Predictive factors of speech understanding in adults with cochlear implants.

OBJECTIVE: The aim of this study was to analyse the factors that influenced speech recognition scores in quiet conditions and speech reception threshold levels (SRT) in fixed noise conditions, after cochlear implant (CI) surgery in adults with postlinguistic deafness. STUDY DESIGN: Combined retrospective and prospective study in a tertiary referral centre. METHODS: We included 66 patients that received implants between 2002 and 2013. We retrospectively collected speech recognition scores and 14 demographic, audiological, and technical factors, including gender, age at implantation, aetiology, hearing loss progression, preoperative Pure Tone Average (PTA), hearing loss onset age and duration, duration and use of hearing aids (HAs); implantation in the best or worst ear; implantation on the right or left side; use of HA after implantation; and the duration and type of CI. We prospectively tested a subgroup of 21 patients for SRT in fixed noise. RESULTS: The hearing loss duration significantly affected speech recognition scores in quiet conditions (H (4) = 10.567, p =0.032) and SRTs in fixed noise conditions (rs = 0.466, p = 0.033). The PTA of the better ear significantly affected only the SRT in fixed noise conditions (rs = 0.57 1, p = 0.007). CONCLUSION: The duration of hearing loss and the PTA of the best ear had significant effects on the outcomes of speech recognition and SRT in quiet and fixed noise conditions, respectively. These findings are important for counselling CI candidates. Further studies in larger study populations are warranted.

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.

A systematic review of light-based home-use devices for hair removal and considerations on human safety.

BACKGROUND: Hair removal with professional light-based devices is established as an effective, mainstream treatment. The field of optical home-based hair removal is evolving and movement from control by physicians into hands of consumers warrants understanding efficacy and human safety. OBJECTIVES: To systematically review and evaluate the efficacy and human safety of currently available home-based optical hair removal devices. METHODS: A comprehensive Pub Med literature search was conducted which systematically identified publications of relevance. Prospective clinical trials were included whether controlled, uncontrolled or randomized and with a sample size of at least 10 individuals. RESULTS: We identified a total of seven studies: one controlled (CT) and six uncontrolled trials (UCTs). No randomized controlled trials (RCT) were recognized. The best evidence was found for IPL (intense pulsed light) (three devices, one CT, five UCTs) and limited evidence for laser devices (one diode laser, one UCT). Most studies evaluated short-term hair reduction up to 3 and 6 months following light exposure at different body sites. Hair reduction percentages ranged from 6% to 72% after repetitive treatments. The most frequently reported side-effect was erythema, but oedema, blistering, crusting and pigment changes were also reported. Theoretical concerns about ocular damage and paradoxical hair growth have not been reported in any of the studies reviewed. CONCLUSIONS: Available evidence from prospective, uncontrolled clinical trials indicates short-term hair removal efficacy of currently available home-use light-based hair removal devices. Additional controlled trials will be helpful to substantiate the efficacy and to better predict the incidence of adverse events associated with optical home-use hair removal.

Best practice options for hair removal in patients with unwanted facial hair using combination therapy with laser: guidelines drawn up by an expert working group.

Hirsutism is a common disorder affecting between 5 and 15% of the population. One of the most devastating consequences of hirsutism is the presence of unwanted facial hair. Treatment of hirsutism involves a two-pronged approach: treating the underlying cause and reduction of visible hair. Laser hair removal is one of the most effective options for reducing visible hair, however, it may not be wholly effective in all patients and combination therapy may need to be considered. Pharmacological therapy is often used in combination with mechanical hair removal due to the time needed for the drug treatment to demonstrate visible results. Clinical data investigating the use of laser treatment in combination with other treatments has focused on laser with topical eflornithine. The expert working group reviews existing data and provides guidance on the use of eflornithine in combination with laser for resistant hirsutism.

Hair removal with an 800-nm pulsed diode laser.

BACKGROUND AND OBJECTIVE: Laser hair removal is a relatively new procedure. Our purpose was to study the efficacy and safety of a high-power, pulsed diode laser array for removing unwanted hair. METHODS: A total of 38 subjects were treated with a prototype of the 800-nm diode laser system. Fluences ranging from 10 to 40 J/cm(2) (mean, 33.4 J/cm(2)) were used and 1 to 4 treatments (mean, 2.7) were performed. Evaluation of hair loss was performed at least 4 months after the last treatment (mean, 8.7 months) by a blinded assessment of clinical photographs. RESULTS: A total of 59% of the subjects had only sparse hair regrowth at the final follow-up. Higher fluences and multiple treatments produced greater long-term efficacy. Transient pigmentary changes occurred in 29% of the subjects and were more common in darker skin types IV to VI (P =. 047). CONCLUSION: The 800-nm diode laser is an efficient and safe technique for hair reduction. Adverse pigmentary effects occur, but are transient.

Reduction of regrowing hair shaft size and pigmentation after ruby and diode laser treatment.

Laser pulses which selectively damage pigmented hair follicles are a useful treatment for hypertrichosis. Clinically, regrowing hairs are often thinner and lighter after treatment. In this study, hair shaft diameter and optical transmission (700 nm) were measured before and after ruby (694 nm) and diode (800 nm) laser irradiation. Hair was collected from 47 and 41 subjects treated with ruby (0.3 ms and 3 ms) and diode (10-20 ms) lasers, respectively. "Responders" were defined as subjects with significant long-term hair loss as determined by hair counts at 9 and/or 12 months after treatment. In ruby laser responders (34/47), regrowing hairs were significantly both thinner (decreased diameter) and lighter (increased transmission). In "nonresponders" (13/47), regrowing hairs were lighter, but not thinner. The regrowing hair shaft absorption coefficient (as calculated assuming Beer's law) was significantly decreased by 0.3 ms ruby laser treatment, but was not changed by 3 ms ruby laser or diode laser treatment. After diode laser treatment, 38 of the 41 subjects were responders and regrowing hairs were both thinner and lighter. These results show that laser treatments can affect structural recovery (size of hair), follicular pigmentation (hair absorption coefficient), or both. Regrowth of thinner hair (decreased shaft diameter) occurs in conjunction with actual loss of hair. After long pulses (3 ms ruby; diode), regrowing hair was thinner and also lighter to an extent related to the decrease in hair diameter. In contrast, short ruby laser pulses (0.3 ms) appeared to be capable of inhibiting follicular pigmentation per se, in addition to affecting the hair diameter. This may account for the complete regrowth of lighter hair in "nonresponders" treated with 0.3 ms pulses. Laser-induced reduction in hair diameter and/or pigmentation are both long-term responses which confer cosmetic benefits in addition to actual hair loss.

Ruby laser hair removal: evaluation of long-term efficacy and side effects.

BACKGROUND AND OBJECTIVE: Although several studies on laser-assisted hair removal have been published, data on long-term follow-up are few. The present study investigated the long-term efficacy and safety of normal-mode ruby laser pulses on hair removal. STUDY DESIGN/MATERIALS AND METHODS: The normal-mode ruby laser (Epilaser; 694 nm, 3 msec) was used to treat a wide range of body sites in 51 volunteers. The mean follow-up after the last treatment was 8.37 months. RESULTS: Sixty-three percent of the patients had sparse regrowth. The mean fluence used was 46.5 J/cm(2) in patients who had sparse hair regrowth and 39.3 J/cm(2) in patients who had moderate hair regrowth (P = 0.0127). Transient pigmentary changes occurred most frequently in patients with skin type 4. CONCLUSION: The normal-mode ruby laser is an efficient and safe method for long-term hair reduction, especially in fair-skinned individuals with dark hair. Higher fluences produce greater long-term efficacy. Adverse effects are minimal and transient.

Hair removal by lasers and intense pulsed light sources.

Unwanted pigmented hair is a common problem for many patients. Traditional methods of hair removal have included shaving, bleaching, plucking, waxing, use of chemical depilatories, and electrolysis. These techniques have been limited by their pain, inconvenience, and poor long-term efficacy. Only electrolysis has offered the potential for permanent hair removal. However, the technique is tedious, highly operator-dependent, and impractical for the treatment of large numbers of hairs. Recently, a number of lasers and other light sources have been developed specifically to target hair follicles. These include ruby, alexandrite, diode, and Nd:YAG lasers and an intense pulsed light source. These devices offer the potential for rapid treatment of large areas and long-lasting hair removal. This article explains the mechanisms of using light to remove hair, examines the attributes of specific laser systems, and explains the importance of patient selection and treatment protocol for the various systems in order to provide a safe and effective treatment.

Laser hair removal affects sebaceous glands and sebum excretion: a pilot study.

BACKGROUND: During laser-assisted hair removal, sebaceous glands closely associated with hair follicles might also be affected. OBJECTIVE: We investigated the effect of the long-pulsed ruby laser on sebaceous glands. METHODS: Sebum excretion rates (SERs) of 16 subjects were measured quantitatively by means of sebum-absorbent tape and analyzed by means of image analysis techniques on laser-treated sites, compared with adjacent untreated areas. Evaluation was done at an average of 9 months (range, 4.5 to 12 months) after the last treatment. Histologic examinations were performed on 3 representative subjects before treatment, immediately after treatment, and 9 months after the last treatment. RESULTS: Significant increases in SERs were observed in 11 of 16 subjects (68.75%). Three subjects (18.75%) showed lower SERs, whereas 2 subjects (12.5%) demonstrated no difference in SERs between treated and untreated areas. Biopsy specimens showed an apparent reduction in sebaceous gland size. Specimens taken immediately after laser irradiation revealed sporadic damage to sebaceous glands. CONCLUSION: In some patients a variable but statistically significant increase in sebum excretion occurs 4 to 12 months after ruby-laser hair removal treatment at high fluences. A reduction in sebaceous gland sizes on laser-treated areas was observed. We hypothesize that decreased resistance to sebum outflow may explain this result, following miniaturization or absence of hair shaft after ruby laser treatment. Further study is needed to assess mechanisms for this interesting response.

Theoretical considerations in laser hair removal.

A systematic and logical approach for laser hair removal demands an understanding of its biologic and physical bases. This article presents an overview of hair anatomy and physiology followed by a mathematically nonrigorous review of tissue optics and thermal responses to laser irradiation. The reader is provided with a step by step approach to laser hair removal.

A clinical overview of hair removal using lasers and light sources.

The tremendous demand for removal of unwanted hair has led to the development of a wide range of noninvasive, user-friendly laser and light source systems; however, despite considerable advances in this field, these devices still have the potential to cause injury when used improperly. It is important to follow precise treatment guidelines in order to attain optimal results. This article gives an overview of the currently available lasers and light sources. It focuses on the practical aspect of laser hair removal by discussing patient selection, safety precautions, techniques using the different systems, pre- and post-laser treatment care, proper treatment endpoints, expected outcome, and possible side-effects and complications.

Contact cooling of the skin.

Skin precooling can be used to reduce epidermal thermal damage in laser procedures (such as hair removal) where the target structures are located up to several millimetres below the skin surface. We have developed and experimentally verified a computational model that describes contact precooling of a multilayered skin structure prior to laser irradiation. The skin surface is assumed to be brought into thermal contact with a cold plate made of material with a high thermal conductivity. The approximate analytical solution for the skin temperature is obtained by considering the plate as a local heat sink. The time evolution of temperature (in both the skin and the plate) is simulated numerically to yield the optimal cooling parameters. To experimentally verify the numerical results of the model, we performed direct measurements of skin temperature for contact cooling with a sapphire plate held at several different temperatures in the range +10 to -30 degrees C.

Permanent hair removal by normal-mode ruby laser.

OBJECTIVE: To assess the permanence of hair removal by normal-mode ruby laser treatment. METHODS: Hair removal was measured for 2 years after a single treatment with normal-mode ruby laser pulses (694 nm, 270 microseconds, 6-mm beam diameter). OBSERVATIONS: Six test areas on the thighs or backs of 13 volunteers were exposed to normal-mode ruby laser pulses at fluences of 30 to 60 J/cm2 delivered to both shaved and wax-epilated skin. In addition, there was a shaved and wax-epilated control site. Terminal hairs were manually counted before and after laser exposure. Transient alopecia occurred in all 13 participants after laser exposure, consistent with induction of telogen. Two years after laser exposure, 4 participants still had obvious, significant hair loss at all laser-treated sites compared with the unexposed shaved and wax-epilated control sites. In all 4 participants, there was no significant change in hair counts 6 months, 1 year, and 2 years after laser exposure. Laser-induced alopecia correlated histologically with miniaturized, velluslike hair follicles. No scarring and no permanent pigmentary changes were observed. CONCLUSIONS: Permanent, nonscarring alopecia can be induced by a single treatment with high-fluence ruby laser pulses. Miniaturization of the terminal hair follicles seems to account for this response.

Hair growth cycle affects hair follicle destruction by ruby laser pulses.

It has been shown that normal mode ruby laser pulses (694 nm) are effective in selectively destroying brown or black pigmented hair follicles in adult Caucasians. This study investigated how the various stages of the hair follicle growth cycle influence follicle destruction by ruby laser treatment, using a model of predictable synchronous hair growth cycles in the infantile and adolescent mice. A range of ruby laser pulse fluences was delivered during different stages of the hair growth cycle, followed by histologic and gross observations of the injury and regrowth of hair. Actively growing and pigmented anagen stage hair follicles were sensitive to hair removal by normal mode ruby laser exposure, whereas catagen and telogen stage hair follicles were resistant to laser irradiation. Selective thermal injury to follicles was observed histologically, and hair regrowth was fluence dependent. In animals exposed during anagen, intermediate fluences induced nonscarring alopecia, whereas high fluences induced scarring alopecia. The findings of this study suggest treatment strategies for optimal laser hair removal.

Damage to hair follicles by normal-mode ruby laser pulses.

BACKGROUND: Although many temporary treatments exist for hirsutism and hypertrichosis, a practical and permanent hair removal treatment is needed. OBJECTIVE: Our purpose was to study the use of normal-mode ruby laser pulses (694 nm, 270 microseconds, 6 mm beam diameter) for hair follicle destruction by selective photothermolysis. METHODS: Histologically assessed damage in ex vivo black-haired dog skin after the use of different laser fluences was used to design a human study; 13 volunteers with brown or black hair were exposed to normal-mode ruby laser pulses at fluences of 30 to 60 J/cm2, delivered to both shaved and wax-epilated skin sites. An optical delivery device designed to maximize light delivery to the reticular dermis was used. Hair regrowth was assessed at 1, 3, and 6 months after exposure by counting terminal hairs. RESULTS: Fluence-dependent selective thermal injury to follicles was observed histologically. There was a significant delay in hair growth in all subjects at all laser-treated sites compared with the unexposed shaven and epilated control sites. At 6 months, there was significant hair loss only in the areas shaved before treatment at the highest fluence. At 6 months, four subjects had less than 50% regrowth, two of whom showed no change between 3 and 6 months. Transient pigmentary changes were observed; there was no scarring. CONCLUSION: Selective photothermolysis of hair follicles with the normal-mode ruby laser produces a growth delay consistent with induction of prolonged telogen with apparently permanent hair removal in some cases.

Thermal relaxation of port-wine stain vessels probed in vivo: the need for 1-10-millisecond laser pulse treatment.

Although thermal relaxation times of cutaneous port-wine stain microvessels have been calculated and used to formulate laser selective photothermolysis, they have never been measured. A scheme to do so was devised by measuring the skin response to pairs of 585-nm dye laser pulses (250-360 microseconds each) as a function of the time interval between the two pulses, in five volunteers with port-wine stains. After a pump pulse delivering 80% of the fluence necessary for causing purpura, the fluence of a second probe pulse necessary to cause purpura was determined and was found to increase with the interval between the two pulses, in a manner consistent with thermal diffusion theory. Biopsy specimens were obtained from four of the five subjects to examine the nature and extent of vessel damage and to measure the port-wine stain vessel diameters. Using diffusion theory, the thermal relaxation time was calculated based on the measured vessel diameters. These calculated values are consistent with the increase in radiant exposure (fluence) of the probe pulse necessary to induce purpura for longer time delays. Two simple models for thermal relaxation of port-wine stain vessels are presented and compared with the data. The data and histologic assessment of the vessel injury strongly suggest that pulse durations for ideal laser treatment are in the 1-10-millisecond region and depend on vessel diameter. No dermatologic lasers presently used for port-wine stain treatment operate in this pulse width domain.

Laser treatment of erythematous/hypertrophic and pigmented scars in 26 patients.

Fifteen patients with erythematous/hypertrophic scars and 11 patients with postinflammatory hyperpigmentation were treated with a flashlamp pumped pulsed-dye laser at 585 nm or a flashlamp pulsed-dye laser at 510 nm. An average of 1.8 treatments resulted in an average improvement of 77 percent. Forty-seven percent of the patients had 100 percent improvement after one to three treatments. Eleven patients with postinflammatory hyperpigmentation were treated with the flashlamp pumped pulsed-dye laser at 510 nm with a pulse width of 300 ns. There was an average of 80 percent improvement with 1.45 treatments. Forty-five percent of the patients had 100 percent improvement after one or two treatments. The pathophysiology of postoperative scarring is reviewed. Theoretical reasons for the efficacy of laser treatment are detailed.