About wound healing with low level lasers

1. Letters to the Editor
The Laser Wound Healing Contradiction
Jan Tune´r, DDS
Dear Editor,
In the recent review of the literature by Loreti et al.,1
the
authors demonstrate the contradictory situation regarding
the scientific documentation for using laser phototherapy
(LPT) to improve wound healing. Although 557 studies were
identified from 2008 up to today, only 31 of these had a score
of 3 or more on the Jadad scale. And merely three of these were
clinical studies. Therefore, although wound healing is the most
studied indication for LPT, the scientific basis is only ac-
ceptable for rodents. And because rodent wound healing is
different from human wound healing, the documentation for
using LPT in a clinical situation remains questionable. So far
the authors have made a good point, but it ends there.
First of all, the authors have only listed the reported doses
(J/cm2
). This is not enough; the applied energy (J) always
has to be taken into account in an analysis. Almost any dose
can be achieved by changing the output power, especially
the spot size. A dose of 4 J/cm2
is sometimes thought to be
‘‘the gold standard’’ for wound healing, but it can be
reached in seconds or in minutes, depending upon the power
of the laser. And if a thin fiber is used, a high dose is reached
much faster than when using a wide fiber. Irradiation time in
itself is an important parameter.2,3
Simply comparing the
numerical values of the doses has no meaning, and can lead
the reader in the wrong direction.4
Additionally, the reported
doses are not always correct.
Next, the authors have chosen to use the lasing compo-
nents instead of reporting the wavelengths. This leaves the
reader unaware of the actual wavelength used, because, for
example, GaAlAs has a wide wavelength range. And, it is not
uncommon to find GaAlAs reported, but with the lasing
components actually being InGaAlP. The latter is reported
twice, as ‘‘phosphide indium-gallium-arsenic (InGaAlp)’’ and
as ‘‘indium-gallium-arsenic (InGaAlp).’’ Both are incorrectly
spelled and are actually the same. Even worse is the ‘‘laser’’
GnbH,’’ which does not exist. It turns out to be a 660 nm laser
from Lasotronic GmbH in Switzerland, ‘‘GmbH’’ meaning
‘‘company with limited liability.’’ And an ‘‘InGasAs’’ laser
turns out to be an ordinary GaAlAs 980 nm laser. This is a
typo in the original article, but a review of the literature
cannot only quote whatever is written. An independent
analysis of the studies used in the review must be performed.
A review of the literature requires less analysis than a
meta-analysis. However, it requires a critical look at the
articles to be quoted. A Jadad evaluation is a good start, but
because ‘‘it is all in the parameters,’’ these parameters have
to be independently checked and analyzed. One of the three
clinical studies5
used 90 J/cm2
, a very high dose, and be-
cause it was achieved by using a 15 W, 980 nm laser for
3 sec per cm2
and increasing the skin temperature up to
maximum 50°, it is obvious that this is not LPT as we know
it, and of course it is not effective.
One further aspect of a review on this topic should be the
use of healthy individuals. Many studies have done so, but it
is now well realized that the effect of LPT on wound healing
in healthy animals is very limited. Instead, modern research
has used, for example, genetically diabetic animals, in
which the positive effect of LPT is more obvious.6,7
A notable part of the discussion says ‘‘The shorter the
wavelength, the higher its action and power of penetration.’’
What does ‘‘action’’ mean? And, actually, it is the other
way around, or, rather with red having low penetration,
*810 nm is the best and then penetration is lowered as the
wavelength is further increased.
In summary, the authors have gathered the best wound
healing studies from recent years and come to the conclu-
sion that the evidence is scarce, especially for the clinical
aspect.1
This is a useful wakeup call, but apart from that, the
review lacks quality and should be read with care.
The average cost of treating a chronic wound in a diabetic
Swedish patient is >3000 USD per year.8
Therefore, if LPT
works as well as is widely anecdotally reported, there are
large potential savings for healthcare decision makers.
Maybe we should leave the rats and mice and continue the
work of Mester from the 1970s.9,10
Out of 1018 patients
with chronic leg ulcers, 74% healed within a few months.
Author Disclosure Statement
No competing financial interests exist.
References
1. Loreti EH, Pascoal VL, Nogueira BV, Silva IV, Pedrosa
DF. Use of laser therapy in the healing process: a literature
review. Photomed Laser Surg 2015;33:104–116.
2. van Breugel, HHFI, Ba¨r PRD. Power density and exposure
time of HeNe laser irradiation are more important than total
energy dose in photo-biomodulation of human fibroblasts
in vitro. Lasers Surg Med 1992;12:528–537.
Private Dental Clinic, Grangesberg, Sweden.
Photomedicine and Laser Surgery
Volume 33, Number 6, 2015
ª Mary Ann Liebert, Inc.
Pp. 343–344
DOI: 10.1089/pho.2015.3905
343

2. 3. Castano AP, Dai T, Yaroslavsky I, Cohen R, Apruzzese
WA, Smotrich MH, Hamblin MR. Low-level laser therapy
for zymosan-induced arthritis in rats: Importance of illu-
mination time. Lasers Surg Med 2007;39:543–550.
4. Tune´r J, Hode L. Low level laser therapy for hand arthritis –
fact or fiction? Clin Rhematol 2010;29:1075–1076.
5. Lecle`re FM, Puechguiral IR, Rotteleur G, Thomas P,
Mordon S. A prospective randomized study of 980 nm di-
ode laser-assisted venous ulcer healing on 34 patients.
Wound Repair Regen 2008;18:580–585.
6. Al-Watban FA. Laser therapy converts diabetic wound
healing to normal healing. Photomed Laser Surg 2009;27:
127–135.
7. Bicalho Rabelo S, Balbin Villaverde A, Amadei Nicolau R,
Castillo Salgado MA, et al. Comparison between wound
healing in induced diabetic and nondiabetic rats after low-
level laser therapy. Photomed Laser Surg 2006;24:474–
479.
8. Andersson P. Leg ulcer treatment from a nursing perspective.
2007. Available at: http://www.researchgate.net/publication/
8679494_How_patients_with_diabetes_who_have_foot_and_
leg_ulcers_perceive_the_nursing_care_they_receive (Last
accessed March 1, 2015).
9. Mester E, Spiry T, Szende B, Tota JG. Effect of laser-rays
on wound healing. Am J Surg 1971;122:532–535.
10. Mester E, Mester AF, Mester A. The biomedical effects of
laser application. Lasers Surg Med 1985;5:31–39.
Address correspondence to:
Jan Tune´r
Spjutvagen 11
Grangesberg 77232
Sweden
E-mail: jan.tuner@swipnet.se
344 TUNE´ R