The effect of 1540‐nm fractional erbium‐glass laser in the treatment of androgenic alopecia

Progress of clinical research on fractional laser treatment of androgenetic alopecia: A review article

BACKGROUND

Androgenetic alopecia (AGA) is a prevalent form of hair loss that affects both men and women, severely impacting patients' quality of life. Traditional treatments include oral medications, topical medications, and hair transplantation, but these methods have certain side effects and limitations. How to safely effectively and maximally promote hair growth has been a key issue in the treatment of AGA. In recent years, fractionated laser therapy, as a noninvasive method, has gradually gained attention due to its minimally invasive and highly effective nature.

AIMS

In this paper, we summarized the studies related to fractional laser treatment of AGA in the past 15 years, and discussed its therapeutic mechanism, clinical effect, future development direction, and advantages and disadvantages compared with traditional treatment methods in the treatment of AGA.

METHODS

An extensive literature search was conducted using PubMed, Google, Google Scholar, Embase, and Scopus. All available articles studying fractional laser treatment of AGA were compiled in March 2024. Titles and abstracts were then screened for relevance and thoroughly examined for patient clinical outcomes. Prospective clinical trials, retrospective chart reviews, case series, and individual case reports were included in the literature review.

CONCLUSIONS

Fractional laser treatment of AGA showed remarkable efficacy and high safety. Compared with traditional treatments, fractional laser has the advantages of minimally invasive, quick recovery, fewer side effects, and a wide range of population applicability, providing an effective treatment option for AGA patients. Further large-scale clinical studies will help optimize the laser parameters and treatment settings to improve the therapeutic effect.

Management of androgenic alopecia: a systematic review of the literature

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.

A study of the biological effects of low-level light

Low-level light therapy (LLLT), also known as photo biomodulation (PBM), is a type of optical therapy that uses red or near-infrared lasers or light-emitting diodes (LEDs) for medical treatment. The laser wavelengths involved in PBM typically range between 600-700 nm and 780-1100 nm, with power densities ranging between 5 mW/cm2 and 5 W/cm2. PBM is a series of biochemical cascades exhibited by biological tissues after absorbing a certain amount of energy from light. PBM has been widely used in clinical practice in the past 20 years, and numerous clinical trials have demonstrated its biological efficacy. However, the underlying mechanisms have not yet been fully explored. In this paper, we have summarized the research into PBM over the past two decades, to identify the important mechanisms of the biological effects of PBM from the perspective of molecular mechanisms, cellular levels, and tissue changes. We hope our study provide a theoretical basis for future investigations into the underlying mechanisms.

Use of fractionated laser therapy for the treatment of androgenetic alopecia: a systematic review and meta-analysis

Procedural management, including fractionated laser therapy, has been increasingly investigated for the management of androgenetic alopecia (AGA). However, no comprehensive resources exist detailing the efficacy of fractionated laser therapies used for the treatment of AGA. A systematic review investigating fractionated laser use for AGA was performed, separated into each distinct fractionated laser modality. A meta-analysis was performed to examine improvement in hair counts and hair shaft diameter. Fourteen studies were included for systematic review, which identified the use of erbium-glass, thulium, erbium-ytrrium:aluminum garnet (YAG), and carbon dioxide (CO2) fractionated laser for the treatment of AGA. In the meta-analysis, fractionated laser combination therapy showed significant improvement in hair shaft diameter (2.51, 95% CI 2.37-2.65, I2 = 90.54). Fractionated laser monotherapy alone significantly improved hair shaft diameter (2.28 95% CI 2.03-2.52, I2 = 91.20%). This effect was durable on subgroup analysis for both erbium-glass (2.36 95% CI 2.01-2.71, I2 = 92.05%) and thulium (1.61 95% CI 1.08-2.15, I2 = < 0.00%). There was no improvement in hair shaft count for any laser modality. Erbium-glass laser is an effective modality as either monotherapy or combination with topical/injectable therapies to improve hair shaft diameter in AGA.

Topical 5% minoxidil versus combined erbium YAG laser and topical 5% minoxidil in androgenetic alopecia: A randomized controlled trial

BACKGROUND

Androgenetic alopecia (AGA) is the most common type of hair loss in men, and several treatment options have been proposed for it. Fractional ablative erbium YAG laser can promote hair growth through trans-epidermal drug delivery and the thermal stimulation of hair follicles; this study therefore aims to evaluate minoxidil alone and in combination with fractional ablative erbium YAG laser in male patients with AGA.

METHODS

This study was performed on 30 male patients with moderate to severe AGA. Patients were equally randomized into two groups, and the intervention group was treated with 1 mL of topical 5% minoxidil twice daily and six sessions of 2940-nm ablative fractional erbium YAG laser, and the control group received topical 5% minoxidil alone. The assessment entailed photography, dermoscopy, and patient satisfaction based on a 7-point grading scale.

RESULTS

Both groups showed statistically significant improvements in terms of patient satisfaction, photography, and dermoscopy scores. The group receiving a combination of laser and minoxidil treatment obtained a higher dermoscopy score than the patients receiving minoxidil alone (p-value = 0.016). Nonetheless, there was no difference between the two groups in terms of the photography score (p-value = 0.13).

CONCLUSION

Laser treatment can stimulate the hair follicles and also enhance the dermal delivery of minoxidil, which was found to be associated with slightly better outcomes in this study.

Effect of Skin Type on Efficacy of Laser Treatment for Androgenetic Alopecia: A Review of the Literature

The use of low-light laser therapy to treat androgenetic alopecia is a promising modality to restore hair growth. However, the effect of skin color on response to laser therapy for hair growth has not been systematically explored in the literature. The objective of this study is to systematically assess through a comprehensive literature search of the MEDLINE database whether skin type data were collected in clinical trials and analyzed in each study and determine if we can estimate an effect. 10/22 studies have defined inclusion criteria as Fitzpatrick skin types I-IV. No studies mentioned effects on darker skin types, Fitzpatrick skin types V-VI. Only 5/10 studies had statistical data on efficacy depending on Fitzpatrick skin type, with four showing no effect and one showing a significant positive effect with darker skin types having faster rate of hair growth. There are not enough data to conclude whether skin type effects laser-induced hair growth in androgenic alopecia. The studies are severely lacking in sample size. One showed a potential effect. Importantly, there are no data on black or brown skin colors. Development of optimal laser irradiating wparameters through the prediction of personalized absorbance based on skin color measurement is needed.

Synergistic Sequential Emission of Fractional 10.600 and 1540 nm Lasers for Skin Resurfacing: An Ex Vivo Histological Evaluation

Background: Fractional ablative and non-ablative lasers are useful treatments for skin rejuvenation. A procedure that provides the sequential application of fractional ablative followed by non-ablative laser treatment may reduce patients' downtime and deliver better cosmetic results than with either laser alone. Objective: The purpose of the current study was to demonstrate the ameliorative and therapeutic effects in skin remodeling of the synergistic use of the two laser wavelengths (fractional ablative CO₂ and non-ablative 1540 nm) with three different types of pulse shapes, S-Pulse (SP), D-Pulse (DP) and H-Pulse (HP), through which the CO₂ laser can emit, performing an ex vivo histological evaluation. Methods: In this prospective study, ex vivo sheep inner thigh skin was chosen due to its similarity to human skin tissue, and a histological evaluation was performed. Three irradiation conditions, using all of the three CO₂ pulse shapes (alone or averaged), were investigated: (1) 10.600 nm alone, the sequential irradiation of the two wavelengths in the same perfectly controlled energy pulses (DOT) for the entire scan area; ((2) 10.600 nm followed immediately by 1540 nm; and (3) 1540 nm followed immediately by 10.600 nm). Results: When comparing ablative to sequential irradiations, the synergy of the two wavelengths did not alter the typical ablative pulse shape of the 10.600 nm laser alone. With the same CO₂ pulse shape, the lesion depth did not vary with the synergy of the two wavelengths, while thermal lesion width increased compared to CO₂ alone. The ablation rate was achieved, while the total thermal lesion coverage in the scanning area of CO₂ - 1540 lasers was greater than when using CO₂ alone and then the other sequential irradiation. Conclusions: This study provides important preclinical data for new and early uses of the novel 10.600/1540 nm dual-wavelength non-ablative fractional laser. The synergy of the two wavelengths enhanced all the benefits already available when using CO₂ laser systems both in terms of tone strengthening, thanks to a greater shrinking effect, and in terms of stimulation and collagen remodeling thanks to a greater volumetric thermal effect.

Clinical Efficacy and Safety of Pulsed Dye Laser Combined with Pingyangmycin on Hyperplastic Scar after Acne

Background

Acne is the most common chronic inflammatory disease of hair follicles and sebaceous glands in dermatology. Hyperplastic scar (HS), a very common sequelae of acne, is also the most common scar type in clinical practice.

Objective

This research analyzed the clinical effectiveness and safety of pulsed dye laser (PDL) combined with pingyangmycin (PI) in the treatment of post-acne HS.

Methods

One hundred and nine patients with post-acne HS admitted in June 2020 were selected and divided into a research group (n = 52) and a control group (n = 57) according to the difference in treatment methods. The efficacy, incidence of adverse reactions, skin repair, treatment comfort, and satisfaction were compared between groups.

Results

The total effective rate was higher in the research group compared with the control group. No statistical difference was observed between groups in the incidence of adverse reactions. The research group showed better scar repair, skin improvement, and granulation tissue maturity than the control group. And compared with the control group, the growth factor of the research group was lower, while the treatment comfort and satisfaction, psychological state, and prognosis quality of life were higher. The two groups showed no notable difference in the recurrence rate.

Conclusions

PDL combined with PI can effectively improve the clinical efficacy, scar repair effect, overall skin status, and treatment experience of patients and boost the psychological state and prognostic quality of life of patients, which has great clinical application prospect for the treatment of HS.

Energy-based Devices for Hair Loss

Treatment options for hair loss have traditionally been limited to topical and systemic therapies. Systemic therapies for inflammatory hair disorders are often immunosuppressive, and systemic treatment of androgenetic hair loss can cause undesired effects on sexual and reproductive health. Topical agents have a favorable side effect profile compared with systemic therapies, but many topicals have poor transcutaneous absorption, limiting their concentration and action at follicular targets in the dermis.

Factors influencing the effect of photobiomodulation in the treatment of androgenetic alopecia: A systematic review and analyses of summary-level data

Low-level laser therapy (LLLT) is used to treat androgenetic alopecia (AGA). The therapeutic effect of LLLT on AGA has been evaluated; however, there is a paucity of studies that investigated device- and usage-related factors that may influence the effect of LLLT on hair regrowth. The literature was systematically searched to identify eligible studies; PubMed, Scopus, EMBASE and clinicaltrials.gov databases were searched on 30 April 2020. Eligible studies were randomized trials that investigated the effect of LLLT on hair density in AGA. Robust linear regressions were used to make comparisons. An increase in the per-session energy fluence by 1 J/cm² is significantly associated with an increase in hair density by 0.23 hairs/cm² (95% CI: 0.21 hairs/cm² , 0.25 hairs/cm² ). The number of laser or light-emitting diodes is not significantly associated with change in hair density. Increasing the total duration of exposure to treatment is associated with a significant increase in hair density (β = .53, P < .05). Switching from continuous to pulse irradiation was associated with a significant increase in hair density (β = 10.11, P < .01). Energy fluence, irradiation session duration, and light pulsing have a significant therapeutic effect on AGA, while the number of diodes does not.