Diagnosis and Grading of Papilledema in Patients

Transcription

Diagnosis and Grading of Papilledema in Patients
CLINICAL SCIENCES
Diagnosis and Grading of Papilledema in Patients
With Raised Intracranial Pressure Using Optical
Coherence Tomography vs Clinical Expert
Assessment Using a Clinical Staging Scale
Colin J. Scott, MD; Randy H. Kardon, MD, PhD; Andrew G. Lee, MD; Lars Frise´n, MD, PhD; Michael Wall, MD
Objectives: To compare and contrast 2 methods of quantitating papilledema, namely, optical coherence tomography (OCT) and Modified Frise´n Scale (MFS).
tographs correlated well (R=0.85). OCT total retinal thickness and MFS grade from photographs had a similar correlation of 0.87. Comparing OCT RNFL thickness with
OCT total retinal thickness, a slope of 1.64 suggests a
greater degree of papilledema thickness change when
using the latter.
Methods: Digital optic disc photographs and OCT fast
retinal nerve fiber layer (RNFL) thickness, fast RNFL map,
total retinal thickness, and fast disc images were obtained in 36 patients with papilledema. Digital optic disc
photographs were randomized and graded by 4 masked
expert reviewers using the MFS. We performed Spearman rank correlations of OCT RNFL thickness, OCT total
retinal thickness, and MFS grade from photographs.
Conclusions: For lower-grade abnormalities, OCT compares favorably with clinical staging of optic nerve photographs. With higher grades, OCT RNFL thickness processing algorithms often fail, with OCT total retinal
thickness performing more favorably.
Results: OCT RNFL thickness and MFS grade from pho-
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P
Author Affiliations:
Department of Ophthalmology
and Visual Sciences, Carver
School of Medicine, University
of Iowa, and Veterans Affairs
Hospital, Iowa City (Drs Scott,
Kardon, Lee, and Wall); and
Institute of Neuroscience and
Physiology, Department of
Clinical Neurosciences,
Sahlgrenska Academy,
University of Gothenburg,
Gothenburg, Sweden
(Dr Frise´n). Dr Lee is now with
the Department of
Ophthalmology, The Methodist
Hospital and the Departments
of Ophthalmology, Neurology,
and Neurosurgery, Weill Cornell
Medical College New York,
New York.
APILLEDEMA, OR OPTIC DISC
swelling due to raised intracranial pressure, has been
graded using the Frise´ n
Scale.1 This scale uses visual
features of the optic disc and peripapillary retina to stage optic disc edema. Its
reproducibility has been validated,1 but it
is limited by use of an ordinal scale.
Optical coherence tomography (OCT)
is a potential tool to quantify changes in the
degree of papilledema and to monitor the
efficacy of treatment interventions. First described in 1991 by Huang et al,2 OCT is a
cross-sectional imaging technique that
quantitatively assesses multiple layers of the
retina, allowing measurement of the retinal nerve fiber layer (RNFL) with a resolution of approximately 10 µm using timedomain variables.3-5 Direct measurements
are calculated by a computer algorithm to
quantify the nerve fiber layer and total retinal thickness. OCT offers several advantages over conventional photographic
imaging such as use with small pupil sizes
and nuclear cataracts. OCT findings are reasonably reproducible on successive measurements in normal eyes and in eyes with
glaucoma.6-11 Despite these advantages, limitations of OCT include the requirement for
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patient fixation stability during imaging
without eye tracking and the failure of segmentation algorithms for defining RNFL
thickness and total retinal thickness in eyes
with severe papilledema.
Although fundus photographs require
subjective interpretation, they show detailed topographic relationships of optic
disc edema that may be difficult to quantify and document on clinical examination. Unlike OCT, photographic artifacts
(eg, defocus or incorrect light exposure)
that could interfere with interpretation are
usually obvious.
OCT is useful in evaluating various ophthalmic disorders such as band atrophy,
glaucoma, diabetic retinopathy, cystoid
macular edema, central serous retinopathy, macular hole formation, optic nerve
head pits, and ischemic optic neuropathy.12-18 Most of these conditions involve
RNFL thinning. Few studies evaluated the
use of OCT in measuring RNFL or total retinal thickening due to papilledema. A 2007
study19 compared the findings of OCT vs
disc photographs in children with idiopathic intracranial hypertension. Another
study20 assessed the importance of RNFL
thickness analysis in intracranial hypertension using imaging laser polarimetry. In pa-
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dopapilledema but did not directly compare OCT vs fundus
photograph grades. To our knowledge, this is the first study
to compare OCT RNFL thickness and OCT total retinal
thickness with fundus disc photographs in adults having
raised intracranial pressure. Our objectives were to compare and contrast OCT and Modified Frise´n Scale (MFS)
grading with the peripapillary RNFL in quantifying optic
disc edema.
METHODS
Grade 0
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
Figure 1. Representative fundus photographs of each Modified Frise´n Scale
grade as summarized in Table 1. A representative optical coherence
tomography image is below each disc grade. Overlayed white lines of the
optical coherence tomography image represent borders of the retinal nerve
fiber layer thickness (upper and middle lines) and the total retinal thickness
(upper and lower lines) estimated using the algorithm (OCT3; Zeiss
Meditech, Dublin, California). Modified Frise´n Scale key features (Table 1) are
well demonstrated.
tients with retinal vein occlusions and inflammatory optic neuropathies, Menke et al21 found that OCT RNFL
thickness was increased compared with that in control subjects. Hoye et al22 used OCT to demonstrate subretinal
macular edema in papilledema, and OCT has been used
to measure RNFL thickness in patients with optic neuritis.23,24 Other studies25-27 compared OCT (as well as automated perimetry) RNFL thickness in papilledema and pseu-
Digital optic disc photographs of the right or left eye were selected for review if corresponding OCT images of the RNFL were
available and if photographs and OCT images were of sufficient
quality. For OCT analysis, the circular image had to be centered on the nerve, the signal strength had to be at least 5 (range,
1[lowest]-10 [highest]), and the proprietary algorithm used by
the manufacturer (OCT3; Zeiss Meditech, Dublin, California)
had to successfully delineate the borders of the RNFL on manual
inspection of the images. The proprietary algorithm creates a bestfit estimate of the inner and outer borders of the RNFL and the
total retinal thickness to calculate the mean thickness, as demonstrated by the overlayed white lines of the B-scan in Figure 1.
Algorithm failure occurred when the borders of the retinal layers delineated by the software were qualitatively incompatible
with the borders inferred by experts (C.J.S. and R.H.K.). For fundus photographs, the optic nerve had to be in focus to allow evaluation of the RNFL at the disc border. Analysis was monocular
rather than binocular because of some poor photographic quality or failure to capture the entire extent of the z-axis by OCT
due to peripapillary elevation and cropping of the B-scan in 1 of
2 eyes. Furthermore, use of both eyes would violate a principle
of parametric statistics, as the results of one eye are not independent of the other eye. Although the relationship between eyes
could be accounted for with nested analysis of variance, using
both eyes in some patients would have complicated our statistical analysis. Patients retrospectively identified as having raised
intracranial pressure at some point in their clinical course from
January 2004 to March 2008 were included in the study, and the
imaging studies chosen were from the patient’s first presentation to our clinic for evaluation. While most cases were idiopathic, the specific etiology was not addressed, as the pathogenesis of disc edema pathogenesis of papilledema was secondary
to raised intercranial pressure in all cases is static and should not
affect comparison of disc appearance with OCT values. No other
cause of visual loss or optic disc edema was present such as optic nerve compression, inflammatory optic neuropathy, or ischemic optic neuropathy. Monocular digital photographs were
randomized and graded by 4 masked expert reviewer neuroophthalmologists (3 from the University of Iowa and 1 from the
University of Gothenburg, Sweden). Photographs were viewed
at 1600⫻1200 resolution (SyncMaster 213T; Samsung, Ridgefield Park, New Jersey).
We used an adaptation of a clinical staging scale initially described by one of us (L.F.) (Table 1 and Figure 1).1 The first 2
grades are primarily dependent on changes surrounding the optic disc such as decreased translucency and opacification of the
peripapillary nerve fiber layer (the term blurring is avoided because it has many meanings, including lack of image focus). Grade
0 represents no optic disc edema, and grades 1 through 5 represent increasing severity of optic disc edema. We modified the
Frise´n Scale by identifying a key feature for each grade, with the
other criteria considered minor. For grade 1, the key feature is
the presence of a C-shaped halo of opacification of the RNFL at
the region of the optic disc border; a gap remained at the location of the maculopapular bundle. Rarely, a thin smooth-edged,
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ring-shaped peripapillary light reflex may be present in normal
anatomy; when present, it is a continuous reflex. Therefore, pathologic designation requires irregularity and breakup of any ringshaped peripapillary reflex (grade 1 in Figure 1). Grade 2 is characterized by a circumferential halo with decreased translucency
(opacification of the RNFL), with complete visualization of each
major retinal artery and vein along its length as it courses over
the optic disc and its border. Grade 3 has loss of visualization
(discontinuity) along a segment of at least 1 major vessel as it
courses over the optic disc margin but continues in the center
of the optic nerve. Grade 4 is characterized primarily by discontinuity due to opacification of at least 1 but not all major vessels
on the optic disc.
In the original description by Frise´n, grade 5 is classified as
follows: “Anterior expansion of the nerve head now dominates
over sideways expansion. The nerve head assumes a relatively
smooth, dome-shaped protrusion, with a narrow and smoothly
demarcated halo. The major retinal vessels climb steeply over
the dome surface. Segments of these vessels may or may not be
totally obscured by overlying swollen tissue.”1(p16) Because this
grade did not have a clear-cut primary feature, we added one in
which grade 5 is reached when there is obscuration of all major
vessels on the optic disc. We excluded grade 5 cases from our
analysis because the few examples did not have OCT images in
which the algorithm did not fail.
Corresponding OCT images of each grade are shown in
Figure 1. Compared with OCT RNFL thickness, OCT total retinal thickness borders may demonstrate a greater degree of neurosensory detachment with increasing edema, but the software algorithm can fail at severe papilledema levels, with borders
appearing beyond the range of visualization by reviewers. For
MFS grading of the optic disc photographs, if there was uncertainty in assigning a grade between 2 increments, the lesser
grade was given an additional “⫹” symbol. For example, if it
was difficult to determine whether there was a C-shaped halo
or a 360° circumferential halo, the disc would be graded as 1⫹.
Because the first sign of papilledema in an experimental monkey model was optic disc elevation,28 grade 0⫹ was used to characterize elevation that exceeded grade 0 but lacked the characteristics of grade 1.
OCT fast RNFL, fast RNFL map, and fast optic disc images
were obtained at the time of digital color photography (Stratus OCT3, Zeiss Meditech). The mean RNFL thickness and total
retinal thickness were obtained if the proprietary algorithm
seemed to follow the expected borders in their entirety on the
displayed B-scan and if the circular image seemed to be centered on the video display. Most RNFL circular image data represented 3 trials of each eye, for which the data were averaged.
The trial with the most accurately appearing fit for RNFL borders along with the highest signal strength was chosen for further analysis. OCT data with low signal strength (⬍5) or for
which no trials had adequate RNFL border tracing over 360°
of the circular image were excluded and tabulated.
Disc grade for each patient was based on majority rule among
3 of us (R.H.K., A.G.L., and M.W.) using the same computer
monitor for evaluation. If all 3 reviewers were not in agreement,
grading by 2 reviewers was used, with the third reviewer’s grade
excluded. To evaluate possible higher correlation, 2 of us (R.H.K.
and M.W.) arranged the photographs in ranked order from lowest to highest amount of disc edema. As a cross-check, grading
was performed by one of us (L.F.) and correlated with OCT findings independent of the 3 reviewers. We performed Spearman
rank correlations of OCT RNFL thickness, OCT total retinal thickness, and MFS grade from photographs.
Because the Stratus OCT3 was not specifically designed to
measure papilledema, the software failure rate of the algorithm for determining RFNL thickness and total retinal thickness was assessed as a function of papilledema grade. A sepa-
Table 1. Modified Frise´n Scale
Papilledema Grade
0 (Normal Optic Disc)
Prominence of the retinal nerve fiber layer at the nasal, superior, and
inferior poles in inverse proportion to disc diameter
Radial nerve fiber layer striations, without tortuosity
1 (Minimal Degree of Edema)
C-shaped halo that is subtle and grayish with a temporal gap; obscures
underlying retinal details a
Disruption of normal radial nerve fiber layer arrangement striations
Temporal disc margin normal
2 (Low Degree of Edema)
Circumferential halo a
Elevation (nasal border)
No major vessel obscuration
3 (Moderate Degree of Edema)
Obscuration of ⱖ1 segment of major blood vessels leaving disc a
Circumferential halo
Elevation (all borders)
Halo (irregular outer fringe with finger-like extensions)
4 (Marked Degree of Edema)
Total obscuration on the disc of a segment of a major blood vessel on
the disc a
Elevation (whole nerve head, including the cup)
Border obscuration (complete)
Halo (complete)
Grade 5 (Severe Degree of Edema)
Obscuration of all vessels on the disc and leaving the disc a
a Key
features (major findings) for each grade.
rate cohort of 101 patients was randomly selected from a database
of 224 patients with known papilledema at initial presentation from the University of Iowa using the same Stratus OCT3
to determine if borders were captured accurately. The image
passed if the OCT algorithm followed the expected borders of
RNFL thickness and total retinal thickness on the B-scan as
evaluated by one of us (C.J.S.). The image failed if the algorithm did not follow the expected borders. The respective disc
photograph for each OCT image was evaluated and excluded
if of insufficient quality. Digital photographs were reviewed and
graded by one of us (C.J.S.) using the MFS as previously described. The failure rate was calculated for each photographic
MFS grade similarly as for each OCT image.
RESULTS
Among 36 patients with papilledema, 7 (19%) had grade
0, 7 (19%) had grade 1, 10 (28%) had grade 2, 4 had grade
3 (11%), and 8 (22%) had grade 4 disc edema using majority rule. The 3 reviewers agreed on grade most of the
time, and only once was there more than a 1-grade difference by 1 reviewer compared with the other 2 reviewers
(Figure 2A). One-grade differences occurred between all
grades, and differences exceeding 1 grade occurred between grades 2 and 4 (Figure 2B). If the “⫹” notation was
added to a grade, it was omitted to establish a numeric
scheme for further quantitative analysis. OCT RNFL thickness and total retinal thickness showed significant correlation with the MFS grade from photographs.
In grading papilledema, we found strong correlation
between the MFS and OCT findings. When OCT RNFL
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A
B
6
Difference of
>1 grade 2.8
Expert 1
Expert 2
Expert 3
Expert 4
Majority rule
(experts 1-3)
Modified Frisén Scale Grade
5
Difference of
1 grade 41.7%
Equal grading
55.5%
4
3
2
1
0
0
5
10
15
20
25
30
35
40
Ranked Order of Modified Frisén Scale Grade
Figure 2. Papilledema grading differences in 36 patients. A, Among 3 reviewers using the Modified Frise´n Scale. B, Between 2 reviewers using the Modified Frise´n
Scale and 1 reviewer using ranked order of Modified Frise´n Scale grade. The y-axis is slightly offset to delineate each expert’s grade. Note the good concordance
among reviewers.
B
450
800
400
700
OCT Total Retinal Thickness, µM
OCT RNFL Thickness, µM
A
350
300
250
200
150
100
R = 0.85
P<.001
50
0
600
500
400
300
200
R = 0.87
P<.001
100
0
0
1
2
3
4
5
0
Modified Frisén Scale Grade
1
2
3
4
5
Modified Frisén Scale Grade
Figure 3. Papilledema grading differences in 36 patients among reviewers. A, Using optical coherence tomography (OCT) retinal nerve fiber layer (RNFL)
thickness vs using Modified Frise´n Scale grade. B, Using OCT total retinal thickness vs using Modified Frise´n Scale grade.
thickness was compared with MFS grade from photographs (using majority rule), Spearman rank correlation
was 0.85 (P ⬍.001). When OCT total retinal thickness
was compared with MFS grade from photographs, Spearman rank correlation was 0.87 (P ⬍.001) (Figure 3).
In cross-check grading by one of us (L.F.), Spearman rank
correlations were 0.79 (P ⬍.001) and 0.83 (P ⬍ .001) for
the latter.
Two of us (R.H.K. and M.W.) also ranked photographs based on lowest to highest amount of disc edema.
This was done to increase stratification of the data to demonstrate potential higher correlation when using a finer scale.
Spearman rank correlation increased to 0.88 (P⬍.001)
when OCT RNFL thickness was compared with ranked order of MFS grade (range, 1-36) (Figure 4). Spearman rank
correlation increased to 0.90 (P⬍.001) when OCT total
retinal thickness was compared with ranked order of MFS
grade. Interobserver Spearman rank correlation between
the 2 reviewers was highly significant at 0.87. In majority
rule when comparing MFS grading from photographs, OCT
total retinal thickness had higher correlation than OCT
RNFL thickness. When comparing OCT RNFL thickness
with OCT total retinal thickness, a strong linear relationship was observed at R2 =0.90 (y=1.64x⫹105.5) (P⬍.001)
(Figure 5). The slope of 1.64 suggests a greater degree of
papilledema thickness change when using OCT total retinal thickness. Among 199 eyes in 101 patients evaluated
to analyze whether the algorithm was able to capture expected borders of the RNFL and total retinal thickness, the
highest failure rates were seen with higher grades of disc
edema (Figure 6). Higher failure rates were found with
OCT RNFL thickness than with OCT total retinal thickness. All photographs were of sufficient quality to assign
an MSF grade without failure, as most patients had several photographs taken at the same time and the highestquality photograph was used for assessment.
COMMENT
We found strong Spearman rank correlation between OCT
RNFL thickness, OCT total retinal thickness, and MFS
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A
B
800
400
700
Total Retinal Thickness, µM
450
RNFL Thickness, µM
350
300
250
200
150
100
R = 0.88
P<.001
50
600
500
400
300
200
R = 0.90
P<.001
100
0
0
0
5
10
15
20
25
30
35
40
0
5
Ranked Order of Modified Frisén Scale Grade
10
15
20
25
30
35
40
Ranked Order of Modified Frisén Scale Grade
Figure 4. Papilledema grading differences in 36 patients. A, Using optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness vs using ranked
order of Modified Frise´n Scale grade. B, Using OCT total retinal thickness vs using ranked order of Modified Frise´n Scale grade.
800
OCT Total Retinal Thickness, µM
grade from photographs. The effect of papilledema can
be seen on RNFL thickness and on RNFL total retinal
thickness. A disproportional increase of total retinal thickness above that of the RNFL represents fluid from neurosensory retinal detachment in the peripapillary retina.
Therefore, OCT total retinal thickness may show proportionally more change per degree of disc edema than
OCT RNFL thickness, which is a new finding.
OCT of total retinal thickness has not been well studied in optic disc conditions; however, Menke et al21 found
that total retinal thickness was increased out of proportion to RNFL thickness in retinal vein occlusions compared with a control group having inflammatory optic neuropathies. It was concluded that differences in the intrinsic
pathogenesis of optic disc edema may differentially affect
the thickness of the RNFL compared with other layers of
the retina. However, their study did not directly compare
RNFL thickness with total retinal thickness in optic disc
edema and in differing severities of edema.
The correlation between OCT and fundus appearance of the disc was greatest when photographs were
ranked in continuous order of edema severity. Variation in OCT measurements at each grade could be partly
explained by the ordinal character of the MFS, as ranking the photographs in order within each grade resulted
in higher correlation between OCT findings and MFS
grade. We modified the Frise´n Scale in an attempt to improve its reproducibility. We avoid the term blur, as the
cause could be multifactorial, including media opacification or other optical anomalies. Instead, we prefer the
term obscuration to more clearly delineate the pathologic effect at the peripapillary nerve fiber layer. We no
longer include retinochoroidal folds as criteria for grade
2 because they can occur at any disc stage. The scale has
been modified to no longer include domed disc in grade
5, as this has been difficult to define. Instead, grade 5 criteria include complete obscuration of all vessels on the
disc and leaving the disc. While the MFS is useful for daily
practice and for clinical trials, limitations remain
(Table 2). Ophthalmoscopic evaluation and grading of
papilledema can show significant variability among observers and can be influenced by media opacities, cataract formation, and pigment epithelium, which can also
700
600
500
400
300
y = 1.64x + 105.5
R 2 = 0.90
P<.001
200
100
0
50
100
150
200
250
300
350
400
450
OCT RNFL Thickness, µM
Figure 5. Note the excellent measurement correlation between optical
coherence tomography (OCT) total retinal thickness and OCT retinal nerve
fiber layer (RNFL) thickness in 36 patients.
affect fundus photographs.29-31 With digital photography, variability may occur for several reasons, including
characteristics and calibration of the viewing monitor.
Variability among examiners could also occur because
of direct examination vs photographic evaluation and due
to magnification and computer monitor variables. OCT
also has limitations (Table 2). For example, the quality
of each image is eye (ie, media opacity) dependent and
operator dependent and can be affected by improper disc
centering and poor fixation. Low signal strength can also
significantly reduce data quality, which was often seen
in higher grades of disc edema; however, data with signal strength of less than 5 were excluded in our study.
Our study also demonstrated increased variability in
the mean OCT RNFL thickness and OCT total retinal
thickness with higher grades of disc edema. One of the
greatest limitations of the OCT3 is the proprietary algorithm to trace the RNFL thickness and the total retinal
thickness, which often cannot accurately outline thicknesses in advanced stages of papilledema. Although our
study found this to be less problematic when measuring
total retinal thickness, the failure rate remained high for
grade 5 papilledema at 33%. Disc hemorrhages can also
affect accuracy, as they may influence reflectivity in an
inconsistent manner. Even with evolving technology to
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B
80
80
70
70
60
60
50
50
No. of Eyes
No. of Eyes
A
40
30
40
30
20
20
10
10
0
Fail
Pass
0
0
1
2
3
4
0
Modified Frisén Scale Grade
1
2
3
4
Modified Frisén Scale Grade
Figure 6. Pass rates and fail rates using optical coherence tomography (OCT) measurements vs Modified Frise´n Scale grade. A total of 199 eyes were evaluated in
101 patients. A, Using retinal nerve fiber layer (RNFL) thickness. B, Using total retinal thickness.
Table 2. Advantages and Disadvantages of Optical
Coherence Tomography and Modified Frise´n Scale Grade
From Photographs for Quantifying Papilledema
Optical Coherence Tomography
Advantage
Reliable at lower grades
Continuous as opposed to ordinal
measurement scale
Not as limited by pupil size
or cataracts
Modified Frise´n Scale Grade
From Photographs
Advantage
More reliable at higher grades
Obvious artifacts can be ignored
when observing key features
Use among many specialties
without specialized
equipment
Requires less observer experience
Disadvantage
In higher grades, possible incorrect
retinal nerve fiber layer thickness or
total retinal thickness borders
More patient cooperation required
No algorithm for optic disc edema
Disadvantage
Cataracts and media opacities
limit quality
Requires pupil dilation
Subjective and dependent on
experience
Various artifacts such as those induced
by poor centering, myopia, or
movement may not be obvious and
may interfere with interpretation
Increased variability and measurement
failure at higher grades
improve OCT, fundus photographs will likely remain an
important and reliable method for the assessment of disc
edema because of their availability, use among multiple
medical disciplines, and few but obvious artifacts, as well
as the ability of the examiner to individually assess edema
using multiple cues.
Our study has several limitations. Our sample size is
small, especially at the higher papilledema grades. Measurement error can occur with OCT and with assessment
of fundus photographs, and OCT algorithm failure rates
can become significant with high grades of papilledema.
This study demonstrates that OCT and MFS are
complementary methods that can be used to follow up
patients with papilledema. However, OCT failure rates
increase as disc edema increases, suggesting that with current algorithms OCT may be more useful at lower grades
of papilledema. The algorithm defining total retinal thickness had a lower failure rate than that defining RNFL
thickness, indicating that OCT total retinal thickness measurement may be more robust, especially at higher grades
of papilledema. The stronger correlation of MFS grade
with total retinal thickness compared with RNFL thickness suggests that more emphasis should be placed on
total retinal measurements.
Optical coherence tomography can be a useful tool in
the evaluation of papilledema by confirming or complementing an examiner’s clinical examination. The advantages are listed in Table 2 compared with digital optic
disc photographs; particularly, OCT quantification uses
a continuous scale, whereas MFS grading from photographs uses an ordinal scale (grade range, 0-5). We do
not recommend OCT in all patients with papilledema but
believe it may be useful to confirm results when diagnosis is challenging. OCT may be especially useful when
there is uncertainty about the presence of optic disc edema.
We are investigating its use in evaluating disc edema
change over time, and good correlation between photographic grading and OCT analysis is encouraging. Our
ability to measure high-grade papilledema should be improved with new segmentation algorithms providing more
robust software analysis of disc edema in conjunction with
higher-quality images, which are easier to obtain with
spectral-domain OCT. Current OCT measurement can
be useful as an adjunct to clinical staging.
Submitted for Publication: January 8, 2009; final revision received September 2, 2009; accepted October 5,
2009.
Correspondence: Michael Wall, MD, Department of Ophthalmology and Visual Sciences, Carver School of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA
52242 ([email protected]).
Financial Disclosure: None reported.
Funding/Support: This study was supported by a postdoctoral fellowship grant from Fight for Sight (Dr Scott),
by merit and rehabilitation grants from the Department
of Veterans Affairs (Drs Kardon and Wall), and by an unrestricted grant from Research to Prevent Blindness.
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Announcement
David H. Abramson, MD, was given a tenure appointment at Memorial Sloan-Kettering Cancer Center, where
he is the first chief of the Ophthalmic Oncology Service. He is the first ophthalmologist to ever receive tenure and is presently a professor in the departments of
surgery, pediatrics, and radiation oncology.
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