Optical coherence tomography helps
differentiate neuromyelitis optica and MS
J.N. Ratchford, MD
M.E. Quigg, BA
A. Conger, BA
T. Frohman, BA
E. Frohman, MD, PhD
L.J. Balcer, MD, MSCE
P.A. Calabresi, MD
D.A. Kerr, MD, PhD
Objective: To evaluate the retinal nerve fiber layer (RNFL) thickness and macular volume in neuro-
myelitis optica (NMO) spectrum patients using optical coherence tomography (OCT).
Background: OCT can quantify damage to retinal ganglion cell axons and can identify abnormali-
ties in multiple sclerosis and optic neuritis (ON) eyes. OCT may also be useful in the evaluation of
patients with NMO.
Methods: OCT and visual function testing were performed in 26 NMO spectrum patients with a
history of ON, 17 patients with isolated longitudinally extensive transverse myelitis (LETM) with-
out ON, 378 patients with relapsing–remitting multiple sclerosis (RRMS), and 77 healthy controls
at 2 centers.
Results: Substantial RNFL thinning was seen in NMO ON eyes (63.6 ?m) relative to both RRMS
ON eyes (88.3 ?m, p ? 0.0001) and control eyes (102.4 ?m, p ? 0.0001). A first episode of ON
was estimated to cause 24 ?m more loss of RNFL thickness in NMO than RRMS. Similar results
were seen for macular volume. ON also was associated with more severe visual impairment in
NMO spectrum patients than in RRMS patients. Eyes in the LETM group and unaffected NMO
eyes were not significantly different from controls, though conclusions about these subgroups
were limited by small sample sizes.
Conclusions: Optical coherence tomography (OCT) shows more severe retinal damage after optic
neuritis (ON) episodes in neuromyelitis optica (NMO) than in relapsing–remitting multiple sclerosis.
Identification of substantial retinal nerve fiber layer loss (?15 ?m) after ON in a non–multiple
sclerosis patient should prompt consideration of an NMO spectrum condition. OCT may be a
useful tool for the evaluation of patients with NMO. Neurology®2009;73:302–308
CI ? confidence interval; ETDRS ? Early Treatment Diabetic Retinopathy Study; IgG ? immunoglobulin G; LETM ? longitudi-
nally extensive transverse myelitis; MS ? multiple sclerosis; NMO ? neuromyelitis optica; OCT ? optical coherence tomogra-
phy; ON ? optic neuritis; RNFL ? retinal nerve fiber layer; RRMS ? relapsing–remitting multiple sclerosis.
Neuromyelitis optica (NMO; Devic disease) is an autoimmune disease that predominantly
affects the spinal cord and optic nerves. Patients with NMO often experience recurrent epi-
sodes of optic neuritis (ON) that can cause severe visual impairment. Previously thought to be
a rare subtype of multiple sclerosis (MS), the identification of the NMO-immunoglobulin G
(IgG) autoantibody has provided strong evidence that NMO is a distinct disorder.1
Optical coherence tomography (OCT) has been used to measure the thickness of the retinal
nerve fiber layer (RNFL) and the macular volume in patients with MS and other conditions.
The RNFL consists of retinal ganglion cell axons that coalesce to form the optic nerve. The
macular volume is determined by the number of retinal ganglion cell bodies, photoreceptors,
and other cell types. Previous studies found a significant decrease in the mean RNFL thickness
and macular volume in MS eyes with and without a history of ON.2-7Moreover, abnormalities
From the Department of Neurology (J.N.R., M.Q., P.A.C., D.A.K.), Johns Hopkins University School of Medicine, Baltimore, MD; Departments of
Neurology and Ophthalmology (A.C., T.F., E.F.), University of Texas Southwestern Medical Center, Dallas, TX; and Departments of Neurology and
Ophthalmology (L.J.B.), University of Pennsylvania School of Medicine, Philadelphia, PA.
Supported by the National Multiple Sclerosis Society and the Nancy Davis Foundation.
Disclosure: Author disclosures are provided at the end of the article.
Address correspondence and
reprint requests to Dr. Douglas A.
Kerr, Johns Hopkins University
School of Medicine, 600 N.
Wolfe St., Pathology 627,
Baltimore, MD 21287
Copyright © 2009 by AAN Enterprises, Inc.
were identified in all MS subtypes,6and
RNFL thinning was found to correlate with
brain atrophy in MS.8
We used OCT to evaluate the retinas of
patients with NMO, patients with longitudi-
nally extensive transverse myelitis (LETM)
without a history of ON, patients with relaps-
ing–remitting MS (RRMS), and healthy con-
trols. The goals of this study were 1) to
compare the effect of optic neuritis on RNFL
thickness, macular volume, and visual func-
tion in patients with NMO and RRMS; 2) to
determine whether LETM patients without a
history of ON have subclinical changes on
OCT; and 3) to identify OCT findings that
suggest a diagnosis of NMO.
METHODS Patients. Subjects were recruited from The
Johns Hopkins Multiple Sclerosis and Transverse Myelitis Cen-
ters and the University of Texas Southwestern Multiple Sclerosis
Center. Subjects were divided into 4 groups. Group 1 was pa-
tients diagnosed with an NMO spectrum disorder who had a
history of optic neuritis. This group included 26 patients, of
whom 19 (73%) had “definite NMO” as defined by the 2006
criteria of Wingerchuk et al.9“Definite NMO” is defined by
these criteria as a history of ON, history of acute myelitis, and 2
of 3 supportive criteria: 1) a contiguous spinal cord MRI lesion
extending over at least 3 vertebral segments, 2) a brain MRI that
does not meet criteria for MS, and 3) NMO-IgG seropositivity.9
Four patients in group 1 (15%) had ON and were NMO-IgG
positive without a history of myelitis, and 3 (12%) were consid-
ered by an experienced clinician to have NMO but did not meet
the above criteria because their myelitis was less than 3 vertebral
segments. When analyzed separately, results for the subset meet-
ing criteria for “definite NMO” did not differ from the other
patients in this group, so these patients were analyzed together.
Group 2 included patients with isolated LETM, defined as my-
elitis spanning 3 or more vertebral segments without evidence of
MS and without a history of ON. Group 3 was patients with
RRMS based on McDonald criteria.10Group 4 was healthy con-
trols. All patients undergoing evaluation for a possible NMO
spectrum disorder during the time period of the study were
asked to participate. The RRMS cohort was an unselected conve-
nience sample of patients with MS evaluated in the Johns Hop-
kins Multiple Sclerosis Center. Healthy controls were recruited
from patient’s families and volunteers. Informed consent was
obtained from all participants, and the study was approved by
the local institutional review boards. Patients were excluded
from analysis if they had a history of glaucoma, diabetes, or reti-
nal disease, which might otherwise affect OCT measurements.
Scans performed in the 3-month period after acute ON were
excluded from analysis to minimize the effect of optic disk swell-
ing on OCT measurements. Data on number of ON episodes
was available for a subset of patients (the Hopkins cohort).
Optical coherence tomography. The OCT scanning proto-
col has been described previously in detail.6Retinal imaging was
performed using a Stratus OCT-3 device with OCT 4.0 software
(Carl Zeiss, Meditec, Dublin, CA). RNFL scans were obtained
with the “Fast RNFL Thickness” protocol, and macular volume
was determined using the “Fast Macular Thickness” scan. Only
scans with signal strength of 7 or above (maximum 10), indicat-
ing a high-quality scan, were considered acceptable for analysis.
OCT scanning failed in 8 eyes (both eyes in 3 patients and one
eye in 2 patients) in the NMO group because of blindness. Im-
aging quality was ensured by validation of optic disk centering
by the technician. Macular volume results were available for a
subset of patients (80%) because this testing was added to the
protocol after the initiation of the study.
Visual function testing. Visual function testing was per-
formed using retroilluminated eye charts. Both full-contrast
Early Treatment Diabetic Retinopathy Study (ETDRS) charts
and low-contrast (1.25% contrast) Sloan letter charts were used.
Testing was performed monocularly, and subjects were asked to
use their habitual distance glasses or contact lenses. Standard
testing protocols were used. Charts were scored letter-by-letter,
so that the number of letters identified correctly (maximum 70)
constituted the summary measure. Snellen equivalents were also
determined for descriptive purposes based on full-contrast visual
acuity (ETDRS chart) scores.
Statistical analysis. Nonparametric statistical methods were
used because of the small sample sizes. The Wilcoxon rank sum
test was used for pairwise analyses. To maintain independence of
all observations, a single eye was analyzed from each patient. In
analyses of ON eyes, the ON eye was chosen. In subjects where
both eyes had the same history of optic neuritis, the right eye was
randomly chosen for use. There was no difference in the results
when the left eye was used. Multivariate linear regression models
were created to control for disease duration and age. A regression
with a linear spline was used to model RNFL thickness as a
function of number of ON episodes. Statistical significance was
defined as p ? 0.05. All analyses were performed using STATA
10.0 (StataCorp, College Station, TX).
RESULTS Patient characteristics are described in ta-
ble 1. Twenty-six patients were included in the group
of NMO spectrum patients with a history of ON.
Seventeen patients were identified with isolated
LETM. The frequency of NMO-IgG positivity was
60% in the NMO spectrum with ON group and 24%
378 patients with RRMS and 77 healthy controls.
and none of the LETM or control subjects.
Optic neuritis eyes. The RNFL thickness for each
group is shown in table 1 and figure 1. ON eyes in the
NMO spectrum group had a mean RNFL thickness of
63.6 ?m compared with 102.4 ?m in controls (p ?
0.0001). This represents a 38% absolute difference in
the RNFL thickness between NMO ON eyes and con-
trols. In NMO spectrum patients, the RNFL was also
considerably thinner in ON eyes than in non-ON eyes
thickness between ON and non-ON eyes is much
greater in NMO spectrum patients than in RRMS
(34.3 ?m in NMO vs 9.6 ?m in RRMS). Data for
figure 2. ON eyes in the NMO spectrum group also
Neurology 73July 28, 2009
had a lower mean macular volume compared with con-
trols (5.83 vs 6.83 mm3, p ? 0.0001).
To compare the effect of ON in patients with
NMO and RRMS, the mean RNFL thickness and
macular volume of ON eyes were compared. The
RNFL was thinner in NMO ON eyes than RRMS
ON eyes (mean 63.6 vs 88.3 ?m, p ? 0.0001). Mac-
ular volume was also lower in the NMO group rela-
tive to RRMS (5.83 vs 6.38 mm3, p ? 0.001). This
difference could result from either a greater severity
or a greater number of ON episodes in patients with
NMO compared with patients with RRMS. Because
NMO ON eyes did have a greater number of ON
events than RRMS eyes, an additional comparison was
performed in the subset of eyes that experienced only 1
episode of ON. Using a multivariate linear regression
analysis to control for age and disease duration, a single
episode of ON was estimated to cause 24 ?m more
RNFL loss in NMO than in RRMS (p ? 0.001).
Thus, ON episodes are associated with greater retinal
damage in NMO than in RRMS. In patients with a
history of unilateral ON, the proportion of patients
with a difference in RNFL thickness between the ON
NMO and 24% in patients with RRMS.
An analysis of the effect of the number of ON
episodes on RNFL thickness found that the first epi-
sode of ON caused greater thinning of the RNFL
than subsequent episodes in both NMO and RRMS.
Using a multivariate linear regression model, a single
in RNFL thickness in patients with NMO (95% confi-
dence interval [CI] 21–42 ?m, p ? 0.001) and a de-
crease of 10 ?m in RRMS (95% CI 6–13 ?m, p ?
0.001). Subsequent episodes of ON in the same eye
were estimated to each cause an additional loss of 10
?m of RNFL thickness in NMO (p ? 0.026) and a
ified by NMO-IgG status, no difference was seen in
RNFL thickness between the antibody-positive and
antibody-negative NMO groups (p ? 0.94).
Non–optic neuritis eyes. In eyes without a history of
ON, the RNFL was mildly thinner in all groups rel-
ative to controls. This difference was only significant
for RRMS eyes (97.4 ?m for RRMS, 97.9 ?m for
NMO, 96.3 ?m for LETM vs 102.4 ?m for controls;
table 1). The number of non-ON eyes was much larger
and LETM (n ? 17) groups. Consequently, the lack of
statistical significance in the NMO and LETM groups
may be due to small sample sizes. Similar results were
seen for macular volume (table 1).
Visual function testing. Visual acuity was tested with
both standard and low-contrast eye charts. The OCT
Demographic data, retinal nerve fiber layer thickness, and macular volumes
RNFL thickness, ?m
Macular volume, mm3
No. of eyes
p Value vs
p Value vs
RNFL ? retinal nerve fiber layer; NMO ? neuromyelitis optica; IgG ? immunoglobulin G; ON ? optic neuritis; LETM ? longitudinally extensive transverse myelitis; RRMS ? relapsing–remitting multiple sclerosis.
Neurology 73July 28, 2009
findings correlated well with the results of visual
function testing. Visual acuity was worst in ON eyes
of NMO spectrum patients. Using full-contrast
charts, the mean number of correct letters in this
group was 27 out of a possible 70, compared with 54
in RRMS ON eyes and 59 in control eyes (p ?
0.001 vs RRMS, p ? 0.001 vs controls; table 2).
This corresponds to a visual acuity of 20/60 for the
NMO ON eyes, 20/20 for the RRMS ON eyes, and
20/16 for controls. The relationship between RNFL
thickness and visual acuity in NMO ON eyes is
shown in figure 3. Graphically, it appears that on a
standard vision chart there is a threshold RNFL
thickness of approximately 60 ?m, below which vi-
sual acuity becomes very poor.
same pattern (mean: 4 correct letters for NMO ON
eyes, 6.5 letters for RRMS ON eyes, and 16 letters for
control eyes). On low-contrast charts, the NMO ON
eyes differed from controls (p ? 0.0001) but not from
Figure 1Box plots of retinal nerve fiber layer thickness by disease type and optic neuritis status
RNFL ? retinal nerve fiber layer; ON ? optic neuritis; NMO ? neuromyelitis optica; LETM ? longitudinally extensive trans-
verse myelitis; RRMS ? relapsing–remitting multiple sclerosis.
Figure 2Box plots of macular volume by disease type and optic neuritis status
ON ? optic neuritis; NMO ? neuromyelitis optica; LETM ? longitudinally extensive transverse myelitis; RRMS ? relapsing–
remitting multiple sclerosis.
Neurology 73 July 28, 2009
RRMS ON eyes (p ? 0.11). Non-ON eyes in the
analysis and compared with non-ON eyes in RRMS
and controls. Using both standard and low-contrast eye
groups in the number of correct letters identified.
DISCUSSION Patients with NMO often have se-
vere episodes of ON which can, in some cases, lead to
blindness. In MS, ON is also common; however, the
attacks tend to be less severe and have a better prog-
nosis. This study used OCT to show that the RNFL
is significantly thinner in NMO eyes that have expe-
rienced ON than both control eyes and MS ON
eyes. The severe thinning of the RNFL is presumably
due to degeneration of the retinal ganglion cell ax-
ons. Macular volume, which in part reflects the num-
ber of retinal ganglion cell bodies, is also significantly
decreased in NMO ON eyes. Furthermore, visual
acuity testing is grossly abnormal in NMO ON eyes
when compared with control and RRMS ON eyes.
Together, these data suggest that ON is a more de-
structive process with greater potential for causing
visual disability in NMO than in MS. We also found
that the first episode of ON seems to cause the great-
est amount of RNFL thinning in patients with
NMO and RRMS, with a lesser degree of thinning
occurring in subsequent episodes of ON. One possi-
ble explanation for this is that after an episode of
ON, axons may make up a smaller percentage of the
RNFL, such that subsequent ON episodes cause a
smaller amount of RNFL change.
In NMO spectrum eyes without a history of
ON, we found that the mean RNFL thickness and
macular volume were slightly lower than controls,
but the difference was not significant. The sample sizes
in these groups were small, so the possibility remains
that there is a true small difference in OCT values for
this group relative to controls, If a true difference does
exist, one could speculate either that ON causes a
small degree of retinal damage to the contralateral
eye or that the retinal abnormalities were due to an
ON-independent process. A larger cohort would be
needed to evaluate this.
Our results concur with French11and Caribbean12
studies of OCT in NMO spectrum patients. They
found significant thinning of the RNFL in patients
with NMO, although they did not stratify eyes by his-
tory of ON. In agreement with our results, a small
group of NMO-IgG–positive LETM patients were an-
alyzed in the French study and no OCT abnormalities
were found. They identified a strong correlation be-
tween RNFL thickness and Expanded Disability Status
Score in patients with NMO.
Table 2Visual function testing results
100% Contrast chart1.25% Contrast chart
Mean no. of
Median no. of
p Value vs
Mean no. of
Median no. of
p Value vs
27 (29)14 (0–68)4 (9)0 (0–27)
59 (10)61 (27–69)0.26 18 (11)18 (0–36) 0.5
54 (15) 57 (0–70)0.0036.5 (8) 2 (0–32)
59 (8)60 (12–70)0.2313 (10)13 (0–36)0.98
59 (5) 60 (42–69)—16 (8)15 (0–35)—
Each chart contains 70 letters.
NMO ? neuromyelitis optica; LETM ? longitudinally extensive transverse myelitis; ON ? optic neuritis; RRMS ? relapsing–
remitting multiple sclerosis.
Figure 3 Number of correct letters on a
standard ETDRS letter chart in
NMO spectrum eyes with a history
of optic neuritis as a function of
ETDRS ? Early Treatment Diabetic Retinopathy Study;
NMO ? neuromyelitis optica; RNFL ? retinal nerve fiber
Neurology 73July 28, 2009
There are several potential limitations to our
study. First, blindness due to severe episodes of ON
prevented successful OCT scanning in 8 eyes in the
NMO group. It is likely that these eyes had the most
dramatic changes in retinal architecture. Conse-
quently, the true average OCT values in NMO ON
eyes may be even more severe than what was esti-
mated in our cohort. Second, because of relatively
small sample sizes it is not possible to rule out small
differences between groups that otherwise seem sim-
ilar. Third, it is possible that our population of pa-
tients with NMO is more severely affected than the
general NMO population because all subjects were
recruited from academic referral centers. However,
most patients with this uncommon condition are re-
ferred to academic centers, and all patients being
evaluated for an NMO spectrum condition at the
study sites were asked to participate in the study to
minimize selection bias.
The identification of the NMO-IgG antibody has
greatly advanced our understanding of NMO and
related conditions. The antibody has a 54% to 71%
sensitivity and ?90% specificity for NMO.13-15
NMO-IgG is also positive in 25% of recurrent ON
patients without MS and 38% to 80% of patients
with isolated LETM.14-17Evidence is mounting that
NMO is a distinct condition, rather than simply a
rare subtype of MS. In support of that idea, we found
a greater degree of retinal damage after ON in NMO
than in MS. Our study did not have sufficient power
to definitively determine whether unaffected NMO
eyes are abnormal, but retinal damage in NMO
seems to be predominantly or exclusively the result of
destructive ON episodes. This differs somewhat
from MS, where OCT can detect retinal abnormali-
ties even in patients with no history of ON (such as
patients with primary progressive MS).6These results
are consistent with the observation that patients with
NMO rarely convert to a secondary progressive
course and that disability in NMO primarily results
from relapses,18whereas in MS, disability can result
either from inflammatory relapses or slowly progres-
sive axonal degeneration.19
In some circumstances, OCT may be a useful ad-
junct for differentiating ON due to NMO from ON
due to MS or isolated ON. In a patient with ON and
a brain MRI not suggestive of MS, clinical character-
istics such as a bilateral presentation, recurrent ON,
or poor visual recovery may suggest a diagnosis of
NMO. In addition, more severe thinning of the
RNFL in a patient with history of ON should
prompt consideration of NMO. We found that in
patients with prior unilateral ON, a ?15-?m differ-
ence in RNFL thickness between the two eyes was
more likely to occur in NMO (75%) than in RRMS
(24%). Consequently, in patients who do not meet di-
agnostic criteria for MS, NMO-IgG testing should be
eral, was recurrent, resulted in poor visual recovery, or
between the eyes when measured ?3 months after the
event. Earlier diagnosis of NMO has the potential to
decrease future disability through earlier initiation of
systemic immunomodulatory treatment.
Statistical analysis was performed by J.N. Ratchford.
J.N.R. has served as a consultant for Teva Neuroscience and receives re-
search support from the Partners Multiple Sclerosis Center in the form of
a Clinical Fellowship Award. M.E.Q., A.C., and T.F. report no disclo-
sures. E.F. serves as a consultant for and on the speakers’ bureaus of
Biogen-Idec, Teva Neuroscience, and Athena Diagnostics. L.J.B. has
served on a scientific advisory board for Biogen-Idec, has served as a con-
sultant for Biogen-Idec, and receives research support from the NIH/
National Eye Institute (grant K24 018136) and the National Multiple
Sclerosis Society (grants RG 3208-A-1, RG 3428-A/2, TR 3760-A-3).
P.A.C. has served as a consultant for EMD Serono, Teva Neuroscience,
Novartis, Biogen-Idec, Amplimmune, Vertex, Eisai, and Diogenix, and
receives research support from EMD Serono, Teva Neuroscience, Biogen-
Idec, and the National Multiple Sclerosis Society. D.A.K. has received
research support from Nerveda in the form of a sponsored research agree-
ment, and serves as a consultant for and holds stock options in Nerveda,
for which he is a founding member.
Received November 13, 2008. Accepted in final form April 17, 2009.
1.Weinshenker B. Neuromyelitis optica is distinct from mul-
tiple sclerosis. Arch Neurol 2007;64:899–901.
2.Parisi V, Manni G, Spadaro M, et al. Correlation between
morphological and functional retinal impairment in multiple
sclerosis patients. Invest Ophthalmol Vis Sci 1999;40:2520–
3. Trip SA, Schlottmann PG, Jones SJ, et al. Retinal nerve
fiber layer axonal loss and visual dysfunction in optic neu-
ritis. Ann Neurol 2005;58:383–391.
4. Fisher JB, Jacobs DA, Markowitz CE, et al. Relation of
visual function to retinal nerve fiber layer thickness in mul-
tiple sclerosis. Ophthalmology 2006;113:324–332.
5. Costello F, Coupland S, Hodge W, et al. Quantifying ax-
onal loss after optic neuritis with optical coherence tomog-
raphy. Ann Neurol 2006;59:963–969.
6.Pulicken M, Gordon-Lipkin E, Balcer LJ, Frohman E,
Cutter G, Calabresi PA. Optical coherence tomography
and disease subtype in multiple sclerosis. Neurology 2007;
7.Henderson AP, Trip SA, Schlottmann PG, et al. An inves-
tigation of the retinal nerve fibre layer in progressive mul-
tiple sclerosis using optical coherence tomography. Brain
8. Gordon-Lipkin E, Chodkowski B, Reich DS, et al. Retinal
nerve fiber layer is associated with brain atrophy in multi-
ple sclerosis. Neurology 2007;69:1603–1609.
9.Wingerchuk DM, Lennon VA, Pittock SJ, Lucchinetti
CF, Weinshenker BG. Revised diagnostic criteria for neu-
romyelitis optica. Neurology 2006;66:1485–1489.
Neurology 73July 28, 2009
10.Polman CH, Reingold SC, Edan G, et al. Diagnostic crite- Download full-text
ria for multiple sclerosis: 2005 revisions to the “McDonald
criteria.” Ann Neurol 2005;58:840–846.
de Seze J, Blanc F, Jeanjean L, et al. Optical coherence
tomography in neuromyelitis optica. Arch Neurol 2008;
Merle H, Olindo S, Donnio A, Richer R, Smadja D,
Cabre P. Retinal peripapillary nerve fiber layer thickness
in neuromyelitis optica. Invest Ophthalmol Vis Sci
Lennon VA, Wingerchuk DM, Kryzer TJ, et al. A serum
autoantibody marker of neuromyelitis optica: Distinction
from multiple sclerosis. Lancet 2004;364:2106–2112.
Jarius S, Franciotta D, Bergamaschi R, et al. NMO-IgG in
the diagnosis of neuromyelitis optica. Neurology 2007;68:
15.Marignier R, De Seze J, Vukusic S, et al. NMO-IgG and
Devic’s neuromyelitis optica: a French experience. Mult
myelitis optica IgG predicts relapse after longitudinally exten-
sive transverse myelitis. Ann Neurol 2006;59:566–569.
Okai AF, Muppidi S, Bagla R, Leist TP. Progressive necro-
tizing myelopathy: part of the spectrum of neuromyelitis
optica? Neurol Res 2006;28:354–359.
Wingerchuk DM, Pittock SJ, Lucchinetti CF, Lennon VA,
Weinshenker BG. A secondary progressive clinical course is un-
Frohman EM, Filippi M, Stuve O, et al. Characterizing
the mechanisms of progression in multiple sclerosis: evi-
dence and new hypotheses for future directions. Arch Neu-
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