Full Text

Imaging
-.
and
ential
of the
Michelle
The
MD
Castillo,
initial
termine
-
Diagnosis
Large
Eye1
Smith,
Mauricio
Differ-
MD
step in the differential
diagnosis
of an
whether
an intraocular
mass is present.
by a mass, seen mainly
in children
with
with or without
neurofibromatosis
also
enlarged
eye is to deThe globe
may be exretinoblastoma.
Buphenlarges
the eye. Dii-
panded
thalmos
fuse enlargement
may be associated
with a connective
tissue disorder
be related
to axial myopia.
Focal enlargement
represents
staphyloma,
which
can be unilateral
or bilateral.
In the presence
of one small eye,
the normal-sized
eye may be incorrectly
diagnosed
as large.
INTRODUCTION
Eye enlargement
is clinically
children,
the sclera
is flexible
or
.
traocular
pressure
establish
the
may
presence
manifested
as proptosis
and is usually
seen in children.
and compliant,
and an intraocular
mass or increased
easily
cause
the
or absence
eye
to enlarge.
of a mass
within
the
Imaging
studies
enlarged
eye
are
(Fig
In
in-
needed
to
1). Retinoblas-
toma is the most common
intraocular
tumor
to produce
generalized
eye enlargement.
Intraocular
tumors
in adults,
however,
do not usually
produce
eye enlargement.
Enlargement
can also occur
without
intraocular
masses.
The most common
cause
of such
enlargement
is axial myopia.
Buphthalmos
is usually
associated
with
neurofibromatosis
type 1 or can be secondary
to childhood
glaucoma.
Abnormally
increased
compliance
of the sclera
associated
with a connective
tissue disorder
may also lead to enlarged
eye.
Focal enlargement
of the cornea
or sclera
is termed
“staphyloma.
Staphyloma
is usu“
ally
idiopathic
occur
‘
entity
This
proach
unilateral
discusses
the
to the
enlarged
eye.
terms:
Eye,
CT,
1994;
the
Department
NC 27599.
requested
Presented
February
RSNA,
be
article
RadloGraphlcs
I From
can
or bilateral.
Apparent
enlargement
when
the contralateral
eye is relatively
small. The
such as facial bones,
which
may also be hypoplastic,
from true eye enlargement.
tunes
index
and
224.1211
.
differential
Eye,
diseases,
diagnosis,
224.899
.
Eye.
imaging
neoplasms.
of one
characteristics
should
help
features,
224.364.
can
structhis
diagnostic
ap-
and
224.3’2.
eye
of other
distinguish
224.61
14:721-728
of Radiology,
CB 7510,
as a scientific
exhibit
10, 1994 and received
University
of North
Carolina
School
1993 RSNA scientific
assembly.
at the
February
21: accepted
March
of Medicine,
Received
11. Address
reprint
Manning
December
requests
Or, Chapel
22. 1993:
to MC.
lull,
revision
1994
721
Figure
.
1.
Algorithm
for the
GENERALIZED
WITH
EYE
INTRAOCULAR
diagnosis
of the
enlarged
ENLARGEMENT
MASSES
eye.
tamed
sion
Retinoblastoma
is a rare, malignant,
congenital
tumor
that arises from primitive
photoreceptors
entirely
beyond
tumor
exten-
with
100%
mortality.
retinoblastoma
persistent
It is now
included
(bilateral
(1). Bilateral
tumors
tients
(2). Leukokoria
the
many
eye
in the
tumors
primitive
plus
pineal
most
common
as 60%
are seen
(white
clinical
of patients.
sign
Other
dur-
in 25%-33%
of papupillary
reflex)
is
and
clinical
is seen
in as
signs
that may be present
initially
include
strabismus,
iris neovascularization,
hyphema,
secondary
angle-closure
glaucoma,
and phthisis
bulbi.
Prognosis
tends
to be better
if the tumor
is con-
hyperplastic
ally
seen
always
eye
normal
generally
blastomas
sity
vitreous,
are
to normal
magnetic
mass,
and
with subretinal
effusions
eye may be enlarged
but
in size.
The
rules
out
seen
as areas
signal
resonance
on
and
and necessitates
Calcifications
of
any shape
or form.
of the tumor
is gener-
as a hyperattenuating
detachments
present.
The
hyperintense
weighted
Exhibit
primary
retinopathy
of prematurity)
enucleation
of the eyeball.
retinoblastoma
may have
The noncalcified
portion
tensity
Scientific
globe;
is associated
neuroectodermal
tumor
group.
Four types of
retinoblastoma
are recognized:
nonheritable
retinoblastoma;
retinoblastoma
inherited
as an
autosomal
dominant
trait; retinoblastoma
associated
with chromosomal
anomalies,
in particular, with chromosomes
1 3 and 14; and trilateral
retina.
tumor)
(1 ). Average
age at diagnosis
is 13
months,
and almost
all cases are diagnosed
ing childhood.
Retinoblastoma
occurs
with
equal
frequency
in male and female
patients
U
the
globe
Computed
tomography
(CT) is an ideal imaging modality
for the initial evaluation
of suspected
retinoblastoma
(Fig 2) and shows
calcification
in more than 90% of tumors
(1). The
presence
of calcifIcations
in a mass is virtually
pathognomonic
for retinoblastoma
(as opposed
to other
common
entities
with leukokoria
but
no calcifications,
such as retrolental
fibroplasia,
in the
722
within
the
T2-weighted
compared
images.
presence
of a small
retinoblastoma.
Retino-
of mild
intensity
(MR)
on
with
Volume
hyperintenTl-weighted
images
images
and
(1).
the
retinal
may be
is almost
hypoin-
Effusions
tumor
14
are
on T2-
Number
4
Figure
2.
(a) Axial contrast
material-enhanced
CT scan shows
a calcified
retinoblastoma
(r) confined
to the
left globe.
Despite
slight tilting
to the right, there
is enlargement
of the involved
globe.
The optic
nerve
is
stretched
but not involved
by tumor.
(b) Axial CT scan obatained
3 mm cephalad
to that in a shows
thickening
of the sclera
(arrowheads)
suggestive
of invasion
by tumor.
The vitreous
is hyperattenuating
compared
with
that of the normal
eye. The lens (open
arrow)
is medially
displaced
by the mass.
though
such lesions
could
conceivably
cause
enlargement
of the eye, the mature
and hard
sclera
in adults
usually
does not permit
the eye
to enlarge.
U GENERAUZED
NO INTRAOCULAR
Figure
3.
Axial
myopia
who had
tion of the globes
The
sclerae
CT scan
of a patient
bilateral
in their
proptosis.
Note
anteroposterior
are thinned
with
spread
Ectopic
pineal
along
axial
elongadiameter.
posteriorly.
myopia
In adults,
mors
July
most important
goal of any imis to detect
tumor
spread.
CT,
contrast
material-enhanced
MR
be used to detect
any tumor
the
tumors
regions.
include
1994
optic
may
the
nerves
be seen
most
common
melanoma
and
and
pathways.
in the
parasellar
intraocular
metastases.
WITH
. Axial
Myopia
Axial myopia
is an idiopathic
enlargement
of
the eyeball
in the anteroposterior
dimension
that causes
convergence
of light anterior
to the
retina.
Axial myopia
is the most common
cause
of macrophthalmia
(3). It commonly
is associated with proptosis
and may be unilateral
or bilateral.
The process
is chronic
with no associated pain. Amblyopia
(impairment
of vision
without
organic
cause)
is usually
present.
Axial
tions,
The second
aging method
but preferably
imaging,
may
ENLARGEMENT
MASSES
may
Grave
also
disease,
be
seen
and
with
orbital
infec-
(3).
staphyloma
At CT imaging,
no intraocular
masses
are
found
and the globes
are enlarged,
generally
in
the anteroposterior
axis (Fig 3). Therefore,
in
axial myopia
the globe
is oval. In addition
to
ocular
elongation,
CT or MR images
may show
thinning
of the sclera.
or
tu-
Al-
Smith
and
Castillo
U
RadioGraphics
U
723
Figure
4. (a) Axial plain CT scan obtained
in a child with neurofibroniatosis
type 1 shows
an enlarged
and proptotic
right eye (r) compared
with the left eye (1). (b) Axial CT scan of an adolescent
with a long history
of glaucoma
shows
an enlarged
left eye (L). The underlying
cause
of the shrunken
and calcified
right eye (phthisis
bulbi)
is not certain.
(Courtesy
of P. Van Tassel,
MD, Medical
University of South Carolina,
Charleston.)
(C) Axial
enhanced
CT image
of a patient
with neurofibromatosis
type 1 shows left-sided
buphthalmos
(1). There is hypoplasia
of the left greater
wing of the sphenoid
(arrows)
and abnormal
soft tissues
(arrowheads)
in the superior
orbital
fissure
su estive
of the presnt.urofihrom
L’
‘IT
‘
-I’
--
It
p.’
1
C.
. Buphthalmos
Diffuse
enlargement
of the eye in children
seeondary
to increased
intraocular
pressure
is
termed
“buphthalmos”
(from
the Greek
bous,
ox, plus ophthalnus,
eye); other
terms
for this
entity
include
hydrophthalmos
and megophthalmos.
This
is almost
uniquely
when
erally
diffuse
enlargement
seen
the sclera
is soft
occurs
secondary
during
of the
globe
childhood,
and deformable.
to congenital
It genor infan-
tile
glaucoma.
tients
the
canal
of Schlemm
or masses
dern’ial
tissue
of Schlemm
located
between
diseases
that
Sturge-Weber
Scientific
Exhibit
Normally,
may
chamber
cornea
cause
syndrome,
such
ocular
mesothe
canal
fluid)
and
for resorption
(anterior
the
by mem-
of aberrant
4a).
syndrome,
homocystinuria,
U
(Fig
in pa-
1 in whom
is obstructed
is responsible
humor
seen
type
composed
(4)
aqueous
sias
is also
neurofibromatosis
branes
torenal)
724
Buphthalmos
with
and
the
of the
iris.
buphthalmos
Lowe
is
Other
are
(cerebrohepa-
mesodermal
dyspla-
or Rieger
anomalies,
aniridia
(4), and, rarely,
as Axenfeld
Volume
14
ac-
Number
4
Figure
5. (a) Axial CT scan obtained
through
the equator
of the eyes
of a patient
with Marfan
syndrome.
The sclerae
are thinned
and have a
“wavy”
contour.
(b) Axial CT scan obtained
3 mm cephalad
to that in a
shows
superomedial
dislocation
of both lenses
(*). The
corneas
(arrowheads)
are thickened
and enlarged,
compatible
with megalocorneas.
quired
glaucoma
is usually
(Fig
to lower
creasing
4b).
The
aqueous
humor
to increase
terior
chamber
or trabeculotomy
sions.
In cases
CT
other
greater
in the
cavernous
anomalies
(Fig
In all cases
a uniformly
round,
Although
it may
glioma,
as dysplasias
globe
oval
Macrophthalmia
may
with
Marfan
Weill-Marchesani
dermal
July
childhood
when
compliant.
At imaging,
can
be
tients
the
described
with
syndrome,
syndrome
dysmorphodystrophy),
1994
be
sclera
the
triad
syndrome,
tients
with
Marfan
tients
with
homocystinuria
no
show
intraocular
globe
is usually
a bizarre
configu-
cation,
but
thought
ments
and
is often
colobomas.
seen
bodies,
myopia,
scleras,
and
Ehier-Danlos
(congenital
and
syndrome,
(in
also
have
(Fig
Patients
Sb).
Pa-
lens
dislo-
inward
(5).
have
and
disorders)
is
to poor
zonular
attach-
with
collagen
and
in pa-
both
associated
In these
may
(5)
inferior
lens
lenses
outward
also
to be secondary
Disorders
in association
syndrome
of the
of arachectopia
of the
and
globe
In pa-
and
dislocation
it is usually
Subluxation
of the
disease,
superior
regardless
and
5a).
cardiovascular
in
in
is immature
(Fig
The
studies
early
as “floppy”
superiorly
orbital
is found
contour
to occur
proptosis
globe
disorders
the
Marfan
nodactyly,
ders,
macrophthalmia
usually
bilateral.
Tissue
these
is present.
ration.
#{149}
Connective
of the
by
tends
with
have
affected
lentis
and
enlarged
or
patients
neurofibromas
imaging
the
be
adhe-
may
of buphthalmos,
anomalies,
enlarged
masses.
or the
pathway
of associated
such
anwith
images
wing,
sinuses
optic
consists
to lyse
MR
in-
of the
associated
and
sphenoidal
fissures,
4c).
and
angle
of buphthalmos
neurofibromatosis,
of the
the
by
(5). Enlargement
nunia
of surgery
pressure
transport
of a goniotomy
demonstrate
goal
intraocular
lenticular
vascular
disor-
ectopia
lentis
are
with
Marfan
syndrome
hypoplasia
of the
ptosis,
megalocorneas,
iris and
ciliary
blue
(5).
glaucoma
mesohomocysti-
Smith
and
Castillo
U
RadioGraphics
U
725
#{149}
Proteus
This
Syndrome
very
rare
anomaly
(named
after
the
Greek
sea god Proteus
[the “polymorphous”],
who
could
change
his appearance
at will) is characterized
by hamartomatous
changes
involving
mesodermal
and ectodermal
tissues
throughout
the body.
Clinical
fmdings
include
macrocrania,
and the skull has multiple
protuberances
due to
exostoses
and hyperostoses
(6). The limbs are
asymmetric,
and there
may be skin changes
(eg,
nevi, pigmented
lesions,
hyperkeratoses,
lipomas).
Clinically,
entiated
tosis
this
disorder
should
be
differ-
from
the more common
neurofibromatype
1 Orbital
abnormalities
include
large
strabismus,
myopia,
anisocoria,
microph.
eye,
thalmos,
oretinitis,
irises
cataracts,
retinal
nystagmus,
(6) (Fig 6).
U FOCAL
detachment,
and
chori-
heterochromia
of the
ENLARGEMENT
Figure
#{149}
Staphyloma
Staphylomas
may
be
isolated
or related
to axial
(7).
When
related
to axial myopia,
the
prevalence
of staphylomas
increases
with the
size of the globe.
Staphylomas
associated
with
axial myopia
generally
occur
on the temporal
myopia
side
of the
riorly
optic
or along
disk
the
7a). Staphylomas
vanced
chorioretinal
ally
due
may
also
of the
be
seen
eye
from
the
optic
disk,
and
pos-
terior
vitreous
detachments
(7). These
changes
lead to increased
prevalence
of choroidal
hemorrhage
and retinal
detachment,
which
are associated
with
a grave
prognosis
for
vision.
Cata-
racts and secondary
glaucoma
may also be seen.
In one series
(9), 139 (34.5%)
of 403 eyes with
posterior
staphylomas
were blind.
In the majority
of cases,
there
is no
effective
may be
and
infections.
Imaging
and
studies
thinning
unilateral
usually
of the
or bilateral
sclera.
(Fig
show
thalmia
is generally
housed
bit
may
to posterior
and
be
persistent
In the
presence
(microphthalmia),
misinterpreted
a focal
Staphylomas
can
be
ret-
trauma
during
childhood.
refers
plete
bony
Scientific
Exhibit
primary
early
to severe
Cryptophthal-
microphthalmia.
In com-
absence
of the globe
(anophthalmia),
the
orbit is also absent.
Hemifacial
microso-
mia
may
(Fig
8).
also
include
an ipsilateral
U SUMMARY
In children,
CT is the
choice
for evaluation
identification
which
are
eye
perative
small
eye
small
eye
a normal-sized
globe
may
microph-
be
masses,
because
ders.
In the
relation
with
result
suggestive
is diffusely
phakomatosis
diagnostic
method
of
of the large eye. CT al-
of intraocular
highly
with
also
U
or-
synor
because
726
bony
colobomas,
vitreous,
mia
hyperplastic
in a small
retinal
folds,
Lowe
therapy,
infections,
If the
7b).
Isolated
due
fibroplasia,
and radiation
lows
bulge
ENLARGEMENT
of a contralateral
as enlarged.
image
rolental
drome,
intraocular
#{149}
APPARENT
T2-weighted
treatment.
Other
conditions
in which
staphyloma
seen include
glaucoma,
trauma,
scleritis,
necrotizing
fast spin-echo
ante-
a high (77%) risk for addegeneration
that is generof the choroid
and retina,
retraction
Axial
(8) (Fig
have
to atrophy
choroid
but
equator
6.
(3,500/93
[repetition
time msec/echo
time msecj,
one excitation)
of a patient
with Proteus
syndrome.
A right-sided
staphyloma
(arrowheads)
is present.
The right eye (r) is enlarged,
whereas
the left eye (1)
is small. Note bilateral
retro-ocular
cysts (). Zones
of bone dysplasia
(*) are present.
calcifications,
of retinoblastoma.
enlarged
clinical
and
buphthalmos
and
absence
other
of systemic
intraocular
congenital
in eye
there
correlation
can
infantile
no
be seen
systemic
disor-
disorders,
pressure
and
are
is im-
cor-
is necessary
glaucoma
may
enlargement.
Volume
14
Number
4
7. (a) Axial T2-weighted
yloma (arrowheads)
in the posterior
Figure
signals
averaged)
temporal
staphyloma
four
of a patient
(arrowheads)
image (2,500/80;
two
signals
averaged)
shows
an incidentally
f’ound staphtemporal
aspect
of the right globe.
(b) Axial Ti-weighted
image
(5(X)/iS,
with glaucoma
who was examined
because
of headaches.
A right posterois present.
Figure
8.
(a) Axial
CT scan
of a patient
with
Goldenhar
dysplasia)
the right
syndrome
(oculo-auriculo-vertebral
and left facial nhicrosomia.
Although
eye appears
enlarged.
it is actually
of
normal
size. Note left-sided
microphthalmia.
(b) Frontal
view from the three-dimensional
reformation
shows
left hemifacia
that includes
the
orbit.
sional
absent
plastic
Lateral
reformation
external
mandible.
(C)
view from the three-dinienalso shows
a small left orbit,
auditory
canal,
and left hypo-
a.
July
1994
Smith
and
Castillo
U
RadioGraphics
U
727
In the adult,
diffuse
eye enlargement
is generally a manifestation
of a systemic
disorder.
Because
intraocular
masses
do not generally
cause
eye enlargement
in adults,
either
CT or MR imaging may be performed.
Focal eye enlargements
(staphyloma)
initially
imaged
with CT or
MR imaging
are local abnormalities
and do not
require
any additional
imaging.
Diffuse
eye enlargement,
however,
may be associated
with
2.
systemic
5,
illnesses
such
as connective
tissue
dis-
orders,
and clinical
correlation
is important.
Finally, in selected
cases,
imaging
should
include
not only the eyes but the entire
face to detect
hemifacial
microsomia,
which
could
lead to the
erroneous
impression
of a contralateral
enlarged
eye.
U REFERENCES
1. Mafee MF, Goldberg
Retinoblastoma
and MR imaging.
3.
4.
6.
7.
MF, Greenwald
and
simulating
Radiol
MJ, et al.
lesions:
Clin North
role
Am 1987;
of CT
25:
8.
667-682.
9.
Hopper
KD, Sherman
JL, Boal DK, Eggli K!).
CT
and MR imaging
of the pediatric
orbit.
RadioGraphics
1992;
12:485-503.
Brodey
PA, Randel
S, Lane B, Fisch AE.
Cornputed
tomography
of axial myopia.
J Comput
Assist Tomogr
1983; 7:484-485.
Castillo
M, Quencer
RM, GlaserJ,
Altman
N.
Congenital
glaucoma
and buphthalmos
in a child
with neurofibromatosis.
j Clin Neuroophthalmol
1988; 8:69-71.
Char DH, Unsold
R, Sobel DF, Salvolini
U, Newton TH.
Ocular
and orbital
pathology.
In: Newton TH, Hasso AN, Dillon WP, eds. Computed
tomography
of the head and neck.
New York,
NY: Raven, 1988; 9-15.
Taybi
H, Lachman
RS.
Proteus
syndrome.
In: Ra-
diolog’
of syndromes,
metabolic
disorders,
and
skeletal
dysplasias.
3rd ed. St Louis, Mo: Mosby,
1990; 380-381.
Swayne
LC, Garfinkle
WB, Bennett
RH.
CT of
posterior
ocular staphyloma
in axial myopia.
Neuroradiology
1984; 26:241-243.
Anderson
RL, Epstein
GA, Dauer EA.
Computed
tomographic
diagnosis
of posterior
ocular
staphyloma.
AJNR 1983; 4:90-91.
Curtin
BJ.
The posterior
staphyloma
of pathologic myopia.
Trans Am Ophthalmol
Soc 1977;
75:67-86.
728
U
Scientific
Exhibit
Volume
14
Number
4