Low-Level Laser Therapy Facilitates Superficial Wound Healing in Humans: A Triple-Blind, Sham-Controlled Study

Transcription

1 Jounal of Athletic Taining 24;39(3): by the National Athletic Taines Association, Inc ow-evel Theapy Facilitates Supeficial Healing in Humans: A Tiple-Blind, -Contolled Study J. Ty Hopkins*; Todd A. Mcoda ; Jeff G. Seegmille ; G. David Baxte *Bigham Young Univesity, Povo, UT; Illinois State Univesity, Nomal, I; Ohio Univesity, Athens, OH; Univesity of Ulste, Belfast, Nothen Ieland J. Ty Hopkins, PhD, ATC; Todd A. Mcoda, PhD, ATC/; and Jeff G. Seegmille, EdD, ATC/, contibuted to conception and design; acquisition and analysis and intepetation of the data; and dafting, citical evision, and final appoval of the aticle. G. David Baxte, DPhil, contibuted to conception and design and citical evision and final appoval of the aticle. Addess coespondence to J. Ty Hopkins, PhD, ATC, Depatment of Physical Education, Bigham Young Univesity, Povo, UT Addess to tyhopkins@byu.edu. Objective: ow-level lase theapy (T) has been pomoted fo its beneficial effects on tissue healing and pain elief. Howeve, accoding to the esults of in vivo studies, the effectiveness of this modality vaies. Ou pupose was to assess the putative effects of T on healing using an expeimental wound model. Design and Setting: We used a andomized, tiple-blind, placebo-contolled design with 2 within-subjects factos (wound and time) and 1 between-subjects facto (goup). Data wee collected in the laboatoy setting. Subjects: Twenty-two healthy subjects (age 21 1 yeas, height cm, mass kg). Measuements: Two standadized 1.27-cm 2 abasions wee induced on the anteio foeam. Afte wound cleaning, standadized digital photos wee ecoded. Each subject then eceived T (8 J/cm 2 ; teatment time 2 minutes, 5 seconds; pulse ate 7 Hz) to 1 of the 2 andomly chosen wounds fom eithe a lase o a sham 46-diode cluste head. Subjects epoted back to the laboatoy on days 2 to 1 to be photogaphed and eceive T and on day 2 to be photogaphed. Data wee analyzed fo wound contaction (aea), colo changes (chomatic ed), and luminance. Results: A goup wound time inteaction was detected fo aea measuements. At days 6, 8, and 1, follow-up testing evealed that the lase goup had smalle wounds than the sham goup fo both the teated and the unteated wounds (P.5). No goup wound time diffeences wee detected fo chomatic ed o luminance. Conclusions: The T esulted in enhanced healing as measued by wound contaction. The unteated wounds in subjects teated with T contacted moe than the wounds in the sham goup, so T may poduce an indiect healing effect on suounding tissues. These data indicate that T is an effective modality to facilitate wound contaction of patial-thickness wounds. Key Wods: modalities, expeimental wound model Allied health pofessionals egulaly cae fo a vaiety of wounds to the skin, among them abasions, tuf buns, sugical incisions, and, pehaps the most difficult to teat, ulceations. Fom acute wound management to augmentation of sca tissue emodeling, the clinician seeks to optimize wound cae to pomote healing. Although low-level lase theapy (T) has eceived only specified US Food and Dug Administation cleaance, its clinical efficacy fo tissue healing has been widely epoted. 1 5 In vito data suggest that T facilitates collagen synthesis, 6 keatinocyte cell motility, 7 and gowth facto elease 8 and tansfoms fiboblasts to myofiboblasts. 9 Many authos of clinical studies have epoted the benefits of T on tissue healing, but othes have shown no effect These conflicting esults ae likely due to vaiations in teatment factos and limitations in expeimental design, including compaison of heteogeneous clinical wounds, lack of contol goups, and limited o no blinding of investigatos. 14,15 Seveal eseaches have used supeficial wounds to assess the putative effects of T on healing. 15 Some have used clinical wounds o ulces of vaious sizes and depths, 1,2,12 and othes have developed supeficial wound models in animals. 1,11,16,17 These diffeent methods have poduced vaied esults and conclusions as to the effectiveness of T. When analyzing healing among wounds, it would be beneficial if the wounds wee as alike as possible; theefoe, the diffeences in healing could be attibuted to the teatment and not to othe factos, such as wound vaiability. Claus et al 18 developed a supeficial wound model fo use in human subjects that contolled fo wound size and depth. This model allows fo evaluation of patial-thickness abasions of contolled size and depth at measuement intevals set by the investigato. Ou pupose was to assess potential changes in healing due to T ove time using a human expeimental wound model. Healing was measued in tems of wound contaction and changes in chomatic ed and luminance. Chomatic ed is an indication of wound healing as a wound changes in colo fom dak ed to pale pink ove time. uminance efes to the homogeneity of a wound as the tissue heals and becomes moe smooth and consistent. Jounal of Athletic Taining 223

2 METHODS We used a factoial design to compae teatment goups (1 goup teated with T and 1 goup teated with a sham teatment) and teatment wounds (teated wound and unteated wound) acoss time intevals. The subject, clinician, and investigato examining the wounds wee blinded as to which teatment goup was the sham. Afte data analysis, the manufactue evealed the tue teatment head. Measuements used to quantify healing included wound aea (pixels), wound colo (chomatic ed), and wound luminance (). Subjects Voluntees (age 21 1 yeas, height cm, mass kg) wee 22 physically active males (13) and females (9) ecuited fom a univesity student population. Subjects wee andomly assigned to eithe the lase goup (5 females, 6 males, age 21 1 yeas, height cm, mass kg) o the sham goup (4 females, 7 males, age 21 1 yeas, height cm, mass kg). Each subject completed a pepaticipation questionnaie to detemine eligibility fo the study. Subjects wee excluded if they wee taking any medications that would thin the blood o affect nomal healing o immune function. Subjects had no histoy of immune suppession, ciculatoy dysfunction, o excessive scaing and wee not tobacco uses. Risks wee explained to all subjects, and each subject povided infomed consent. Human subject appoval was obtained fom the univesity s institutional eview boad. All subjects complied with teatments and measuements fo the entie 2-day peiod. Pocedues A supeficial wound model was adapted fom Claus et al. 18 All Occupational Safety and Health Administation guidelines fo handling blood and bodily fluids wee followed. 19 Sandpape was autoclaved befoe use, and wound templates wee steilized befoe contact with the skin. All investigatos woe latex gloves duing the pocedues. Subjects wee pepaed to eceive two 1.27-cm 2 cicula abasions to a cental aea of the anteio foeam (Figue 1) of the nondominant am. If needed, the aea was shaved with electic hai clippes. A 1-minute ice-massage teatment was fist applied to the anteio foeam to help desensitize the aea and then an anesthetic ceam (EMA [2.5% lidocaine and 2.5% pilocaine], Asta USA, Inc, Westboo, MA) was applied to aeas that wee to be abaded. The anteio foeam was then cleaned with a Betadine scub (Pudue Phama P, Stamfod, CT) and allowed to ai dy. A25 1-cm template made of.15-mm clea vinyl was affixed to the nondominant am with eukotape (BSN-Jobst, Inc, Chalotte, NC) so that two 1.27-cm 2 cicula holes allowed skin to potude though the template. The cicula holes wee spaced 6.35 cm cente to cente. A cm piece of 6-git autoclaved sandpape was attached to a weighted (2.73-kg) sanding sled. The sled measued cm with an attached handle that allowed the sled to be pulled acoss the template without applying additional downwad pessue. The sled was pulled back and foth acoss the cicula cutouts to the beat of a metonome (6 beats/s) fo 5 passes. Pilot wok povided a detemination of the optimal numbe of passes fo appopiate wound depth. We defined the Figue 1. Expeimental wounds befoe teatment on day 1. appopiate wound depth as an abasion that extended patially into the demis. We wee able to detemine this depth by obseving how many passes wee necessay to poduce even bleeding fom the suface of the wound. The template and sandpape wee emoved and discaded using standad Occupational Safety and Health Administation pocedues. Bleeding was contolled by diect pessue with steile gauze. s wee then thooughly insed with hydogen peoxide and allowed to ai dy. Subjects andomly selected cads identifying which of the 2 wounds was to be teated. Subjects wee also andomly assigned to 1 of the 2 teatment goups (T o sham) fo which identical teatment heads wee used, diffeentiated with a numbe on the head. abels wee placed on the foeam identifying the subject numbe, day, and teatment wound (Figue 1). The subject s am was placed unde a lighted copy stand, and a digital camea (Sony DSC-S75, Tokyo, Japan) was mounted 4 cm pependicula to the subject s foeam. Digital images (16 12 pixels, JPEG fomat) wee ecoded. Subjects completed a daily questionnaie that pemitted them to ate thei level of pain on a visual analog scale, help investigatos identify signs of infection, tack compliance with instucted wound cae, and examine peceptions of the lase theapy. These data wee used to help identify any poblems associated with infection that might put the subject at isk o ceate outlying data and to objectively examine the blinding pocedue. An adhesive steile bandage was applied to the unteated wound in pepaation fo teatment of the othe wound. The foeam was then coveed with neopene (2-mm thickness); a 5-cm-diamete cicula cutout exposed the wound to be teated. Iadiation was deliveed to the exposed wound fom a 46- diode cluste head (Omega Excel, Omega Systems, Cawley, UK). The cluste head (suface aea 19.6 cm 2 ) has a single lase (82 nm) in the cente suounded by concentic ings of supeluminous diodes of vaying wavelengths (Table 1). The aveage enegy density of the teatment was 8 J/cm 2 (teatment time 2 minutes, 5 seconds; pulse ate 7 Hz). These settings eflect common clinical pactice 15 and the guidelines of the manufactue. 2 Duing teatment, the cluste head was centeed ove the wound and held stationay while contact was maintained with the neopene template. The neo- 224 Volume 39 Numbe 3 Septembe 24

3 Table 1. Technical Specifications of the 46-Diode Cluste Pobe 2 Wavelength Powe Powe Density Classification 1 66-nm diode 1 95-nm diode 1 87-nm diode 1 88-nm diode 5 94-nm diode 1 82-nm lase 15 mw 15 mw 25 mw 25 mw 25 mw 15 mw.75 W/cm 2 3B lase pene template pevented diect contact between the teatment head and the wound, poviding a 2-mm gap between the two. Both the subject and the administato woe lase safety goggles befoe, duing, and afte the teatment. The goggles pevented detection of light fom the lase, peventing potential detection of the lase head by eithe the subject o the administato. Additionally, the cluste head was placed ove the template befoe the settings wee established, peventing any visible light fom the lase. Teatment was administeed using the same potocol fo the sham goup. Afte teatment, an adhesive steile bandage was applied ove the teated wound. Subjects wee instucted to emove the bandages only to showe, eapply new bandages afte the showe, and eplace both bandages if 1 was emoved. Fo 1 days, subjects etuned daily fo a photogaph, teatment, and assessment session. Subjects etuned on day 2 fo a final pictue and assessment of the wounds. Subjects completed a daily questionnaie befoe each session. Duing each session, the wounds wee flushed with steile saline and allowed to ai dy. abels wee then applied to specify the day, subject, teatment wound, and goup. Digital images wee then ecoded unde the same conditions (distance, lighting, settings) as the oiginal images. The T was administeed unde the same conditions peviously descibed. All images wee analyzed using image-measuement softwae (Pofessional Vesion; Besoft Inc, Ottawa, ON, Canada). Each wound was analyzed fo aea, chomatic ed, and luminance. Aea was measued to analyze wound contaction as a function of healing using the automatic aea-measuement component of the softwae. This allowed fo the wound bodes to be defined with the pixels that wee within a specific colo ange of the open o unhealed potion of the wound. We defined the wound aea though test analysis as the total aea that was 1 pixels (ed value) fom a cluste of pixels located in the open potion (cente) of the wound. The total numbe of pixels within the colo ange epesented the elative wound aea. Chomatic ed and luminance wee calculated by ecoding the mean ed, geen, and blue values fo a standad aea acoss all wounds. Supeficial wounds tend to lighten fom ed to pale pink and become moe homogeneous and moe consistent in textue as they heal. 21 Calculations of chomatic ed and luminance help to make these subjective obsevations objective. Chomatic ed deceases and luminance inceases as a wound heals, epesenting these subjective changes. A 2- pixel cicula aea was selected fom the cente of each wound. The softwae povided mean ed (R), geen (G), and blue (B) values fo each selected aea. Additionally, a 2-pixel aea was selected fom an aea of uninjued skin between the 2 wounds fo nomalization of all colo values. Fo colo nomalization, each colo value (R, B, and G) fom the wound aea was divided by the coesponding colo value fom the uninjued skin aea and multiplied by 1. Chomatic ed () and luminance () wee calculated fo both wounds using the following fomulae fom Hansen et al 22 : (1 R)/(R G B) (R G B)/3 Statistical Analysis We used data fom days 1, 4, 6, 8, 1, and 2 in analyses. Mixed-facto, 3-way analyses of vaiance wee computed to detect diffeences between goups (lase and sham) and wounds (teated and unteated) ove time fo each dependent vaiable. Follow-up, 2-way analyses of vaiance wee computed to detect diffeences between goups and wounds at each time inteval. We used the Tukey Honestly Significant Diffeence test fo post hoc compaisons (P.5 fo all tests). Desciptive statistics wee computed fo questionnaies. RESUTS Summay data fo measues of aea,, and ae pesented in Table 2, and pecentage changes fom baseline aea measuements ae pesented in Table 3. A goup wound time inteaction (F 5, , P.1) was detected fo aea measuements. Follow-up goup wound inteactions wee detected at days 6 (F 1, , P.1), 8 (F 1, , P.4), and 1 (F 1,2 7.36, P.13). At days 6, 8, and 1, follow-up testing evealed that the lase goup had smalle wounds than the sham goup fo both the teated and the unteated wounds (P.5) (Figue 2). Effect size was also calculated fo diffeences identified between goups at days 6 (2.11), 8 (1.46), and 1 (1.18). Futhe, the teated wound in the lase goup was smalle than the unteated wound (P.5) at days 6, 8, and 1. The effect sizes fo diffeences detected between the 2 wounds in the lase goup wee.53 (day 6),.55 (day 8), and.69 (day 1). All wounds wee completely contacted when the subjects etuned fo a final assessment on day 2. No diffeences wee detected between wounds within subjects at each time inteval (P.5). No goup wound time diffeences wee detected fo o (Figues 3 and 4; P.5). Desciptive data fo the daily questionnaie ae pesented in Table 4. DISCUSSION Ou pimay finding was that the lase goup had geate wound contaction than the sham goup. The geatest diffeence between goups in wound contaction was seen on teatment day 6, when the lase-teated wounds of the study goup demonstated 153% geate wound contaction than the teated wounds of the sham goup (see Figue 2). On day 8, the lase goup exhibited 55% geate wound contaction and on day 1, 22%. The healing cuve coelates with data collected by Jounal of Athletic Taining 225

4 Table 2. Day Aea, Chomatic Red, and uminance Ove Time* Goup Measue Teated Unteated Teated Goup Unteated 1 Aea 4 Aea 6 Aea 8 Aea 1 Aea * * * * * * Aea *Aea (pixels); chomatic ed ( [1 x R]/[R G B]); luminance ( [R G B]/3). *Diffeent fom sham goup (P.5). Diffeent fom unteated wound (P.5). Table 3. Day Pecentage Change Fom Day 1 Aea Measuement Teated Goup Unteated Teated Goup Unteated * 21.6* 47.9* * 28.9* 11.2* *Diffeent fom sham goup (P.5). Diffeent fom unteated wound (P.5) Figue 2. Aveage wound aeas (pixels) of all goups ove time. *Diffeent fom sham goup fo both teated and unteated wounds (P.5). Diffeent fom the unteated wound in the lase goup. Bon et al, 21 who found that healing afte skin-gaft emoval was difficult to evaluate befoe day 6 but then pogessed until it was consideed complete afte day 12. Although wounds in both goups wee completely healed by day 2, T appeaed to facilitate the epai phase of healing, in which the stength of the ganulation tissue would be affected. Numeous case epots and clinical tials with humans have shown impessive wound healing outcomes using T. 1 3,5 Futhe wok with animals has also suppoted the use of T to facilitate wound healing. 16,17 Convesely, seveal goups have shown no advantage in healing with T To complicate mattes, light absoption may be specific to cell and tissue type, 15 educing the ability to genealize the esults of animal data to human wounds. With few contolled clinical tials and diffeent methods and eseach goals, it is difficult to compae cuent esults with these studies. In addition to the use of T in the teatment of skin lesions, clinicians and investigatos have sought othe potential applications fo the theapeutic modality in the spots injuy setting. The esults have been mixed as to the effectiveness of T in teating pain and estoing function in musculoskeletal injuy o disease Beckeman et al 23 concluded that methodologic eos among studies pefomed using theapeutic lase did not pemit adequate conclusions to be dawn elative to the effectiveness of the modality. Absent fom most studies wee caefully contolled and blinded pocedues to claify and quantify the appaent diffeences between laseteated wounds and nonlase-teated wounds. Futhemoe, clinicians often employ a vaiety of stategies simultaneously, which makes it difficult to measue the effects of a single intevention. The numeous intinsic and extinsic factos associated with the inflammatoy esponse and healing make well-designed investigations mandatoy befoe definitive conclusions can be dawn. Ou data ae a solid beginning to systematic study of this elatively new modality. 226 Volume 39 Numbe 3 Septembe 24

5 Figue 4. luminance () values of all goups ove time. (R G B)/3. Figue 3. chomatic ed () values of all goups ove time. (1 R)/(R G B). The exact mechanism by which T facilitates wound healing is lagely unknown. Howeve, seveal theoies may help explain the enhanced wound contaction obseved hee. In vito studies have shown an incease in fiboblast polifeation afte iadiation, 6,3 suggesting that T theapy may facilitate fiboplasia duing the epai phase of tissue healing. Ou data suppot this suggestion. We did not obseve diffeences between the T and sham goups until day 6, when wounds would have been well into the epai phase of soft tissue healing. Howeve, it should also be noted that othe investigatos found no in vito changes in fiboblast polifeation afte T. 31,32 The dispaity could be due to changes in specific lase iadiation settings, such as wavelength, duation, powe, and intensity. 15 Facilitated wound contaction may also be suppoted by wok fom Poueau-Schneide et al, 9 who epoted that lase iadiation tansfoms fiboblasts into myofiboblasts. Myofiboblasts ae diectly involved in ganulation tissue contaction, and inceased numbes could lead to facilitated wound contaction. A myofiboblast is a modified fiboblast with ultastuctual and functional popeties of fiboblasts and muscle cells. 33 Cytoplasmic fibils of actomyosin allow fo contaction of myofiboblasts, pulling on the bodes of the wound and educing the size duing the epai phase of soft tissue healing. 33 Because ou data povided suppot that T enhanced wound contaction but did not necessaily enhance othe vaiables ( and changes) associated with supeficial wound healing, myofiboblast stimulation may be a viable explanation. Ou data suggest that T has an indiect healing effect on suounding tissues. The T was applied to 1 of 2 andomly chosen wounds spaced 5 cm apat. Although we found a slight diffeence in wound contaction between the 2 wounds in the lase goup, both the teated and the unteated wounds showed enhanced healing compaed with those in the sham goup. These data ae suppoted by Baveman et al, 34 who found augmented tensile stength in abbit wounds teated with T and in contol wounds on the contalateal limb. They suggested that T may have caused elease of tissue gowth factos into ciculation, which may have affected suounding tissues o entie systems. Indiect healing could be a vey ben- Table 4. Summay Data Fom the Daily Questionnaie Completed Befoe Daily Teatment Question Goup Day 1 Day 4 Day 6 Day 8 Day 1 Pain (visual analog scale, 5) Any seepage fom lase-teated wound?* (1 yes, 2 no) Any seepage fom non laseteated wound? (1 yes, 2 no) Any itching of lase-teated wound? (1 yes, 2 no) Any itching of non lase-teated wound? (1 yes, 2 no) Do you feel any sensations fom the lase? (1 yes, 2 no) Do you believe the lase has helped the wound heal? (1 yes, 2 no) *Seepage efes to any fluid coming fom the wound. Jounal of Athletic Taining 227

6 eficial effect of this modality in teating tissue damage of lage size o at multiple locations. It might also suggest that deepe tissues could be affected by light theapy. Although we demonstated enhanced wound contaction using T, ou data did not suppot significant wound healing in tems of changes in o. Supeficial wounds tend to lighten fom ed to pale pink and become moe homogeneous and consistent in textue as they heal. 21 These 2 qualitative changes may be quantified though peviously mentioned fomulas fo and. 22 In elation to the qualitative changes, should decease ove time, while should incease. The fact that we saw no significant effect in o could point to the potential lack of sensitivity of these measues, and pehaps these measues ae not good indicatos of healing. It does not, howeve, take away fom the tissue-contaction data. Fiboblast polifeation and enhanced myofiboblast convesion could explain enhanced wound contaction while not having any measuable effect on o. The questionnaie in this study was used to help identify any signs of infection, ensue compliance in caing fo the wounds, and validate the blinding pocedues used in this poject. Also notewothy is that the subjects did not peceive that T was effective in eithe goup, even though wounds contacted moe in the teatment goup. This could be due to the fact that both wounds, teated and unteated, on each subject healed at a faste ate than those in the sham goup. Because the teated wound did not heal any faste than the unteated wound, the subjects peceived the teatment to be ineffective. Evidence exists fo the usefulness of T fo vaious conditions, but cuently this may be of little consequence in the United States because of Food and Dug Administation guidelines on the use of lases fo the teatment of humans. In 1983, the Food and Dug Administation efused to suppot sales of T as a wound-teatment device because of a lack of contolled human investigations suppoting the theapy. 35 Since that time, the Food and Dug Administation has taken the stance that lase devices fom individual manufactues fo selective theapeutic benefits may be consideed fo cleaance/ pemission to legally maket the device. To date, such devices have been cleaed fo adjunctive use in the tempoay elief of neck and shoulde pain of musculoskeletal oigin, wist and hand pain associated with capal tunnel syndome, and iliotibial band syndome pain. The T devices may also be impoted fo use in the United States fo contolled clinical tials with institutional eview boad appoval, as was the case in ou study. Futhe well-designed investigations should ultimately detemine if T is a safe and effective modality fo specific conditions. A citicism of many in vivo expeiments designed to examine the efficacy of T has been lack of contol, poo expeimental design, and inadequate specification of teatment settings. 15 Although we made evey effot to contol as many of these vaiables as possible, a few limitations to this study do exist. The standadized wound model is limited to acute, patial-thickness wounds that extend into the demis. The healing pocess may be simila thoughout othe tissues of the body, but we have collected no diect evidence that simila effects would be obseved in wounds of othe tissues o in chonic wounds. Ou data ae also limited to the specific iadiation settings we used. These settings eflect common clinical pactice 15 and the manufactue s ecommendations and guidelines. 2 The cluste pobe used in this investigation was a combination of 1 (82-nm) lase and 45 supeluminous diodes and epesents common clinical pactice in that the less expensive semiconducto-based diode lases ae moe popula. 15 Anothe limitation to ou study was that we did not apply the cluste head diectly in contact with the open wound. We used a neopene template that coveed the aeas aound the wound and on which the im of the cluste head ested duing teatment. This esulted in a 2-mm gap between the cluste head and the wound and some assumed divegence of the lase light and eduction of iadiation intensity to the tissue. Although the wound model used in this study is faily well standadized, vaiations among subjects did exist in tems of numbe of pixels. We assume this vaiation to be the esult of individual diffeences in tissue elasticity and compliance when the vinyl template was applied to the am. In othe wods, the amount of tissue potuding though the holes allowed fo slight vaiation, depending on the subject. CONCUSIONS The T is an effective teatment fo enhancing wound contaction of patial-thickness abasions. It also facilitates wound contaction of unteated wounds on the same am, suggesting an indiect effect on suounding tissues. Although ou data focused on enhanced contaction of supeficial wounds, we believe they ae the fist step in fomulating meaningful conclusions egading T. Futhe contolled data ae necessay to detemine the efficacy of T in facilitating healing and educing pain associated with musculoskeletal disodes. REFERENCES 1. Chomey PA. The efficacy of cabon dioxide lase sugey fo adjunct ulce theapy. Clin Podiat Med Sug. 1992;9: Gogia PP, Hut BS, Zin TT. management with whilpool and infaed cold lase teatment: a clinical epot. Phys The. 1988;68: Schindl A, Schindl M, Schindl. Successful teatment of pesistent adiation ulce by low powe lase theapy. J Am Acad Dematol. 1997;37: Schindl M, Keschan K, Schindl A, Schon H, Heinzl H, Schindl. Induction of complete wound healing in ecalcitant ulces by low-intensity lase iadiation depends on ulce cause and size. Photodematol Photoimmunol Photomed. 1999;15: Sugue ME, Caolan J, een EJ, Feeley TM, Mooe DJ, Shanik GD. The use of infaed lase theapy in the teatment of venous ulceation. Ann Vasc Sug. 199;4: Abegel RP, Meeke CA, am TS, Dwye RM, esavoy MA, Uitto J. Contol of connective tissue metabolism by lases: ecent developments and futue pospects. J Am Acad Dematol. 1984;11: Haas AF, Isseoff RR, Wheeland RG, Rood PA, Gaves PJ. ow-enegy helium-neon lase iadiation inceases the motility of human keatinocytes. J Invest Dematol. 199;94: Yu W, Naim JO, anzafame RJ. The effects of photo-iadiation on the secetion of TGF and PDGF fom fiboblasts in vito. s Sug Med Suppl. 1994;6:8. 9. Poueau-Schneide N, Ahmed A, Soudy M, et al. Helium-neon lase teatment tansfoms fiboblasts into myofiboblasts. Am J Pathol. 199; 137: Allendof JD, Bessle M, Huang J, et al. Helium-neon lase iadiation at fluences of 1, 2, and 4 J/cm 2 failed to acceleate wound healing as assessed by wound contactue ate and tensile stength. s Sug Med. 1997;2: Hunte J, eonad, Wilson R, Snide G, Dixon J. Effects of low enegy lase on wound healing in a pocine model. s Sug Med. 1984;3: undebeg T, Malm M. ow-powe HeNe lase teatment of venous leg ulces. Ann Plastic Sug. 1991;27: Volume 39 Numbe 3 Septembe 24

7 13. Sapeia D, Glassbeg E, yons RF, et al. Demonstation of elevated type I and type III pocollagen mrna levels in cutaneous wounds teated with helium-neon lase: poposed mechanism fo enhanced wound healing. Biochem Biophys Res Commun. 1986;138: Basfod JR. ow-enegy lase theapy: contovesies and new eseach findings. s Sug Med. 1989;9: Baxte GD. Theapeutic s: Theoy and Pactice. Edinbugh, UK: Chuchill ivingstone; Dyson M, Young S. Effect of lase theapy on wound contaction and cellulaity in mice. s Med Sci. 1986;1: Meste E, Jaszsagi-Nagi E. The effect of lase adiation on wound healing and collagen synthesis. Studia Biophys. 1973;35: Claus EE, Fusco CF, Ingam T, Ingesoll CD, Edwads JE, Melham TJ. Compaison of the effects of selected dessings on the healing of standadized abasions. J Athl Tain. 1998;33: Anold B. A eview of selected blood-bone pathogen position statements and fedeal egulations. J Athl Tain. 1995;3: Omega Systems Excel System Manual. 2nd ed. West Sussex, UK: Omega Systems td; Bon FX, Biand E, Guichad S, et al. Quantitative and kinetic evolution of wound healing though image analysis. IEEE Tans Med Imaging. 2;19: Hansen G, Spaow E, Kokate J, eland KJ, Iaizzo PA. status evaluation using colo image pocessing. IEEE Tans Med Imaging. 1997; 16: Beckeman H, de Bie RA, Boute M, De Cuype HJ, Oostendop RAB. The efficacy of lase theapy fo musculoskeletal and skin disodes: a citeia-based meta-analysis of andomized clinical tials. Phys The. 1992;72: Bosseau, Welch V, Wells G, et al. ow level lase theapy fo osteoathitis and heumatoid athitis: a meta-analysis. J Rheumatol. 2;27: de Bie RA, de Vet HCW, enssen TF, van den Wildenbeg FAJM, Koosta G, Knipschild PG. ow-level lase theapy in ankle spains: a andomized clinical tial. Ach Phys Med Rehabil. 1998;79: Gam AN, Thosen H, onnbeg F. The effect of low-level lase theapy on musculoskeletal pain: a meta-analysis. Pain. 1993;52: Gü A, Kaakoc M, Nas K, Cevik R, Saac J, Demi E. Efficacy of low powe lase theapy in fibomyalgia: a single-blind, placebo-contolled tial. s Med Sci. 22;17: Gü A, Kaakoc M, Nas K, Cevik R, Saac J, Ataoglu S. Effects of low powe lase and low dose amitiptyline theapy on clinical symptoms and quality of life in fibomyalgia: a single-blind, placebo-contolled tial. Rheumatol Int. 22;22: Simunovic Z, Ivankovich AD, Depolo A. healing of animal and human body spot and taffic accident injuies using low-level lase theapy teatment: a andomized clinical study of seventy-fou patients with contol goup. J Clin Med Sug. 2;18: Boulton M, Mashall J. He-Ne lase stimulation of human fiboblast polifeation and attachment in vito. s in ife Sci. 1986;1: Colve GB, Piestly GC. Failue of HeNe to affect components of wound healing in vito. B J Dematol. 1989;121: Hallman HO, Basfod JR, O Bien JF, Cummins A. Does low-enegy helium-neon lase iadiation alte in vito eplication of human fiboblasts? s Sug Med. 1988;8: Specto TD, Axfod JS. An Intoduction to Geneal Pathology. 4th ed. Edinbugh, UK: Chuchill ivingstone; Baveman B, McCathy RJ, Ivankovich AD, Fode DE, Ovefield M, Bapna MS. Effect of helium-neon and infaed lase iadiation of wound healing in abbits. s Sug Med. 1989;9: Foney R, Mauo T. Using lases in diabetic wound healing. Diabetes Technol The. 1999;1(2): Jounal of Athletic Taining 229