the ability of lasers to induce hair growth was incidentally noted as early as 1967 when mester et al . used low - level laser therapy ( lllt ) to treat cancer in mice with shaved backs . since then
, hypertrichosis has been recognized to be a possible side - effect of laser treatment .
first described in 2002 with intense pulsed light therapy , this phenomenon has now been widely acknowledged to occur with an incidence rate ranging from 0.6% to 10% with low fluences and all laser types .
it is thought to be the result of suboptimal fluences that are too low to induce thermolysis , but high enough to stimulate follicular growth .
eventually , lllt has been developed for the treatment of androgenetic alopecia ( aga ) .
as opposed to other currently marketed systems , the laser comb utilizes hair parting teeth for optimal delivery of laser energy to the exposed scalp . in 2007 , the hairmax laser comb ( lexington international , llc ) received 510 ( k ) clearance from the food and drug administration ( fda ) for the treatment of aga for men , and 2011 for women .
this clearance means that the device is considered a moderate - risk medical device by the fda and is thereby solely screened for safety .
the hairmax laser comb has been tested in a company - sponsored study of 110 male patients with the claim of a significant increase in mean terminal hair density when compared to a sham device .
avram and rogers conducted the first independent blinded study of lllt and hair growth with seven patients and found that on average , there was a decrease in the number of vellus hairs , an increase in the number of terminal hairs , and an increase in shaft diameter . a consensus written by hair loss experts
states that based on anecdotal experience , lllt , particularly 650 - 900 nm wavelengths at 5 mw , may be an effective treatment option for patients with aga . in recent times , kim et al . reported an increase of hair density with the use of lllt , when compared to the sham device in a 24-week , randomized , double - blind , sham - device - controlled trial . to evaluate efficacy of the 655 nm - hairmax laser comb either as monotherapy or as concomitant therapy for treatment of male and female aga
, we performed a retrospective observational study of global photographic assessments of patients in an office - based setting .
patients who had purchased a hairmax laser comb between july 2011 and july 2013 for treatment of aga at the center for dermatology and hair diseases prof .
treb were retrieved for assessment of global photographic images performed at follow - up visits .
patients on concomitant treatment had been treating with topical minoxidil or oral finasteride for at least 9 months , before starting therapy with the hairmax laser comb .
patients used the hairmax laser comb at home according to instructions 3 times weekly between 8 and 15 min depending on the model purchased ( advanced 7 , lux 9 , or professional 12 ) .
global photographs were performed at 3 , 6 , 12 , and 24 months of treatment follow - up in a standardized manner with a stereotactic camera device of canfield scientific inc . , in which the patient 's chin and forehead are fixed and on which digital camera and flash device are mounted , ensuring that view and lighting are the same at consecutive visits , thus enabling precise follow - up of the same scalp area of interest with frontal and vertex views .
global photographs were evaluated by two of the authors ( am and rmt ) , and scored as significant , moderate , or no improvement . in the case of diverging opinions ,
in total , 32 patients with aga were involved in the study , of which 21 were females , aged 22 - 73 ( mean : 43.6  15.19 standard deviation [ sd ] ) , and 11 were males , aged 20 - 70 ( mean : 39  15.01 sd ) total mean : 42  15.1 sd .
the duration of hair loss in years for men and women was mean 7.1  5.2 sd .
the duration of lllt in months for men and women was mean 8.7  5.2 [ table 1 ] .
the patient characteristics , with respect to gender , age , classification of aga according to ludwig and hamilton - norwood scales , duration of hair loss , and concomitant treatments are recorded in table 2 .
the results for the scoring of the global photographic assessment in relation to treatment duration with the hairmax laser comb are demonstrated in table 3 . in summary ,
eight patients ( three female , five male ) showed significant improvement , 20 patients ( 14 female , six male ) moderate improvement , and four patients ( four female , zero male ) no improvement [ figure 1 ] .
of 32 patients , the hairmax laser comb was used as monotherapy in six patients ( two female , four male ) , and as a concomitant therapy in 26 patients ( 19 female , seven male ) . in the monotherapy group ,
two patients ( one female , one male ) showed significant improvement [ figure 2 ] , four patients ( one female , three male ) moderate improvement , and zero patients no improvement [ table 3 ] . in the concomitant therapy group , six patients ( two female , four male ) showed significant improvement [ figures 3 and 4 ] , 16 patients ( 13 female , three male ) moderate improvement , and four patients ( four female , zero male ) no improvement .
there was no statistical significant difference between lllt monotherapy and concomitant therapy with either minoxidil and/or finasteride ( p = 0.829 ) , and regarding male or female aga ( p = 0.091 ) [ table 4 ] .
improvement of alopecia in relation to the variables : age , duration of hair loss , and duration of lllt patient characteristics graphic summary of results monotherapy in a 54-year - old male ( a ) before treatment , and improvement after ( b ) 6 months , and ( c ) 12 months of low - level laser therapy scoring of global photographic assessment in relation to treatment duration concomitant treatment with topical 5% minoxidil in a 55-year - old male adding on low - level laser therapy ( lllt ) to 4 year pretreatment with 5% topical minoxidil solution ( a ) before , and ( b ) after 3 months of added lllt concomitant treatment with topical 5% minoxidil and 1 mg oral finasteride in a 34-year - old male ( a ) before , ( b ) after 9 months treatment with 1 mg oral finasteride and topical 5% minoxidil solution bid , and ( c ) after 3 months after adding on low - level laser therapy comparative assessment of efficacy between monotherapy and concomitant for male and female androgenetic alopecia treatment was well tolerated and no serious adverse events were reported .
. currently , topical 2% and 5% minoxidil solution and 1 mg oral finasteride are the treatments with the highest levels of medical evidence , but patients who exhibit intolerance or poor response to these treatments are in need of additional treatment modalities .
although low - level energy lasers have been therapeutically used in medicine for photobiostimulation in a variety of indications more than 30 years , it has only recently found the attention of the scientific community for the treatment of aga . we have chosen the 655 nm - hairmax laser comb for several reasons : first ,
it represents the device with the most clinical study reports regarding its efficacy , secondly , the cost of the device is affordable , and thirdly , the device is simple enough for patients to use at home . finally , the fact that the device is safe , for which it received 510 ( k ) clearance from the fda for the treatment of aga , was also an important consideration .
our study demonstrates clinical efficacy of the device for treatment of male and female aga , both as monotherapy and as concomitant therapy , in terms of clinically relevant improvement of appearance of hair .
of 32 patients , eight patients ( 25% ) showed significant improvement , and 20 patients ( 62.5% ) showed moderate improvement in global photographic assessments .
the effect was observed as early as 3 months of treatment , and was sustained up to a maximum observation time of 24 months .
the technology appears to work better for some than for others , and predictive factors which will most benefit from lllt are to be determined .
it seems though , that patients with intermediate alopecia ( hamilton - norwood iii and iv , and ludwig i and ii , respiratory ) respond best , since effective photobiostimulation depends on a minimum of hair for effective photobiostimulation , and on a maximum of hair for the laser beam to reach the scalp without absorption or interference from existing hairs .
the hypothesized mechanisms of action of lllt are increased adenosine tri - phosphate ( atp ) production , modulation of reactive oxygen species ( ros ) , and induction of transcription factors .
the proposed cellular chromosphere responsible for the effect of visible light is cytochrome c oxidase ( cox ) with absorption peaks in the near infrared , and mitochondria the likely site for the initial effects .
it is believed that lllt displaces nitric oxid from cox allowing an influx of oxygen to bond to cox and progress forward in the respiratory process to atp production and ros signaling .
these effects in turn lead to increased cellular proliferation , modulation in levels of cytokines , growth factors and inflammatory mediators , and increased tissue oxygenation . while the effects of these biochemical and cellular changes have broadly been studied in both animal models and clinical studies with patients , and have shown benefits in diverse conditions , such as increased healing in chronic wounds , improvements in sports injuries and carpal tunnel syndrome , pain reduction in arthritis and neuropathies , and amelioration of damage after heart attacks , stroke , nerve injury and retinal toxicity , the effects on hair growth stimulation have only recently gained the attention of the scientific community .
from our own observations , we share with other authors the opinion that lllt represents a safe and potentially effective treatment option for patients with aga who do not respond or are not tolerant to standard treatment of aga .
moreover , combining lllt with topical minoxidil solution and oral finasteride may act synergistic to enhance hair growth . due to the known beneficial effect on wound healing
, it is conceivable that lllt as an adjunctive therapy in hair transplant surgery may also reduce postoperative shedding , reduce healing time , and increase graft patency .
the scientific basis for such an approach is given , but there is a need for controlled studies with a higher number of patients to establish an increase in efficacy of combination regimens .
 background : androgenetic alopecia ( aga ) is the most common form of hair loss in men and in women . currently , minoxidil and finasteride are the treatments with the highest levels of medical evidence , but patients who exhibit intolerance or poor response to these treatments are in need of additional treatment modalities.objective:the aim was to evaluate the efficacy and safety of low - level laser therapy ( lllt ) for aga , either as monotherapy or as concomitant therapy with minoxidil or finasteride , in an office - based setting.materials and methods : retrospective observational study of male and female patients with aga , treated with the 655 nm - hairmax laser comb , in an office - based setting . efficacy was assessed with global photographic imaging.results:of 32 patients ( 21 female , 11 male ) , 8 showed significant , 20 moderate , and 4 no improvement . 
 improvement was seen both with monotherapy and with concomitant therapy . 
 improvement was observed as early as 3 months and was sustained up to a maximum observation time of 24 months . 
 no adverse reactions were reported.conclusions:lllt represents a potentially effective treatment for both male and female aga , either as monotherapy or concomitant therapy . combination treatments with minoxidil , finasteride , and lllt may act synergistic to enhance hair growth . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSION