Treatment of scars - Lasers and Energy Devices for the Skin - page 208

a nonablative laser (1064 Nd:YAG CoolGlide Vantage®, Cutera)
in order to reduce complications and improve the effi cacy
(156). Twenty Asian subjects were divided into two groups
that received three monthly treatments with an AFR using
high energy (Group A) and low energy (Group B) on one half
of the face and an AFR with low energy plus a nonablative laser
on the other half. At 3 months after last treatment, the low-
energy (15-35 mJ, 20% density) fractional CO 2 plus Nd:YAG
(30 ms, 5-mm spot, and 40-50 J/cm 2 ) group yielded slightly
better results than the high-energy low-density fractional CO 2
group (50-70 mJ and 20% density). The average downtime
decreased by 50% (3.6 vs. 7.5 days) with the dual treatment
compared with the high-energy fractional CO 2 . The average
duration of erythema (2 vs. 6 days) and hyperpigmentation
(1 vs. 3 weeks) was clearly reduced in the dual treatment group.
Cho and colleagues reported the use of combining two
treatment modes of an ablative 10,600-nm CO 2 fractional
laser system (UltraPulse Encore laser, Lumenis Inc., Santa
Clara, California, USA) for the treatment of acne scars in
Korean patients (157). Twenty patients with atrophic acne
scars of all types received a single session of a CO 2 fractionated
laser using the Deep FX mode to the scars (10-20 mJ, density
2, and 300 Hz) and the Active FX mode (50-100 mJ, 68% cov-
erage, 75 Hz) over the entire face. At 3 months after the treat-
ment, one patient had 76-100% improvement, nine had
51-75% improvement, seven had 26-50% improvement, and
three had 25% improvement or less. One patient developed
PIH that spontaneously resolved within 1 month. The authors
advocated for the short-term use of systemic prednisolone to
reduce the risk of post-therapy infl ammatory reactions and
subsequent pigmentary changes, particularly in Asian patients.
Shek and colleagues used the Active FX to evaluate the effi cacy
and the risk of PIH after the treatment of acne scars in Asian skin
(158). Ten Chinese patients underwent a single treatment session
using 100 mJ, 50 Hz, pattern 3, size 5, and density 2. At 3 months
after treatment, 70% of patients reported moderate to signifi cant
improvement. Few instances of mild PIH were noted.
Cassuto and colleagues treated 30 patients with acne scar-
ring, wrinkling, and tissue laxity with a microfractional CO 2
laser system (Mixto Sx Slim Evolution®, Lasering, Modena,
Italy) (159). Subjects were divided into three groups to com-
pare the use of higher energies with short pulse duration ver-
sus lower energies with longer pulse duration versus average
energies and pulse duration. The settings were as follows: spot
size 300

10,600-nm CO 2 fractional lasers for acne scars (161). Eight
patients, Fitzpatrick skin type IV, with mild-to-severe atrophic
acne scars had one side of the face treated with the Fraxel SR
1500 using 40 mJ and treatment level 6 (17% coverage). The
other side of the face received the Deep FX mode on acne scars
with 10-20 mJ, density 2 (10% coverage), and 300 Hz followed
by the Active FX mode with 50-100 mJ, density 2 (68% cover-
age), 75 Hz. Three months after treatment, the mean grade of
clinical improvement based on clinical assessment was 2.0 ±
0.5 for NAFL and 2.5 ± 0.8 for AFR ( p = 0.158) on a 4-point
scale. On each side treated using NAFR and AFR, the mean
duration of post-therapy crusting and scaling was 2.3 ± 2.9 and
7.4 ± 2.4 days, respectively, and that of post-therapy erythema
was 7.5 ± 5.7 and 11.5 ± 5.2 days, respectively. The mean visual
analog scale pain score was 3.9 ± 2.0 for NAFR and 7.0 ± 2.0 for
AFR. Only one patient developed PIH that spontaneously
resolved within 2 weeks. The authors concluded that both
NAFR and AFR were effective after a single session for acne
scarring in Asian patients, but the AFR showed slightly greater
effi cacy while it caused more pain and more adverse effects.
Hedelund et al. (164) performed a single-blinded randomized
controlled trial of treatment of moderate-to-severe atrophic
acne scars using CO 2 AFR. Two facial areas of similar size repre-
senting similar scar morphology were compared at three and six
monthly treatment sessions, using very conservative treatment
parameters (topical anesthetic only and 2-3 days for healing).
Statistically signifi cant ( p <0.0001) mild-to-moderate improve-
ment in atrophy and texture were seen on the treated side.
Manuskiatti and colleagues reported higher incidence of
PIH (92% of the subjects) noted after fractionated CO 2 laser
for treatment of acne scars in Asian skin (162). Thirteen
patients with mild-to-moderate atrophic facial acne scars
underwent three sessions with a 15-W CO 2 laser (Ellipse Juvia,
Ellipse A/S, Hørsholm, Denmark) on an average of 7-week
interval. A single pass treatment was performed with pulse
energies ranging from 75 to 105 mJ depending on the severity
of the scars and density of 49 MTZ/cm 2 (9.6% coverage).
At the 6-month follow-up, 85% of patients were rated as
having at least 25-50% improvement of scars. At 1-month
follow-up, image analysis evaluated by a UVA-light video cam-
era (Visioscan VC 98, Courage-Khazaka, Köln, Germany)
revealed that both surface smoothness ( p = 0.03) and scar
volume ( p <0.001) had signifi cant improvement compared
with baseline measurements. Mild-to-moderate PIH was
experienced by 12 of 13 subjects treated and lasted 2-16 weeks
(average 5 weeks). All patients were successfully treated with
hydroquinone 4% cream. The authors concluded that CO 2
AFR is an effective and well-tolerated treatment for dark-
skinned patients with acne scarring that showed improved
effi cacy over nonablative dermal remodeling devices.
Fractionated resurfacing, including nonablative fraction-
ated lasers and ablative fractionated lasers, represents a new
treatment paradigm for acne scarring as well as scars overall
as it combines the lesser risks of side effects such as delayed-
onset hypopigmentation, PIH, scarring, and prolonged ery-
thema compared with traditional ablative laser resurfacing
with a more predictable clinical response compared with
nonablative lasers. Another major advantage of fractional
resurfacing is the possibility to treat off-face. In the senior
author's experience, NAFR has a greater range in its spectrum

m, energy 8-13 W, pulse duration 2.5-5 ms, and
density 20% or 40%. The average improvement (71-85%)
was similar in all three groups.
In 2010, Wang and colleagues confi rmed the safety and effi -
cacy of fractionated CO 2 laser (MiXto SX®; Lasering) in Asian
skin (160). Five patients with moderate-to-severe atrophic
acne scarring underwent two sessions, 6-8 weeks apart, with
28 J/cm 2 , 2.5 ms, 300-

μ

m spot size, 20% skin coverage, and
single pass. At 2 months after last treatment, four patients had
mild improvement and one had moderate improvement. No
complications, including PIH, were observed. The authors
attribute the modest results found in their patients to the con-
servative parameters used.
Cho and colleagues conducted a split-face study with blinded
response evaluation to compare the effi cacy of single-session
treatments of nonablative 1550-nm Er:Glass and ablative

μ