Laser therapy has gone from near obscurity to one of the top modalities and services being discussed and implemented in veterinary practices today. Reasons for this include a more thorough understanding of the physiologic principles behind photobiomodulation, the evolution and improvement in laser equipment, and, most importantly, the overwhelmingly consistent positive patient responses.
The three broad responses laser therapy initiates are commonly listed as analgesic, anti-inflammatory, and bio-stimulatory or healing. This case study illustrates the very rapid and measurable anti-inflammatory effects. The patient is a MN, 10-year-old, 90 pound Labrador retriever named Bruno. He presented with a history of being attacked by a neighbor’s dog. The attack resulted in a full thickness tear on the proximal medial aspect of the left hind limb. Bruno was taken to a local emergency clinic for treatment and repair of the laceration. The accompanying history indicated that the wound was cleaned and debrided and then sutured with 3-0 Securolon. The patient was administered antibiotics, anti-inflammatories, and analgesics and released.
Four days later Bruno was presented to Dr. Boaz Man due to concern over the swelling and discharge from the injury site. Upon examination the area was edematous with a significant amount of bruising and serous drainage. The suture line was still intact. Dr. Man recommended laser therapy which was initiated that day. The laser used was a K-Laser Cube 4. This laser delivers 4 therapeutic wavelengths simultaneously:
- 660nm for superficial absorption and wound healing
- 800nm for accelerated ATP production
- 905nm for enhanced O2 release
- 970nm for increasing blood flow.
An edema/congestion setting was used that delivers the energy primarily in a series of modulated pulse frequencies. Using pulse delivery in addition to continuous wave delivery has been shown in many studies to enhance the clinical effects of laser therapy particularly in wound healing. An average power of 2.5 W was used to deliver a total dose of 1050 Joules in a non-contact scanning mode. This was approximated to deliver 5J/cm2.
Examination the following day showed obvious improvement. A second laser therapy treatment was administered. The next day the area looked well on its way to proper healing with no discharge and very little evidence of any swelling and bruising. One more treatment was administered and the owner was instructed to return at the prescribed date for suture removal.
This case is typical of the consistent anti-inflammatory responses observed with laser therapy. The primary photochemical reactions initiate a cascade of secondary and tertiary reactions, including:
- Increased production of NO along with other mediators which stimulate vasodilation and activation of the lymphatic channels to reduce edema and facilitate removal of cellular debris.
- Angiogenesis is stimulated which increases oxygen and nutrient transport to improve tissue repair. It also reduces ischemia and all the negative events associated with a negative oxygen balance in tissue.
- Production of ROS and SOD to help stabilize cellular membranes and balance the detrimental effects of free radical activity.
- Enhanced WBC activity aiding in the removal of cellular debris.
- Increased production of PGI2, which has anti-inflammatory activity similar to other COX inhibitors.
Reduction in Interleukin 1 and other pro-inflammatory cytokines. These reactions along with increased ATP production facilitate a more rapid tissue healing and repair, which leads to the kind of clinical response evidenced by this case. Proper training and good understanding of the principles behind laser therapy are still essential for optimal success.
To review the complete case study, please visit http://www.k-laser.com/VHA to download - and don't miss Dr. Bradley discussing this case and more during his session "Laser Therapy Simplified: What You Really Need to Know" at the 2016 VHA Expo on November 3, 2016!
About the Author:
David Bradley, DVM, FASLMS graduated from UF in 1987. He has practiced for over 27 years in Mixed, SA, Equine, and Exotics with a special interest in surgery. Dr. Bradley began using Lasers in private practice in 1999. He has lectured nationally and internationally on both surgical and therapeutic veterinary laser use.