the contralateral side with a standard 4-mm-diameter spot ("MAX-OFF" setting). Photographs were taken 8 weeks following each treatment and each half-tattoo was evaluated for clearance on a 10-point scale by physicians blinded to the treatment conditions. Tattoo clearance was greater on the side treated with the MAX-ON setting in a statistically significant manner following the 1st through 4th treatments, with the MAX-OFF treatment site approaching the clearance of the MAX-ON treatment site after the 5th and 6th treatments. This high-energy, Q-switched Nd:YAG laser with a continuously variable spot-size safely and effectively removes tattoos, with greater removal when using a larger spot-size.

Deep subsurface cavities in skin utilizing mechanical optical clearing and femtosecond laser ablation

High precision subsurface ablation can be produced in transparent materials using femtosecond laser pulses and multiphoton absorption. Light scattering limits application of the same technique to most biological tissues. Previously, subsurface ablation was demonstrated at superficial depths (50-250 µm) in highly scattering tissues including murine skin and human sclera. We report application of mechanical optical clearing to produce deeper subsurface femtosecond ablation in rodent skin. Ability to target deeper structures in skin using subsurface ablation may allow novel clinical applications for dermatological laser surgery. Operation of a prototype tissue optical clearing device (TOCD) was verified with white light photography in ex vivo rodent skin. A focused femtosecond beam transmitted through the TOCD and was scanned across rodent skin to produce subsurface ablation at increasing focal depths. Histological sections with H&E staining of the laser irradiated rodent skin were examined for subsurface ablation features following laser irradiation. Subsurface cavities were observed as deep as 1.7 mm below the skin surface in histological tissue sections. Diameter of subsurface cavities varied from tens of microns to over 100 μm. Subsurface cavities produced by scanning the focused femtosecond beam were contiguous and formed a continuous cut. Mechanical disruption of the overlying tissues was not observed. Mechanical optical clearing can be applied directly to in situ rodent skin and produces an optical clearing effect. High precision subsurface ablation can be produced at positions substantially deeper than previously demonstrated. Future studies may be targeted in in vivo human skin to investigate potential clinical applications of subsurface femtosecond ablation using mechanical optical clearing.

Erratum to: Review of Lidocaine/Tetracaine Cream as a Topical Anesthetic for Dermatologic Laser Procedures.

The online version of the original article can be found under doi:10.1007/s40122-013-0010-2.

Monte Carlo simulation of cutaneous absorption and reflectance for clear, matt and dark biological tissue with varicosities: an investigation for dermatological laser

We are interested in modeling the interaction between light and biological tissue from the Monte Carlo method which is an approach used to solve modeling problems in different physical domains. Through the Monte Carlo approach we are going to try to interpret the spectral response absorption, reflectance, transmittance of normal human tissue under its three dominant tints in the visible range (350–700) nm. Then we will focus on the spectral response of the human tissue with varicosities in order to determinate the optimal conditions of operating the semiconductor laser for esthetic aim.

Review of lidocaine/tetracaine cream as a topical anesthetic for dermatologic laser procedures.

There are multiple different topical anesthetic options available to minimize the pain associated with cosmetic dermatologic procedures. These options, either alone or in combination, have diverse profiles for effectiveness, ease of use, application time, need for occlusion, and side effects. The lidocaine/tetracaine cream (Pliaglis®, Galderma Laboratories, Texas, USA), one of the newer combination options, offers effective pain alleviation that has been evaluated in numerous clinical trials. This combination anesthetic is associated with a very favorable profile because of its ease of use and mild side effects compared to other topical local anesthetics. An overview of available topical local anesthetics will be provided with an outline of clinical study characteristics and results regarding the use of lidocaine/tetracaine cream.

THE LAST AND FOND FAREWELL

THE LAST AND FOND FAREWELL

Current Laser Resurfacing Technologies: A Review that Delves Beneath the Surface

Numerous laser platforms exist that rejuvenate the skin by resurfacing its upper layers. In varying degrees, these lasers improve the appearance of lentigines and rhytides, eliminate photoaging, soften scarring due to acne and other causes, and treat dyspigmentation. Five major classes of dermatologic lasers are currently in common use: ablative and nonablative lasers in both fractionated and unfractionated forms as well as radiofrequency technologies. The gentler nonablative lasers allow for quicker healing, whereas harsher ablative lasers tend to be more effective. Fractionating either laser distributes the effect, increasing the number of treatments but minimizing downtime and complications. In this review article, the authors seek to inform surgeons about the current laser platforms available, clarify the differences between them, and thereby facilitate the identification of the most appropriate laser for their practice.

Application of photodynamic therapy combined with pre-illumination microneedling in the treatment of actinic keratosis in organ transplant recipients

British Journal of DermatologyVolume 167, Issue 5 p. 1193-1194 Correspondence Application of photodynamic therapy combined with pre-illumination microneedling in the treatment of actinic keratosis in organ transplant recipients P.L. Bencini, P.L. Bencini Institute of Surgery and Laser in Dermatology (ICLID), Via della Moscova 42, 20121 Milan, ItalySearch for more papers by this authorM.G. Galimberti, M.G. Galimberti Institute of Surgery and Laser in Dermatology (ICLID), Via della Moscova 42, 20121 Milan, ItalySearch for more papers by this authorG. Pellacani, G. Pellacani Dermatology Unit, University of Modena and Reggio Emilia, Reggio Emilia, Italy Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova – IRCCS, Reggio Emilia, Italy E-mail: info@laserforum.itSearch for more papers by this authorC. Longo, C. Longo Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova – IRCCS, Reggio Emilia, Italy E-mail: info@laserforum.itSearch for more papers by this author P.L. Bencini, P.L. Bencini Institute of Surgery and Laser in Dermatology (ICLID), Via della Moscova 42, 20121 Milan, ItalySearch for more papers by this authorM.G. Galimberti, M.G. Galimberti Institute of Surgery and Laser in Dermatology (ICLID), Via della Moscova 42, 20121 Milan, ItalySearch for more papers by this authorG. Pellacani, G. Pellacani Dermatology Unit, University of Modena and Reggio Emilia, Reggio Emilia, Italy Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova – IRCCS, Reggio Emilia, Italy E-mail: info@laserforum.itSearch for more papers by this authorC. Longo, C. Longo Dermatology and Skin Cancer Unit, Arcispedale Santa Maria Nuova – IRCCS, Reggio Emilia, Italy E-mail: info@laserforum.itSearch for more papers by this author First published: 12 May 2012 https://doi.org/10.1111/j.1365-2133.2012.11051.xCitations: 13 Funding sources: none. Conflicts of interest: none declared. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume167, Issue5November 2012Pages 1193-1194 RelatedInformation

Reply

To the Editor: We are pleased that Fitzpatrick et al found our commentary regarding the need for improvement in laser nomenclature interesting, and we appreciate their willingness to offer constructive suggestions. That being said, we disagree that the term “ablative” is unrelated to depth of injury or that it does not involve structurally breaching the epidermis, as we are unsure how the epidermis could be ablated without having an injury of greater than zero depth in the original untreated skin, or how the epidermis could be removed if its structure were not affected in any way. Fitzpatrick et al also put forth that ablation or the lack thereof has no association with erosions, serous weeping, bleeding or other wound healing events. While this may be true in a theoretical framework, cutaneous lasers are used on people, who do bleed, ooze, and heal. If it were not for the fact that nonablative and ablative lasers are different with association to wound management, the descriptors “nonablative” and “ablative” would be irrelevant to patient care and laser companies would not be so adamant about specifying the relevant degree of ablation in their promotional literature. With regard to the term “subsurfacing,” Fitzpatrick et al agree that this is an awkward term and, as awkwardness is to be avoided in issues of nomenclature, we are unsure as to why they are insistent in wanting to preserve it. Similarly, we are surprised that Fitzpatrick et al compare the term “partially ablative” to the impossibility of being “partially pregnant” after noting that they can see at least two different ways in which a partially ablative treatment could occur. Which is it? Are there two types of partial ablation or no partially ablative treatments or does ablation occur along a continuum? Fitzpatrick et al also state that our definition of the appropriate pixel size of a fractional laser covers only 99% of the observed instances. If this figure is accurate, as they assert, we feel we are to be commended for devising a definition that is almost always right and is far preferable to the confusion that currently prevails. We would rather stand with the 99% than the 1%. We certainly agree with Fitzpatrick et al that terminology should be standardized for communicating fractional resurfacing treatment density, or the proportion of the skin surface per unit area that is actively treated during one pass or session. Our original commentary was designed to highlight a few specific issues of laser nomenclature and, given space limitations, was not meant to be a comprehensive document. We are delighted that Fitzpatrick et al applaud us for highlighting the deficiencies in the nomenclature currently in use in cutaneous laser surgery. Regarding their suggestion that a committee address these problems in greater detail, as they know, such a committee has already been formed under the aegis of the American Society for Dermatologic Surgery. Several of them, and of us, now serve on this committee. As to why there is so much disagreement on the issues described above, we believe it may stem from a misguided view of the function of nomenclature in this context. Different cutaneous laser and energy devices are often not strictly comparable, and yet they have significant clinical effects that we need to predict to some extent to ensure patient safety and comfort. So uniform nomenclature, a common language, can facilitate practical communication in an efficient manner. However, endless argument over minute details is probably not constructive since no set of terms will work in every instance or please everyone. The goal is to develop a simple naming system that most can live with, that is easy to use, and that usually conveys necessary information with acceptable accuracy and precision. We believe the focus should be on achieving consensus on a reasonable set of improvements rather than aiming for an elusive perfection. Since dermatologists are collegial and cooperative, we should succeed in this and, in so doing, perform a service for our patients, other physicians, and even laser manufacturers. Nomenclature proposal on laser ablation and nonablationJournal of the American Academy of DermatologyVol. 67Issue 4PreviewTo the Editor: Although there is a need for improving definitions used in dermatologic laser surgery, we believe that the suggestions by Alam et al1 are inaccurate and in many instances further confuse laser surgery terminology. Full-Text PDF

The effect of cold-air anesthesia during fractionated carbon-dioxide laser treatment: Prospective study and review of the literature

Forced cold-air anesthesia has been reported to decrease the discomfort associated with various dermatologic laser therapies. We sought to evaluate the effect of cold-air anesthesia on patient comfort during ablative fractionated carbon-dioxide (CO(2)) laser treatment for photoaging. We conducted a prospective split-face study to evaluate the effect of cold-air anesthesia on patient comfort during ablative fractionated CO(2) laser treatment for photoaging. Both patients and physicians rated the perceived discomfort of the treatment on each half of the face on a pain scale of 0 to 10. In addition, patients were asked to evaluate the side effects of the procedure (erythema, edema, crusting, scaling) on each half of the face. At 6 months posttreatment, blinded physician photograph evaluation was performed of 5 clinical indicators of photoaging. For the side of the face treated with topical anesthesia alone, the mean patient-reported pain score was 7.47. On the side treated with cold-air anesthesia and topical anesthesia, the mean pain score was 4.27 (P < .01). For the side treated with topical anesthesia alone, the mean physician-reported pain score was 7.8, relative to the side treated with cold-air anesthesia and topical anesthesia, for which the mean physician-reported pain score was 3.73 (P < .01). Although significant differences were found in pain tolerance with fractionated CO(2) laser with the use and absence of forced-air cooling, additional large-scale studies are needed to confirm the device's use in patient tolerability and side-effect profile. The use of forced cold-air device in conjunction with topical anesthesia provides a well-accepted modality for patient comfort during ablative fractionated CO(2) resurfacing.

The future and prospects of lasers in dermatology

The field of pediatric dermatology has been rich in new developments. Part II of this continuing medical education article will focus on new therapeutic modalities for several entities encountered in pediatric dermatology. The treatment of atopic dermatitis, exciting advances in the use of propranolol and other beta-blockers for the use of infantile hemangiomas, the use of rapamycin for vascular anomalies, the use of biologics in children, the central nervous system risks of general anesthesia in young children, side effects in the use of isotretinoin, the treatment of tinea capitis, treatment of herpes simplex infections, and the use of technologies such as texting and social media in medicine will be discussed.

An experimental study on the spray and thermal characteristics of R134a two-phase flashing spray

Flashing spray of volatile liquids is a common phenomenon observed in many industrial applications such as fuel injection of engines, accidental release of flammable and toxic pressure-liquefied gases, failure of a vessel or pipe in the form of a small hole in chemical industry, and cryogenic spray cooling in laser dermatology, etc. In flashing spray, the volatile liquid is depressurized rapidly at the exit of a nozzle (or a hole in a vessel) and becomes superheated. Such superheated liquid (in the form of either a jet or droplets) will lead to explosive atomization with fine droplet and a short spray distance. This paper presents an experimental investigation to the spray and thermal characteristics of flashing spray using cryogen R134a. A photographic study of the spray is firstly conducted to visualize the spray formation and the dynamic characteristics of the spray. Afterwards, the spray characteristics are measured by the phase Doppler Particle Analyzer (PDPA). The distributions of the diameter reveals the dramatic dynamic variation of the liquid droplets due to explosive atomization of large droplets in the region near the exit of nozzle, while the self-similar velocity profiles are fitted by two empirical correlations to describe the non-dimensional axial and radial velocities, respectively. The temperature field within the spray is measured by a small thermocouple. The temperature measurements provide detailed quantitative information of both radial and axial temperature distributions of droplets within the spray. These experimental results provide deep understanding into the whole characteristics of two-phase flashing spray of volatile liquids.

Treatment of Macular Seborrheic Keratoses Using a Novel 1927-nm Fractional Thulium Fiber Laser

Macular seborrheic keratoses (SK) are common, benign growths. A novel fractionated 1927-nm thulium fiber laser was selected to investigate efficacy and safety in the clearance of macular SK in nonfacial areas at a private dermatologic laser center. Six subjects (average age 56.8 ± 9.5) with at least four 3-mm or larger macular SK on one extremity, neck, or chest were enrolled and provided informed consent. Subjects received three treatments at 3- to 4-week intervals. Subjects were treated at settings of 10 to 20 mJ with 30% to 55% surface area coverage and four to eight passes at each session. Investigators performed a global extremity SK count, an SK count within a 5- by 5-cm (25 cm(2)) square on transparency mapping, and lesion thickness grading. Side effects were assessed. Patients rated pain using a visual analog scale. At baseline, average global SK count was 43.2 ± 27.3. At 1-month follow-up, 20.7 ± 16.6 lesions remained. At 3- and 6-month follow-up, 17.7 ± 23.8 and 14.7 ± 18.6 lesions remained, respectively. A decrease in thickness and SK counts within the 5- by 5-cm square was also observed. Moderate erythema and mild edema were post-treatment responses. Nonablative fractional resurfacing using the 1927-nm thulium fiber laser is a safe and effective treatment modality to decrease nonfacial macular SK.

Guidelines on the safety of light‐based home‐use hair removal devices from the European Society for Laser Dermatology

In the past 5 years since their US introduction, there has been a rapid proliferation of light-based hair removal devices intended for home-use. In the last 2 years in Europe, sales already run into many tens of thousands of units with well-known multi-national companies entering the market. These guidelines provide a definition of light-based home-use technology, to inform healthcare professionals about home-use light-based technology and encourage manufacturers wishing to sell in Europe to adopt 'best practice'. The review presents the current status on standards and regulation issues and considers home-use safety issues, encompassing human, device and electrical safety, given risks to the eyes and skin from optical radiation both to the consumer and persons in the vicinity. Proposed technical measurement methodology is considered with focus on recognized critical parameters for the safe use of light-based hair removal technology including recording the technical performance and safety claims of a range of home-use hair removal devices. The literature review emphasizes potential adverse incidents and safety aspects of treating cosmetic conditions, such as unwanted hair growth. Although some regulations exist, they differ from region to region and there is a specific need for international common principles and guidelines relating to the manufacture, marketing and use of intense pulsed light and laser devices, including manufacturing standards for home-use products intended, amongst others, for cosmetic hair removal and photo-rejuvenation procedures. In these guidelines, the European Society for Laser Dermatology (ESLD) provides a professional view of what 'best practice' may imply for manufacturers and consumers alike.

Textbook of Laser and Light Dermatology in the Asian Skin

Textbook of Laser and Light Dermatology in the Asian Skin

激光手术中喷嘴尺寸对制冷剂闪蒸喷雾冷却表面传热特性的影响

激光手术中喷嘴尺寸对制冷剂闪蒸喷雾冷却表面传热特性的影响

Nevus of Ota in Dark Skin—An Uncommon but Treatable Entity

Nevus of Ota can be effectively and safely treated since the arrival of q-switched lasers in dermatology. However, available literature is scarce regarding the treatment of Nevus of Ota in skin types darker than IV. We report about four Fitzpatrick phototype V patients treated for Nevus of Ota with a q-switched Nd:YAG laser at 1,064 nm. Four patients with Fitzpatrick phototype V were treated for Nevus of Ota with a q-switched Nd:YAG laser at 1,064 nm in a private practice setting. Pulse diameter for the treatments was 2 mm and pulses were applied typically in a non-overlapping fashion. Treatment energies ranged from 4.1 to 9.5 J/cm(2) . All four patients of this case series showed significant cosmetic improvement. Improvement ratings, based upon pre- and post-treatment photographs rated by blinded investigators, were in between 6 and 10 with a mean of 8.5 on a 10-point scale. Side effects were mostly short termed and typical for this laser technique. No post-inflammatory hyperpigmentation was observed however one case of permanent drop-like hypopigmentation was encountered. A 1,064 nm q-switched Nd:YAG laser treatment could be an effective and reasonably safe treatment for patients with Nevus of Ota and Fitzpatrick skin type V. Patients should be counselled before treatment regarding the risk of permanent hypopigmentation.