The Effect of Low Level Laser Therapy on Platelet-related Coagulation Factors
(VIII and vWF)

Abstract

Low level laser therapy (LLLT) has been empirically used in the treatment of
various medical conditions stimulating certain intracellular biological activities resulting
in acceleration of wound healing due to various biostimulatory effects. It has been
widely tested on cell culture studies; the mechanism of action is complex, in general it
involves absorption of light on subcellular level particularly the electron chain system in
the mitochondria resulting in the biostimulatory effect.
LLLT have been shown to reduce chronic inflammatory process in periodontal
tissue with subsequent release of metalloproteinase’s and collagenases resulting in
improvement in tissue healing and wound remodeling. It has been also shown to cause
smooth muscle relaxation and subsequent vasodilatation. Several in vitro studies have
shown that LLLT at certain wavelengths may stimulate fibroblast proliferation.
Furthermore; (He-Ne) LLLT has been shown to have stimulatory effect on cultured
osteoblast resulting in enhancement of proliferation, differentiation and calcification.
Other empirical uses of laser therapy include analgesia, antimicrobial activity, laser
curettage and relieving trigeminal neuralgia.
Objectives and Results:
This study was designed to measure two of the coagulation factors of whole
blood samples obtained from 25 healthy male and female adult volunteers before and
after LLLT using three different wavelengths (650, 532 and 405 nm), namely factor VIII
and von-Willebrand factor; both of these factors are available within platelets granules.
The mean concentration of VIII and vWF in all samples were 1.15 and 4.46 ng/ml
respectively. The mean concentration and the percent change in individual samples of
VIII and vWF after LLLT are listed respectively as follows: 650 nm (0.84, 6.23 and
4.42, 1.48), 532 nm (0.97, - 8.23 and 4.17, -4.24), and 405 nm (0.91, 5.81 and 4.33, 1.42).

Paired T-test showed no significant change on VIII including the concentration
and percent. The percent change was in VIII concentration was in general towards a
negative value for both 650 and 532 nm LLLT, while LLLT with 405 nm resulted in a
slight increase in overall samples.