Ex vivo penetration of low-level laser light through equine skin and flexor tendons

Katja F. Duesterdieck-Zellmer Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331

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Maureen K. Larson Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331

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Thomas K. Plant School of Electrical Engineering and Computer Science, College of Engineering, Oregon State University, Corvallis, OR 97331

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Andrea Sundholm-Tepper Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331

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Mark E. Payton Department of Statistics, College of Arts and Sciences, Oklahoma State University, Stillwater, OK 74078.

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Abstract

OBJECTIVE To measure penetration efficiencies of low-level laser light energy through equine skin and to determine the fraction of laser energy absorbed by equine digital flexor tendons (superficial [SDFT] and deep [DDFT]).

SAMPLE Samples of skin, SDFTs, and DDFTs from 1 metacarpal area of each of 19 equine cadavers.

PROCEDURES A therapeutic laser with wavelength capabilities of 800 and 970 nm was used. The percentage of energy penetration for each wavelength was determined through skin before and after clipping and then shaving of hair, through shaved skin over SDFTs, and through shaved skin, SDFTs, and DDFTs (positioned in anatomically correct orientation). Influence of hair color; skin preparation, color, and thickness; and wavelength on energy penetration were assessed.

RESULTS For haired skin, energy penetration was greatest for light-colored hair and least for dark-colored hair. Clipping or shaving of skin improved energy penetration. Light-colored skin allowed greatest energy penetration, followed by medium-colored skin and dark-colored skin. Greatest penetration of light-colored skin occurred with the 800-nm wavelength, whereas greatest penetration of medium- and dark-colored skin occurred with the 970-nm wavelength. As skin thickness increased, energy penetration of samples decreased. Only 1% to 20% and 0.1% to 4% of energy were absorbed by SDFTs and DDFTs, respectively, depending on skin color, skin thickness, and applied wavelength.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that most laser energy directed through equine skin was absorbed or scattered by the skin. To achieve delivery of energy doses known to positively affect cells in vitro to equine SDFTs and DDFTs, skin preparation, color, and thickness and applied wavelength must be considered.

Abstract

OBJECTIVE To measure penetration efficiencies of low-level laser light energy through equine skin and to determine the fraction of laser energy absorbed by equine digital flexor tendons (superficial [SDFT] and deep [DDFT]).

SAMPLE Samples of skin, SDFTs, and DDFTs from 1 metacarpal area of each of 19 equine cadavers.

PROCEDURES A therapeutic laser with wavelength capabilities of 800 and 970 nm was used. The percentage of energy penetration for each wavelength was determined through skin before and after clipping and then shaving of hair, through shaved skin over SDFTs, and through shaved skin, SDFTs, and DDFTs (positioned in anatomically correct orientation). Influence of hair color; skin preparation, color, and thickness; and wavelength on energy penetration were assessed.

RESULTS For haired skin, energy penetration was greatest for light-colored hair and least for dark-colored hair. Clipping or shaving of skin improved energy penetration. Light-colored skin allowed greatest energy penetration, followed by medium-colored skin and dark-colored skin. Greatest penetration of light-colored skin occurred with the 800-nm wavelength, whereas greatest penetration of medium- and dark-colored skin occurred with the 970-nm wavelength. As skin thickness increased, energy penetration of samples decreased. Only 1% to 20% and 0.1% to 4% of energy were absorbed by SDFTs and DDFTs, respectively, depending on skin color, skin thickness, and applied wavelength.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that most laser energy directed through equine skin was absorbed or scattered by the skin. To achieve delivery of energy doses known to positively affect cells in vitro to equine SDFTs and DDFTs, skin preparation, color, and thickness and applied wavelength must be considered.

Contributor Notes

Dr. Sundholm-Tepper's present address is Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164.

Address correspondence to Dr. Duesterdieck-Zellmer (katja.zellmer@oregonstate.edu).
  • 1. Ramey DW, Basford JR. Laser therapy in horses. Compend Contin Educ Pract Vet 2000; 22: 263271.

  • 2. Tumilty S, Munn J, McDonough S, et al. Low level laser treatment of tendinopathy: a systematic review with meta-analysis. Photomed Laser Surg 2010;28: 316.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3. Marcos RL, Leal ECP Jr, de Moura Messias F, et al. Infrared (810 nm) low-level laser therapy in rat Achilles tendinitis: a consistent alternative to drugs. Photochem Photobiol 2011; 87: 14471452.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4. Alfredo PP, Bjordal JM, Dreyer SH, et al. Efficacy of low level laser therapy associated with exercises in knee osteoarthritis: a randomized double-blind study. Clin Rehabil 2012; 26: 523533.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5. Bjordal JM, Johnson MI, Lopes-Martins RA, et al. Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials. BMC Musculoskelet Disord 2007; 8: 51.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6. Hawkins D, Houreld N, Abrahamse H. Low level laser therapy (LLLT) as an effective therapeutic modality for delayed wound healing. Ann N Y Acad Sci 2005; 1056: 486493.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7. Vladimirov YA, Osipov AN, Klebanov GI. Photobiological principles of therapeutic applications of laser radiation. Biochemistry (Mosc) 2004; 69: 8190.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8. Chung H, Dai T, Sharma SK, et al. The nuts and bolts of low-level laser (light) therapy. Ann Biomed Eng 2012; 40: 516533.

  • 9. Karu T, Pyatibrat L, Kalendo G. Irradiation with He-Ne laser increases ATP level in cells cultivated in vitro. J Photochem Photobiol B 1995; 27: 219223.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10. Benedicenti S, Pepe IM, Angiero F, et al. Intracellular ATP level increases in lymphocytes irradiated with infrared laser light of wavelength 904 nm. Photomed Laser Surg 2008; 26: 451453.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11. Passarella S, Casamassima E, Molinari S, et al. Increase of proton electrochemical potential and ATP synthesis in rat liver mitochondria irradiated in vitro by helium-neon laser. FEBS Lett 1984; 175: 9599.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12. Yu W, Naim JO, McGowan M, et al. Photomodulation of oxidative metabolism and electron chain enzymes in rat liver mitochondria. Photochem Photobiol 1997; 66: 866871.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13. Lavi R, Shainberg A, Friedmann H, et al. Low energy visible light induces reactive oxygen species generation and stimulates an increase of intracellular calcium concentration in cardiac cells. J Biol Chem 2003; 278: 4091740922.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14. Grossman N, Schneid N, Reuveni H, et al. 780 nm low power diode laser irradiation stimulates proliferation of keratinocyte cultures: involvement of reactive oxygen species. Lasers Surg Med 1998; 22: 212218.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15. Zhang J, Xing D, Gao X. Low-power laser irradiation activates Src tyrosine kinase through reactive oxygen species-mediated signaling pathway. J Cell Physiol 2008; 217: 518528.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16. Lubart R, Eichler M, Lavi R, et al. Low-energy laser irradiation promotes cellular redox activity. Photomed Laser Surg 2005; 23: 39.

  • 17. Chen CH, Tsai JL, Wang YH, et al. Low-level laser irradiation promotes cell proliferation and mRNA expression of type I collagen and decorin in porcine Achilles tendon fibroblasts in vitro. J Orthop Res 2009; 27: 646650.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18. Tsai WC, Hsu CC, Pang JHS, et al. Low-level laser irradiation stimulates tenocyte migration with up-regulation of dynamin ii expression. PLoS ONE 2012; 7: e38235.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19. Kaneps AJ, Hultgren BD, Riebold TW, et al. Laser therapy in the horse: histopathologic response. Am J Vet Res 1984; 45: 581582.

  • 20. Marr CM, Love S, Boyd JS, et al. Factors affecting the clinical outcome of injuries to the superficial digital flexor tendon in National Hunt and point-to-point racehorses. Vet Rec 1993; 132: 476479.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21. Huang YY, Chen AC, Carroll JD, et al. Biphasic dose response in low level light therapy. Dose Response 2009; 7: 358383.

  • 22. Ryan T, Smith R. An investigation into the depth of penetration of low level laser therapy through the equine tendon in vivo. Ir Vet J 2007; 60: 295299.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 23. Curtis H, Barnes NS. Photosynthesis, light, and life. In: Curtis H, Barnes NS, eds. Invitation to biology. 5th ed. New York: Worth Publishers, 1994; 161175.

    • Search Google Scholar
    • Export Citation
  • 24. Tsai WC, Cheng JW, Chen JL, et al. Low-level laser irradiation stimulates tenocyte proliferation in association with increased NO synthesis and upregulation of PCNA and cyclins. Lasers Med Sci 2014; 29: 13771384.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25. Jain SM, Pandey K, Lahoti A, et al. Evaluation of skin and subcutaneous tissue thickness at insulin injection sites in Indian, insulin naive, type-2 diabetic adult population. Indian J Endocrinol Metab 2013; 17: 864870.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26. Yu W, Naim JO, Lanzafame RJ. The effect of laser irradiation on the release of bFGF from 3T3 fibroblasts. Photochem Photobiol 1994; 59: 167170.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27. Hutchison AM, Beard DJ, Bishop J, et al. An investigation of the transmission and attenuation of intense pulsed light on samples of human Achilles tendon and surrounding tissue. Lasers Surg Med 2012; 44: 397405.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28. Hosaka Y, Kirisawa R, Yamamoto E, et al. Localization of cytokines in tendinocytes of the superficial digital flexor tendon in the horse. J Vet Med Sci 2002; 64: 945947.

    • Crossref
    • Search Google Scholar
    • Export Citation

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