Permanent hair removal by normal-mode ruby laser

Photoinactivation and Photoablation of Porphyromonas gingivalis

Several types of phototherapy target human pathogens and Porphyromonas gingivitis (Pg) in particular. The various approaches can be organized into five different treatment modes sorted by different power densities, interaction times, effective wavelengths and mechanisms of action. Mode 1: antimicrobial ultraviolet (aUV); mode 2: antimicrobial blue light (aBL); mode 3: antimicrobial selective photothermolysis (aSP); mode 4: antimicrobial vaporization; mode 5: antimicrobial photodynamic therapy (aPDT). This report reviews the literature to identify for each mode (a) the putative molecular mechanism of action; (b) the effective wavelength range and penetration depth; (c) selectivity; (d) in vitro outcomes; and (e) clinical trial/study outcomes as these elements apply to Porphyromonas gingivalis (Pg). The characteristics of each mode influence how each is translated into the clinic.

Efficacy of Laser in Hair Removal: A Network Meta-analysis

BACKGROUND

Laser hair removal is an increasingly prevalent trend of cosmetic procedures. The purpose of this study was to assess the effectiveness of hair reduction among several types of laser interventions.

METHODS

The selected studies searched in PubMed and EMBASE were assessed for quality of evidence, and extracted data on absolute hair count and hair reduction rate. Qualitative data were synthesized using standardized mean difference (SMD) in frequentist network meta-analysis because various measurement units were used among selected studies. Inconsistency and small study effects were examined by design-by-treatment interaction model and comparison-adjusted funnel plot.

RESULTS

A total of 13 randomized controlled trials (RCTs) (n = 652) were contributed to network meta-analysis. Pooled results revealed that diode laser showed significantly lower absolute hair count within three-month (SMD = -13.21, 95% confidence interval [CI]: -22.25 to -4.17) and around six months follow-up (SMD = -11.01, 95% CI: -18.24 to -3.77) as compared with those in control group, but no significant difference among laser interventions. All side effects observed were transient without leaving any permanent scars.

CONCLUSION

Eliminating unwanted hair with lasers or intense pulsed light is safe and effective; however, which type of intervention is more beneficial in the long-term process should be studied with a longer follow-up time.

Measurements of hair temperature avalanche effect with alexandrite and Nd:YAG hair removal lasers

BACKGROUND AND OBJECTIVES

In this study, we investigate the photothermal response of human hair using a pulsed laser source employed in the hair removal treatment. The purpose is to understand the dynamics behind the most common clinical practice to better define the salient features that may contribute to the efficiency of the process.

STUDY DESIGN/MATERIALS AND METHODS

Temperature changes of hair samples (dark brown color) from a human scalp (skin type Fitpatrick II) were measured by a thermal camera following irradiation with single and multiple neodymium: yttrium-aluminum-garnet (Nd:YAG) (1064 nm) and alexandrite (755 nm) laser pulses. Particularly, the hair was treated with an individual laser pulse of a sufficiently high fluence, or with a series of lower fluence laser pulses. We investigated the temperature increase in a broad range of fluence and number of pulses. From the data analysis we extrapolated important parameters such as thermal gain and threshold fluence that can be used for determining optimal parameters for the hair removal procedure. Our experimental investigations and hypothesis were supported by a numerical simulation of the light-matter interaction in a skin-hair model, and by optical transmittance measurements of the irradiated hair.

RESULTS

An enhancement of the temperature response of the irradiated hair, that deviates from the linear behavior, is observed when hair is subjected to an individual laser pulse of a sufficiently high fluence or to a series of lower fluence laser pulses. Here, we defined the nonlinear and rapid temperature built-up as an avalanche effect. We estimated the threshold fluence at which this process takes place to be at 10 and 2.5 J/cm² for 1064 and 755 nm laser wavelengths, respectively. The thermal gain expressed by the degree of the deviation from the linear behavior can be higher than 2 when low laser fluence and multiple laser pulses are applied (n = 50). The comparison of the calculated gain for the two different laser wavelengths and the number of pulses reveals a much higher efficiency when low fluence and multiple pulses are delivered. The avalanche effect manifests when the hair temperature exceeds 45°C. The enhanced temperature increase during the subsequent delivery of laser pulses could be ascribed to the temperature-induced changes in the hair's structural properties. Simulations of the hair temperature under Nd:YAG and alexandrite irradiation indicate that the avalanche phenomenon observed in the hair suspended in air may apply also to the hair located within the skin matrix. Namely, for the same fluence, similar temperature increase was obtained also for the hair located within the skin.

CONCLUSION

The observed "avalanche" effect may contribute to the reported clinical efficacy of laser hair removal and may at least partially explain the observed efficacy of the brushing hair removal procedures where laser fluence is usually low. The repeated irradiation during the brushing procedure may lead to an avalanche-like gradual increase of the hair's thermal response resulting in sufficiently high final hair temperatures as required for effective hair reduction.

Comparison of Permanent Hair Removal Procedures before Gender-Affirming Vaginoplasty: Why We Should Consider Laser Hair Removal as a First-Line Treatment for Patients Who Meet Criteria

Introduction

Permanent genital hair removal is required before gender-affirming vaginoplasty to prevent hair-related complications. No previous studies have directly compared the relative efficacy, costs, and patient experiences with laser hair removal (LHR) vs electrolysis treatments. Food and Drug Administration (FDA) oversight of medical devices is poorly understood and commonly misrepresented, adversely affecting patient care.

Aim

This study compares treatment outcomes of electrolysis and LHR for genital hair removal and investigates FDA regulation of electrolysis and LHR devices.

Methods

Penile-inversion vaginoplasty and shallow-depth vaginoplasty patients completed surveys about their preoperative hair removal, including procedure type, number/frequency of sessions, cost, and discomfort. Publicly available FDA-review documents and databases were reviewed.

Main Outcomes Measure

Compared to electrolysis, LHR was associated with greater efficiency, decreased cost, decreased pain, and improved patient satisfaction.

Results

Of 52 total (44 full-depth and 8 shallow-depth) vaginoplasty patients, 22 of 52 underwent electrolysis only, 15 of 52 underwent laser only, and 15 of 52 used both techniques. Compared to patients that underwent LHR only, patients that underwent only electrolysis required a significantly greater number of treatment sessions (mean 24.3 electrolysis vs 8.1 LHR sessions, P < .01) and more frequent sessions (every 2.4 weeks for electrolysis vs 5.3 weeks for LHR, P < .01) to complete treatment (defined as absence of re-growth over 2 months). Electrolysis sessions were significantly longer than LHR sessions (152 minutes vs 26 minutes, P < .01). Total treatment costs for electrolysis ($5,161) were significantly greater than for laser ($981, P < .01). Electrolysis was associated with greater pain and significantly increased need for pretreatment analgesia, which further contributed to higher net costs for treatment with electrolysis vs laser. Many LHR and electrolysis devices have been FDA-cleared for safety, but the FDA does not assess or compare clinical efficacy or efficiency.

Clinical Implications

For patients with dark-pigmented hair, providers should consider LHR as the first-line treatment option for preoperative hair removal before gender-affirming vaginoplasty.

Strength and Limitations

This is the first study to compare electrolysis and LHR for genital hair removal. The discussion addresses FDA review/oversight of devices, which is commonly misrepresented. Limitations include the survey format for data collection.

Conclusion

When compared with electrolysis, LHR showed greater treatment efficiency (shorter and fewer treatment sessions to complete treatment), less pain, greater tolerability, and lower total cost. Our data suggests that, for patients with dark genital hair, providers should consider recommending laser as the first-line treatment for permanent genital hair removal before vaginoplasty.

Yuan N, Feldman A, Chin P, et al. Comparison of Permanent Hair Removal Procedures before Gender-Affirming Vaginoplasty: Why We Should Consider Laser Hair Removal as a First-Line Treatment for Patients Who Meet Criteria. Sex Med 2022;10:100545.

Depilatory laser miniaturizes hair by inducing bystander dermal papilla cell necrosis through thermal diffusion

OBJECTIVES

Depilatory laser targeting melanin has been widely applied for the treatment of hypertrichosis. Both selective photothermolysis and thermal diffusion have been proposed for its effect, but the exact mechanism of permanent hair reduction remains unclear. In this study, we explore the role of thermal diffusion in depilatory laser-induced permanent hair loss and determine whether nonpigmented cells are injured by thermal diffusion.

MATERIALS AND METHODS

C57BL/6 mice in anagen and telogen were treated with alexandrite laser (wavelength 755 nm, pulse duration 3 milliseconds, fluence 12 J/cm² , spot size 12 mm), respectively. Histological analysis, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, and transmission electron microscopic imaging were employed to evaluate the injury to hair follicle (HF) cells. The proliferation status of HF cells was examined by 5-bromo-2'-deoxyuridine pulse labeling. The number of HF stem cells was quantified by fluorescence-activated cell sorting. The size of the regenerated hair was determined by measuring its length and width.

RESULTS

We found that irradiating C57BL/6 mice in anagen with alexandrite laser led to hair miniaturization in the next anagen. In addition to thermal disruption of melanin-containing cells in the precortex region, we also detected necrosis of the adjacent nonpigmented dermal papilla cells due to thermal diffusion. Dermal papilla cells decreased by 24% after laser injury, while the number of bulge stem cells remained unchanged. When the laser was delivered to telogen HFs where no melanin was present adjacent to the dermal papilla, thermal necrosis and cell reduction were not detected in the dermal papilla and no hair miniaturization was observed.

CONCLUSION

Our results suggest that depilatory laser miniaturizes hair by inducing thermal necrosis of dermal papilla cells due to secondary thermal diffusion from melanin-containing precortex cells in the anagen hair bulbs.

Three wavelengths integrated: Efficacy and safety of a novel combination for hair removal

BACKGROUND

Laser hair removal is one of the most popular aesthetic procedures.

AIMS

The study aimed to assess the efficacy and safety of a novel applicator combining three wavelengths (1064 nm, 810 nm, and 755 nm) for hair removal.

PATIENTS/METHODS

This prospective study included a four-session hair removal treatment with three wavelengths combined and emitted simultaneously using an in-motion technique. Patients were treated in eight-week intervals between each session and a follow-up of 3 months.

RESULTS

Twenty-two men (mean age 41.5 years, SD = 6.1) were included: two (9.1%) Fitzpatrick skin type II, 19 (86.4%) type III, and one (4.5%) type IV. Treated areas were two abdomens (14%), fourteen backs (64%), and five thoraxes (23%). Hair characteristics were evaluated with a dermatoscopic imaging system. Three months after the last session, the mean decrease in the hair count was of 75.6% (SD 5.9) (p < 0.0001), in hair density of 75.6% (SD 5.9) (p < 0.0001), in the terminal hair number of 60.1% (SD 55.0) (p < 0.0001), and in the vellus hair number of 39.7% (SD 72.9) (p = 0.0001).

CONCLUSION

The combined three different wavelengths in a single device provided a wide range of absorption and penetration, allowing for a safe and effective treatment.

The results of the diode laser hair reduction treatments after the IPL hair reduction treatments

Introduction: Lasers and IPL action are similarly based on the selective photo thermolysis principle, where the melanin acts as chromatophore. There are, however, fundamental differences in the way they are built and in the light they emit.The goal of this paper is to compare the results of epilation treatments by a laser and by an IPL and to rate the effectiveness of a diode laser epilation following a non-coherent light therapy.Methods: 45 healthy females, 21-23 years old, skin type II-III took part in the study.805 nm diode laser and the IPL device with a wavelength of 640-1200 nm, was used. The informed consent for participation and treatment was obtained during a consultation. The participants were randomly divided into three groups of 15: I - one IPL treatment was followed by three diode laser treatments, II - two IPL treatments followed by three diode laser treatments, III- three IPL treatments followed by three diode laser treatments.Results: A percentage average of hair loss among patients treated with a diode laser as a control group is higher which indicates the laser's higher effectiveness.Conclusion: The IPL has been shown to negatively impact the effectiveness of a diode laser. This is linked with the way non-coherent light weakens and thins the hair that impedes the absorption of laser light by the melanin and adversely affects the treatment results.

Using the Hair Removal Laser in the Axillary Region and its Effect on Normal Microbial Flora

Introduction: The axillary hair removal laser is one of the most often used procedures to treat unwanted hairs in that region. Employing this technology can be helpful in decreasing the bromhidrosis. Methods: In the present research, a clinical trial study over the effect of the hair removal laser on normal microbial flora at the axillary region is presented. The intervention group consisted of 30 women referred to the dermatologic clinic for the purpose of removing axillary hair by the alexandrite 755 nm laser and the control group consisted of 30 women referred to the same clinic for any other reasons. Both groups were evaluated for the type of bacterial strains on the first visit and after three and six months. Results: The results showed that the sense of sweat smell improved by about 63% after the last laser session. The frequency of all bacterial strains decreased in the intervention group except Staphylococcus epidermidis which was significant. In the control group, there was no significant decrement in any bacterial strains and even the prevalence of more strains including Staphylococcus aureus and S. epidermidis increased. Counting the mean bacterial colon showed a slight decrement of the bacterial count following the laser. Conclusion: The use of laser radiation, even with the aim of hair removal, can alter the microbial flora, and it can be accompanied by the improvement of the smell of sweat. The effect of the laser on different bacterial strains is quite different, which can depend on the amount of energy, the wavelength, the characteristics of the area under the laser, and also the structural properties of the membrane of the microorganism itself.

The qualification and training of laser/intense pulse light hair removal operators within South Africa

BACKGROUND

Lasers and intense pulse light (IPL) sources are powerful devices that can cause skin burns, pigmentary changes, and scarring if used incorrectly. Adequate training is essential, and regulations are required to limit complications.

AIMS

The purpose was to investigate the qualifications and training obtained by laser hair removal operators in South Africa.

METHODS

Questionnaires were distributed and information gathered from owners/managers of laser clinics, suppliers of laser devices in South Africa, individuals in the workplace performing laser hair removal procedures, and accredited tertiary institutions.

RESULTS

A majority of clinic owners/managers (94.45%) felt that more emphasis should be placed on laser hair removal training at a tertiary level, and 66.67% outsource additional training provided by the manufacturer of laser devices. Based on the survey to manufacturers, 50% did not require any formal qualification as a minimum requirement, while 33.33% indicated laser hair removal training is incorporated at a NQF level 4 (National/Senior Certificate). The majority of individuals (68.89%) received training from tertiary institutions; however, they did not receive any practical training, and 60.87% felt the amount of training was insufficient. According to the survey sent to tertiary institutions in South Africa, only 27.78% offer laser hair removal training, and of these, 20% offer no practical training and 50% indicated that no practical examination is provided.

CONCLUSIONS

There is a clear lack of training in laser hair removal in South Africa. The industry should have standard requirements in terms of minimum practical and theoretical hours with regards to the therapy.

Solid-Phase Synthesis of Peptide-Conjugated Perylene Diimide Bolaamphiphile and Its Application in Photodynamic Therapy

Here, we describe a rapid and efficient synthetic method of peptide-conjugated perylene diimide (P-PDI) using solid-phase peptide synthesis (SPPS). Due to severe insolubility of perylene dianhydride (PDA) as a starting material of perylene diimide (PDI), PDA was initially conjugated with amino acids to obtain soluble PDI derivatives. Target peptides were synthesized on a 2-chlorotrityl chloride resin using the SPPS method and then conjugated with the amino acid-appended PDI. Various conditions such as loading levels, reaction times and solvents were optimized for introducing the peptides to both sides of the amino acid-appended PDI. The final P-PDI was obtained with a maximum yield of 80% in 12 h. Its singlet oxygen-derived phototoxicity on cells was confirmed, which could be applicable to photodynamic therapy.

Polyvinyl chloride as a multimodal tissue-mimicking material with tuned mechanical and medical imaging properties

PURPOSE

The mechanical and imaging properties of polyvinyl chloride (PVC) can be adjusted to meet the needs of researchers as a tissue-mimicking material. For instance, the hardness can be adjusted by changing the ratio of softener to PVC polymer, mineral oil can be added for lubrication in needle insertion, and glass beads can be added to scatter acoustic energy similar to biological tissue. Through this research, the authors sought to develop a regression model to design formulations of PVC with targeted mechanical and multimodal medical imaging properties.

METHODS

The design of experiment was conducted by varying three factors-(1) the ratio of softener to PVC polymer, (2) the mass fraction of mineral oil, and (3) the mass fraction of glass beads-and measuring the mechanical properties (elastic modulus, hardness, viscoelastic relaxation time constant, and needle insertion friction force) and the medical imaging properties [speed of sound, acoustic attenuation coefficient, magnetic resonance imaging time constants T₁ and T₂, and the transmittance of the visible light at wavelengths of 695 nm (T_λ695) and 532 nm (T_λ532)] on twelve soft PVC samples. A regression model was built to describe the relationship between the mechanical and medical imaging properties and the values of the three composition factors of PVC. The model was validated by testing the properties of a PVC sample with a formulation distinct from the twelve samples.

RESULTS

The tested soft PVC had elastic moduli from 6 to 45 kPa, hardnesses from 5 to 50 Shore OOO-S, viscoelastic stress relaxation time constants from 114.1 to 191.9 s, friction forces of 18 gauge needle insertion from 0.005 to 0.086 N/mm, speeds of sound from 1393 to 1407 m/s, acoustic attenuation coefficients from 0.38 to 0.61 (dB/cm)/MHz, T₁ relaxation times from 426.3 to 450.2 ms, T₂ relaxation times from 21.5 to 28.4 ms, T_λ695 from 46.8% to 92.6%, and T_λ532 from 41.1% to 86.3%. Statistically significant factors of each property were identified. The regression model relating the mechanical and medical imaging properties and their corresponding significant factors had a good fit. The validation tests showed a small discrepancy between the model predicted values and experimental data (all less than 5% except the needle insertion friction force).

CONCLUSIONS

The regression model developed in this paper can be used to design soft PVC with targeted mechanical and medical imaging properties.

Development of a Novel Automated Hair Counting System for the Quantitative Evaluation of Laser Hair Removal

OBJECTIVE

We aimed to develop and validate a novel computer-assisted automated hair counting system for the quantitative evaluation of laser hair removal (LHR).

METHODS

We developed a computer-aided image processing system to count hairs on shaved skin and validated its performance through clinical trials. Five volunteers of Fitzpatrick skin type III-IV volunteered and were tested on both thighs. The system automatically detects hair and places a "+" sign on each hair site for every positive detection. This method allows clinicians to check whether a hair has been counted or not. We analyzed the difference in the hair counts between the proposed system (automatic) and those by human observers (manual).

RESULTS

The hair counts from the proposed system and the manual counts were compared. The percentage error between automatic and manual counting was <5% in each subject. The data of the two groups were statistically verified with Student's independent t-test. The averages were statistically equivalent between the two groups. The proposed system showed significant time saving in terms of counting.

CONCLUSIONS

A dependable, accurate, and fast method of counting hairs on shaved skin through a computer-aided image processing system was developed and validated. The "+" signs on the image to indicate detection allows clinicians to compare with the original image and detect any omission or redundancy. The proposed system is expected to be reliable in analyzing the results of multiple skin-related treatments, including LHR and hair transplantation. Further, it is expected to be widely applicable for use in the clinic.

The role of lasers and intense pulsed light technology in dermatology

The role of light-based technologies in dermatology has expanded dramatically in recent years. Lasers and intense pulsed light have been used to safely and effectively treat a diverse array of cutaneous conditions, including vascular and pigmented lesions, tattoos, scars, and undesired hair, while also providing extensive therapeutic options for cosmetic rejuvenation and other dermatologic conditions. Dermatologic laser procedures are becoming increasingly popular worldwide, and demand for them has fueled new innovations and clinical applications. These systems continue to evolve and provide enhanced therapeutic outcomes with improved safety profiles. This review highlights the important roles and varied clinical applications that lasers and intense pulsed light play in the dermatologic practice.

Bioabsorbable polymer optical waveguides for deep-tissue photomedicine

Advances in photonics have stimulated significant progress in medicine, with many techniques now in routine clinical use. However, the finite depth of light penetration in tissue is a serious constraint to clinical utility. Here we show implantable light-delivery devices made of bio-derived or biocompatible, and biodegradable polymers. In contrast to conventional optical fibres, which must be removed from the body soon after use, the biodegradable and biocompatible waveguides may be used for long-term light delivery and need not be removed as they are gradually resorbed by the tissue. As proof of concept, we demonstrate this paradigm-shifting approach for photochemical tissue bonding (PTB). Using comb-shaped planar waveguides, we achieve a full thickness (>10 mm) wound closure of porcine skin, which represents ∼10-fold extension of the tissue area achieved with conventional PTB. The results point to a new direction in photomedicine for using light in deep tissues.

Light-based therapies are of growing importance in medicine, though penetrating tissue and reaching the targeted area can be difficult. Here, the authors report the use of biodegradable waveguides capable of directing light where desired, and demonstrate the potential for wound healing.

A study on the development of a robot-assisted automatic laser hair removal system

Abstract Background and Objective: The robot-assisted automatic laser hair removal (LHR) system is developed to automatically detect any arbitrary shape of the desired LHR treatment area and to provide uniform laser irradiation to the designated skin area.

METHODS

For uniform delivery of laser energy, a unit of a commercial LHR device, a laser distance sensor, and a high-resolution webcam are attached at the six axis industrial robot's end-effector, which can be easily controlled using a graphical user interface (GUI). During the treatment, the system provides real-time treatment progress as well as the total number of "pick and place" automatically.

RESULTS

During the test, it was demonstrated that the arbitrary shapes were detected, and that the laser was delivered uniformly. The localization error test and the area-per-spot test produced satisfactory outcome averages of 1.04 mm error and 38.22 mm(2)/spot, respectively.

CONCLUSIONS

RESULTS showed that the system successfully demonstrated accuracy and effectiveness. The proposed system is expected to become a promising device in LHR treatment.

Long-term efficacy of linear-scanning 808 nm diode laser for hair removal compared to a scanned alexandrite laser

BACKGROUND AND OBJECTIVE

Alexandrite and diode lasers are commonly used for hair removal. To date, the available spot sizes and repetition rates are defining factors in terms of penetration depth, treatment speed, and efficacy. Still, larger treatment areas and faster systems are desirable. To compare the efficacy, tolerability, and subject satisfaction of a continuously linear-scanning 808 nm diode laser with an alexandrite 755 nm laser for axillary hair removal.

STUDY DESIGN

A total of 31 adults with skin types I-IV received 6 treatments at 4-week intervals with a 755 nm alexandrite laser (right axilla) and a continuously linear-scanning 808 nm diode laser (left axilla). Axillary hair density was assessed using a computerized hair detection system.

RESULTS

There was a significant reduction in axillary hair after the 6th treatment (P < 0.05) on both sides (left, 808 nm: hair clearance of 72.16%; right, 755 nm: hair clearance of 71.30%). The difference in reduction between the two lasers was not significant, but both were persistant at 18 months follow-up (left: hair clearance of 73.71%; right: hair clearance of 71.90%). Erythema and perifollicular edema were more common after alexandrite laser treatment, but all side effects were transient. While 62.50% of patients reported more pain in response to treatment with the new diode laser, all patients rated treatment with either laser tolerable.

CONCLUSION

Treatment with either the alexandrite or the linear-scanning diode laser results in significant, comparable, persistent (at least 18 months) axillary hair reduction among individuals with skin types I-IV.

Long-term removal of unwanted hair using light

Laser (or light) hair removal, also referred to as photoepilation, is the most commonly used laser or light-based cosmetic medical procedure. The extended theory of selective photothermolysis is the basic principle for destruction of hair follicles using light. In this type of laser application the chromophore is follicular melanin. Several types of lasers and light sources have been effective for hair reduction, including the ruby, alexandrite, diode, and neodymium:yttrium-aluminum-garnet lasers and broadband, intense pulsed light sources. This article provides a broad overview of how hair can be removed using light, with an emphasis on practical considerations.

TRASER--Total Reflection Amplification of Spontaneous Emission of Radiation

Background and Objective

Light and lasers in medical therapy have made dramatic strides since their invention five decades ago. However, the manufacture of lasers can be complex and expensive which often makes treatments limited and costly. Further, no single laser will provide the correct parameters to treat all things. Hence, laser specialists often need multiple devices to practice their specialty. A new concept is described herein that has the potential to replace many lasers and light sources with a single ‘tunable’ device.

Study Design/Material and Methods

This device amplifies spontaneous emission of radiation by capturing and retaining photons through total internal reflection, hence the acronym Total Reflection Amplification of Spontaneous Emission of Radiation, or TRASER.

Results

Specific peaks of light can be produced in a reproducible manner with high peak powers of variable pulse durations, a large spot size, and high repetition rate.

Conclusion

Considering the characteristics and parameters of Traser technology, it is possible that this one device would likely be able to replace the pulsed dye laser and many other light based systems.

Comparison of hair reduction with three lasers and light sources: prospective, blinded and controlled study

OBJECTIVE

The main goal of this study was to compare the hair removal efficacy of three methods: intense pulsed light (IPL), a combination of IPL and radio frequency (RF) and diode laser (810 nm).

METHODS

Forty participants were treated within three standardized squares on lateral sites on their legs. Each of these squares was treated twice with an interval of 4-6 weeks. The fourth square was left as a control. A blinded physician counted the hairs in each square before the first treatment and 8 months after the second treatment. Immediate and delayed side effects as well as pain scores were recorded.

RESULTS

The mean hair count reduction achieved by the diode laser, IPL and IPL+RF was 49.90%, 39.16% and 47.15%, respectively. This study did not show any serious side effects and the number of side effects was minimal. The mean pain scores for the first and second treatments by diode laser, IPL and IPL+RF were 4.65 and 4.58, 2.43 and 2.53, and 3.95 and 4.03, respectively. At the end of the study, a free hair removal treatment for both legs was chosen by patients in the proportion 20 diode laser, 10 IPL and eight IPL+RF.

CONCLUSIONS

The combination of RF and optical energies proved its safety and efficacy for hair removal, which is comparable with diode lasers and approximately 20% more efficient than 'pure' IPL.

One-year follow-up using an intense pulsed light source for long-term hair removal

BACKGROUND

The long-term removal of unwanted hair is a challenge for health care providers. Peer-reviewed scientific data for many of the hair removal laser systems is lacking.

OBJECTIVE

This paper provides a chronicle of 24 of the 31 patients who participated in the original 3-month trial for hair removal utilizing an intense pulsed light source.

METHODS

A total of 24 of the original 31 patients who took part in the one treatment, 3-month, intense pulsed light trial were examined again at 1 year following the treatment.

RESULTS

Long-term epilation of 75% hair removal was found in this group of patients after 1 year with a single treatment.

CONCLUSION

The intense pulsed light source is an effective method for providing long-term epilation of unwanted hair.

Photo-assisted epilation — review and personal observations

The perception of unwanted hair is culturally dependent, and its removal is a multibillion-dollar business in North America each year. Examples of hair removal techniques on the market today include shaving, depilatories, wax, epilation, electrolysis and photo-epilation. Electrolysis, or electrothermolysis, was the only known permanent hair removal modality to date. However, long term or permanent hair removal with lasers is becoming a reality for treatment of hirsuitism or unwanted hair. Laser hair removal is an exciting new field with improvements occurring continually, making it difficult to stay abreast of the newest treatments and their effectiveness. This review provides an overview of hair follicle anatomy, mechanisms of photo-destruction to hair follicles and physics of lasers and the skin. The different types of lasers used for hair removal, their mechanisms and clinical research are reviewed.

Treatment of terminal and vellus non‐pigmented hairs with an optical/bipolar radiofrequency energy source—with and without pre‐treatment using topical aminolevulinic acid

OBJECTIVE

The present study compares the 6-month hair removal efficacy of a combined pulsed light bipolar radiofrequency device with and without pre-treatment using topical aminolevulinic acid.

MATERIALS AND METHODS

Fifteen adult females, skin phenotypes II-IV were entered into the study. Ten subjects were determined to have white terminal hairs; an additional five females presented with fine facial vellus hairs. Unwanted facial hair was treated twice at 4-6 week intervals with a combined optical bipolar radiofrequency source. At each treatment half of the treatment area was pre-treated with topical aminolevulinic acid; the other half was not. Follow-up visits were undertaken at 6 months after the second treatment. Hair counts were obtained before treatment and 6 months after the final treatment.

RESULTS

An average terminal white hair removal of 35% was observed at 6 months after treatment with the combined pulsed light bipolar radiofrequency device. When pre-treatment with topical aminolevulinic acid was provided the average hair removal of terminal white hairs was found to be 48%. None of the five subjects with vellus hair were noted to respond to either treatment.

CONCLUSIONS

Combined radiofrequency and optical light treatment leads to effective hair removal of terminal white hairs. This improvement is increased with pre-treatment use of topical aminolevulinic acid. Vellus nonpigmented hairs did not respond to treatment.

Hair removal with a second generation broad spectrum intense pulsed light source — a long-term follow-up

BACKGROUND

There is an increasing demand for safe and efficient hair removal. Although long-term hair removal has been demonstrated using lasers and non-coherent light sources, permanent hair removal has been difficult to claim due to the long growth/rest cycle of normal human hair follicles.

OBJECTIVE

To evaluate bikini line hair removal with a second generation intense pulsed light (IPL) source.

METHOD

Ten females (20 bikini lines) with dark hair and skin types II-IV were treated with an IPL (600 nm) four times with a 1-month interval. Counting of the hair follicles was carried out with a computer imaging system before treatment, and 4 and 8 months after the treatments.

RESULTS

Hair reduction of 74.7% (SD +/- 18.3%) was seen 4 months after the treatments and 80.2% (SD +/- 20.3%) 8 months after the last treatment. Only minimal side effects were noted and no pain or other discomfort was registered during the treatments.

CONCLUSION

The present study demonstrated that this new IPL system is both efficient and safe for hair removal. Because the follow up period of 8 months is twice the cycle time for hairs in the bikini line area, the obtained hair reduction in this study was long-lasting.

Intense pulsed light treatment of hirsutism: case reports of skin phototypes V and VI

Removal of unwanted hair is a common cosmetic concern. For hirsute women, treatment often requires drug therapy and various methods to physically remove the hair. Traditional methods of hair removal include shaving, waxing, tweezing, depilatory creams and electrolysis. Hair removal methods based on light technology, such as lasers and intense pulsed light systems, are alternative methods for longer-term hair removal. Intense pulsed light has been used in our clinic during the past 2 years to treat light-to-dark skinned patients, including skin types V and VI. We present here the treatment, using an intense pulsed light source, of three dark skinned patients with hirsutism. Patients were treated during multiple sessions (five to seven) for unwanted facial hair. Sessions were conducted monthly and patients were evaluated at follow-up sessions 2-7 months after the final treatment. Successful clearance of unwanted hair was achieved in all three patients with no pigmentary changes observed during the final follow-up sessions. Folliculitis and hyperpigmentation from tweezing were also treated by the intense pulsed light source. These results suggest that intense pulsed light is an effective source for hair removal and may, with proper parameter selection, be useful in the treatment of very dark skin types.

Hair removal with an Athos Nd:YAG 3.5 ms pulse laser: a 3-month clinical study

INTRODUCTION/OBJECTIVE

This study aimed to evaluate the safety and efficacy of a 3.5 ms Nd:YAG laser for the removal of hair in subjects with Fitzpatrick skin types I-IV. Thanks to a pulse shorter than the hair Thermal Relaxation time (TRT), photothermolysis was thus achieved.

METHODS

This study assessed the percentage of hair reduction at 1 month and at 3 months after a single Nd:YAG laser treatment (Athos; Quantel Médical, France); 3.5 ms pulse, single shot to 3 Hz, a maximum fluence of 80 J/cm2, 4 mm spot, no cooling system, no anaesthesia. The treatment sites consisted of three adjacent squares (optimum fluence, no treatment, -20% optimum fluence). Computerized hair counting was realized on digital pictures. The phototype, pain, side effects and patient's satisfaction were noted. Biopsies were performed 15 min after treatment. The enrolment consisted of 17 women, 22-60 years old, phototypes I-IV, with a follow-up at 1 month and 3 months of 25 sites.

RESULTS

Counting at 1 month and at 3 months revealed a significant hair reduction compared with the control sites: 60% at 1 month (P < 0.001) and 24% at 3 months (P < 0.05) for optimal fluence (25-80 J/cm2), compared with 31% and 0% on the control sites; values similar to those published for Nd:YAG or diode lasers. There were no adverse effects at all. Biopsies showed lesions from necrosis coagulation of the root sheaths and hair disruption to isolated apoptotic cells in the outer root sheath, depending on the fluence applied.

CONCLUSION

Results from this study show that the Athos Nd:YAG is efficient and safe for removing pigmented hair in phototypes I-IV.

A structured treatment protocol improves results with laser hair removal

BACKGROUND

As laser epilation has become a widely accepted method for hair removal, questions regarding timing and frequency of treatments have arisen.

OBJECTIVE

To determine whether a structured treatment protocol for laser hair removal improves clinical results in reducing hair growth.

METHODS

A group of 100 patients (Group A) underwent laser epilation with four regularly spaced treatments; a group of 100 patients (Group B) determined their own treatment plan with respect to timing and frequency (not exceeding four treatments).

RESULTS

Group A experienced a 78 +/- 8% reduction in hair with four treatments per patient while Group B experienced a 48 +/- 12% reduction with an average of 2.5 +/- 0.5 treatments per patient. These differences were statistically significant (P < 0.05). Patient satisfaction was significantly improved in Group A compared with Group B (P < 0.05). A positive linear relationship was identified in Group B between treatment frequency and hair reduction (r = 0.94) and between treatment frequency and patient satisfaction (r = 0.89).

CONCLUSION

This study concludes that patients who participate in a structured treatment protocol note superior clinical results following laser hair removal.