•       LLLT was discovered serendipitously in the 1960s when mice irradiated with a low fluence red laser grew hair.

•       It traditionally uses infrared rays which are non-invasive and cause non-thermal biostimulation of the hair.

•       Light source used here is an LED device or light energy below a specific energy threshold with a specific wavelength

•       Since it does not produce heat (cold laser), the therapy is safe and does not cause a burn.

•       Various lasers that have been tried for hair loss management include- Excimer (308nm) helium, neon (632nm) and fractional erbium glass laser (1550nm)

•       LLLT uses devices with diode that emit red light (630-670nm). It is available in the form of :-

  1. Hoods / overhead panels
  2. Bonnet or laser head caps
  3. Hand held device

HOW DOES LLLT WORK ?

  1. LLLT increases the blood flow to the scalp and stimulates the metabolism in telogen and catagen hair.
  2. LLLT is proposed to act by stimulation of mitochondria to produce more ATP and cyclic AMP, with activation of response to oxidative stress, displacing nitric oxide from the cells and allowing more oxygen to enter. Released nitric oxide also induces vasodilatation and improves blood flow to the hair roots.
  3. Induction of transcription factors such as nuclear factor kappa B and hypoxia-inducible factor-1 occurs which in return causes protein synthesis that triggers further effects down-stream, such as increased cell proliferation and migration, alteration in the levels of cytokines, growth factors and inflammatory mediators, and increased tissue oxygenation. (6-8)
  4. Weiss and coworkers, by using RT-PCR and microarray analysis, demonstrated that depending on the treatment parameters, LLLT modulates 5-α reductase expression (which converts testosterone into DHT), alters vascular endothelial growth factor gene expression as wells as matrix metalloproteinase (MMP-2) which have significant roles in hair follicle growth. (9)
  5. LED uses broader beam of light to cover wider area of the scalp.
  6. LLLT has been demonstrated to modulate inflammatory processes and immunological responses, which may also have an effect in hair regrowth thus it may also be used in hair transplant patients post operatively to promote wound healing and expedite hair growth.

BENEFITS OF LASER THERAPY

  • Effective in both men and women
  • Can be used in a variety of non-scarring alopecias- AA, AGA, alopecia occurring after chemotherapy.
  • Non-surgical and non-invasive method of hair restoration.
  • No major adverse effects reported
  • Painless, no chances of burns.
  • Relatively inexpensive
  • Minimal time commitment
  • Portable device

REFERENCES:

  1. Kalia S, Lui H. Utilizing electromagnetic radiation for hair growth: a critical review of phototrichogenesis. Dermatol Clin. 2013 Jan;31(1):193-200.
  2. McElwee KJ and Shapiro J. Promising Therapies for treating and/or preventing androgenic alopecia . Skin Therapy Lett. 2012 Jun; 17(6):1-4.
  3. Schweiger ES, Boychenko O, Bernstein RM. Update on the pathogenesis, genetics and medical treatment of patterned hair loss. J Drugs Dermatol. 2010 Nov;9(11):1412-9.
  4. Castex-Rizzi N, Lachgar S, Charveron M, Gall Y. Implication of VEGF, steroid hormones and neuropeptides in hair follicle cell responses. Ann Dermatol Venereol. 2002;129(5 Pt 2):783–786.
  5. Weiss R, McDaniel DH, Geronemus RG, Weiss M. LED photomodulation induced hair growth stimulation. 2005;36(S17):27.
  6. Yano K, Brown LF, Detmar M. Control of hair growth and follicle size by VEGF-mediated angiogenesis. J Clin Invest. 2001;107:409–417.
  7. Yamazaki M, Tsuboi R, Lee YR, Ishidoh K, Mitsui S, Ogawa H. Hair cycle-dependent expression of hepatocyte growth factor (HGF) activator, other proteinases, and proteinase inhibitors correlates with the expression of HGF in rat hair follicles. J Investig Dermatol Symp Proc. 1999;4(3):312–315.
  8. Low level laser (light) therapy (LLLT) for treatment of hair loss: Laser Surg Med: 2014,Feb; 46(2): 144-151