Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Lasers Surg Med ; 51(6): 481-490, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30681170

RESUMEN

OBJECTIVES: This review has the following objectives: Firstly, it provides an explanation of the evolution of laser/intense pulsed light (IPL) hair reduction modalities from high fluence professional devices to low fluence home-use appliances. Secondly, it summarises published literature reviews on home-use devices (HUDs) as evidence of their growing credibility. Thirdly, it proposes mechanistic differences in light delivery regimes and the resulting divergences in mode of action. MATERIALS AND METHODS: An extensive literature search was performed to review the progress of laser/IPL-induced hair reduction and determine what evidence is available to explain the mode of action of professional and HUDs for hair removal. Establishing the likely biological mode of action of professional high-fluence systems versus home-use low-fluence appliances was performed by combining data obtained using ex vivo hair follicle (HF) organ culture and the clinical results involving human participants. RESULTS: Significant basic science and clinical evidence has been published to confirm the clinical efficacy and technical safety of many laser and IPL home-use devices for hair removal. Clearly, HUDs are different compared to professional systems both in terms of fluence per pulse and in terms of biological mechanisms underlying hair removal. Here we presented data showing that a single low fluence pulse of both 810 nm laser (6.6 J/cm2 , 16 ms) and IPL (9 J/cm2 , 15 ms and 6.8 J/cm2 , 1.9 ms) leads to induction of catagen transition. Catagen transition was characterized by morphological changes similar to what occurs in vivo with occasional detection of apoptosis in the dermal papilla and outer root sheath cells. This suggests that high hair reduction can be expected in vivo and longer-term treatment might result in HF miniaturization due to a cumulative effect on the dermal papilla and outer root sheath cells. In line with this hypothesis, in this review we demonstrate that long-term application of a commercially-available home-use IPL appliance resulted in persistent hair reduction (80%) one year after last treatment. These data are in line with what was previously reported in the literature, where clinical studies with home-use IPL appliances demonstrated high efficacy of hair reduction on female legs, armpits and bikini zones, with full hair regrowth after four treatments following cessation of IPL administration. Limitations of HUDs include lack of hair clearance for very dark skin types and low speed of treatment compared with professional devices. Numerous uncontrolled and controlled clinical efficacy studies and technical safety investigations on consumer-use appliances support many of the leading manufacturers' claims. ANALYSIS & CONCLUSIONS: Manufacturers make consumer appliances safe and easy to use by considering "human factors," needs and capabilities of a variety of users. Safety is of primary concern to manufacturers, regulators and standards bodies as these appliances may be accessible to children or their use attempted on unsuitable skin types without full awareness of potential side effects. Consumer cosmetic appliances are provided with warnings and obvious safety notices describing the nature of any ocular or dermal hazard and precautions for reducing risk of accidental injury, infection, etc. HUDs employing optical energy are provided with design and engineering controls such as safety switches, alarms and sensors to prevent their incorrect operation or eye exposure. In-vivo studies demonstrated that low fluence home-use hair removal devices can result in high hair reduction efficacy after a short treatment regime, while prolonged and less frequent (once in six weeks) maintenance treatment over a year can lead to high and sustained hair reduction even one year after cessation of treatment. Home-use hair removal devices can be a useful adjunct to professional in-office treatments with high professional awareness. There are sufficient positive arguments for practitioners to make the case to patients for HUDs as "companion" products to professional treatments. In addition, devices for hair removal can be used effectively as stand-alone products by the consumer if they are willing to adopt a regime of regular or frequent use. Further clinical studies involving dynamic observation of HF cycle stage and type (terminal vs. vellus) over the total duration of treatment, for example, using biopsies or non-invasive imaging are necessary to confirm the proposed mode of action of low fluence pulses in a combination with treatment and maintenance regimes. Lasers Surg. Med. 51:481-490, 2019. © 2019 Wiley Periodicals, Inc.


Asunto(s)
Remoción del Cabello , Tratamiento de Luz Pulsada Intensa , Humanos
2.
Lasers Med Sci ; 32(8): 1927-1933, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28884244

RESUMEN

The development and use of light and lasers for medical and cosmetic procedures has increased exponentially over the past decade. This review article focuses on the incidence of reported cases of skin cancer post laser or IPL treatment. The existing evidence base of over 25 years of laser and IPL use to date has not raised any concerns regarding its long-term safety with only a few anecdotal cases of melanoma post treatment over two decades of use; therefore, there is no evidence to suggest that there is a credible cancer risk. Although laser and IPL technology has not been known to cause skin cancer, this does not mean that laser and IPL therapies are without long-term risks. Light therapies and lasers to treat existing lesions and CO2 laser resurfacing can be a preventative measure against BCC and SCC tumour formation by removing photo-damaged keratinocytes and encouraged re-epithelisation from stem cells located deeper in the epidermis. A review of the relevant literature has been performed to address the issue of long-term IPL safety, focussing on DNA damage, oxidative stress induction and the impact of adverse events.


Asunto(s)
Tratamiento de Luz Pulsada Intensa , Rayos Láser , Neoplasias Cutáneas/terapia , Epidermis/patología , Humanos , Especies Reactivas de Oxígeno/metabolismo , Factores de Riesgo , Neoplasias Cutáneas/patología
3.
J Cosmet Laser Ther ; 18(6): 355-62, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26983796

RESUMEN

INTRODUCTION AND OBJECTIVES: This qualitative review of paradoxical hair growth, following professional treatments reviews, clarifies whether low fluence is the most probable cause of unwanted hair regrowth after at home light-based treatments. MATERIALS AND METHODS: The proposed causes of unexpected hair regrowth are examined, and our scientific understanding of absorption and scattering of light in turbid tissue is reviewed. Published reports of paradoxical hair growth are assessed. RESULTS: Early laser hair removal studies failed to record the occurrence of hair induction despite the significant numbers of subjects treated. Neither published paradoxical hair growth studies following home-based laser or intense pulsed light (IPL) hair removal treatments, nor randomised or controlled studies documenting paradoxical hair growth following professional treatments could be found. Several authors directly proposed inflammatory response to be the primary cause of hair growth induction. CONCLUSIONS: It is unlikely that hair regrowth several centimetres or more away from the irradiated tissue can be attributed to the laser or IPL used. In many cases of paradoxical hair growth, other causes may be responsible for the unexpected hair growth. The primary cause of instances of 'true' paradoxical hair growth is probably limited to darker phototypes with one or more other characteristics including polycystic ovarian syndrome or other androgen hormonal irregularities following high energy treatments with the corresponding inflammatory sequelae.


Asunto(s)
Remoción del Cabello/métodos , Hipertricosis/etiología , Terapia por Luz de Baja Intensidad/efectos adversos , Femenino , Folículo Piloso/lesiones , Remoción del Cabello/efectos adversos , Humanos , Masculino , Medición de Riesgo , Factores de Riesgo
4.
J Cosmet Laser Ther ; 15(3): 133-42, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23445341

RESUMEN

BACKGROUND AND OBJECTIVE: This study considers end point tissue responses and side effects to determine whether 'square pulse' IPL is more or less effective than the traditional IPL. Supporting histological data and computational modelling results are provided. It provides guidance for IPL users unfamiliar with constant spectrum IPL devices and redirects attention to treatment end points. MATERIALS AND METHODS: Twenty subjects of Fitzpatrick Skin Types I-III, presenting with various epidermal pigmented lesions, were treated 1-3 times with two different IPLs. Coupling gel was used and firm pressure was applied to exclude blood from the treatment area. Immediate and post-treatment side effects, degree of discomfort and end results at fourteen and thirty days were evaluated by professional observation, digital photography and a patient questionnaire. RESULTS: Both IPLs showed a mean clearance of over 80% after 1-3 treatments but the free discharge IPL demonstrated a greater side effect profile with a higher incidence of ulceration, crusting and erythema. CONCLUSIONS: Clinical observation and mathematical modelling suggests that the square pulse, partial discharge IPL system may provide the IPL operator with greater control over the coagulation of pigment and is therefore the more efficient device for effective pigment lightening with fewer side effects.


Asunto(s)
Tratamiento de Luz Pulsada Intensa/métodos , Trastornos de la Pigmentación/terapia , Adolescente , Adulto , Anciano , Biopsia , Femenino , Humanos , Tratamiento de Luz Pulsada Intensa/efectos adversos , Masculino , Persona de Mediana Edad , Método de Montecarlo , Necrosis , Fotograbar , Encuestas y Cuestionarios , Resultado del Tratamiento
5.
J Biophotonics ; 16(2): e202200257, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36151769

RESUMEN

The efficacy of blue light therapy in dermatology relies on numerous clinical studies. The safety remains a topic of controversy, where potentially deleterious effects were derived from in vitro rather than in vivo experiments. The objectives of this work were (1) to highlight the nuances behind "colors" of blue light, light propagation in tissue and the plurality of modes of action; and (2) to rigorously analyze studies on humans reporting both clinical and histological data from skin biopsies with focus on DNA damage, proliferation, apoptosis, oxidative stress, impact on collagen, elastin, immune cells, and pigmentation. We conclude that blue light therapy is safe for human skin. It induces intriguing skin pigmentation, in part mediated by photoreceptor Opsin-3, which might have a photoprotective effect against ultraviolet irradiation. Future research needs to unravel photochemical reactions and the most effective and safe parameters of blue light in dermatology.


Asunto(s)
Luz , Fototerapia , Humanos , Piel/efectos de la radiación , Rayos Ultravioleta , Apoptosis
6.
J Appl Clin Med Phys ; 13(5): 3702, 2012 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-22955640

RESUMEN

The objective of this work is the investigation of intense pulsed light (IPL) photoepilation using Monte Carlo simulation to model the effect of the output dosimetry with millisecond exposure used by typical commercial IPL systems. The temporal pulse shape is an important parameter, which may affect the biological tissue response in terms of efficacy and adverse reactions. This study investigates the effect that IPL pulse structures, namely free discharge, square pulse, close, and spaced pulse stacking, has on hair removal. The relationship between radiant exposure distribution during the IPL pulse and chromophore heating is explored and modeled for hair follicles and the epidermis using a custom Monte Carlo computer simulation. Consistent square pulse and close pulse stacking delivery of radiant exposure across the IPL pulse is shown to generate the most efficient specific heating of the target chromophore, whilst sparing the epidermis, compared to free discharge and pulse stacking pulse delivery. Free discharge systems produced the highest epidermal temperature in the model. This study presents modeled thermal data of a hair follicle in situ, indicating that square pulse IPL technology may be the most efficient and the safest method for photoepilation. The investigation also suggests that the square pulse system design is the most efficient, as energy is not wasted during pulse exposure or lost through interpulse delay times of stacked pulses.


Asunto(s)
Folículo Piloso/efectos de la radiación , Remoción del Cabello , Luz , Modelos Teóricos , Piel/efectos de la radiación , Simulación por Computador , Humanos , Método de Montecarlo
7.
Lasers Med Sci ; 25(6): 773-80, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20625788

RESUMEN

The domestic market for home-use hair removal devices is rapidly expanding and there are numerous intense pulsed light (IPL) products now available globally to consumers. Technological challenges for the design of such devices include the need to be cost-effective in mass production, easy to use without training, and most importantly, clinically effective while being eye-safe. However inexpensively these light-based systems are produced, they are designed to cause biological damage to follicular structures, so precautions to prevent both ocular and epidermal damage must be considered. At present, there are no dedicated international standards for IPL devices. This review directly compares three leading domestic IPL hair removal devices: iPulse Personal (CyDen, UK), Silk'n/SensEpil (Home Skinovations, Israel), and SatinLux/Lumea (Philips, Netherlands) for fluence, emitted wavelength spectrum, time-resolved footprint, and spatial distribution of energy. Although each device has a primary mechanical or electrical safety feature to ensure occlusion of the output aperture on the skin to prevent accidental eye exposure, the ocular hazard of each device has been measured to IEC TR 60825-9 standard using an Ocean Optics HR2000+ photo spectrometer for both potential corneal and retinal damage. Using established measurement methods, this review has shown that the measured output parameters were significantly different for the three systems. Using equipment traceable to national standards, one device was judged at its two highest settings to be hazardous for naked eye viewing. This investigation also reports on the significantly different pulse durations of the devices measured and considers the potential impact on safety and efficacy in the light of the theory of selective photothermolysis. Although these devices offer low-cost personal convenience of treatment in the privacy of the home, ocular safety may be inadequate in the event of primary safety mechanism failure.


Asunto(s)
Remoción del Cabello/efectos adversos , Remoción del Cabello/instrumentación , Terapia por Láser/efectos adversos , Terapia por Láser/instrumentación , Seguridad de Equipos/normas , Lesiones Oculares/etiología , Lesiones Oculares/prevención & control , Remoción del Cabello/normas , Humanos , Terapia por Láser/normas , Dispositivos Ópticos/efectos adversos , Dispositivos Ópticos/normas , Autocuidado/efectos adversos , Autocuidado/instrumentación
8.
J Cosmet Laser Ther ; 11(2): 98-105, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19396717

RESUMEN

OBJECTIVE: To evaluate the reduction in unwanted body and facial hair at various body sites of Fitzpatrick skin types I-III and the efficacy, comfort and safety of this treatment intended for home-use by the general public. METHODS: In this non-randomized study, 29 individuals were given three sequential weekly treatments on a total of 31 body and facial areas including the axilla, bikini area, abdomen, neck, chin and upper lip using a novel intense pulsed light device. All participants completed a simple self-assessment questionnaire, as well as an evaluation of pain/discomfort. RESULTS: The mean reduction in terminal hair counts was 47% at 4 weeks' follow-up and 41% at 6 months' follow-up after completing three sequential weekly treatments. Overall, 84% of participants showed a significant percentage of hair reduction (p<0.01) at the 6-month follow-up, with a mean of 51% (range 25-86%). No treatment-related side effects were reported, with little or no discomfort reported during the treatment. Only mild erythema was noted immediately post-treatment. In total, 85% of the participants were either pleased or very pleased with the results 1 month after the third treatment. CONCLUSIONS: In simulated consumer use, this home-use IPL demonstrated a significant, quantifiable and sustainable reduction in unwanted body and facial hair with minimal side effects.


Asunto(s)
Remoción del Cabello/instrumentación , Remoción del Cabello/métodos , Luz , Adolescente , Adulto , Femenino , Remoción del Cabello/efectos adversos , Humanos , Luz/efectos adversos , Masculino , Persona de Mediana Edad , Dolor/etiología , Satisfacción del Paciente , Adulto Joven
9.
J Cosmet Laser Ther ; 11(3): 157-68, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19626523

RESUMEN

BACKGROUND: Laser and intense pulsed light (IPL) devices are used routinely by healthcare professionals for hair removal, but laser and light technology devices intended for home use have so far had little impact in the consumer market. However, as multinational companies enter this market, there will be an explosion in the use of such devices by the consumer. OBJECTIVES: This investigation focuses on the technical performance of the devices tested and although no clinical data are presented, the measured parameters are those that will directly impact efficacy in hair reduction, efficient coverage of skin, and safety in terms of unintentional eye exposure to the light source or incorrect settings for a given skin type. Consumers will consult healthcare professionals with experience of light-based therapies for guidance and this study provides useful reference information on available home-use devices. METHODS: Previously published standard test methods were used to evaluate the devices tested. RESULTS: Some of the devices measured in this study showed significant discrepancies between claims made by the manufacturers and the parameters measured. CONCLUSIONS: There is an urgent need for early ratification of the draft international IEC 60601-1 intense light standard, which will encompass manufacturing standards for both professional and home-use hair removal devices.


Asunto(s)
Remoción del Cabello/instrumentación , Terapia por Láser , Rayos Láser , Autocuidado , Ingeniería Biomédica , Seguridad de Productos para el Consumidor , Diseño de Equipo , Remoción del Cabello/economía , Humanos
10.
Lasers Surg Med ; 40(2): 83-92, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18306158

RESUMEN

BACKGROUND AND OBJECTIVES: High quality IPLs can offer simple, safe and effective treatments for long-term hair removal, removal of benign vascular and pigmented skin abnormalities, skin rejuvenation and acne treatments. Significant differences in clinical outcome have been recorded among different free-discharge and constant current IPLs despite identical settings. We investigated the differences in optical output of 19 IPLs in normal clinical use in the UK to evaluate spectral output, energy density values and pulse structure and propose a correlation between light-tissue interaction and spectral output as measured by time-resolved photo-spectrometry. STUDY DESIGN/MATERIALS AND METHODS: Using a fast spectrometer, generating 1,000 full spectral scans per second, time resolved spectral data of IPL outputs was captured with a resolution of 0.035 nm. IPL spectral outputs were calculated and graphically modelled using MathCAD software for comparison. RESULTS: Several IPLs, which professed matching of pulse durations to the thermal relaxation times of specific follicular or vascular targets were shown to have effective pulse durations that were vastly shorter than those claimed. Some IPLs claiming 'square pulse' characteristics failed to show constant spectral output across the duration of the pulse or sub-pulses. CONCLUSIONS: This study provides a suitable method to determine accurately key parameters of the emitted light pulses from IPLs and confirms the direct correlation between the electrical discharge current profile and the output energy profile. The differences measured between first generation free discharge systems and modern square pulse systems may have important clinical consequences in terms of different light-tissue interactions and hence clinical efficacy and safety. IPL manufacturers should provide time-resolved spectroscopy graphs to users.


Asunto(s)
Terapia por Láser/instrumentación , Fototerapia/instrumentación , Piel/efectos de la radiación , Transferencia de Energía , Análisis de Falla de Equipo , Seguridad de Equipos , Humanos , Espectrofotometría , Factores de Tiempo
11.
J Cosmet Laser Ther ; 9(3): 148-60, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17763023

RESUMEN

BACKGROUND: Unlike medical lasers, intense pulsed light (IPL) devices are largely unregulated and unclassified as to degree of safety hazard. With the exception of most of the USA, the United Kingdom and parts of Europe, the Far East and Australia, the sale of IPLs is generally unrestricted, with the majority being sold into the beauty therapy and spa markets. Standards are only imposed on manufacturers for technical performance data and operating tolerances determined by CE-compliance under electrical safety standards or the EU Medical Device Directive. Currently, there is no requirement for measurement of key IPL performance characteristics. OBJECTIVE: To identify the key IPL parameters, emphasize their importance in terms of safe and effective treatment and provide examples of preliminary measurement methods. These measurements can highlight changes in an IPL device's performance, improving patient safety and treatment efficacy. METHODS: Five key parameters were identified as having an important role to play in the way light interacts with the skin, and therefore an important role in patient safety and effective treatment. Simple methods were devised to measure the parameters, which include fluence, pulse duration, pulse profile, spectral output and time-resolved spectral output. RESULTS: The measurement methods permitted consistent and comparable measurements to be made by two of the authors at working clinic locations on 18 popular IPL devices and allowed assessment of output variations. Results showed discrepancies between the measured IPL device outputs and those values displayed on the system or claimed by the manufacturers. The importance of these discrepancies and their impact is discussed. CONCLUSIONS: This study, of 18 popular devices in regular daily use in England and Wales, provides example methods for measuring key IPL device parameters and highlights the need for regular measurement of at least those five key parameters measured in this study. These methods can help service technicians to check performance and eliminate device malfunction.


Asunto(s)
Técnicas Cosméticas/instrumentación , Fototerapia/instrumentación , Técnicas Cosméticas/efectos adversos , Técnicas Cosméticas/normas , Seguridad de Equipos , Humanos , Fototerapia/efectos adversos , Fototerapia/normas
12.
J Cosmet Laser Ther ; 4(2): 45-7, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12470518

RESUMEN

BACKGROUND: Surgical treatment of pilonidal sinus disease of the natal cleft has a significant failure rate. Reported here is the case of a 33-year-old man who first presented at the age of 18 with a pilonidal sinus. METHOD: The patient's scar was treated with a ruby laser using a pulse length of 2 ms and energy densities of 6.0-7.2 J/cm(2). Treatment was performed five times at 6-week intervals. RESULT: The sinus healed and has not recurred to date, 6 months after the last treatment. CONCLUSION: It is felt that there may be a future for this treatment, either as primary treatment or as an adjunct to surgery in refractive cases. It could also be useful in preventing the growth of hairs into wounds that have been left open and allowed to granulate.


Asunto(s)
Remoción del Cabello/métodos , Terapia por Láser/métodos , Seno Pilonidal/cirugía , Adulto , Humanos , Masculino , Recurrencia , Cicatrización de Heridas/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA