Lasers in Surgery and Medicine 42:597–601 (2010)
Prophylactic Low-Level Light Therapy for the Treatment of
Hypertrophic Scars and Keloids: A Case Series
Daniel Barolet, MD
* and Annie Boucher, PhD
RoseLab Skin Optics Research Laboratory, Montreal, Quebec, Canada H3R 3L5
Dermatology Division, Department of Medicine, McGill University, Montreal, Quebec, Canada H3A 1A1
Background and Objectives: Hypertrophic and keloid
scars result from alterations in the wound healing process.
Treating abnormal scars remains an important challenge.
The aim of this case series was to investigate the
effectiveness of near infrared (NIR) light emitting diode
(LED) treatment as a prophylactic method to alter
the wound healing process in order to avoid or attenuate
the formation of hypertrophic scars or keloids.
Study Design/Patients and Methods: Three patients
(age 27–57) of phototypes I– III with hypertrophic scars or
keloids due to acne or surgery participated in this case
series. Following scar revision by surgery or CO
ablation on bilateral areas, one scar was treated daily by the
patient at home with non-thermal, non-ablative NIR LED
(805 nm at 30 mW/cm
) for 30 days. Efﬁcacy assessments,
conducted up to a year post-treatment, included the
Vancouver Scar scale (VSS), clinical global assessment
of digital photographs, and quantitative proﬁlometry
analysis using PRIMOS. Safety was documented by
adverse effects monitoring.
Results: Signiﬁcant improvements on the NIR-treated
versus the control scar were seen in all efﬁcacy measures.
No signiﬁcant treatment-related adverse effects were
Conclusion: Possible mechanisms involved are inhibition
of TGF-bI expression. Further studies in larger group of
patients are needed to evaluate this promising technique.
Lasers Surg. Med. 42:597–601, 2010.
ß2010 Wiley-Liss, Inc.
Key words: CO
laser ablation; near infrared (NIR);
photobiomodulation; prevention; surgical scars; trans-
forming growth factor beta-I
Wound healing is a complex tissue-response to injury
leading to skin restoration. Alterations in the wound
healing process can result in hypertrophic or keloid
scarring. Cutaneous aberrant scaring, characterized by
an imbalance between cell growth and excessive extrac-
ellular matrix deposition, can form after surgery, laser
treatment or acne. Keloids take the form of a raised
distorted growth that grow beyond the boundaries of the
original wound site and are frequently associated with
pruritus and pain. Hypertrophic scars have the clinical
appearance of a red raised lump on the skin, do not extend
beyond the original skin trauma area, and often regress
with time to a certain extent. Aside from their appearance,
clinical features and histological characteristics also dis-
tinguish between hypertrophic scars and keloids .
Recent research has underlined a lowered self-esteem and
impaired quality of life in affected individuals which
underlines the need for better treatment options for these
patients . Treating abnormal scars remains an important
challenge for both the clinician and the affected person.
A wide range of surgical (e.g., cryotherapy, excision),
non-surgical (e.g., pharmacological, mechanical pressure,
silicone gel dressings), and laser therapies (CO
dye, fractional ablative, and non-ablative lasers) have been
tested with variable success [1,3,4]. The inconsistencies
and sub-optimal results obtained to date call for the
investigation of new therapeutic interventions. Moreover,
potential differential effects on keloids and hypertrophic
scars must be considered in the search for new treatments
Wound healing is a complex cascade of multistep
physiologic events regulated at the biochemical level by a
vast array of signaling mechanisms. Understanding the
molecular mechanisms involved in the dysregulation of
wound healing leading to aberrant scaring might allow the
development of targeted therapies for keloids and hyper-
trophic cells. Recent evidence point to the transforming
growth factor beta-I (TGF-bI) has a major player in the
formation of hypertrophic scars and keloids [6–8]. Results
of wound healing research over the past decades have
demonstrated that keloidal and hypertrophic scar tissues
show higher expression levels of receptors, overproduction
No conﬂict of interest declared.
Contract grant sponsor: RoseLab Skin Optics Laboratory.
*Correspondence to: Daniel Barolet, MD, RoseLab Skin Optics
Laboratory, 3333 Graham Blvd., Suite 206, Montreal, Quebec,
Canada H3R 3L5. E-mail: email@example.com
Accepted 11 June 2010
Published online 15 July 2010 in Wiley InterScience
ß2010 Wiley-Liss, Inc.
and poor regulation of TGF-bI, leading to ﬁbroblastic proli-
feration and excess collagen deposition. Thus, TGF-bI
appears to be a prom ising target for therapeutic int ervention.
It has been shown that low-level light therapy (LLLT) can
trigger natural intracellular photobiochemical reactions
involved in wound healing, including TGF-bI modulation
[9– 11]. LLLT with red light and near infrared (NIR) light
acts on the mitochondria and at the cell membrane level
. Absorbed light converted to chemical kinetic energy
causes changes in membrane permeability, improves
signaling between mitochondria, nucleus and cytosol, nitric
oxide formation and increase oxidative metabolism to
produce more ATP, ultimately leading to normalization of
cell activity [13–16]. Hence, LLLT might be helpful in scar
treatment. The aim of this case series was to investigate
the efﬁcacy of LLLT, by means of light emitting diode
(LED), as an adjunct prophylactic therapy to conventional
scar revision interventions in the healing process of
In the present case series, patients with bilateral
abnormal scars were treated with LED in the NIR
spectrum (805 nm, 30 mW/cm
) following scar revision by
surgery or CO
laser ablation on both sides. Patients self
treated at home and daily for 30 days on one side of the
affected area while the other side served as control, not
receiving LED treatment (split-study; the patient being its
own control). Clinical improvements were assessed with in
vivo 3D microtopography quantitative measurement for
scar height, blinded clinical assessment of change using
digital photographs, and the Vancouver Scar scale (VSS).
Cutaneous adverse response was also documented. It
was expected that the NIR-treated side would yield
better clinical outcomes in comparison to the control side.
STUDY DESIGN/PATIENTS AND METHODS
The patient was a Caucasian 57-year old female with
Fitzpatrick phototype II. The patient underwent face-lift
surgery for treatment of facial chalasia (rhytides and
laxity). The patient had no history of abnormal scarring.
She was not taking any medication prior to and after
surgery. Post-operative care consisted of standard wound
care. The post-operative course was unremarkable until
day 20 when abnormal wound healing was noted on pre-
auricular areas bilaterally. Wound care then included
massage and silicon sheets. On post-operative day 45, the
diagnosis was conﬁrmed (keloids) and the patient was
referred to our clinic. Scar revision for this patient consisted
in surgical removal of the scars with primary closure (see
Fig. 1; upper panels; 1 week post-revision). Scar revision
was performed 8 months after the facelift.
The patient was a 27-year-old Caucasian male with
Fitzpatrick skin type I. The patient presented with hyper-
trophic scars due to abnormal wound healing post-acne
lesions of the chest (sternal area). The scars were 6-year old.
His past medical history was negative. He did not receive
any medical treatment but used a topical cream with
vitamin E. CO
laser ablation was performed to remove scar
tissue. First, local anesthesia was completed with Xylo-
caine 2% with epinephrine 1:100,000. Then, the CO
was used in the focused bistouri mode (1 mm spot size, 15 W,
CW mode) for debulking the scar in order to reduce the
volume of the ﬁbrotic lesion. What was left at the base of the
lesion was further treated but in the resurfacing mode
using a scanner to remove very thin layers of scar tissue.
laser parameters were the following; 18 W, 7.1 mm
dia, circles, 0.1 second on/0.1 second off, with up to ﬁve
consecutive passes performed until normal skin was
reached. Bilateral lesions (similar ones on each side) were
chosen and treated the same way. Post-treatment wound
care included daily application of topical antibiotics and a
telfa dressing for 10 days.
This patient was a 36-year old Caucasian female with
Fitzpatrick phototype III presenting several bilateral
hypertrophic scars as a result of surgical removal of nevi
(areola area). The scars were 3-year old. She had experi-
enced abnormal wound healing in the past with residual
textural changes after trauma. Hypertrophic scars were
raised by 2– 5 mm and showed diffuse telangiectasia. No
pain was present with occasional pruritus. CO
resurfacing was performed as described for Case 2.
Table 1 presents a summary of the patients character-
Following scar revision, one side was randomly selected
(ﬂip of a coin) for NIR treatment by the patient at home
and daily for 15 minutes with LED emitting at 805 nm
Fig. 1. Case 1 after pre-auricular scar revision (upper panel)
and 1-year follow-up (lower panel). Left: NIR-treated side;
Right: control side. [Figure can be viewed in color online via
598 BAROLET AND BOUCHER
) at a treatment distance of 2.5 cm, for 30 days
(total dose ¼27 J/cm
). Patients were instructed to start the
NIR treatment upon their return home. Before returning
home, patients received post-treatment wound care
instructions, which included applying a topical antibiotics
and a daily telfa dressing for 10 days. Furthermore,
following the acute healing phase, sun avoidance and the
use of a sunscreen (SPF 30) was mandatory in the unlikely
event of direct sun exposure on the treated area. Digital
photographs of the NIR-treated and control scars (Canon
Dual Flash EOS 10D, Canon, Tokyo, Japan with EX
SIGMA 50 mm 1:2.8 macro lens; Sigma, Aizu, Japan) were
taken at base line and at follow-up visits. Each photograph
was taken maintaining identical ambient lighting, pose,
and camera angles.
Clinical Global Impression of Change (CGIC)
The photographs were analyzed for clinical improvement
by a blinded non-treating physician using a 5-point scale for
degree of improvement from baseline for NIR-treated and
control scars (0 ¼none; 1 ¼mild; 2 ¼moderate; 3 ¼good;
A scar severity score was determined using the VSS for
the NIR-treated and control scars by a blinded non-treating
physician . The Vancouver scale consists of four
variables: vascularity, height (thickness), pliability, and
pigmentation. Each variable has 4–6 possible scores. A
total score ranges from 0 to 14, whereby a score of 0 reﬂects
Skin Surface Topography
The measurements of the skin surface topography were
performed using the Phaseshift Rapid in vivo Measure-
ment of Skin optical 3D device (PRIMOS
, GFM, Teltow,
Germany) on the NIR-treated and control areas to quantify
scar height (Cases 2 and 3). To accurately assess the degree
of improvement, scars were analyzed to determine the
cross-sectional area after the pre- and post-topographical
images were aligned. A cross-sectional line graph across
each scar compared 24 points to determine the mean
change from baseline to post-treatment. Related Samples
Wilcoxon’s signed rank test was used to assess the differ-
ence between pre- and post-scar heights.
On each visit, the presence of adverse effects including
erythema, edema, pruritus, hypopigmentation, hyperpig-
mentation, and textural changes were documented.
The CGIC assessment revealed a greater improvement
on the NIR-treated scars in comparison to the control scars
in the three patients (Table 2): clinical improvements were
deemed ‘‘moderate’’ to ‘‘excellent’’ (scores 2– 4) on the NIR-
treated scars while the control scars yielded lesser degrees
of improvements (score of 1 or mild). Clinical improvements
in appearance and outline of the scars and can be noted for
Case 1 in Fig. 1. Similarly, the VSS revealed a greater
reduction in severity score on the NIR-treated scars in all
cases in comparison to the control scars at follow-up. The
greatest reduction in VSS for the NIR-treated scars was of
77% (Case 1) whereas for the control scars, of 29% (Case 2;
Table 3). The measurements of the skin surface micro-
topography revealed that scar height was signiﬁcantly
reduced for the NIR-treated scars (Case 2: P¼0.07; Case 3:
P<0.001) but not for the control scars (Case 2: P¼0.55;
Case 3: P¼0.31). Fig. 2 depicts digital photographs and
surface microtopography analyses for the NIR-treated and
control scars at baseline and post-treatment for Case 2.
Treatment was overall well tolerated with patients
reporting a slight but bearable sensation of heat during
the procedure. Aside from slight erythema and mild
crusting following CO
, no other adverse signs, such as
post-inﬂammatory hyperpigmentation (PIH), were observed
TABLE 2. Clinical Global Impression of Change
Case 1 4 1
Case 2 3 1
Case 3 2 1
TABLE 1. Patient Characteristics
ID Case 1 Case 2 Case 3
Gender F M F
Age 57 27 36
Phototype II I III
Scar type Pre-auricular linear keloids
Hypertrophic scars on chest
Hypertrophic scars on back
Scaring cause Post-face lift Post-acne Post-excision
Scar revision method Surgical scar revision/excision CO
laser resurfacing CO
Scar age 8 months 6 years 3 years
Last assessment visit Week 77 Week 12 Week 8
LLLT TREATMENT OF HYPERTROPHIC SCARS AND KELOIDS 599
Keloids and hypertrophic scars are benign skin tumours
and are the effect of a dysregulated wound-healing process.
These scar types are difﬁcult to eradicate and conventional
treatments are not always successful. In the present study,
we investigated the effect of LLLT by LED therapy in the
reduction of aberrant scars following scar revision by CO
or surgery. Patients were treated in a within-subject design
with NIR (805 nm) on one area while the other area served
The results from this case series revealed that abnormal
wound healing can potentially be modulated with LLLT
and that the volume of scar tissue, reduced after surgical
scar revision or CO
laser resurfacing in prone patients.
The results from this case series also showed that LED
therapy was well tolerated with no signiﬁcant adverse
reactions, likely due to the low-level characteristics of this
treatment modality. Other light sources, such as PDL,
often induce, although transiently, important adverse
effects such as severe swelling, purpura, and erythema
which may compel subjects to discontinue treatment. From
a clinical perspective, the absence of thermal injury (peak
power effects) to the skin during light treatment may yield a
signiﬁcant advantage over laser-based methods, given that
improvements can be achieved without thermal damage
and with limited adverse reactions.
NIR irradiation may enhance the wound healing process
presumably by its biomodulatory effects. The mechanisms
at play have not been investigated in the present context. It
is possible that multiple cell signaling pathways contrib-
uted to the observed therapeutic effect. TGF-bI and other
families of molecules have been shown to be modulated by
LLLT, including transforming growth factor platelet-
Fig. 2. Digital photographs (a) and PRIMOS color coded
topographic images (b) obtained from Case 2 shows that
there is a notable improvement in the scars height. This is
represented by the increase of red to blue hue, and the loss of
yellow hue. c: Cross-sectional representation of the scar height
at baseline and post-treatment for the NIR-treated and control
scars. Twenty-four points between these curves were compared
to assess the overall mean improvement post-treatment in scar
height for the NIR-treated and control scars. [Figure can be
viewed in color online via www.interscience.wiley.com.]
TABLE 3. Vancouver Scar Scale Individual Results
Pre Post % Reduction Pre Post % Reduction
Case 1 9 2 77.78 9 8 11.11
Case 2 11 7 36.36 7 5 28.57
Case 3 8 7 12.50 6 6 0.00
600 BAROLET AND BOUCHER
derived growth factor (PDGF), interleukins (IL-6, 13, 15)
and matrix metalloproteinases (MMPs) which are all also
associated with (abnormal) wound repair . Moreover, it
has been shown that CO
therapy can reduce TGF-bI
expression, which might have played a part in the overall
effect in patients treated with this modality .
LED preconditioning with NIR irradiation was shown to
reduce abnormal scars in our three patients, and may
possibly become a clinically signiﬁcant at home self-
administered treatment modality. The results from the
present case series are encouraging and underscore the
need for controlled studies on a larger number of patients.
Future trials should include long-term follow-up examina-
tions to assess if results are maintained over time. Further
studies are also necessary to identify the cellular processes
underlying the therapeutic effects.
This study was funded by RoseLab Skin Optics Labo-
ratory. The authors acknowledge Diane Lamalice for her
technical assistance and Isabelle Lussier, PhD from
MedStrategis for the manuscript preparation.
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