Laser and intense pulsed light hair removal technologies: from professional to home use

Trunk hair removal treatment with diode laser 810 nm in men population

In the last years, hair removal has been one of the most common treatments performed for aesthetic purposes, especially in women. Nevertheless, even if it is less popular, the demand within men population has risen. The study aimed to assess the acceptability of the diode 810 nm treatment for hair removal on the back and chest area in men thanks to the speed of treatment and the absence of undesirable effects. For this study, 20 patients were treated for hair removal. They were men with a mean age of 30.5 (±7.3). They underwent 4 treatment sessions at 40-day intervals on the trunk (chest and back area). Patients ranged between a Fitzpatrick phototype I (20%, 4/20) to IV (15%, 3/20) (40% were type II and 25% type III). Moreover, patients were asked to report pain intensity sensation with a visual analogue scale. Overall, in the study population, a hair reduction of 80.6% (±2.8) was registered in the treated areas. The device described in this study was demonstrated to be highly efficient in extended body areas and on difficult-to-treat hair follicles like on the back and chest in the men population.

Treatment of Dry Eye Disease (DED) in Asia: Strategies for Short Tear Film Breakup Time-Type DED

Dry eye disease (DED) is a multifactorial disorder in which tear fluid homeostasis is lost, resulting in increased tear film osmolarity and ocular surface irritation. In Asia, the short tear film breakup time-type DED, which has become a global problem in recent years, is common. While the mainstay of DED treatment in the West is the suppression of inflammation, the first goal of treatment is the stabilization of the tear film in Asia. To date, artificial tears and steroid eye drops have been the main treatment for DED. However, artificial tears require frequent administration of eye drops and thus pose adherence problems, while steroids have problems with side-effects (cataracts, increased intraocular pressure). This review evaluates the new generation therapies in Asia based on what is known about them and demonstrates that they are more effective for DED than traditional therapies such as artificial tears and steroids. Based on considerations, it is proposed that the optimal treatment for the short tear film breakup time-type DED is the initial application of mucin-secretion-enhancing eye drops (long-acting diquafosol) and oral supplements; and if additional treatment is needed, cyclosporine eye drops and the adjunctive therapies presented in this review are added.

Optimal Timing of Laser Hair Removal in Expanded Forehead Flap in the Reconstruction of Facial Defects: During or After Tissue Expansion?

Background: The optimal timing of laser epilation with expanded forehead flaps in facial defect reconstruction remains undetermined. Objective: To compare the efficacy and safety of hair removal during or after flap expansion. Methods: This prospective exploratory study included 15 (11 women and 4 men, 16.47 ± 16.331 years of age) and 26 (19 women and 7 men, 10.69 ± 10.899 years of age) patients who underwent 755 nm long-pulsed alexandrite laser epilation during flap expansion and after surgery, respectively. Facial reconstruction was performed in these patients because of congenital melanin nevus, scar or port-wine stains. Evaluation included hair reduction rate, patient satisfaction, and adverse events. Results: The median number of laser sessions for hair removal during flap expansion was significantly lower than that after surgery (2.00 vs. 3.00, p < 0.01), and the hair reduction rate was also significantly higher during flap expansion (79.5% ± 21.93% vs. 68.3% ± 17.44%, p < 0.05). No severe adverse events were reported. Conclusion: Laser hair removal is safe and efficient when performed both during flap expansion period and after surgery, but its efficacy was significantly higher, and fewer sessions were required when performed during tissue expansion. Clinical trial registration information: ChiCTR1900026090.

A Review of Applications and Intracellular Mechanisms of Intense Pulsed Light in Eyelid Inflammatory Diseases

Objective: To evaluate relevant clinical outcomes and conclude possible mechanisms of intense pulsed light (IPL) in eyelid inflammation. Background: IPL devices were primarily applied in cutaneous vascular malformations and have been used in ocular diseases for about 20 years, mostly including meibomian gland dysfunction (MGD), blepharitis, and ocular rosacea. Recent findings: Seventy-two original clinical researches were included, 57 for MGD, 4 for blepharitis or blepharitis-related keratoconjunctivitis, and 11 for rosacea. Dry eye symptoms, (tear) break-up time (BUT), and meibomian structure and/or functions were improved in most patients, but production of reactive oxygen species is an important link in the photobiomodulation mediated by IPL, which can influence numerous signal pathways to achieve anti-inflammatory, anti-infective, and prodifferentiation effects. Conclusions: The evidence suggests that IPL is an effective therapeutic tool for most patients with MGD, but more clinical evidence is needed for other indications.

Novel laser hair removal in all skin types

BACKGROUND

Laser has been long accepted as a solution for excess or unwanted hair growth yet traditional lasers are not always ideal for safe and effective outcome for all skin types and hair characteristics. A diode laser module combining three wavelengths (755, 810, and 1064 nm) in a single pulse was developed to provide a fast and long-term solution for subjects with various profiles.

AIMS

To evaluate the safety and efficacy of a Triple wavelength diode laser module for hair removal treatment in all skin types (Fitzpatrick I-VI).

SUBJECTS AND METHODS

This was a prospective, dual centered, single-arm study. Subjects were treated with a novel diode laser module. Thirty-six subjects were enrolled, sixteen with Fitzpatrick skin types I-IV (46%) and twenty with Fitzpatrick skin types V-VI (54%). Treatment areas were axilla and bikini lines. Subjects underwent 4 treatment sessions at 6 weeks ± 5 days intervals and attended a follow-up visit 3 months after the last treatment session. 2D digital photographs were taken at baseline and at the follow-up visit, and a hair count was conducted by three blinded evaluators.

RESULTS

A significant reduction in hair count between baseline and the 3-month follow-up visit was observed in both axilla and bikini lines for all skin types. The mean hair reduction was 41.5 ± 19.4% and 48.1 ± 20.9% in the axilla and bikini line, respectively. A significant hair reduction was also observed within skin type groups; mean hair reduction 45.5 ± 16.9% and 40.3 ± 17.2% in skin types I-IV and V-VI, respectively, indicating similar efficacy for both light and dark skin types. No serious adverse events were reported.

CONCLUSIONS

This study demonstrates that the Soprano Titanium laser platform is safe and effective for hair removal treatment in all skin types.

Hypertrophic Scars of the Hand: The Role of Electrophotobiomodulation Theory as a Recent Line of Treatment

BACKGROUND

A more enduring strategy for the treatment of hypertrophic scars of the hand is still a challenge facing restorative dermatologists and plastic surgeons. Nonetheless, with the use of nonablative devices, intense pulsed light and different types of lasers have started to yield promising outcomes and are close to becoming an effective and dependable technique. The advances in radiofrequency energy have brought new life to optical-based frameworks. Radiofrequency current delivers an unadulterated heat effect according to the electrical response characteristics of each tissue. The purpose of this study was to assess the patient satisfaction, safety, and clinical efficacy of the use of electrophotobiomodulation (combined intense pulsed light and radiofrequency energy) in the treatment of postburn hypertrophic scars of the hand.

METHODS

This was a prospective clinical study that was performed on 56 patients who presented with postburn hypertrophic scars on the hands between March of 2013 and January of 2020.

RESULTS

The clinical appraisal showed excellent results in 33 patients (58.9%), good results in 18 patients (32.2%), fair results in five patients (8.9%), and no poor results.

CONCLUSION

The use of radiofrequency energy combined with intense pulsed light was effective for the treatment of hand scars on people with various skin tones.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

The Efficacy and Safety of New-Generation Intense Pulsed Light in the Treatment of Meibomian Gland Dysfunction-Related Dry Eye: A Multicenter, Randomized, Patients-Blind, Parallel-Control, Non-Inferiority Clinical Trial

Introduction

This study aimed to evaluate the efficacy and safety of a new-generation intense pulsed light (IPL) device in improving the symptoms and signs of meibomian gland dysfunction (MGD)-related dry eye, and compare it with a traditional IPL device.

Methods

This multicenter randomized controlled trial enrolled 132 patients with MGD-related dry eye from two centers. Patients were randomly assigned into the new-generation IPL (Eyesis) group or traditional IPL (E-Eye) group, and then blinded to receive treatment on days 0 and 7. Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer test, and meibomian gland signs were evaluated on days 0, 7, and 14. The primary outcome was defined as the effective rate of treating MGD at day 14. Any adverse events were recorded for safety assessment. Intergroup comparisons and non-inferiority analysis were performed. p values less than 0.05 were considered statistically significant.

Results

Basic information showed no significant difference between treatment groups. The intergroup difference of the effective rate was − 1.7% in the left eye and 1.6% in right eye, verifying the non-inferiority of the Eyesis device (p = 0.927). Significant improvements in OSDI, TBUT, Schirmer test, TMH, CFS, and meibomian gland signs were observed in Eyesis group on days 7 and 14 (all p < 0.05). Compared to the E-Eye group, the Eyesis group achieved more significant improvements in OSDI, TBUT, Schirmer test, TMH, and meibum quality (all p < 0.05). There was no significant difference in the incidences of adverse events between groups (p = 1.000).

Conclusions

The new-generation IPL was effective and safe in relieving the symptoms and signs of MGD-related dry eye, exhibiting a non-inferior effective rate compared to the traditional IPL. Additionally, Eyesis showed more clinical benefits over E-Eye in alleviating symptoms, increasing tear film stability and improving meibomian gland function.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00556-1.

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.

Das schöne, glatte Bein: Haarentfernung durch Laser und lichtbasierte Verfahren

Die Fotoepilation zählt zu den meistgefragten nichtchirurgischen Eingriffen in der ästhetischen Dermatologie. Haarlose, glatte Beine gelten dabei als Schönheitsideal.

Fotoepilation mittels Laser oder hochenergetischer Blitzlampen (sog. Intensed-Pulsed-Light-Geräte) stellt ein sicheres und effektives Verfahren dar. Der Wirkmechanismus beruht auf dem Prinzip der selektiven Fotothermolyse, wobei eine gezielte thermische Schädigung pigmentierter Haarfollikel unter Schonung des umliegenden Gewebes erfolgt. Melaninpigment des Haarschaftes absorbiert als Zielchromophor Licht eines speziellen Wellenlängenspektrums und führt durch Wärmediffusion zur Schädigung der für das Haarwachstum wichtigen Stammzellen im äußeren Haarwurzelschaft.

Patienten müssen über die Notwendigkeit wiederholter Behandlungen sowie den häufig nur partiellen und temporären Haarverlust aufgeklärt werden. Dunkle Terminalhaare bei hellen Hauttypen lassen sich effektiv entfernen. Bei dunklen Hauttypen besteht aufgrund des erhöhten epidermalen Melaninvorkommens ein erhöhtes Risiko für Nebenwirkungen wie Verbrennungen, Dyspigmentierungen und Narben. Sehr feine, helle oder rote Haare lassen sich kaum mit konventionellen Fotoepilationsverfahren entfernen. Haarentfernungsgeräte für den Heimgebrauch sind eine kostengünstige, einfach anzuwendende Alternative, weisen aber im Vergleich zur professionellen Fotoepilation eine geringere Effektivität auf.

Using blend wavelengths in order to improve the safety and efficacy of laser hair removal

BACKGROUND

As the pursuit for a safe and effective device for laser hair removal continues, the use of simultaneous multiple wavelengths in a single device requires further exploration.

AIM

To evaluate the safety and efficacy of a novel multi-wavelength laser device for hair removal.

PATIENTS AND METHODS

This retrospective cohort study included adult participants of both sexes with Fitzpatrick skin types of III and IV. Hairy sites were treated by a multiple wavelength (810nm, 940nm, and 1064nm) laser device (Primelase, Coccoon medical, Barcelona, Spain). Laser parameters included: fluence of 14-20 J/cm² , pulse duration of 7-30 ms, and spot size of 20*9 mm² . Participants underwent up to 7 treatments at 6-8 weeks intervals and were followed for 6 months after the last treatment session. "Before" and "after" clinical photographs were acquired and were used to evaluate efficacy by 2 independent dermatologists. They employed the Global Aesthetic Improvement Scale (GAIS; scale of 0 [no improvement] to 4 [excellent improvement; Over 75% hair reduction]). Participants' satisfaction was rated on a scale of 1 (not satisfied) to 5 (very satisfied). Pain perception and adverse events were recorded as well.

RESULTS

Eighteen participants (6 men, 12 women) were included with a total of 49 treatment sites. Mean hair reduction was 3.6 out of 4 in the GAIS. Participants' satisfaction rate was high (mean 4.5). Beside mild transient discomfort during the procedure, no adverse events were recorded.

CONCLUSION

The use of a multiple wavelengths' laser device is safe and effective for hair removal.

Das schöne, glatte Bein: Haarentfernung durch Laser und lichtbasierte Verfahren

Die Fotoepilation zählt zu den meistgefragten nichtchirurgischen Eingriffen in der ästhetischen Dermatologie. Haarlose, glatte Beine gelten dabei als Schönheitsideal.

Fotoepilation mittels Laser oder hochenergetischer Blitzlampen (sog. Intensed-Pulsed-Light-Geräte) stellt ein sicheres und effektives Verfahren dar. Der Wirkmechanismus beruht auf dem Prinzip der selektiven Fotothermolyse, wobei eine gezielte thermische Schädigung pigmentierter Haarfollikel unter Schonung des umliegenden Gewebes erfolgt. Melaninpigment des Haarschaftes absorbiert als Zielchromophor Licht eines speziellen Wellenlängenspektrums und führt durch Wärmediffusion zur Schädigung der für das Haarwachstum wichtigen Stammzellen im äußeren Haarwurzelschaft.

Patienten müssen über die Notwendigkeit wiederholter Behandlungen sowie den häufig nur partiellen und temporären Haarverlust aufgeklärt werden. Dunkle Terminalhaare bei hellen Hauttypen lassen sich effektiv entfernen. Bei dunklen Hauttypen besteht aufgrund des erhöhten epidermalen Melaninvorkommens ein erhöhtes Risiko für Nebenwirkungen wie Verbrennungen, Dyspigmentierungen und Narben. Sehr feine, helle oder rote Haare lassen sich kaum mit konventionellen Fotoepilationsverfahren entfernen. Haarentfernungsgeräte für den Heimgebrauch sind eine kostengünstige, einfach anzuwendende Alternative, weisen aber im Vergleich zur professionellen Fotoepilation eine geringere Effektivität auf.

Multipass low fluence, high-frequency 755-nm alexandrite laser versus high fluence, low-frequency 1064-nm long-pulsed Nd: YAG laser in axillary hair reduction of dark skin phototypes: an intra-individual randomized comparative study

BACKGROUND

Laser hair removal has become popular means of achieving hair reduction with improved quality of life.

OBJECTIVE

This study aimed to assess the safety and efficacy of Multipass low fluence, high-frequency 755-nm Alexandrite laser versus the high fluence, low-frequency 1064-nm long-pulsed Nd: YAG laser on axillary hair reduction in women with dark skin phototypes.

PATIENTS AND METHODS

This study was carried out on 30 adult women [skin type, IV-VI)] who seek axillary hair reduction. These subjects were adjusted to receive 5 laser sessions with a 1-month interval. One side received high fluence, low-frequency 1064-nm laser where the other side received multipass low fluence, high-frequency 755 nm laser. The follow up was done using photographs, folliscope, patients' visual analog pain scale.

RESULTS

The mean percentage of hair density reduction showed significant improvement in both treated sides being higher in the Alex treated side with corresponding significant decreases in the mean hair thickness.

CONCLUSION

Multipass low fluence, high-frequency 755-nm Alex laser practice was verified to be safe and effective for hair removal in dark skin phototypes compared to the high fluence, low frequency 1064-nm long pulsed Nd:YAG laser.

Efficacy and safety of ND:YAG 1064 nm lasers for photoepilation: a systematic review

Using light sources in phototherapy has presented promising results regarding several types of facial and body skin affections for centuries. The neodymium-doped yttrium aluminum garnet (ND:YAG) 1064 nm laser has become a standard treatment in dermatology for dermatological disturbances related to the pilous follicle and the structures surrounding it. Despite the reports of its clinical benefits, few scientific studies show its actual safety and efficacy. To substantiate the effects, benefits, and safety of applying an ND:YAG 1064 laser in the epilation process during esthetic treatment, a systematic review was carried out between October 2018 and January 2019, on studies published in the last 20 years. Randomized clinical trials in humans were considered that evaluated the efficacy, safety, and benefits of ND:YAG laser application at 1064 nm wavelengths for hair removal. A total of 198 articles were identified; 58 articles remained after their titles and abstracts were read; and 21 articles were selected after the removal of duplicates. After the integral reading, 13 of these articles were included in the systematic review (734 patients). The ND:YAG 1064 nm laser presents safety and promising, beneficial effects in epilation. However, further scientific studies with better methodologic quality are necessary to better standardize ND:YAG laser therapy and clarify its parameters for photoepilation.

Lasers for reduction of unwanted hair in skin of colour: a systematic review and meta-analysis

Light-based therapies are one of the most effective and widely used strategies for removal of undesired hair, with a broadly favourable safety profile. However, subjects with pigmented skin are found to be more prone to laser-related adverse events. While prolonged pulse-width and longer treatment duration were proposed to minimize adverse events, the optimal treatment option among available phototherapy modalities - long-pulsed (Nd:YAG), pulsed diode and alexandrite lasers as well as intense pulsed light (IPL) - remains unclear, particularly for skin of colour. To determine superiority in terms of effectiveness and tolerability, we conducted a systematic review of literature on different types of in-office laser and IPL for hair removal in subjects with Fitzpatrick skin types III-VI. The meta-analysis was performed using Review Manager (RevMan) version 5.3 and included 12 eligible comparative trials (nine randomized controlled trials and three quasi-randomized). In terms of hair count reduction, pooled effect estimates for long-pulsed ND:YAG laser [OR: 0.26, 95% CI (0.1, 0.78)] and diode laser [standardized mean difference (SMD): -0.11, 95% CI (-0.62, 0.39)] were not statistically significant from those of IPL; in contrast, alexandrite laser was found to be superior to IPL in reducing hair count [SMD: -1.7, 95% CI (-2.6, -0.78)]. In terms of adverse events, the pooled effect estimates favoured long-pulsed Nd:YAG laser to IPL with respect to postinflammatory hyperpigmentation [OR: 0.26, 95% CI: (0.1, 0.78)]. However, both pulsed diode and alexandrite lasers exhibited a comparable safety profile to IPL, despite higher pain scores with lasers. In conclusion, this systematic review suggests that treatment outcomes for different in-office laser devices and IPL in subjects with skin type III-VI are broadly similar; nevertheless, we observed a trend towards greater hair reduction following laser therapy compared with IPL.

Photothermal effect by 808-nm laser irradiation of melanin: a proof-of-concept study of photothermal therapy using B16-F10 melanotic melanoma growing in BALB/c mice

The photothermal effect is undergoing great interest due to advances in new photosensitizing materials and better-suited light sources, but studies are frequently hampered by the need to employ exogenous photothermal agents and expensive irradiation devices. Here we present a simple strategy based on direct NIR irradiation of the melanin pigment with a commercial 808-nm laser pointer. Proof-of-concept studies showed efficient photothermal effects on melanin in vitro and in vivo. After NIR irradiation, BALB/c mice bearing B16-F10 melanotic melanoma tumors revealed severe histopathological damage and massive necrosis in melanin-containing tumor tissue, while surrounding healthy tissues showed no damage. Therefore, the feasibility of this approach may allow implementing direct procedures for photothermal therapy of pigmented tumors.

Light-based home-use devices for hair removal: Why do they work and how effective they are?

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.

Effect of Intense Pulsed Light Therapy on Tear Proteins and Lipids in Meibomian Gland Dysfunction

PURPOSE

To assess the effect of a novel intense pulsed light (IPL) therapy on tear proteins and lipids in eyes with Meibomian gland dysfunction (MGD).

METHODS

Twenty-four eyes of 12 patients with MGD were recruited and received five overlapping flashes (565-1400 nm) directed at the lower eyelid. The IPL parameters include intensity: 2.5 to 6.5 J/cm2, voltage: 100 to 240 V, frequency: 50 to 60 Hz, input: 16 W, maximum optical energy: 23 J, pulse duration: <2.0 ms, and repetition time: 1-3.5 s. Tear samples were evaluated immediately before and 2 weeks after IPL therapy and included measurements of protein concentration, electrophoretic mobility by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, lipid profile assessments, and thin-layer chromatography (TLC) for phospholipids.

RESULTS

Significant improvements were observed in tear protein concentrations and molecular weight after IPL therapy. The most pronounced effect was in the molecular weight of tear lysozyme, lactoferrin, and albumin. Tear lipids showed an improvement in the concentrations of total lipids, triglycerides, cholesterol, and phospholipids. On TLC, the tears in patients with MGD had significantly lower amounts of anionic phosphatidylethanolamine, phosphatidylinositol, and phosphatidylserine but amounts zwitterionic neutral phospholipid phosphatidylcholine were normal. These anionic phospholipids showed obvious recovery after IPL therapy.

CONCLUSION

IPL therapy is effective in eyes with MGD. It improved tear protein and lipid content and composition. The anionic phospholipids were more responsive to IPL therapy than were the other zwitterionic phospholipids.

Infrared thermography as control of handheld IPL device for home-use

Infrared thermography as contactless method for determining the temperature distribution on the surface is used for analyzing the impact of intense pulsed light hair removal device (IPL) on the skin. Depth of light penetration depending of wavelength is described as well as absorption curves and IPL impulse shapes. Energy balance and IPL impulse influence on the skin is analyzed. Melanin temperature rise by different fluence operation and temperature distribution in the modeled hair is used in order to determine overall skin temperature rise. Estimated energy balance provided by mathematical model has been confirmed with experimental results. Performed measurements, beside determination of the right emissivity, required the identification of most significant parameter in the process which proved to be the skin reference temperature and real temperature rise. Practical IPL application with detailed body temperature analysis is comprehensively described and thermal imaging interpretation problem and determination of the temperature rise is observed.

Photoepilation and Skin Photorejuvenation: An Update

The effectiveness of intense pulsed light (IPL) and laser devices is widely accepted in aesthetic dermatology for unwanted hair removal and treatment of a variety of cutaneous conditions. Overall, most comparative trials have demonstrated similar effectiveness for IPL and laser devices. Literature studies alternatively favor the IPL and laser concepts, but the incidence of severe local pain and side effects were generally lower with IPL. IPL phototherapy, already established as a sound option in photoepilation and treatment of photoaging, hyperpigmentation and other skin conditions, is also considered first choice in the phototherapy of skin vascular malformations. When treating large areas, as often required in photoepilation and many aesthetic dermatology indications, IPL technologies show advantages over laser-based devices because of their high skin coverage rate. Compared to lasers, the wide range of selectable treatment settings, though a strong advantage of IPL, may also imply some more risk of local thermal side effects, but almost only in the hands of poorly trained operators. Overall, the strongest advantages of the IPL technologies are robust technology, versatility, lower purchase price, and the negligible risk of serious adverse effects in the hands of skilled and experienced operators.

Side effects from intense pulsed light: Importance of skin pigmentation, fluence level and ultraviolet radiation-A randomized controlled trial

BACKGROUND AND OBJECTIVE

Intense pulsed light (IPL) is a mainstream treatment for hair removal. Side effects after IPL are known, but risk factors remain to be investigated. The objective of this study was to assess the contribution of skin pigmentation, fluence level, and ultraviolet radiation (UVR) on IPL-induced side effects.

METHODS

The study was a blinded, randomized intra-individual controlled trial including 16 healthy subjects with Fitzpatrick Skin Types (FST) II-V. Three test areas were each divided into four sites, randomized to a single IPL exposure of 22, 34, 46 J/cm² or triple stacking of 46 J/cm² . Areas were subsequently randomized to no UVR or single solar-simulated UVR exposure of 3 Standard Erythema Dose at 30 minutes or 24 hours after IPL. Each area had a corresponding control, resulting in 15 treatment sites. Follow-up visits were scheduled up to 4 weeks after IPL. Outcome measures were: (i) blinded clinical skin reactions; (ii) objectively measured erythema and pigmentation; (iii) pain measured by visual analog scale (VAS); (iv) histology (H&E, Fontana-Masson); and (v) mRNA-expression of p53.

RESULTS

Fifteen subjects with FST II-IV completed the protocol. IPL induced a wide range of skin reactions, including erythema (87% of subjects), purpura (27%), blisters (20%), edema (13%), crusting (13%), hyper- (60%), and hypopigmentation (20%). Darker skin pigmentation and increasing IPL fluence were determinants for IPL-induced side effects (P ≤ 0.002), while a single exposure of UVR did not exacerbate side effects (P ≥ 0.180). Clinical findings were confirmed objectively by reflectance spectrometry and qualitatively by histological changes in skin architecture, inflammatory infiltration, and pigmentation. Marker of cellular DNA damage, that is, p53, did not increase after IPL (P ≥ 0.24).

CONCLUSIONS

Skin pigmentation and IPL fluence are major determinants of side effects after IPL exposure, while a single exposure to three SED of UVR at 30 minutes or 24 hours after IPL, does not amplify such side effects. Lasers Surg. Med. 49:88-96, 2017. © 2016 Wiley Periodicals, Inc.

Evaluation of the Safety and Effectiveness of Intense Pulsed Light in the Treatment of Meibomian Gland Dysfunction

Purpose. This study aims to explore the safety and efficacy of a novel treatment-intense pulsed light (IPL) in MGD eyes. Methods. This study is a prospective and open label study. Forty eyes of 40 MGD patients were recruited in the study and received 4 consecutive IPL treatments on day 1, day 15, day 45, and day 75. Ten ocular surface symptoms were evaluated with a subjective face score at every visit. Best spectacle corrected visual acuity, intraocular pressure (IOP), conjunctival injection, upper and lower tear meniscus height (TMH), tear break-up time (TBUT), corneal staining, lid margin and meibomian gland assessments, and meibography were also recorded at every visit, as well as the adverse effects on the eye and ocular surface. Results. Significant improvements were observed in single and total ocular surface symptom scores, TBUT, and conjunctival injection at all the visits after the initial IPL treatment (P < 0.05). Compared to baseline, the signs of eyelid margin, meibomian gland secretion quality, and expressibility were significantly improved at every visit after treatments. There was no regional and systemic threat observed in any patient. Conclusion. Intense pulsed light (IPL) therapy is a safe and efficient treatment in relieving symptoms and signs of MGD eyes.

Ultraviolet radiation after exposure to a low-fluence IPL home-use device: a randomized clinical trial

The prevailing advice is to avoid sun exposure after intense pulsed light (IPL) hair removal. However, no systematic evaluation of ultraviolet radiation (UVR) after IPL hair removal exits. Therefore, we investigated the occurrence of side effects in subjects receiving solar-simulated UVR after a low-fluence IPL treatment with a home-use device. Sixteen subjects with Fitzpatrick skin types (FST) II-V were enrolled. Three constitutive buttock blocks (4.4 × 6.4 cm) were each subdivided into four sites, randomized to one IPL exposure of 0, 7, 8, or 10 J/cm2 (spectral output 530-1100 nm). Blocks were randomized to no UVR or three standard erythema doses (SEDs) UVR either 30 min or 24 h after IPL. Follow-up visits were 48 h, 1 week, and 4 weeks after IPL. Outcome measures were (i) clinical skin reactions, (ii) reflectance measurements of erythema and pigmentation, and (iii) pain. Subjects with FST II-IV experienced no skin reactions up to 4 weeks after IPL, neither erythema, edema, blisters, crusting, textual, nor pigment changes. Reflectance confirmed no change in erythema and pigmentation (p ≥ 0.090). UVR exposure induced erythema and increased pigmentation. The combination of IPL and UVR induced skin reactions not different to responses from UVR (IPL-UVR vs. UVR, p ≥ 0.164). Pain was generally low (median 1, range 0-4) and correlated positively with fluence and pigmentation (Spearman's rho ≥ 0.394, p < 0.001). One subject with FST V experienced perifollicular hyperpigmentation after IPL and slightly more intense when exposed to UVR. A single UVR exposure of three SEDs either shortly or 1 day after low-fluence IPL causes no amplification of skin responses in constitutive skin of individuals with FST II-IV.

Interventions for hirsutism (excluding laser and photoepilation therapy alone)

BACKGROUND

Hirsutism occurs in 5% to 10% of women of reproductive age when there is excessive terminal hair growth in androgen-sensitive areas (male pattern). It is a distressing disorder with a major impact on quality of life. The most common cause is polycystic ovary syndrome. There are many treatment options, but it is not clear which are most effective.

OBJECTIVES

To assess the effects of interventions (except laser and light-based therapies alone) for hirsutism.

SEARCH METHODS

We searched the Cochrane Skin Group Specialised Register, CENTRAL (2014, Issue 6), MEDLINE (from 1946), EMBASE (from 1974), and five trials registers, and checked reference lists of included studies for additional trials. The last search was in June 2014.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in hirsute women with polycystic ovary syndrome, idiopathic hirsutism, or idiopathic hyperandrogenism.

DATA COLLECTION AND ANALYSIS

Two independent authors carried out study selection, data extraction, 'Risk of bias' assessment, and analyses.

MAIN RESULTS

We included 157 studies (sample size 30 to 80) comprising 10,550 women (mean age 25 years). The majority of studies (123/157) were 'high', 30 'unclear', and four 'low' risk of bias. Lack of blinding was the most frequent source of bias. Treatment duration was six to 12 months. Forty-eight studies provided no usable or retrievable data, i.e. lack of separate data for hirsute women, conference proceedings, and losses to follow-up above 40%.Primary outcomes, 'participant-reported improvement of hirsutism' and 'change in health-related quality of life', were addressed in few studies, and adverse events in only half. In most comparisons there was insufficient evidence to determine if the number of reported adverse events differed. These included known adverse events: gastrointestinal discomfort, breast tenderness, reduced libido, dry skin (flutamide and finasteride); irregular bleeding (spironolactone); nausea, diarrhoea, bloating (metformin); hot flushes, decreased libido, vaginal dryness, headaches (gonadotropin-releasing hormone (GnRH) analogues)).Clinician's evaluation of hirsutism and change in androgen levels were addressed in most comparisons, change in body mass index (BMI) and improvement of other clinical signs of hyperandrogenism in one-third of studies.The quality of evidence was moderate to very low for most outcomes.There was low quality evidence for the effect of two oral contraceptive pills (OCPs) (ethinyl estradiol + cyproterone acetate versus ethinyl estradiol + desogestrel) on change from baseline of Ferriman-Gallwey scores. The mean difference (MD) was -1.84 (95% confidence interval (CI) -3.86 to 0.18).There was very low quality evidence that flutamide 250 mg, twice daily, reduced Ferriman-Gallwey scores more effectively than placebo (MD -7.60, 95% CI -10.53 to -4.67 and MD -7.20, 95% CI -10.15 to -4.25). Participants' evaluations in one study with 20 participants confirmed these results (risk ratio (RR) 17.00, 95% CI 1.11 to 259.87).Spironolactone 100 mg daily was more effective than placebo in reducing Ferriman-Gallwey scores (MD -7.69, 95% CI -10.12 to -5.26) (low quality evidence). It showed similar effectiveness to flutamide in two studies (MD -1.90, 95% CI -5.01 to 1.21 and MD 0.49, 95% CI -1.99 to 2.97) (very low quality evidence), as well as to finasteride in two studies (MD 1.49, 95% CI -0.58 to 3.56 and MD 0.40, 95% CI -1.18 to 1.98) (low quality evidence).Although there was very low quality evidence of a difference in reduction of Ferriman-Gallwey scores for finasteride 5 mg to 7.5 mg daily versus placebo (MD -5.73, 95% CI -6.87 to -4.58), it was unlikely it was clinically meaningful. These results were reinforced by participants' assessments (RR 2.06, 95% CI 0.99 to 4.29 and RR 11.00, 95% CI 0.69 to 175.86). However, finasteride showed inconsistent results in comparisons with other treatments, and no firm conclusions could be reached.Metformin demonstrated no benefit over placebo in reduction of Ferriman-Gallwey scores (MD 0.05, 95% CI -1.02 to 1.12), but the quality of evidence was low. Results regarding the effectiveness of GnRH analogues were inconsistent, varying from minimal to important improvements.We were unable to pool data for OCPs with cyproterone acetate 20 mg to 100 mg due to clinical and methodological heterogeneity between studies. However, addition of cyproterone acetate to OCPs provided greater reductions in Ferriman-Gallwey scores.Two studies, comparing finasteride 5 mg and spironolactone 100 mg, did not show differences in participant assessments and reduction of Ferriman-Gallwey scores (low quality evidence). Ferriman-Gallwey scores from three studies comparing flutamide versus metformin could not be pooled (I² = 62%). One study comparing flutamide 250 mg twice daily with metformin 850 mg twice daily for 12 months, which reached a higher cumulative dosage than two other studies evaluating this comparison, showed flutamide to be more effective (MD -6.30, 95% CI -9.83 to -2.77) (very low quality evidence). Data showing reductions in Ferriman-Gallwey scores could not be pooled for four studies comparing finasteride with flutamide as the results were inconsistent (I² = 67%).Studies examining effects of hypocaloric diets reported reductions in BMI, but which did not result in reductions in Ferriman-Gallwey scores. Although certain cosmetic measures are commonly used, we did not identify any relevant RCTs.

AUTHORS' CONCLUSIONS

Treatments may need to incorporate pharmacological therapies, cosmetic procedures, and psychological support. For mild hirsutism there is evidence of limited quality that OCPs are effective. Flutamide 250 mg twice daily and spironolactone 100 mg daily appeared to be effective and safe, albeit the evidence was low to very low quality. Finasteride 5 mg daily showed inconsistent results in different comparisons, therefore no firm conclusions can be made. As the side effects of antiandrogens and finasteride are well known, these should be accounted for in any clinical decision-making. There was low quality evidence that metformin was ineffective for hirsutism and although GnRH analogues showed inconsistent results in reducing hirsutism they do have significant side effects.Further research should consist of well-designed, rigorously reported, head-to-head trials examining OCPs combined with antiandrogens or 5α-reductase inhibitor against OCP monotherapy, as well as the different antiandrogens and 5α-reductase inhibitors against each other. Outcomes should be based on standardised scales of participants' assessment of treatment efficacy, with a greater emphasis on change in quality of life as a result of treatment.

Trial of human laser epilation technology for permanent wool removal in Merino sheep

OBJECTIVE

To assess whether human laser epilation technology can permanently prevent wool growth in sheep.

DESIGN

An observational study.

METHODS

Two commercial human epilation lasers (Sharplan alexandrite 755 nm laser, and Lumenis LightSheer 800 nm diode laser) were tested at energies between 10 and 100 J/cm2 and pulse widths from 2 to 400 ms. Wool was clipped from flank, breech, pizzle and around the eyes of superfine Merino sheep with Oster clippers. After initial laser removal of residual wool to reveal bare skin, individual skin sites were treated with up to 15 cycles of laser irradiation. Behavioural responses during treatment, skin temperature immediately after treatment and skin and wool responses for 3 months after treatment were monitored.

RESULTS

A clear transudate was evident on the skin surface within minutes. A dry superficial scab developed by 24 h and remained adherent for at least 6 weeks. When scabs were shed, there was evidence of scarring at sites receiving multiple treatment cycles and normal wool growth in unscarred skin. There was no evidence of laser energy level or pulse width affecting the response of skin and wool to treatment and no evidence of permanent inhibition of wool growth by laser treatment. Laser treatment was well tolerated by the sheep.

CONCLUSIONS

Treatment of woolled skin with laser parameters that induce epilation by selective photothermolysis in humans failed to induce permanent inhibition of wool growth in sheep. Absence of melanin in wool may have contributed to the result.

Quantitative assessment of growing hair counts, thickness and colour during and after treatments with a low-fluence, home-device laser: a randomized controlled trial

BACKGROUND

At-home laser and intense pulsed-light hair removal continues to grow in popularity and availability. A relatively limited body of evidence is available on the course of hair growth during and after low-fluence laser usage.

OBJECTIVES

To assess growing hair counts, thickness and colour quantitatively during and after cessation of low-fluence laser treatment.

METHODS

Thirty-six women with skin phototypes I-IV and light to dark-brown axillary hairs were included. Entire axillary regions were randomized to zero or eight self-administered weekly treatments with an 810-nm home-use laser at 5·0-6·4 J cm(-2). Standardized clinical photographs were taken before each treatment and up to 3 months after the final treatment for computer-aided quantification of growing hair counts, thickness and colour.

RESULTS

Thirty-two women completed the study protocol. During sustained treatment, there was a reduction in growing hair that reached a plateau of up to 59%, while remaining hairs became up to 38% thinner and 5% lighter (P < 0·001). The majority of subjects (77%) reported 'moderately' to 'much less hair' in treated than untreated axilla, and assessed remaining hairs as thinner and lighter (≥ 60%). After treatment cessation, hair growth gradually returned to baseline levels, and 3 months after the final treatment the count and thickness of actively growing hair exceeded pretreatment values by 29% and 7%, respectively (P ≤ 0·04).

CONCLUSIONS

Sustained usage of low-fluence laser induced a stable reduction of growing hair counts, thickness and colour. The reduction was reversible and hairs regrew beyond baseline values after cessation of usage. Computer-aided image analysis was qualified for quantification of hair counts, thickness and colour after laser epilation.

The role of natural and UV-induced skin pigmentation on low-fluence IPL-induced side effects: a randomized controlled trial

BACKGROUND AND OBJECTIVES

The risk of adverse skin effects following light-based hair removal is greater in pigmented skin based on the theory of selective photothermolysis. Thus sunlight-induced pigment i.e., facultative pigmentation, increases the risk of adverse skin effects, perhaps disproportionately. The aim of this study was to evaluate the influence of constitutive and facultative skin pigmentation on low-fluence intense pulsed light (IPL)-induced adverse skin effects.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-one subjects with Fitzpatrick skin type II-IV were enrolled. Two buttock blocks were randomized to receive 0 or 8 solar simulated ultraviolet radiation (UVR) exposures of consecutively increasing Standard Erythema Doses (2-4 SED). Each block was subdivided into four sites, randomized to receive IPL of 0, 7, 8, or 10 J/cm(2) , once a week for 3 weeks. Biopsies were taken 16-24 hours after the first IPL exposure and subjects were seen 1 and 4 weeks after the last IPL exposure. Outcome measures were: (i) skin reactions, (ii) pain, (iii) mRNA expression of pigment-markers microphthalmia-associated transcription factor (MITF) and pro-opiomelanocortin (POMC), and (iv) clinical appearance of biopsy wounds.

RESULTS

Skin pigmentation increased after UVR (baseline median 13.8%, after UVR 28.1%, P = 0.0001) in all skin types. Subjects reported low pain intensities (median 1.5, scale 0-10) and experienced transient erythema immediately after IPL exposure. No persistent erythema, blisters, crusting, textual, or pigment changes were observed. The risk of erythema and pain intensities increased with IPL dose and skin pigmentation (P < 0.03). There was no difference in pain or skin reactions in skin with similar degree of natural and facultative pigmentation (P ≥ 0.104). Expression of cellular pigment-markers was not influenced by IPL exposure, neither in constitutive nor in facultative pigmented skin. Clinical appearance of biopsy wounds was unaffected by IPL exposure.

CONCLUSION

The prevalence and intensity of low-fluence IPL-induced adverse skin effects depended on IPL dose and skin pigmentation regardless of the origin, i.e., constitutive versus UV induced.

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.