Evaluation of the 1,540-nm Erbium:Glass Laser in the ... - CMS

Evaluation of the 1,540-nm Erbium:Glass Laser in the Treatment
of Inflammatory Facial Acne
MELISSA A. BOGLE, MD, y JEFFREY S. DOVER, MD, FRCPC, yz KENNETH A. ARNDT, MD, yzyJ AND
SERGE MORDON, PHD z
BACKGROUND The erbium:glass laser is approved to treat inflammatory acne on the back.
OBJECTIVE This aim of this study was to evaluate the use of the 1,540-nm erbium:glass laser in the
treatment of moderate to severe inflammatory acne on the face.
METHODS AND MATERIALS An erbium:glass laser (Aramis, Quantel Medical, Clermont-Ferrand,
France) was used to treat 15 patients with moderate to severe acne four times at 2-week intervals.
Active lesions were first treated with six pulses at 10 J/cm 2 . The entire face was then treated with a single
pass using bursts of four pulses at 10 J/cm 2 . Sebum measurements were performed. Six patients continued
in a double-arm study to determine whether an additional treatment at 6 months would prolong
the lesion-free period. Final evaluation was at 9 months.
RESULTS At 6-month follow-up, patients rated improvement as 68%, and the mean investigator improvement
assessment was 78%. Sebum measurements did not change. No patients required anesthesia,
and no side effects were observed. A single retreatment session 6 months after the initial course held
clearance at 80% at 9-month follow-up, whereas patients without retreatment had 72% clearance.
CONCLUSION Treatment of inflammatory facial acne with the 1,540-nm erbium:glass laser is effective
and relatively painless. Papules, pustules, and nodules all respond well to therapy. Additional treatment
sessions may prolong the lesion-free period, and maintenance therapy should be included as a part of
the treatment course.
Quantel Medical (France) supplied funding and equipment for the study.
Avariety of light, laser, and other energy sources
have been shown to be effective for the treatment
of acne. 1–5 Midinfrared devices including the
1,320- and 1,450-nm diode lasers have been demonstrated
to be effective in acne clearance, but often
require topical anesthesia and can be limited by patient
pain during the procedure. 6–8
The 1,540-nm erbium:glass laser is a newer midinfrared
laser and may be useful in the treatment of
acne. The wavelength is absorbed primarily by
water, targeting the sebaceous glands and surrounding
dermal matrix. Minimal absorption by melanin
makes the laser essentially safe for the treatment of
dark-skinned or tanned individuals. 9 One of the
most appealing facets of the laser is that discomfort
during the procedure has been shown to be minimal
to none during prior studies using the device for
nonablative remodeling. 9,10 The purpose of this
study is to evaluate the effectiveness of the 1,540-nm
erbium:glass laser in the treatment of moderate to
severe inflammatory acne on the face.
Materials and Methods
Patient Selection
A flashlamp-pumped erbium:glass laser (Aramis,
Quantel Medical, Clermont-Ferrand, France;
1,540-nm, 4-mm spot, 3.3 ms, 500 ms between
The Laser and Cosmetic Surgery Center of Houston, Houston, Texas; y SkinCare Physicians, Chestnut Hill, Massachusetts;
z Department of Dermatology, Yale School of Medicine, New Haven, Connecticut; y Department of Medicine
(Dermatology), Dartmouth Medical School, Hanover, New Hampshire; J Department of Dermatology, Harvard Medical
School, Boston, Massachusetts; z INSERM, Lille, France
& 2007 by the American Society for Dermatologic Surgery, Inc. Published by Blackwell Publishing
ISSN: 1076-0512 Dermatol Surg 2007;33:1–8 DOI: 10.1111/j.1524-4725.2007.33174.x
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Er:GLASS LASER TREATMENT OF ACNE
pulses, contact cooling 1 51C) was used to treat 15
patients with moderate to severe acne. The study was
open to male or female patients, age 16 years or
older, with Fitzpatrick skin types (I–VI). All subjects
had at least 10 inflammatory lesions at baseline and
were rated greater than Grade 3 on the Burton acne
scale at their screening visit. [Grade 0 = no lesions,
Grade 1 = subclinical acne, Grade 2 = comedonal
acne, Grade 3 = mild acne, Grade 4 = moderate acne
(many inflamed papules and pustules), Grade
5 = severe nodular acne, Grade 6 = severe cystic acne
with scarring].
Patients were not allowed to use any systemic, topical,
or other light-based acne treatment products during
the course of their involvement in the study. Exclusion
criteria for prior acne therapy included isotretinoin
therapy within 12 months, systemic antibiotic therapy
(for any indication) within 1 month, and topical acne
preparations or intralesional steroid injections within
2 weeks of the start of laser treatment.
The Laser
The 1,540-nm wavelength is obtained via a codoped
Yb-Er:phosphate glass material optimized for high efficient
pumping absorption (Patent 5.897.549). The
wavelength is absorbed primarily by water in the
dermis and sebaceous glands. The laser can
emit single laser shots or a train of pulses. The
pulse train mode allows a set number of pulses at a
preset energy with each depression of the foot pedal.
Both the energy and the number of pulses in the train
can be varied. The beam is delivered by an optical fiber,
and a red diode laser functions as an aiming beam.
Epidermal cooling is provided by an autoregulated
contact cooling system at 1 51C within the handpiece.
Purified tetrafluoroethane circulates through
a circular chamber around a sapphire glass with an
8-mm viewing area. The handpiece is connected to
an electronic unit and monitors real-time temperature
from the skin to ensure temperature stability
within 11C during treatment.
DERMATOLOGIC SURGERY
Six-Month Study: Clinical Protocol
Active lesions were first treated with one pulse
within which was a train of six pulses tuned at
10 J/cm 2 (cumulative fluence, 60 J/cm 2 ). The pulse
train mode was chosen to reach the mid to deep
dermis, where the mean depth of sebaceous glands is
approximately 200 to 1000 mm below the stratum
corneum. 8 Ideally the target penetration depth of
light in the skin for the treatment of acne is approximately
400 mm to thermally injure the sebaceous
gland and the follicular infundibulum. 8 The
optical penetration depths in skin of the 1,320-,
1,450-, and 1,540-nm lasers are 1490, 270, and
400 mm, respectively 11 (Table 1). Skin cooling was
achieved by means of an integrated contact cooling
device in the handpiece set at 1 51C and held on the
skin for 2 seconds before each pulse train. The entire
face was then systematically treated in rows with no
more than 20% overlap and one second of precooling,
using a train of four pulses at 10 J/cm 2 each
(cumulative fluence, 40 J/cm 2 ). The protocol permitted
decreasing the train of pulses from 4 to 3 if
the patient complained of significant discomfort. No
patients required this reduction, however.
The procedure was performed four times at 2-week
intervals. No anesthesia (systemic or topical) was
used. Standardized photographs were taken before
the first treatment, 1 month after the final treatment,
and 6 months after the final treatment using standardized
lighting and positioning equipment.
TABLE 1. Comparison of Optical Properties of Infrared
Lasers Used for the Treatment of Acne
Wavelength
(nm)
Optical
penetration
depth in skin
(mm)
Absorption
coefficient
(cm 1 )
1,320 1,490 1 14
1,450 270 16 12
1,540 400 10 11
Effective
scattering
coefficient
(cm 1 )
The optical penetration depth is the distance through tissue
over which diffuse light decreases in fluence rate to 1/e or 37% of
its initial value. (Adapted from Dahan et al. 11 )

Treatment success was measured by lesion counts
(papules, nodules, and pustules), photographs, and
subjective improvement evaluations by the patient
and investigator. Patients and investigators were
blinded as to each others answers during the study so
as not to influence one another. They were allowed
to compare the current state of the patient to baseline
photographs. Comedonal (noninflammatory)
acne was not evaluated in the study.
Sebum Measurements
Sebum measurements were performed using a sebum
measurement device (Sebumeter SM-815, Courage-
Khazaka, Koln, Germany) at four times during the
course of the study: before the first treatment, before
the third treatment, 1 month after the final treatment,
and 6 months after the final treatment.
Patients were instructed not to wash their faces for
4 hours before measurements.
Three measurements were taken from the forehead:
one centered vertically and approximately 2 cm
above the glabellar region, the second 2 cm to the left
of the first measurement, and the third 2 cm to the
right of the first measurement.
Extended Follow-up Arm: Clinical Protocol
Six of the 15 patients chose to continue in an extended
follow-up, double-arm study to determine
whether an additional treatment at 6 months would
prolong the lesion-free period. Three subjects received
an additional fifth treatment on the same protocol as
their original four treatments at the 6-month followup
visit, and 3 subjects received no additional laser
treatment. The final evaluation for the extended
group was 3 months later (9 months after completion
of the initial four treatment sessions).
Results
Six-Month Study
Twelve of 15 patients completed the 6-month follow-up
and were included in the data analysis. Two
% of Improvement
100
90
80
70
60
50
40
30
20
10
0
after 1 Tx
after 2 Tx
12 Patients
Investigator Assessment
Patient Evaluation
after 3 Tx
1 month FU
BOGLE ET AL
6 months FU
Figure 1. Subjective improvement assessment by physician
and patient. Tx, treatment; FU, follow-up.
patients were lost to follow-up and the third dropped
out because of scheduling conflicts. The mean Burton
acne scale rating at baseline was 4.2. Mean subjective
percent improvement in acne severity by both the
patient and the investigator is shown in Figure 1. Both
the patient and the investigator reported that the acne
severity improved nearly one-third after one treatment.
The improvement steadily continued to peak at
6 months after the fourth treatment with a mean 78%
investigator improvement assessment and a mean
68% patient improvement assessment.
In addition to percent improvement, subjects and
investigators were asked to rank their improvement
on an index scale of 1 to 5 (with 1 indicating no
improvement and 5 indicating excellent improvement).
Results of the improvement index and a key
to interpreting the values can be found in Table 2.
After one treatment, both the physician and the patient
reported mean improvement indices were 2.8
and 2.7, respectively (both good improvement) and
by the 6-month follow-up mean improvement indices
had risen to 4.2 and 3.8, respectively (both very
good improvement).
In terms of objective improvement data, Figure 2
illustrates decreasing numbers of lesions (papules,
nodules, and pustules) over time. Figure 2
demonstrates that 100% of lesions are present at
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Er:GLASS LASER TREATMENT OF ACNE
TABLE 2. Mean Physician and Patient Improvement
Index
Mean improvement index
Investigator
assessment
After one treatment 2.8 2.7
After two treatments 3.5 3.0
After three treatments 3.8 3.3
1-month follow-up 4.1 3.1
6-month follow-up 4.2 3.8
Patient
evaluation
1 = no improvement; 2 = poor improvement; 3 = good improvement;
4 = very good improvement; 5 = excellent improvement.
baseline. After two treatments, 66% of lesions are
remaining, at 1 month after treatment 42% of lesions
are remaining, and at 6 months after treatment
only 21% of lesions are remaining. This number
indicates a total lesion clearance of 79% at 6 months
after treatment, which correlates with the 6-month
subjective investigator improvement assessment of
78% (Figure 1).
Table 3 presents the sum of lesion counts for all
patients over time by lesion type (papules, nodules,
or pustules). All types of lesions continued to decrease
in number 1 month after the fourth treatment.
Papules and nodules continued to decrease in number
at the 6-month follow-up visit, while pustules
had a small, statistically insignificant increase from
the 1- to 6-month follow-up.
Although nearly all patients subjectively reported
that their skin felt less oily after a series of treatments
with the erbium:glass laser, sebum measurements did
TABLE 3. Lesion Counts (by Lesion Type) over Time
% remaining lesions
100
90
80
70
60
50
40
30
20
10
0
before
after 2 Tx
12 patients
1 month FU
6 months FU
Figure 2. Percentage of remaining lesions (papules, nodules,
and pustules) over time.
not change over the course of the study. Results of
the Sebumeter measurements are found in Figure 3.
All patients tolerated the procedure well without the
need for anesthesia. It took approximately 400
All lesions Papules Nodules Pustules
Before 470 392 16 62 14–79
After two treatments 311 269 8 34 F
1-month follow-up 195 184 4 7 3–44
6-month follow-up 80 69 0 11 1–11
Individual subject
range (all lesions)
Numbers in the first four columns are the sum of lesions for all patients in the study. The far right column gives the range of lesion counts
in individual study subjects. Note the high standard deviation of the Sebumeter measurements (SD, 60–65 for all visits).
DERMATOLOGIC SURGERY
mean sebum (au)
200
180
160
140
120
100
80
60
40
20
0
12 patients
before after 3 Tx 1 month FU 6 months FU
Figure 3. Mean sebum measurements over time.

TABLE 4. Summary of Results of an Additional Treatment with the Erbium:Glass Laser at 6 Months
pulses to cover a full face with the 4-mm spot over
15 to 20 minutes. The mean pain rating was a 2.6
(1 = no pain, 2 = minimal, 3 = bearable, 4 = unbearable).
All patients developed mild transient erythema
after each treatment lasting approximately 5 to
10 minutes. One patient developed a mild, superficial
crust on the nasal ala, which resolved without
sequelae in 1 to 2 days.
Extended Follow-up Arm
Six patients chose to continue in a double-arm, extended
follow-up study to determine whether an
additional treatment at 6 months would prolong the
lesion-free period. The three patients who underwent
an additional single treatment session at 6 months
held their 80% clearance rate at 9 months whereas
the three patients who did not undergo retreatment
dropped slightly to 72% clearance at 9 months. Data
comparing the two arms of the extended follow-up
study can be found in Table 4. Treatment photographs
illustrating improvement 1 month after four
treatments, 6 months after four treatments, and 9
months after four treatments can be found in Figures
4 through 6.
Discussion
Mean percent improvement Mean improvement index
Investigator Patient Investigator Patient
Retreatment 85 58 4.7 3.3 20
No retreatment 78 68 4.3 3.7 28
Both subjects and investigators were highly satisfied
with the results from the treatments with the Er:glass
laser. Clearance rates peaked at roughly 80% reduction
in lesion counts 6 months after the initial
four treatment sessions, with papules, nodules, and
pustules all responding well to therapy. Nine months
after the treatments ended, patients still had a 72%
reduction in lesion counts from their baseline without
any additional treatment. In the group who
underwent an additional maintenance session at the
BOGLE ET AL
Percentage of remaining lesions
(by lesion counts)
6-month follow-up, clearance rates remained at
80%. Although further studies are warranted to determine
the most advantageous time interval for
maintenance treatments, these data indicate that
patients may have a prolonged lesion-free period by
undergoing additional laser sessions at a set schedule
after the initial clearing phase.
Figure 4. Two subjects (A and B) showing good clearance in
papules, nodules, and pustules 1 month after four treatments.
All patients in the study had continued improvement
and reduction in lesion counts at the 6-month follow-up
visit.
33:7:JULY 2007 5

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Er:GLASS LASER TREATMENT OF ACNE
Figure 5. (A) Six months after treatment the patient has no
active lesions, only postlesional erythema that had not yet
faded from his prior acne. Note that he still has active
breakouts on the neck (which was not treated with the laser),
serving as an internal ‘‘control.’’ (B) Subjects had good
clearance in papules, nodules, and pustules at the final
6-month follow-up.
Results of the reduction in facial acne lesions with
the 1,540-nm Er:glass laser are comparable to those
published with the 1,450 nm diode laser. 6 The
1,450-nm diode laser has shown a 37% decrease in
inflammatory facial acne lesions after one treatment,
58% after two treatments, and 83% after three
treatments with sessions spaced at 4- to 6-week intervals.
1 In the current study, the 1,540-nm Er:glass
laser treatments were spaced at 2-week intervals,
closer together than the 1,450-nm diode laser study;
however, both studies reached approximately a 35%
lesion clearance 1 month after starting treatment
regardless of temporal spacing and had a peak
DERMATOLOGIC SURGERY
clearance of roughly 80%. There are currently no
published studies on the 1,320-nm infrared laser for
the treatment of active acne.
Comparison to noninfrared lasers is favorable. The
532-nm potassium titanyl phosphate (KTP) laser has
demonstrated a mean clearance of 60% to 70% after
six treatments with more than half of patients
maintaining their results for 4 months. 12 Results
with the 585-nm pulsed dye laser have been variable,
with some studies showing a reduction in acne
counts by 49% after one treatment, 13 whereas others
showed no difference in lesion counts compared to
untreated skin after 12 weeks. 14 The main advantage
to using infrared lasers over the KTP and pulsed dye
lasers is that there appears to be a longer remission
after completing therapy with the infrared lasers.
One split-face study which compared the 595-nm
pulsed dye laser to the 1,450-nm diode laser found
that both lasers were effective in initial reduction of
lesions; however, the 1,450-nm laser resulted in a
longer lesion-free remission period by at least
3 months after the completion of therapy. 15
Perhaps the most encouraging observation with
Er:glass laser treatment was effectiveness with minimal
procedure discomfort. No anesthesia, topical or
otherwise, was required in the study, and patients
rated the pain as minimal to bearable. The insignificant
pain associated with the 1,540-nm Er:glass
laser treatments compared to the 1,320- and
1,450-nm lasers may be due to the smaller 4-mm
spot size along with the contact cooling mechanism
in the handpiece, which further adds to decrease
discomfort in the treatment area. As with other infrared
lasers, discomfort was greatest when treating
directly over inflamed papules or nodules. This was
kept to a minimum by contact cooling for approximately
2 seconds before each laser burst over the
active lesions.
The 1,320-nm Nd:YAG and 1,450-nm diode lasers
used for acne clearance both employ a 6-mm spot
and a cryogen cooling spray device rather than
contact cooling. The 4-mm spot of the Er:glass laser

has less than half the surface area of a 6-mm spot,
resulting in doubling of the amount of time it
takes to treat an equivalent zone. Eliminating
the need for topical anesthesia, however, decreases
treatment time by 1 hour or more and decreases
total cost.
Results of the Sebumeter studies indicate that the
amount of sebum production during the course of
treatment remained steady. Almost all patients,
however, stated that their skin felt less oily after the
treatment series, and the investigator subjectively
noted that the subjects’ skin appeared less oily on
visual inspection. The standard deviation of the sebum
counts was extremely high (60–65 for all visits),
indicating a lack of consistency in the Sebumeter
readings, rendering the validity of these results
questionable. The mechanism of how infrared lasers
affect acne has been attributed to thermal damage to
the sebaceous glands, temporarily arresting their sebaceous
output. 12 Although our study is not conclusive
enough to disprove this theory, it may be that
the laser is able to regulate sebum production by
thermally altering the gland such that the sebum is
thinner and less sticky. Patients’ skin may look and
feel less oily because sebum production from the
sebaceous glands occurs in a more even, controlled
fashion, rather than in spurts and globules, allowing
it to evaporate normally although total production
stays the same.
Conclusions
The 1,540-nm erbium:glass laser is an effective and
almost completely painless device for the treatment
of inflammatory facial acne. Papules, nodules,
and pustules all respond well to therapy, with
total clearance approaching 80% 6 months after
four treatments. Additional treatment sessions
may prolong the lesion-free period. The optimal
interval for maintenance treatments has yet to be
determined.
References
1. Bhardwaj SS, Rohrer TE, Arndt K. Lasers and light therapy for
acne vulgaris. Semin Cutan Med Surg 2005;24:107–12.
2. Rotunda AM, Bhupathy AR, Rohrer TE. The new age of acne
therapy: light, lasers, and radiofrequency. J Cosmet Laser Ther
2004;6:191–200.
3. Elman M, Lebzelter J. Light therapy in the treatment of acne
vulgaris. Dermatol Surg 2004;30(2 Pt 1):139–46.
4. Hirsch RJ, Shalita AR. Lasers, light, and acne. Cutis
2003;71:353–4.
BOGLE ET AL
Figure 6. Subject showing maintenance of clearance in all acne lesions 9 months after four treatments with good resolution
of postlesional erythema. Note the continued improvement in lesion counts at long-term posttreatment follow-up. This was
typical in all of the study subjects.
5. Charakida A, Seaton ED, Charakida M, et al. Phototherapy in the
treatment of acne vulgaris: what is its role? Am J Clin Dermatol
2004;5:211–6.
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DERMATOLOGIC SURGERY
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Address correspondence to: Melissa Bogle, MD, The
Laser and Cosmetic Surgery Center of Houston, 3700
Buffalo Speedway #700, Houston, TX 77098, or
e-mail: mabogle@hotmail.com