Evaluation of a new super-long-pulsed 810 nm diode laser for the removal of unwanted hair: the concept of thermal damage time

810 nm diode laser for hair reduction with Chill-tip technology: prospective observational analysis of 55 patients of Fitzpatrick skin types III, IV,V

Background: Various light based technologies like Diode, long pulsed Nd:Yag and Intense Pulsed Light are used commonly for long-term hair reduction. The commonest indication is hirsutism.Aim: 1. To evaluate efficacy and safety of 810 nm Diode laser in Fitzpatrick skin types III, IV and V.2. To assess percentage of cases on the basis of indications, average number of sessions, fluence required, the long-term results and complications using diode laser in darker skin types.Methods: A prospective observational study of 55 consecutive patients who came for laser hair reduction by 810 nm Light Sheer Diode laser with Chill tip technology was carried out. The sessions were conducted at an interval of 4-6 weeks and the patients were followed up over a period of 2 years. Data was analyzed using software SPSS (Statistical Package for Social Science. Ver.12, Inc. Chicago, USA).Results: Fifty-five patients (51 females and 4 males) were studied. 67.3% (n = 37) had skin type IV. The most common area treated was chin (n = 23). The average growth reduction of terminal hair at the end of three sessions was 61.25%. Only 8% (n = 4) had short-term side effects.Conclusion: Diode laser is highly effective for long-term hair reduction of terminal hair growth in Fitzpatrick skin type III, IV and V with no permanent side effects.Abbreviations: LHR (Laser Hair Reduction).

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.

Efficacy and Safety of Hair Removal with a Long-Pulsed Diode Laser Depending on the Spot Size: A Randomized, Evaluators-Blinded, Left-Right Study

BACKGROUND

The efficacy of the long-pulsed diode laser (LPDL) in hair removal is determined with various physical parameters. Recently, LPDLs with a larger spot size are commercially available; however, the independent effect of spot size on hair removal has not been studied.

OBJECTIVE

This study aimed to compare the efficacy of the LPDL in hair removal depending on the spot size.

METHODS

A randomized, evaluators-blind, intrapatient comparison (left vs. right) trial was designed. Ten healthy Korean women received three hair removal treatment sessions on both armpits with the 805-nm LPDL and followed for 3 months. A 10×10 mm handpiece (D1) or a 10×30 mm handpiece (D3) was randomly assigned to the right or left axilla. The fluence, pulse duration, and epidermal cooling temperature were identical for both armpits. Hair clearance was quantified with high-resolution photos taken at each visit. Postprocedural pain was quantified on a visual analogue scale. Adverse events were evaluated by physical examination and the patients' self-report.

RESULTS

The mean hair clearance at 3 months after three treatment sessions was 38.7% and 50.1% on the armpits treated with D1 and D3, respectively (p=0.028). Procedural pain was significantly greater in the side treated with D3 (p=0.009). Serious adverse events were not observed.

CONCLUSION

Given that the pulse duration, fluence, and epidermal cooling were identical, the 805-nm LPDL at the three times larger spot size showed an efficacy improvement of 29.5% in axillary hair removal without serious adverse events.

Photothermal ablation of amyloid aggregates by gold nanoparticles

Amyloid peptide (Abeta) is found in the brain and blood of both healthy and diseased individuals alike. However, upon secondary structure transformation to a beta-sheet dominated conformation, the protein aggregates. These aggregates accumulate to form neuritic plaques that are implicated in the pathogenesis of Alzheimer's disease. Gold nanoparticles are excellent photon-thermal energy converters. The extinction coefficient of the surface plasmon band of gold nanoparticles is very large when compared to typical organic dyes. In this study, gold nanoparticle-Abeta conjugates were prepared and the photothermal ablation of amyloid peptide aggregates by laser irradiation was studied. Monofunctional gold nanoparticles were prepared using a recently reported solid phase modification method and then coupled to fragments of Abeta peptide, namely Abeta(31-35) and Abeta(25-35). The conjugates were then mixed with Abeta fragments in solution. The aggregated peptide formation was studied by a series of spectroscopic and microscopic techniques. The peptide aggregates were then irradiated by a continuous laser. With gold nanoparticle-Abeta conjugates present the aggregates were destroyed by photothermal ablation. Gold nanoparticles without Abeta conjugation were not incorporated into the aggregates and when irradiated did not result in photothermal ablation. With gold nanoparticle-Abeta conjugates the ablation was selective to the site of irradiation and minimal damage was observed as a result of thermal diffusion. In addition to the application of photoablation to a protein-based sample the nanoparticles and the chemistry involved provide an easily monofunctionalized photothermal material for the biological conjugation.

Laser hair removal

Since 1996, there have been numerous advances in hair laser removal that utilize melanin as a chromophore. All of the devices on the market may be used in patients with light skin (phototypes I-III) and yield hair reduction near 75%. The ruby (694 nm) laser, alexandrite (755 nm) laser, and diode (810 nm) laser, as well as intense pulsed light are commonly used devices for hair laser removal. The long-pulsed Nd:YAG (1064 nm) laser represents the safest device for hair removal in dark-skinned patients because of its long wavelength, although the diode laser, alexandrite laser, and intense pulse light may be used. For treatment of light hair, combination radiofrequency and optical devices as well as photodynamic therapy are under investigation.

Hair removal using an 800-nm Diode Laser: Comparison at different treatment intervals of 45, 60, and 90 days

BACKGROUND

Some laser irradiation parameters such as wavelength, fluence, pulse duration, and spot size have been shown to influence the damage of any target inside the skin, however, the role of some patients' factors such as hair growth cycle is still under debate.

OBJECTIVE

To determine the association of treatment interval and laser treatment outcome.

METHODS

In a retrospective chart review of 176 patients undergoing laser-assisted hair removal with a diode laser 24 patients were selected. All accepted to cease the therapy, and be followed-up for 5 months. At the end of the study the patients were questioned about the efficacy of the treatment as well as the adverse effects. Hair counting was also performed. The adverse effects (pain, blister or erosion, hyperpigmentation, hypopigmentation, and folliculitis) were questioned during the follow-up period.

RESULTS

The mean hair reduction was 78.1%, 45.8%, and 28.7% in 45, 60, and 90-day interval groups, respectively (P < 0.0001).

CONCLUSION

The treatment interval was related to the treatment outcome in our study.

Laser Hair Removal: Comparison of Long-Pulsed Nd:YAG, Long-Pulsed Alexandrite, and Long-Pulsed Diode Lasers

BACKGROUND

Advances in laser technology over the past several years have led to the development of numerous lasers for the treatment of unwanted hair. Laser wavelength is a key factor influencing treatment efficacy and complication rates.

OBJECTIVE

To compare the efficacy and safety of laser hair removal using three different laser systems.

METHODS

A retrospective study of 805 consecutive laser-assisted hair removal treatments, conducted on 75 patients by means of either a long-pulsed Nd:YAG, a long-pulsed alexandrite, or a long-pulsed diode laser is reported. All patients were evaluated at least 3 months after the last treatment, and their present conditions were compared with the 1st-day photographs.

RESULTS

The mean hair reduction was 42.4%, 65.6%, and 46.9% in Nd:YAG, alexandrite, and diode lasers, respectively. When the number of treatment sessions was taken into account, the efficacy of alexandrite and diode lasers was not significantly different, whereas both systems were more efficacious than Nd:YAG. Neither of the laser systems showed better results for a particular skin type. The occurrence of side effects was not significantly different between three laser systems.

CONCLUSION

Both long-pulsed alexandrite and long-pulsed diode laser systems are effective in the treatment of unwanted hair, and they are more efficacious than Nd:YAG laser.

Lasers in dermatology: four decades of progress

Advances in laser technology have progressed so rapidly during the past decade that successful treatment of many cutaneous concerns and congenital defects, including vascular and pigmented lesions, tattoos, scars, and unwanted hair-can be achieved. The demand for laser surgery has increased substantially by patients and dermatologists alike as a result of the relative ease with which many of these lesions can be removed, combined with a low incidence of adverse postoperative sequelae. Refinements in laser technology and technique have provided patients and practitioners with more therapeutic choices and improved clinical results. In this review, the currently available laser systems with cutaneous applications are outlined, with primary focus placed on recent advancements and modifications in laser technology that have greatly expanded the cutaneous laser surgeon's armamentarium and improved overall treatment efficacy and safety.

The use of a new diode laser for hair removal

BACKGROUND

Diode and long-pulse 1064 Nd:YAG lasers, because of their long wavelengths and extended pulse durations, have gained popularity over the last several years for photoepilation in individuals with dark skin phenotypes.

OBJECTIVE

To analyze the clinical efficacy and histologic features of a new 810-nm diode laser in the treatment of unwanted hair in individuals with Fitzpatrick skin types II-IV.

METHODS

Twenty-four female subjects (mean age, 33; range, 17-53) were treated three times at monthly intervals with the MeDioStarâ diode laser (Zeiss-Meditech, Jenna, Germany): wavelength 810 nm, spot size 12 mm, pulse duration 50 msec; fluence 25-35 J. Patients had skin types II-IV and light to dark brown hair. Hair counts were carried out using handheld magnifiers at baseline and at months 1, 2, 3, and 6. Six individuals had biopsies taken after treatment and at 3 and 6 months.

RESULTS

A mean hair removal efficiency of 74% and 79% was noted at 3 and 6 months, respectively, and was best in those individuals with skin type III. Hair counts after treatment and at last follow-up were significantly lower when compared with the baseline counts (P<0.0001). Histologic analysis revealed a range from early catagen induction to complete follicular destruction.

CONCLUSIONS

This study supports the clinical photoepilatory efficiency of a new 810-nm diode laser in producing 70% clinical hair removal efficiency at 6 months. Histopathologic evaluation suggests that this decrease in hair counts is probably secondary to heat trauma to the follicular epithelium, resulting in complete follicular destruction and stopping of anagen phase.