Recent advances in laser dermatology.
TL;DR: This article will look at five new concepts in laser physics and selective photothermolysis that will allow dermatologists to use them either primarily or in combination with more conventional methods.
Abstract: Lasers have revolutionized the practice of modern dermatology. Our understanding of laser physics and selective photothermolysis has expanded greatly over the last 20 years. In the last 2 years, we have looked beyond the traditional lasers and explored new concepts. This article will look at five of these new concepts. A strong understanding of these new techniques will allow dermatologists to use them either primarily or in combination with more conventional methods.
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TL;DR: Clinicians with limited exposure to lasers are given a basic understanding of the underlying science of laser technology so they can confidently make appropriate decisions as to the best device to use on a patient and purchase for a practice.
28 citations
TL;DR: Together, laser and robotic technology offered a more consistent, expedient, and precise tool for microsurgery, while neuroArm decreased intra- and intersurgeon variability.
Abstract: Despite the potential increase in precision and accuracy, laser technology is not widely used in neurological surgery. This in part relates to challenges associated with the early introduction of lasers into neurosurgery. Considerable advances in laser technology have occurred, which together with robotic technology could create an ideal platform for neurosurgical application. In this study, a 980-nm contact diode laser was integrated with neuroArm. Preclinical evaluation involved partial hepatectomy, bilateral nephrectomy, splenectomy, and bilateral submandibular gland excision in a Sprague-Dawley rat model (n = 50). Total surgical time, blood loss as weight of surgical gauze before and after the procedure, and the incidence of thermal, vascular, or lethal injury were recorded and converted to an overall performance score. Thermal damage was evaluated in the liver using tissue samples stained with hematoxylin and eosin. Clinical studies involved step-wise integration of the 980-nm laser system into four neurosurgical cases. Results demonstrate the successful integration of contact laser technology into microsurgery, with and without robotic assistance. In preclinical studies, the laser improved microsurgical performance and reduced thermal damage, while neuroArm decreased intra- and intersurgeon variability. Clinical studies demonstrate dutility in meningioma resection (n = 4). Together, laser and robotic technology offered a more consistent, expedient, and precise tool for microsurgery.
16 citations
Dissertation•
01 Jan 2010
TL;DR: This paper presents a meta-analysis of the phytochemical properties of the fruit extract of lemon balm, which has shown promise as a treatment for cancer-like symptoms in women.
Abstract: xvi, 251 leaves :ill (some col) ; 30 cm Includes bibliographical references University of Otago department: Physiotherapy
7 citations
Dissertation•
01 Jan 2012
TL;DR: New strategies to generate endogenous porphyrins from exogenously provided compounds for fluorescence photodetection (PD) and photodynamic therapy (PDT) and the discovery, characterization and preliminary exploitation of a PPIX generating mechanism from heme in E.coli are presented.
Abstract: The present thesis presents new strategies to generate endogenous porphyrins from exogenously provided compounds for fluorescence photodetection (PD) and photodynamic therapy (PDT). One method is to administer the heme precursor 5-aminolevulinic acid (5-ALA), which leads to the accumulation of fluorescent intermediates of the heme cycle, notably protoporphyrin IX (PPIX).The hexyl ester of 5-ALA (HAL) has gained marketing authorization for the detection of bladder cancer from the european, australian and american regulatory offices. However, its impact for other indications such as interstitial tumors is relatively small due limited systemic bioavailability. Aiming at reducing the systemic toxicity and improving the circulation half-life of the compound, the first part of the thesis focuses on the encapsulation of HAL into polymeric nanoparticles. The second part of the thesis relates to the discovery, characterization and preliminary exploitation of a PPIX generating mechanism from heme in E.coli.
6 citations
01 Jan 2013
TL;DR: In this paper, the wavelength and frequency of light are inversely related to one another and shorter wavelengths of light have higher frequencies and more energenic photons than longer wavelengths have lower frequencies and less energetic photons, and the number of wave crests that pass a given point in a second determines the frequency for each source of EMS energy.
Abstract: Light is a very complex system of radiant energy that is composed of waves and energy packets known as photons. It is arranged into the electromagnetic spectrum (EMS) according to the length of those waves. The distance between two successive troughs or crests of these waves, measured in meters, determines the wavelength. For the visible portion of the EMS, the wavelength determines the color of the laser light. The number of wave crests (or troughs) that pass a given point in a second determines the frequency for each source of EMS energy. The wavelength and frequency of light are inversely related to one another. Thus, shorter wavelengths of light have higher frequencies and more energenic photons than longer wavelengths of light which have lower frequencies and less energenic photons.
3 citations
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TL;DR: Hemodynamic, histological, and ultrastructural responses are discussed and a simple, predictive model is presented, showing selective damage to cutaneous microvessels and melanosomes within melanocytes after selectively absorbed optical radiation pulses.
Abstract: Suitably brief pulses of selectively absorbed optical radiation can cause selective damage to pigmented structures, cells, and organelles in vivo. Precise aiming is unnecessary in this unique form of radiation injury because inherent optical and thermal properties provide target selectivity. A simple, predictive model is presented. Selective damage to cutaneous microvessels and to melanosomes within melanocytes is shown after 577-nanometer (3 x 10(-7) second) and 351-nanometer (2 x 10(-8) second) pulses, respectively. Hemodynamic, histological, and ultrastructural responses are discussed.
3,017 citations
TL;DR: In the ongoing clinical trial of ALA-induced Pp IX photodynamic therapy, the response rate for basal cell carcinomas following a single treatment has been 90% complete response and 7.5% partial response for the first 80 lesions treated.
Abstract: 5-Aminolaevulinic acid (ALA) is a precursor of protoporphyrin IX (Pp IX) in the biosynthetic pathway for haem. Certain types of cells have a large capacity to synthesize Pp IX when exposed to an adequate concentration of exogenous ALA. Since the conversion of Pp IX into haem is relatively slow, such cells tend to accumulate photosensitizing concentrations of Pp IX. Pp IX photosensitization can be induced in cells of the epidermis and its appendages, but not in the dermis. Moreover, since ALA in aqueous solution passes readily through abnormal keratin, but not through normal keratin, the topical application of ALA in aqueous solution to actinic keratoses or superficial basal cell or squamous cell carcinomas induces Pp IX photosensitization that is restricted primarily to the abnormal epithelium. Subsequent exposure to photoactivating light selectively destroys such lesions. In our ongoing clinical trial of ALA-induced Pp IX photodynamic therapy, the response rate for basal cell carcinomas following a single treatment has been 90% complete response and 7.5% partial response for the first 80 lesions treated. The cosmetic results have been excellent, and patient acceptance has been very good.
1,546 citations
TL;DR: This work introduces and clinically examine a new concept of skin treatment called fractional photothermolysis (FP), achieved by applying an array of microscopic treatment zones (MTZ) of thermal injury to the skin.
Abstract: Background and Objectives: We introduce and clinically examine a new concept of skin treatment called fractional photothermolysis (FP), achieved by applying an array of microscopic treatment zones (MTZ) of thermal injury to the skin. Study Design/Materials and Methods: Two prototype devices emitting at 1.5 mm wavelength provided a pattern of micro-exposures with variable MTZ density. Effects of different MTZ densities were tested on the forearms of 15 subjects. Clinical effects and histology were assessed up to 3 months after exposure. Treatment of photoaged skin on the periorbital area in an additional 30 subjects receiving four treatments over a period of 2–3 weeks was also tested. Tissue shrinkage and clinical effects were assessed up to 3 months after treatment. Results: Pattern densities with spacing of 250 mm or more were well tolerated. Typical MTZ had a diameter of 100 mm and penetrated 300 mm into the skin. Reepithelialization was complete within 1 day. Clinical effects were assessed over a 3-month period. Histology at 3 months revealed enhanced undulating rete ridges and increased mucin deposition within the superficial dermis. Periorbital treatments were well tolerated with minimal erythema and edema. Linear shrinkage of 2.1% was measured 3 months after the last treatment. The wrinkle score improved 18% (P < 0.001) 3 months after the last treatment. Conclusions: FP is a new concept for skin restoration treatment. Safety and efficacy were demonstrated with a prototype device. Further clinical studies are necessary to refine the optimum parameters and to explore further dermatological applications. Lasers Surg. Med. 34:426– 438, 2004. 2004 Wiley-Liss, Inc.
1,369 citations
"Recent advances in laser dermatolog..." refers background in this paper
...Final collagen remodeling occurs 3 months after treatment (9,10)....
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TL;DR: Resurfacing of photoaged skin by means of a high-energy, microsecond-domain pulsed CO 2 laser with a specific clinical treatment protocol results in predictable improvement in perioral and periorbital wrinkling and photodamage with minimal risks.
Abstract: Background and Design: Public demand for procedures to rejuvenate photoaged skin have stimulated the use of high-energy short-pulsed carbon dioxide lasers as a precise and predictable treatment modality. The purpose of this study was to determine the degree of clinical improvement achieved in treating perioral and periorbital wrinkles with a high-energy, microseconddomain pulsed CO2laser. Photodamaged skin in the perioral (n=73) and periorbital (n=38) regions was treated with multiple passes of confluent single pulses of CO2laser energy (10 600 nm, 3-mm collimated beam, Results: All three classes (mild, moderate, and severe) of photoaging of the skin responded equally well, showing an average wrinkling score reduction of 2.25 for the periorbital region and 2.34 for the perioral region, the most superficial wrinkles and photodamage being eliminated and the more severe being markedly improved. An unexpected finding was tightening of loose and folded skin. Side effects included transient erythema and postinflammatory hyperpigmentation, and one instance of an isolated hypertrophic scar. Conclusions: Resurfacing of photoaged skin by means of a high-energy, microsecond-domain pulsed CO2laser with a specific clinical treatment protocol results in predictable improvement in perioral and periorbital wrinkling and photodamage with minimal risks. Heatinduced collagen shrinkage appears to contribute to these results by tightening loose skin and folds. (Arch Dermatol. 1996;132:395-402)
558 citations
TL;DR: There was clinical and statistically significant clearance of inflammatory acne by aminolevulinic acid plus red light, for at least 20 wk after multiple treatments and 10 wK after a single treatment, in an open-label prospective human study of acne vulgaris.
528 citations
"Recent advances in laser dermatolog..." refers background in this paper
...injected porphyrins) were initially used for the treatment of non-melanoma cutaneous neoplasms, topical photosensitizing agents are now preferred for their shortened phototoxic effects and the ability to use these agents to treat focal areas (15)....
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...acnes and/or a reduction of follicular obstruction by increased keratinocyte shedding and reduced hyperkeratosis (14,15)....
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...Rare postoperative complications include acneiform folliculitis and postinflammatory hyperpigmentation (15)....
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