Photobiomodulation by helium neon and diode lasers in an excisional wound model: A single blinded trial


1 Department of Physiotherapy, Manipal College Of Allied Health Sciences, Manipal, Karnataka, India

2 Department of Pathology, Kasturba Medical College, Manipal, Karnataka, India

3 Department of Pharmacology, Kasturba Medical College, Manipal, Karnataka, India

4 Department of Medicine, Kasturba Medical College, Manipal, Karnataka, India

5 Department of Surgery, Manipal University, Manipal, Karnataka, India


Background: Application of different kinds of lasers in clinical and experimental studies causes photobiomodulation that works at localized cellular and humoral level on various biological systems. Increased numbers of fibroblasts, myofibroblast, and degranulation of mast cells have been the observed benefits post-irradiation.
Objective: Was to find out the effect of irradiation with energy densities of 3.38 J/cm 2 , 8 J/cm 2 , and 18 J/cm 2 on animal tissue (albino wistar rats) in an excisional wound model and to assess changes in biochemical (hydroxyproline) and histopathological levels in excisional wound model.
Materials and Methods: The animals were divided into 4 groups, which were labeled as L1, diode laser (18 J/cm 2 ), L2 Helium-neon (He-Ne, 8 J/cm 2 ), L3 diode laser (3.38 J/cm 2 ), and sham treatment for control was depicted by C, respectively. Histological and hydroxyproline analysis was performed on 7, 14, 21 days of post-wounding. One-way analysis of variance, ANOVA and Bonferroni's multiple comparison tests were done for tissue hydroxyproline levels.
Results: There was no significant increase in the hydroxyproline content (P < 0.005) when observed in study group and compared to controls. Whereas significant epithelizations was seen in group treated with He-Ne laser of intensity of 8 J/cm 2 .
Conclusion: The experimental observations suggest that low intensity helium-neon laser of 8 J/cm 2 intensity facilitated photo stimulation by tissue repair, but failed to show significant tissue hydroxyproline levels in excisional wound model.


1. Henry M, Thompson J. Wound healing and management. Clinical Surgery. 2nd edn. London: Elsevier Saunders Limited; 2002. p. 105-13.  Back to cited text no. 1
2. Kumar V, Abul AK, Nelson F, Richard M. Acute and chronic inflammation. Robbins Basic Pathology, 8th edition. New Delhi: Reed Elsevier India private limited; 2007. p. 31-58.  Back to cited text no. 2
3. Robertson V, Ward A, Low J, Reed A. Infrared and visible radiations. Electrotherapy explained principles and practice. 4th ed. Noida: Reed Elsevier India Private limited; 2009. p. 459-98.  Back to cited text no. 3
4. Morton JJ, Malone MH. Evaluation of vulnerary activity by an open wound procedure in rats. Arch Int Pharmacodyn Ther 1972;196:117-26.  Back to cited text no. 4
5. McMinn RH, Pritchard JJ. Tissue repair. New York and London: Academic Press; 1969:1-40.  Back to cited text no. 5
6. Nayak BS, Maiya A, Kumar P. Influence of helium-neon laser photostimulation on excision wound healing in wistar rats. Online J Biol Sci 2007;7:89-92.  Back to cited text no. 6
7. Sullivan S, Schmitz T. Vascular, lymphatic and integumentary disorders. Physical rehabilitation, 5th ed. Philadelphia: FA Davies Company; 2001. p. 643.  Back to cited text no. 7
8. Jahangiri Noudeh Y, Shabani M, Vatankhah N, Hashemian SJ, Akbari K. A combination of 670 nm and 810 nm diode lasers for wound healing acceleration in diabetic rats. Photomed Laser Surg 2010;28:621-7.  Back to cited text no. 8
9. Reddy GK. Comparison of the photostimulatory effects of visible He-Ne and infrared Ga-As lasers on healing impaired diabetic rat wounds. Lasers Surg Med 2003;33:344-51.  Back to cited text no. 9
10. Mendez TM, Pinheiro AL, Pacheco MT, Nascimento PM, Ramalho LM. Dose and wavelength of laser light have influence on the repair of cutaneous wounds. J Clin Laser Med Surg 2004;22:19-25.  Back to cited text no. 10
11. Mester E, Mester AF, Mester A. The biomedical effects of laser application. Lasers Surg Med 1985;5:31-9.  Back to cited text no. 11
12. Mester E, Spiry T, Szende B. Tota JG. Effect of laser rays on wound healing. Am J Surg 1971;122:532-5.  Back to cited text no. 12
13. Vijendra P, Rao SBS, Kumar P, Rao L, Mahato KK. Photobiomodulatory effects of He-Ne laser on excision wounds. Proc of SPIE 2011;7887.  Back to cited text no. 13
14. Flemming K, Cullum NA. Laser therapy for venous leg ulcers. Cochrane Database Syst Rev 1999.  Back to cited text no. 14
15. Lucas C, Poublon C, Cockrell C, Haan RJ. Wound healing in cell studies and animal experimental mode by Low level Laser therapy were clinically justified? A systematic review. Lasers Med Sci 2002; 17:100-34.  Back to cited text no. 15
16. Sommer AP, Pinheiro AL, Mester AR, Franke RP, Whelan HT. Biostimulatory windows in low-intensity laser activation: Lasers, scanners, and NASA's light-emitting diode array system. J Clin Laser Med Surg 2001;19:29-33.  Back to cited text no. 16
17. Petersen SL, Botes C, Olivier A, Guthrie AJ. The effect of low level laser therapy (LLLT) on wound Healing in Horses. Equine Vet J 1999;31:228-31.  Back to cited text no. 17