Peripapillary choroidal thickness in healthy controls and patients with focal, diffuse, and sclerotic glaucomatous optic disc damage.

Abstract

To examine peripapillary choroidal thickness in healthy controls and in patients with glaucoma who have focal, diffuse, and sclerotic optic disc damage.
Healthy controls (n=92) and patients with glaucoma who have focal (n=34), diffuse (n=35), and sclerotic (n=34) optic disc damage were imaged with spectral-domain optical coherence tomography (12° circular scan protocol centered on optic nerve head). Peripapillary choroidal thickness was measured as the distance between the automatically segmented retinal pigment epithelium/Bruch's membrane and the manually outlined interface between the posterior choroid and the anterior border of the sclera in eyes in which the anterior scleral border was visible over more than 85% of the scan circumference.
The anterior scleral border was visible in 76 controls (83%) and 89 patients (86%). Peripapillary choroidal thickness in healthy controls decreased linearly with age (-11 μm/decade; P.001; r2=0.16), with a predicted value of 137 μm at age 70 years (95% prediction interval, 62-212 μm). While this value was similar in patients with focal and diffuse optic disc damage (126 and 130 μm, respectively; P=.22 compared with controls), it was approximately 30% lower in patients with sclerotic optic disc damage (96 μm; P.001 compared with controls).
The peripapillary choroid of patients with glaucoma who have sclerotic optic disc damage was approximately 25% to 30% thinner compared with that in patients with focal and diffuse optic disc damage and with that in healthy controls. The role of the choroid in the pathophysiology of sclerotic glaucomatous optic disc damage needs further investigation.

Full text

Page 1

ONLINE FIRST
Peripapillary Choroidal Thickness in Healthy
Controls and Patients With Focal, Diffuse, and
Sclerotic Glaucomatous Optic Disc Damage
CLINICAL SCIENCES
Kenneth F. Roberts, MD; Paul H. Artes, PhD; Neil O’Leary, PhD; Alexandre S. C. Reis, MD; Glen P. Sharpe, MSc;
Donna M. Hutchison, BSc; Balwantray C. Chauhan, PhD; Marcelo T. Nicolela, MD
Objective: To examine peripapillary choroidal thick-
ness in healthy controls and in patients with glaucoma
who have focal, diffuse, and sclerotic optic disc damage.
Methods: Healthy controls (n=92) and patients with
glaucoma who have focal (n=34), diffuse (n=35), and
sclerotic(n=34)opticdiscdamagewereimagedwithspec-
tral-domain optical coherence tomography (12° circu-
lar scan protocol centered on optic nerve head). Peri-
papillarychoroidalthicknesswasmeasuredasthedistance
betweentheautomaticallysegmentedretinalpigmentepi-
thelium/Bruch’smembraneandthemanuallyoutlinedin-
terface between the posterior choroid and the anterior
border of the sclera in eyes in which the anterior scleral
border was visible over more than 85% of the scan cir-
cumference.
Results:Theanteriorscleralborderwasvisiblein76con-
trols(83%)and89patients(86%).Peripapillarychoroi-
dalthicknessinhealthycontrolsdecreasedlinearlywith
age (−11 µm/decade; P?.001; r2=0.16), with a pre-
dicted value of 137 µm at age 70 years (95% prediction
interval,62-212µm).Whilethisvaluewassimilarinpa-
tients with focal and diffuse optic disc damage (126 and
130 µm, respectively; P=.22 compared with controls),
it was approximately 30% lower in patients with scle-
roticopticdiscdamage(96µm;P?.001comparedwith
controls).
Conclusions:Theperipapillarychoroidofpatientswith
glaucoma who have sclerotic optic disc damage was ap-
proximately 25% to 30% thinner compared with that in
patientswithfocalanddiffuseopticdiscdamageandwith
that in healthy controls. The role of the choroid in the
pathophysiologyofscleroticglaucomatousopticdiscdam-
age needs further investigation.
Arch Ophthalmol.
Published online April 9, 2012.
doi:10.1001/archophthalmol.2012.371
T
ment of spectral-domain optical coher-
ence tomography (OCT) has recently
improvedtheabilitytovisualizeandmea-
sure the choroidal thickness in vivo, and
several groups have previously reported
subfoveal choroidal thickness measure-
mentsinhealthyanddiseasedeyes.8-14Be-
cause disturbed perfusion of the peripap-
illary choroid may play a role in the
pathogenesis of glaucomatous optic neu-
ropathy,2,15,16peripapillarychoroidalthick-
ness (PCT) may be also be highly rel-
evant in this disease.17
Glaucomatousdamagetotheopticdisc
can manifest with different morphologi-
cal patterns (Figure 1).18,19In patients
with focal optic disc damage, the neuro-
retinal rim has a localized notch inferi-
HE CHOROID PROVIDES
metabolic support to the
prelaminar portion of the
opticnervehead1-4andmay
therefore play an impor-
tant role in glaucoma.5-7The develop-
orlyorsuperiorly,whiletheremainingtis-
sueisrelativelywellpreserved.Inpatients
with diffuse damage, the cup is concen-
trically enlarged and there are no local-
ized areas of neuroretinal rim loss or pal-
lor. Patients with sclerotic damage have
shallowcuppingwithmarkedareasofperi-
papillary atrophy. In patients with high
myopia,progressivestretchingofthepos-
terior ocular tissues may contribute to a
myopic type of glaucomatous disc dam-
age characterized by a tilted appearance
with shallow cupping and a myopic cres-
cent of peripapillary atrophy. Groups of
patientswithdistinctpatternsofopticdisc
damage differ with respect to the inci-
dence and severity of visual field and op-
tic disc progression.20They also have dif-
ferentdemographiccharacteristicsandrisk
factors.19,21,22Morphological subtypes of
glaucomatous optic disc damage may
thereforehelptodifferentiatemoreeffec-
tivelywithinthewideclinicalspectrumof
open-angle glaucoma. In this article, we
Author Affiliations:
Department of Ophthalmology
and Visual Sciences, Faculty of
Medicine, Dalhousie University,
Halifax, Nova Scotia, Canada.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012WWW.ARCHOPHTHALMOL.COM
E1
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.comDownloaded from

Page 2

report PCT in patients with open-angle glaucoma who
havefocal,diffuse,andsclerotictypesofopticdiscdam-
age compared with PCT in healthy controls.
METHODS
The data for this cross-sectional investigation were obtained
from 2 ongoing studies at the Queen Elizabeth II Health Sci-
ences Centre in Halifax, Nova Scotia, Canada.23,24In accor-
dance with the Declaration of Helsinki, the institutional re-
search ethics board had approved the protocols, and all
participants gave written informed consent.
PATIENTS
Data from patients with glaucoma were obtained from a pro-
spectivelongitudinalstudyonprogressionwithdifferenttypes
of optic disc damage.23These patients were recruited from the
glaucoma clinics. One of us (M.T.N.), masked to the patients’
identity and clinical information, selected consecutive partici-
pants based on optic disc stereo photographs. To be eligible
for inclusion, at least 1 eye had to have focal, diffuse, or scle-
rotic optic disc damage. Other criteria included a diagnosis of
open-angleglaucoma,includingprimary,pseudoexfoliative,or
pigmentary glaucoma, best-corrected visual acuity equal to or
better than ?0.3 logMAR (20/40) in the study eye, refractive
error within ±6.00 diopters (D) sphere and ±3.00 D astigma-
tism, and visual field damage (defined as Glaucoma Hemifield
Test results outside normal limits or a mean deviation [MD]
worsethan−2.0dB).Exclusioncriteriawereconcomitantocu-
lardisease,systemicmedicationknowntoaffecttheopticnerve
and/orthevisualfield,andanMDworsethan−20.0dB.Ifboth
eyeswereeligible,1eyewasrandomlychosenasthestudyeye.
CONTROLS
Healthy controls are being followed in another longitudinal
study24andhadbeenrecruitedfrompatients’relatives,church
groups, and a local telephone company. They had normal eye
examination findings, intraocular pressure lower than 21
mm Hg, best-corrected visual acuity equal to or better than
?0.3 logMAR, refractive error within ±5.00 D sphere and
±3.00 D astigmatism, and normal visual fields (defined as
Glaucoma Hemifield Test results within normal limits and an
MD equal to or better than −2.0 dB). One eye was randomly
selected as the study eye.
IMAGING
Subjects underwent imaging on a spectral-domain OCT sys-
tem (Spectralis; Heidelberg Engineering) in high-resolution
mode. The circular scans (12° diameter, corresponding to ap-
proximately 3.5 mm in a typical emmetropic eye) consisted of
1536 A-scans, and 16 images were averaged using automatic
real-time image tracking.
Images were analyzed using Heidelberg Eye Explorer soft-
ware (hraviewer version 5.3.2.0). First, files with the soft-
ware-derived segmentations corresponding to the internal
limiting membrane (upper segmentation line) and the retinal
pigment epithelium/Bruch’s membrane (lower segmentation
line) were exported. Subsequently, 1 observer masked to all
clinical information (K.F.R.) manually edited the lower seg-
mentation line such that it corresponded to the interface of
the choroid and anterior sclera. Only that part of the circum-
ference over which the anterior sclera was clearly visible was
segmented. Where the anterior sclera was not clearly visible,
thesegmentationlinewasdeleted.Threeofus(P.H.A.,A.S.R.,
M.T.N.) reviewed the segmentations and, if appropriate,
made modifications by consensus. A second set of files was
then exported, and PCT profiles were calculated from the dif-
ference between both sets of files.
ANALYSIS
Images were included in the analysis if the anterior border of
the sclera was visible over more than 85% of the circumfer-
ence. Multiple regression analyses were performed to estimate
the relationships between PCT, age, and glaucoma. The sever-
ity of global visual field damage (ie, MD), thickness of the
retinalnervefiberlayer,andaxiallengthwereevaluatedascon-
tinuous covariates. All analyses were performed in the open-
source environment R.25
RESULTS
CONTROL AND PATIENT GROUPS
Datawereavailablefrom92healthycontrolsand103pa-
tients with glaucoma. Of the latter, the disc damage was
focalin34patients,diffusein35,andscleroticin34.For
inclusion in the subsequent analyses, the anterior sclera
had to visible over more than 85% of the scan circum-
ference, and images from 76 controls (83%) and 89 pa-
ABC
Figure 1. Typical examples of distinct morphological patterns of glaucomatous optic disc damage. A, Focal damage with localized inferior rim loss. B, Diffuse
damage with concentric enlargement of the cup. C, Sclerotic damage with a shallow cup and a ring of surrounding peripapillary atrophy.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012WWW.ARCHOPHTHALMOL.COM
E2
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.comDownloaded from

Page 3

tients (86%) met this criterion. There was no relation-
ship between the proportion of visible sclera and OCT
signal strength, age, or disease group (multiple regres-
sion, P?.10), and none of these variables was signifi-
cantly different in patients who were excluded because
of poor visibility of the anterior sclera (Friedman analy-
sis of variance by ranks and ?2test, P?.10).
Relevant characteristics of the included subjects are
given in Table 1. Patients were, on average, 15 years
older than controls (P?.001) and had early to moder-
ate visual field damage (median MD, −3.4 dB). Patients
with focal optic disc damage had somewhat more ad-
vanced visual field damage than those with diffuse and
scleroticdamage(medianMD,−5.5vs−3.4and−2.3dB,
respectively; P?.01) and a lower global retinal nerve fi-
berlayerthickness(median,67vs75and71µm,respec-
tively;P?.05).Axiallengthsweresimilarinthe4groups
ofsubjects(P=.41).Signalstrengthwashighestinhealthy
controls followed by patients with focal, sclerotic, and
diffuseloss(P?.001),althoughthedifferencesweresmall.
The ethnic mix of patients and controls reflected the
makeupofaNovaScotianpopulation;approximately90%
of participants were of Northern European ancestry.
GLOBAL PCT IN PATIENTS
AND CONTROLS
SummarystatisticsforPCTincontrolsandpatientswith
glaucomaareshowninTable2.Inhealthycontrols,PCT
declined with age at a rate of −11 µm/decade (95% CI,
−5 to −17 µm/decade; P?.001) (Figure 2). Age ex-
plained approximately 20% of the nearly 4-fold varia-
tion in PCT between healthy individuals (r2=0.16). The
predictedmeanPCTforahypothetical70-year-oldhealthy
subject was 137 µm, with a 95% prediction interval of
62 to 212 µm. There were no significant differences be-
tween men and women (P=.24).
The age-related decrease of PCT appeared similar in
patientswithglaucoma(P=.59),buttheirPCTwasthin-
ner than that of healthy controls (−18 µm; 95% CI, −32
to −3 µm; P=.02) (Figure 2). The PCT predicted for a
70-year-old patient with glaucoma was 117 µm, with a
95% prediction interval of 27 to 208 µm.
Table 1. Details of Healthy Controls and Patients With Glaucoma
Characteristic
Age, y
MD, dB
RNFL thickness, µm
Axial length, mm
IOP, mm Hg
OCT signal strength, dB
Median (IQR)
Controls
(n = 76)
Patients With Glaucoma
(n = 89)
Focal
(n = 33)
Diffuse
(n = 27)
Sclerotic
(n = 29) All
56.1 (44 to 65)
?0.57 (−0.14 to ?1.15)
98 (91 to 103)
23.8 (23.1 to 24.6)
17.2 (12.8 to 17.3)
33 (30 to 35)
71.1 (60 to 79)
−5.5 (−10.7 to −3.2)
67 (60 to 71)
24.0 (23.5 to 25.0)
15.0 (12.0 to 16.8)
31 (28 to 34)
65.6 (54 to 76)
−3.4 (−4.5 to −2.2)
75 (68 to 89)
23.8 (23.4 to 24.3)
15.4 (13.8 to 17.9)
29 (27 to 31)
74.7 (68 to 79)
−2.3 (−5.2 to −1.7)
71 (68 to 84)
23.9 (23.6 to 24.7)
15.1 (12.0 to 18.0)
30 (28 to 32)
71.1 (61 to 79)
−3.4 (−6.5 to −2.1)
71 (65 to 82)
23.9 (23.5 to 24.7)
14.8 (11.7 to 17.7)
30 (28 to 33)
Abbreviations: IOP, intraocular pressure; IQR, interquartile range; MD, mean deviation; OCT, optical coherence tomography; RNFL, retinal nerve fiber layer.
Table 2. Peripapillary Choroidal Thickness in Healthy Controls and Patients With Glaucoma
PCT
Mean (SD), µm
Median (IQR), µm
Controls
(n = 76)
154 (40)
148 (130-180)
Patients With Glaucoma
(n = 89)
Focal
(n = 33)
126 (44)
110 (94-154)
Diffuse
(n = 27)
135 (57)
125 (100-147)
Sclerotic
(n = 29)
92 (30)
84 (70-107)
All
118 (48)
105 (88-141)
Abbreviations: IQR, interquartile range; PCT, peripapillary choroidal thickness.
250
150
200
100
50
20 40305060 708090
Age, y
PCT, µm
Healthy controls
Patients with glaucoma
Figure 2. Peripapillary choroidal thickness (PCT) in healthy controls and
patients with glaucoma. The relationship between age and PCT was similar in
healthy controls and patients with glaucoma except for a constant difference
of 18 µm.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012WWW.ARCHOPHTHALMOL.COM
E3
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.com Downloaded from

Page 4

Inamultivariateanalysiswithage,glaucoma,andaxial
length as predictors, PCT decreased by 10 µm for each
1.0-mm increase in axial length (95% CI, −1 to −19 µm;
P=.04).Axiallengthexplained8%ofthevarianceinthe
combined model. There was no statistical relationship
between PCT and either MD or retinal nerve fiber layer
thickness when these variables were added to the model
(P=.85 and .33, respectively).
PCT IN PATIENTS WITH FOCAL, DIFFUSE,
AND SCLEROTIC OPTIC DISC DAMAGE
Patients with sclerotic optic disc damage had the lowest
PCT (difference compared with controls, −41 µm; 95%
CI, −59 to −23 µm; P?.001), followed by patients with
focal disc damage (−13 µm; 95% CI, −31 to ?5 µm;
P=.22) and diffuse disc damage (−5 µm; 95% CI, −25 to
?14 µm; P=.62) (Figure 3). The mean PCTs pre-
dicted for a hypothetical 70-year-old patient with focal,
diffuse, and sclerotic disc damage were 126, 130, and
96 µm, respectively.
PERIPAPILLARY VARIATION
IN CHOROIDAL THICKNESS
Onaverage,thePCTtendedtobegreatersuperiorlyand
nasallyandsmallerinferiorlyandtemporally(Figure 4).
The variation in choroidal thickness around the optic
nerveheadwasmoderate;themedianratiosbetweenthe
smallestandlargestvalueswere0.55incontrolsand0.44,
0.46, and 0.36 in patients with focal, diffuse, and scle-
rotic optic disc damage, respectively. These differences
were statistically significant (Kruskal-Wallis test,
P?.001).
EXAMPLES
The examples in Figure 5, Figure 6, and Figure 7
illustratetypicalcasesoffocal,diffuse,andscleroticdisc
damage.TheOCTimagesshowthesoftware-derivedseg-
mentationoftheinternallimitingmembraneandBruch’s
membraneaswellasthemanualsegmentationofthean-
terior scleral border. The location of the scanning circle
is shown in the infrared scanning laser ophthalmo-
scopic images, and the optic disc is shown in color pho-
tographs. The grayscales show the corresponding visual
field damage.
COMMENT
The aim of this study was to investigate the thickness of
the choroid around the optic nerve head in healthy con-
trols and patients with 3 morphological types of glauco-
matous optic disc damage. Most previous investigators
have reported choroidal thickness measurements ob-
tained from line or volume scans centered on the fo-
vea.9-12,14However, given the role of the choroidal vas-
culature in the blood supply of the anterior optic nerve
head, the peripapillary choroid may be a relevant target
for investigation in patients with glaucoma.17
Although differences in scan location, equipment,
imaging parameters, and measurement procedures
make it problematic to compare the thickness estimates
with those from previous reports, the values estimated
in our material compare closely to those reported by
other groups. The most temporal part of the scan circle
in our study was approximately 2.55 mm (median;
interquartile range, 2.43-2.72 mm) nasal from the
fovea. At a similar retinal locus, 2.50 mm nasal from the
fovea, Margolis and Spaide14reported a choroidal thick-
ness of 170 µm from a group of 30 healthy subjects
with an average age of 50 years, while Manjunath et al13
obtained a mean thickness of 157 µm in 34 healthy
controls with a mean age of 51 years. Both of these esti-
mates are close to our value of approximately 160 µm
obtained by interpolating to an age of 50 years in our
250
150
200
100
50
50 60708090
Age, y
PCT, µm
Focal
Diffuse
Sclerotic
Figure 3. Peripapillary choroidal thickness (PCT) in patients with focal,
diffuse, and sclerotic optic disc damage.
250
150
200
100
50
TTSS NSN NII TIT
Controls
Diffuse
Focal
Sclerotic
PCT, µm
Controls
Focal
Diffuse
Sclerotic
AB
Figure 4. Profile of peripapillary choroidal thickness (PCT). A, Lines show
the mean PCT profiles of healthy controls and patients with focal, diffuse,
and sclerotic optic disc damage. T indicates temporal; TS, temporal-superior;
S, superior; NS, nasal-superior; N, nasal; NI, nasal-inferior; I, inferior; and
TI, temporal-inferior. B, Box plots show the variation of mean PCT in the 4
groups. Error bars indicate the 5th and 95th percentiles; boxes, interquartile
ranges; horizontal white lines, medians; and dots, means.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012 WWW.ARCHOPHTHALMOL.COM
E4
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.comDownloaded from

Page 5

data from healthy controls (Figure 2). In subjects of
similar age to ours, Mwanza et al26reported mean cho-
roidal thickness of 170 and 174 µm in controls and
patients with glaucoma, respectively, at a location 3.0
A
BCD
TemporalSuperior
100 µm
S
N
T
I
NasalInferior
Figure 5. Example of a patient with focal optic disc damage in the left eye. The mean peripapillary choroidal thickness was 155 µm. The retinal nerve fiber layer
was thin (mean, 62 µm) with complete absence inferior-temporally. A, An optical coherence tomographic image shows the software-derived segmentation of the
internal limiting membrane (dashed white line) and Bruch’s membrane (dashed blue line) as well as the manual segmentation of the anterior scleral border (blue
dots). B, A scanning laser ophthalmoscopic image shows the location of the scanning circle. I indicates inferior; N, nasal; S, superior; and T, temporal. C, A color
photograph shows the optic disc, which is notched inferiorly with a hemorrhage at the 6-o’clock position. D, The visual field shows extensive damage of the
superior hemifield (mean deviation, −10.4 dB).
A
BCD
TemporalSuperior
100 µm
S
N
T
I
NasalInferior
Figure 6. Example of a patient with diffuse optic disc damage in the left eye. The mean peripapillary choroidal thickness was 104 µm, and the mean retinal nerve
fiber layer thickness was 77 µm. A, An optical coherence tomographic image shows the software-derived segmentation of the internal limiting membrane (dashed
white line) and Bruch’s membrane (dashed blue line) as well as the manual segmentation of the anterior scleral border (blue dots). B, A scanning laser
ophthalmoscopic image shows the location of the scanning circle. I indicates inferior; N, nasal; S, superior; and T, temporal. C, A color photograph shows deep
concentric cupping of the optic disc. D, The visual field shows mainly diffuse damage with a mean deviation of −5.9 dB.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012WWW.ARCHOPHTHALMOL.COM
E5
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.comDownloaded from

Page 6

mm nasal from the fovea. All of these estimates are
somewhat lower than those of Ikuno et al,27who
reported a mean of 227 µm from a group of 43 Japanese
subjects (mean age, 39 years). In addition, the cross-
sectional estimate of age-related choroidal thinning in
our data (11 µm/decade; 95% CI, 5-17 µm) is similar to
the rate of 16 µm/decade reported for subfoveal choroi-
dal thickness measurements by Margolis and Spaide14
and to the rates of 13 and 16 µm/decade in controls and
patients with glaucoma, respectively, reported by
Mwanza et al.26Also, the inverse relationship between
PCT and axial length in our study (−10 µm/mm of axial
length) was close to that estimated by the latter group
(−12 µm/mm).
Our data show that PCT in patients with glaucoma
who have sclerotic optic disc damage was approxi-
mately 40 µm lower than age-corrected normal values.
Incontrast,nosignificantdifferencescomparedwithcon-
trolswereseeninpatientswithfocalordiffuseopticdisc
damage.Giventhattheage-relatedrateofchoroidalthin-
ningestimatedfromcross-sectionaldataisonlyapproxi-
mately10to20µm/decade,thereductionof25%to30%
seen in patients with sclerotic optic disc damage is sub-
stantialandaddstotheevidencethattheremaybeacon-
nectionbetweenchoroidalatrophyandglaucomatousop-
tic disc damage of the sclerotic type.9,28
Inpatientswithscleroticopticdiscdamage,largecho-
roidal vessels are often clearly visible ophthalmoscopi-
cally, suggesting a loss of choriocapillaris, smaller and
medium-sizedvessels,andpigmentarycells.21,29Thisap-
pearance has been described as choroidal sclerosis and
has been linked to age-related atrophy of the choroidal
circulation.9,30In comparison with patients with other
glaucomatous optic disc appearances, those with scle-
rotic disc damage have an increased resistance index as
measured with color Doppler imaging in the ophthal-
micartery,centralretinalartery,andshortposteriorcili-
ary arteries31as well as reduced pulsatile ocular blood
flow.32Scleroticopticdiscdamageisassociatedwithcar-
diovascular conditions, particularly systemic hyperten-
sionandischemicheartdisease,18,19suggestingthatsmall-
vessel disease might be involved in the pathogenesis of
this particular type of disc damage.
Mwanza et al26did not identify a difference in cho-
roidal thickness between patients with glaucoma and
healthy controls. Similarly, Maul et al17did not find dif-
ferences in PCT between patients with established glau-
coma and those with suspected glaucoma, even though
choroidal thickness at the macula tended to be lower in
those with established damage. One possible explana-
tion for this discrepancy is that their samples may have
includedfewerpatientswithscleroticopticdiscdamage
compared with our study. The lower PCT in our patient
group was almost entirely caused by the substantial re-
duction in patients with sclerotic disc damage; in pa-
tients with focal or diffuse optic disc damage, the differ-
ences from controls were small and not statistically
significant.
The anterior boundary of the sclera was well visible
inmostsubjects,butapproximately15%ofsubjectswere
excluded from the analysis because the boundary could
not be distinguished with confidence. Because a thicker
choroid may cause the anterior sclera to be less visible,
itispossiblethatouraveragesunderestimatethetrueval-
A
BCD
Temporal Superior
100 µm
S
N
T
I
NasalInferior
Figure 7. Example of a patient with sclerotic optic disc damage in the right eye. The mean thickness of the peripapillary choroid was 67 µm, and the mean retinal
nerve fiber layer thickness was 65 µm. A, An optical coherence tomographic image shows the software-derived segmentation of the internal limiting membrane
(dashed white line) and Bruch’s membrane (dashed blue line) as well as the manual segmentation of the anterior scleral border (blue dots). B, A scanning laser
ophthalmoscopic image shows the location of the scanning circle. I indicates inferior; N, nasal; S, superior; and T, temporal. C, A color photograph shows the
optic disc, with extensive peripapillary atrophy. D, The visual field shows a mean deviation of −3.9 dB.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012 WWW.ARCHOPHTHALMOL.COM
E6
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.com Downloaded from

Page 7

ues. However, the proportions of visible anterior sclera
in the 4 groups of subjects were not markedly different
and are therefore unlikely to have affected our findings.
There is evidence that the recently developed technique
of enhanced depth imaging10can improve the visibility
of more posterior tissues. Also, OCT systems with lon-
ger wavelengths (eg, 1080 nm) and better tissue pen-
etrationarebeingdeveloped.29Thesedevelopmentsmay
furtherenhancethevisibilityofthechoroidallayersand
improve the feasibility of in vivo measurements.
Patientswithmyopicopticdiscdamagehadnotbeen
included in the original study on progression with dif-
ferent disc types23from which the current material was
drawn, and we therefore cannot comment on choroidal
thicknessinthesepatients.Therelationshipbetweenmyo-
pia (and myopic-type glaucomatous disc damage) and
choroidalthicknessmaybeaparticularlyinterestingtopic
for future research.
Insummary,ourstudyidentifiedasubstantialreduc-
tion in PCT in patients with glaucoma who have scle-
rotic optic disc damage. This adds to the evidence that
morphological patterns of optic disc damage may help
to distinguish clinically meaningful subtypes of glau-
coma within the diverse spectrum of the disease. Obser-
vations of patients over time are needed to investigate
whetherthereducedPCTobservedinpatientswithscle-
roticopticdiscdamageispartofthecause,orpartofthe
consequence, of the glaucomatous disease process.
Submitted for Publication: May 31, 2011; final revision
receivedDecember20,2011;acceptedJanuary17,2012.
Published Online: April 9, 2012. doi:10.1001
/archophthalmol.2012.371
Correspondence:PaulH.Artes,PhD,DepartmentofOph-
thalmology and Visual Sciences, Dalhousie University,
Room 2035, West Victoria, 1276 S Park St, Halifax, NS
B3H 2Y9, Canada (paul@dal.ca).
Financial Disclosure: None reported.
Funding/Support:ThisworkwassupportedbytheGlau-
comaResearchFoundation(DrArtes)andbygrantsMOP-
11357(DrChauhan)andMOP-62783(DrNicolela)from
the Canadian Institutes of Health Research.
Previous Presentation: This work was presented as a
posteratthe2011AnnualMeetingoftheAssociationfor
ResearchinVisionandOphthalmology;May3,2011;Fort
Lauderdale, Florida.
REFERENCES
1. FlammerJ,Orgu ¨lS,CostaVP,etal.Theimpactofocularbloodflowinglaucoma.
Prog Retin Eye Res. 2002;21(4):359-393.
2. Hayreh SS. Blood supply of the optic nerve head and its role in optic atrophy,
glaucoma, and oedema of the optic disc. Br J Ophthalmol. 1969;53(11):721-
748.
3. Linsenmeier RA, Padnick-Silver L. Metabolic dependence of photoreceptors on
the choroid in the normal and detached retina. Invest Ophthalmol Vis Sci. 2000;
41(10):3117-3123.
4. Alm A. Ocular circulation. In: Kaufman PL, Alm A, eds. Adler’s Physiology of the
Eye. 10th ed. St Louis, MO: Mosby; 2005.
5. Cristini G, Cennamo G, Daponte P. Choroidal thickness in primary glaucoma.
Ophthalmologica. 1991;202(2):81-85.
6. Yin ZQ, Vaegan, Millar TJ, Beaumont P, Sarks S. Widespread choroidal insuffi-
ciency in primary open-angle glaucoma. J Glaucoma. 1997;6(1):23-32.
7. Spraul CW, Lang GE, Lang GK, Grossniklaus HE. Morphometric changes of the
choriocapillaris and the choroidal vasculature in eyes with advanced glaucoma-
tous changes. Vision Res. 2002;42(7):923-932.
8. McCourt EA, Cadena BC, Barnett CJ, Ciardella AP, Mandava N, Kahook MY. Mea-
surement of subfoveal choroidal thickness using spectral domain optical coher-
ence tomography. Ophthalmic Surg Lasers Imaging. 2010;41(suppl):S28-S33.
9. SpaideRF.Age-relatedchoroidalatrophy.AmJOphthalmol.2009;147(5):801-810.
10. Spaide RF, Koizumi H, Pozzoni MC. Enhanced depth imaging spectral-domain
optical coherence tomography. Am J Ophthalmol. 2008;146(4):496-500.
11. FujiwaraT,ImamuraY,MargolisR,SlakterJS,SpaideRF.Enhanceddepthimaging
optical coherence tomography of the choroid in highly myopic eyes. Am J
Ophthalmol. 2009;148(3):445-450.
12. Imamura Y, Fujiwara T, Margolis R, Spaide RF. Enhanced depth imaging optical
coherencetomographyofthechoroidincentralserouschorioretinopathy.Retina.
2009;29(10):1469-1473.
13. ManjunathV,TahaM,FujimotoJG,DukerJS.Choroidalthicknessinnormaleyes
measuredusingCirrusHDopticalcoherencetomography.AmJOphthalmol.2010;
150(3):325-329, e1.
14. Margolis R, Spaide RF. A pilot study of enhanced depth imaging optical coher-
ence tomography of the choroid in normal eyes. Am J Ophthalmol. 2009;147
(5):811-815.
15. Francois J, Neetens A. Vascularity of the eye and the optic nerve in glaucoma.
Arch Ophthalmol. 1964;71:219-225.
16. DranceSM.Dischemorrhagesintheglaucomas.SurvOphthalmol.1989;33(5):
331-337.
17. Maul EA, Friedman DS, Chang DS, et al. Choroidal thickness measured by spec-
tral domain optical coherence tomography: factors affecting thickness in glau-
coma patients. Ophthalmology. 2011;118(8):1571-1579.
18. BroadwayDC,NicolelaMT,DranceSM.Opticdiskappearancesinprimaryopen-
angle glaucoma. Surv Ophthalmol. 1999;43(suppl 1):S223-S243.
19. Nicolela MT, Drance SM. Various glaucomatous optic nerve appearances: clini-
cal correlations. Ophthalmology. 1996;103(4):640-649.
20. Reis AS, Artes PH, Chauhan BC, Nicolela MT. Visual field and optic disc pro-
gression in patients with glaucoma and different patterns of optic disc damage.
Invest Ophthalmol Vis Sci. 2011;52:2121.
21. Geijssen HC, Greve EL. The spectrum of primary open angle glaucoma, I: senile
sclerotic glaucoma vs high tension glaucoma. Ophthalmic Surg. 1987;18(3):
207-213.
22. GeijssenHC,GreveEL.Focalischaemicnormalpressureglaucomavshighpres-
sure glaucoma. Doc Ophthalmol. 1990;75(3-4):291-301.
23. Nicolela MT, McCormick TA, Drance SM, Ferrier SN, LeBlanc RP, Chauhan BC.
Visual field and optic disc progression in patients with different types of optic
disc damage: a longitudinal prospective study. Ophthalmology. 2003;110(11):
2178-2184.
24. ArtesPH,NicolelaMT,LeBlancRP,ChauhanBC.Visualfieldprogressioninglau-
coma: total vs pattern deviation analyses. Invest Ophthalmol Vis Sci. 2005;
46(12):4600-4606.
25. R Development Core Team. R: A Language and Environment for Statistical
Computing. Vienna, Austria: R Foundation for Statistical Computing; 2011.
26. Mwanza JC, Hochberg JT, Banitt MR, Feuer WJ, Budenz DL. Lack of association
between glaucoma and macular choroidal thickness measured with enhanced
depth-imagingopticalcoherencetomography.InvestOphthalmolVisSci.2011;
52(6):3430-3435.
27. IkunoY,KawaguchiK,NouchiT,YasunoY.ChoroidalthicknessinhealthyJapa-
nese subjects. Invest Ophthalmol Vis Sci. 2010;51(4):2173-2176.
28. Jonas JB. Biomorphometrie des Nervus Opticus: Volume 120, Bu ¨cherei des
Augenarztes. Stuttgart, Germany: Verlag; 1989.
29. Povazay B, Hermann B, Hofer B, et al. Wide-field optical coherence tomography
of the choroid in vivo. Invest Ophthalmol Vis Sci. 2009;50(4):1856-1863.
30. Sarks SH. Senile choroidal sclerosis. Br J Ophthalmol. 1973;57(2):98-109.
31. Nicolela MT, Walman BE, Buckley AR, Drance SM. Various glaucomatous optic
nerve appearances: a color Doppler imaging study of retrobulbar circulation.
Ophthalmology. 1996;103(10):1670-1679.
32. Belliveau AC, LeBlanc RP, Chauhan BC, Nicolela MT. Pulsatile ocular blood flow
inglaucomapatientswithdifferentopticdiscphenotypes.InvestOphthalmolVis
Sci. 2007;48:4385.
ARCH OPHTHALMOLPUBLISHED ONLINE APRIL 9, 2012WWW.ARCHOPHTHALMOL.COM
E7
©2012 American Medical Association. All rights reserved.
at DALHOUSIE UNIVERSITY-DAL-11762, on April 18, 2012 www.archophthalmol.comDownloaded from