Stimulation of the natural hair cycle with fractional non-ablative Er:YAG laser
Dr Iva Talaber
Androgenetic alopecia is the most prevalent hair-loss disorder in men. It can exert a profoundly negative eff ect on identity and self-image. With different pharmacological, surgical, light-based, and nutraceutical treatments available, selecting the most suitable therapy can be challenging.
Androgenetic alopecia (AGA) or male pattern baldness, is a multifactorial disorder caused by genetic factors, hor-monal dysregulation, environmental and systemic factors, and aging (1). AGA is estimated to aff ect 50% of Caucasian males and females by the ages of 50 and 80, respectively (2). The prevalence and severity of AGA in Asian and African ethnicities is lower than in Caucasians (3,4). The incidence of AGA is increasing with age in both genders across all ethnicities(5). As hair is an important component of identity and self-image, patients with androgenetic alopecia may experience a distorted body image and a decrease in quality of life (6,7), with early-age onset being especially important as a possible source of depression in young adults (8). Available treatment options for AGA include diff erent oral and topical pharmaceuticals, nutraceuticals, laser therapy, platelet-rich plasma (PRP) and a variety of surgical transplant procedures (9).
The pharmaceuticals include two FDA-approved drugs, oral finasteride and topical minoxidil. Many patients seek alternatives to pharmacological treatment, which can present a plateauing of the response as well as undesirable side effects (8). AGA is characterised by a gradual and progressive miniaturisation of hair follicles, accompanied by a decrease in the ratio of the active growth to the resting stages of the hair cycle (8). Hair follicles are rich in stem cells, which regenerate in continuous cycles consisting of three stages: growth (anagen), involution (catagen), and rest (telogen), all of which are largely aff ected by the Wnt/β-catenin signal-ling pathway (10,11).
The dermal papilla of the hair follicle is a major regulator of the hair cycle, including progenitor cell activation (10). Interestingly, the upregulation of Wnt/β-catenin signalling pathways has been indicated in several of the AGA treatment options, with a demonstrated efficacy, including minoxidil(12), PRP (13,14) and laser treatment (15). Numerous studies have demonstrated efficacy of laser therapy for AGA (2,10,16) and an absence of adverse effects (17,18). Whereas low-level laser therapy utilises photobiomodulation mechanisms to induce cellular metabolism,(19) high-energy medical lasers induce tissue regeneration through photothermal effects (9,10).
Laser hair regrowth treatment is associated with minimal risk and potentially better outco-mes compared to standard pharmacological treatment (2,9). Studies on murine models suggest that laser irradiation aff ects the hair cycle by promoting telogen-to-anagen tran-sitions (20) in both non-ablative (1550 nm erbium-glass (20)) and ablative treatment (2940 nm erbium-YAG15 and 10600 nm CO2 laser (21)). In addition, the laser energy acts by increasing blood flow at the dermal papilla (22). Both ablative and non-ablative lasers have already been successfully used in monotherapy to treat androgenetic alopecia in men and women (1540 nm Er:glass23, 1550 nm Er:glass (20,24,25), 2940 nm Er:YAG26–28, 1927 nm thulium (29) and 10600 nm CO221 laser).
In recent years combining laser therapy with other modalities, such as pharmaceu-ticals (30–33), exosomes and PRP (29) is on the rise. Fotona’s HAIRestart® laser therapy relies on the 2940 nm Er:YAG wavelength to perform a non-ablative procedure using a patented SMOOTH™ mode, consisting of trains of sub-ablative laser pulses. The advantage of Er:YAG laser used in SMOOTH™ mode is that laser light is absorbed in the most superfi cial (<10 μm) layer of the skin, with only heat diff using to the deeper layers, making it a very safe form of energy, which is especially important when treating the scalp.
The heat pulses penetrate the skin to approximately 0.5 mm in depth, resulting in tissue hyperthermia as well as in paracrine signaling that activates fibroblasts to initiate regenerative processes in the skin (34,35). The HAIRestart® therapy’s effects on the scalp include improved blood supply to the hair follicles (22), stimulation of the hair cycle by promoting faster telogen-to-anagen transitions (20), an increase in hair density and thickness (36) and prevention of further hair loss (26). HAIRestart® is suitable as an alternative to pharmaceuti-cals in the form of a monotherapy, as an adjunct treatment to other modalities, to stabilise hair thinning before a hair transplant, or as maintenance treatment. This unique versatility allows it to fill several niches in AGA therapy.
Dr. Iva Talaber
PhD, is a Clinical Affairs Associate at Fotona. She collaborates with doctors and healthcare professionals on clinical studies of the Er:YAG laser for hair stimulation and assists in developing the HAIRestart® protocol.
References
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