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Ophthalmic Ultrasonography
10
A
Figure 10.12 Retinal cyst. B-scan ultrasonogram showing multiple
intraretinal macrocysts in a chronic retinal detachment.
B
Figure 10.10 Retinoschisis. B-scan transverse view demonstrates a smooth,
thin, dome shaped membrane (A, arrowhead). On A-scan a thin, 100%
single peaked spike can be seen just anterior to the retina. (B, S – sclera, V
– vitreous, R – retina).
Waheed N. Vitreoretinal Disorders. Ultrasound Clin 2008; 3(2):217–228.
Reproduced with permission from: Sharma S, Ventura ACM,
Figure 10.11 Disciform lesion. B-scan shows mildly elevated lesion in the
macular region (A, arrowheads). A-scan shows multiple highly reflective
peaks (arrows) corresponding to the lesion (B, S – sclera, V – vitreous).
Reproduced with permission from: Sharma S, Ventura ACM, Waheed N. Vitreoretinal
Disorders. Ultrasound Clin 2008; 3(2):217–228.
A
B
Figure 10.13 Retinal cysticercosis. B-scan ultrasonogram of the subretinal
cyst (A, arrow). Magnetic resonance images (T-2) of the orbits showing
involvement of the left globe with a cystic structure containing a fluid–fluid
level and an eccentric mass within the cyst (B). These findings are consistent
with a cysticercus and accompanying scolex (arrow).
permission from: Chung GW, Lai WW, Thulborn KR, et al. Magnetic resonance imaging
in the diagnosis of subretinal cysticercosis. Am J Ophthalmol 2002; 134(6):931–932.
Reproduced with
50
106
Vitreoretinal Diseases
10
Figure 10.14 Scleral buckle. B-scan showing scleral indentation
(arrowhead, B – scleral buckle). Reproduced with permission from: Sharma S,
Ventura ACM, Waheed N. Vitreoretinal Disorders. Ultrasound Clin 2008; 3(2):217–228.
MIRAgel implant
A hydrogel implant, MIRAgel implant was commonly
used for scleral buckling in the 1980s and early 1990s.
Due to its physical properties, the implant would swell
extensively over time (>10 years) causing conjunctival
bulging, limitation of ocular motility, diplopia, ocular
pain, ocular inflammation, and protrusion of the
implant.
52,53
Rarely, the swollen MIRAgel implant can
present as an orbital tumor.54 The epibulbar location of
the implant, density consistent with a scleral buckle, and
orbital shadowing allows for differentiation from an
orbital mass. The extensive swelling of the implant can
necessitate removal of the buckle which is often complicated by fragmentation of the implant on removal.
55
On ultrasonography the MIRAgel implant causes intrusion of the retina, choroid and sclera into the vitreous
cavity, similar to all scleral buckles. MIRAgel implants
have lower reflectivity than a regular buckle, but still cause
shadowing behind the implant (Figure 10.15). The
implant may also extrude through the sclera into the
vitreous cavity.
Gas/air bubbles
Intraocular gases are commonly used to assist in the
repair of retinal detachment. The high surface tension
present between gas and liquid functions to tamponade
the retina and prevent the flow of fluid into the subretinal
space from the vitreous cavity. Second, the buoyancy of
the gas bubble exerts a force on the retina and holds it
against the pigment epithelium. Various gases including
sulfur hexafluoride and perfluoropropane are preferred
over air since they maintain therapeutic size for a longer
duration of time.
Sound penetration is possible through a gas bubble
that completely fills the vitreous cavity. However, if the
Figure 10.15 MIRAgel implant. B-scan longitudinal view showing intrusion
of the retina, choroid, and very thin sclera (arrowhead). Swelling of the
buckle (M) can be seen, with associated orbital shadowing from the buckle.
Reproduced with permission from: Sharma S, Ventura ACM, Waheed N. Vitreoretinal
Disorders. Ultrasound Clin 2008; 3(2):217–228.
Figure 10.16 Intravitreal gas. B-scan longitudinal view shows probable
meniscus of gas (arrowheads). No structures are visible behind the gas
bubble due to extensive shadowing.
S, Ventura ACM, Waheed N. Vitreoretinal Disorders. Ultrasound Clin 2008; 3(2):217–228.
Reproduced with permission from: Sharma
bubble is small enough it can be moved by head position
to allow ultrasonographic evaluation of the posterior
segment (Figure 10.16).
Silicone oil
Silicone oil tamponade is utilized in lieu of gas/air
bubbles in cases of severe retinal detachment caused
by proliferative diabetic retinopathy, proliferative vitreoretinopathy, giant retinal tears, in repeat operations for
retinal detachment, and if the patient is unable to comply
with positioning requirements of gas/air bubbles.56
Silicone oil has a lower specific gravity than water and
will rise to the top of the vitreous cavity when the patient
is upright; therefore it is best suited for cases where the
107
Ophthalmic Ultrasonography
10
A B
Figure 10.17 Silicone oil. B-scan longitudinal view demonstrates echographic elongation of the vitreous cavity by silicone oil and extremely limited visibility
of posterior ocular structures (A). Normal appearance of an eye following removal of silicone oil (B). The few droplets of oil that remain in the eye are visible
as highly reflective surfaces (arrowheads, B – scleral buckle).
2008; 3(2):217–228.
Reproduced with permission from: Sharma S, Ventura ACM, Waheed N. Vitreoretinal Disorders. Ultrasound Clin
detachment/tear is located superiorly. Once stable attachment of the retina has been achieved the silicone oil
is removed, usually between 6 weeks and 3 months
postoperatively.
Silicone oil has a significantly lower sound velocity
than the vitreous resulting in significant reductions in
penetration of the ultrasound signal and limiting observation of the posterior ocular wall (Figure 10.17A). The
lower sound velocity also causes a 50% echographic elongation of the vitreous cavity.57 Secondary to these acoustic
boundaries, conventional ophthalmic B-scan is unreliable in the differential diagnosis of intraocular structures
in silicone filled globes. There is usually a small amount
of silicone oil remaining in the eye after it is removed
surgically, which on ultrasonography appear as highly
reflective echoes scattered in the vitreous cavity (Figure
10.17B
).
Retained perfluorocarbon liquids
Perfluorocarbon liquids are often used as a vitreous sub-
Figure 10.18 Retained subretinal perfluorocarbon. B-scan demonstrating
disorganized vitreous opacities and membranes with linear highly reflective
densities (arrowheads) causing orbital shadowing.
from: Sharma S, Ventura ACM, Waheed N. Vitreoretinal Disorders. Ultrasound Clin 2008;
3(2):217–228.
Reproduced with permission
stitute during vitreoretinal surgery to aid in the repair of
complicated retinal detachments due to their very high
specific gravity and ability to provide counter-traction
and retinal stabilization.58 Small amounts of perfluorocarbon liquid can be retained postoperatively due to
poor visualization of the liquid.59 Several studies have
demonstrated there is significant retinal and corneal toxicity associated with intraocular retention of perfluorocarbon liquids.
60,61
Retained perfluorocarbon liquids can be
visualized on ultrasonography as highly reflective echoes
causing shadowing of the orbit (Figure 10.18).
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Video material online
C H A P T E R
11
Intraocular Tumors
Mary E. Turell • Brandy C. Hayden • Lynn Schoenfield • Arun D. Singh
Introduction
While rare in comparison to other forms of ocular disease,
intraocular tumors in particular require precise and
accurate characterization utilizing ocular imaging techniques. Intraocular tumors comprise a heterogeneous
group ranging from benign asymptomatic lesions to
vision and life threatening malignancies. Ophthalmic
ultrasonography has long been utilized as a powerful,
non-invasive, and economical tool for characterizing and
following the clinical course of intraocular tumors.
Ophthalmic ultrasonography, in combination with computed tomography (CT), magnetic resonance imaging
(MRI), and optical coherence tomography (OCT) provide
a ready means for determining overall tumor dimensions,
configuration, location, presence of extraocular extension, and associated features such as retinal detachment
or calcification. The key in differentiating one tumor type
from another based upon ultrasonographic features lies
in the variable histopathologic compositions of each
entity. These differences can be elucidated using both
one-dimensional reflectivity analysis (A-scan) and twodimensional acoustic sectioning techniques (B-scan).
Combining information regarding reflectivity and sound
attenuation provides useful information about the acoustic internal texture of intraocular tumors. Furthermore,
ultrasonography provides an important means by which
to follow tumor progression or stability over time and is
critical in formulating management strategies. The following chapter provides a review of the ultrasonographic
and clinicopathologic features of many of the more
commonly encountered intraocular tumors seen in
ophthalmic practice.
Retinoblastoma
Retinoblastoma is the most common intraocular malignancy of childhood and occurs with a frequency of
approximately one in 14,000 to 20,000 live births.1
Ninety percent of cases are diagnosed in children under
the age of 3 years. Ultrasonography along with other
forms of imaging is invaluable in establishing the diagnosis of retinoblastoma.
Clinical features, symptoms, and signs
While leukocoria is the most common presenting
symptom of retinoblastoma, strabismus, decreased vision,
ocular inflammation, and other rarer symptoms have also
been observed.1 In general, the presentation varies with
the stage of the disease at the time of diagnosis. In its
earliest clinical stage, retinoblastoma appears as a flat
transparent to slightly whitish colored lesion in the
sensory retina. Dilated and tortuous feeding retinal vessels
may be evident. As the tumor enlarges, it loses its transparency and takes on a creamy yellow to whitish coloration with foci of chalk-like calcification. As it grows
beyond the boundary of the sensory retina, retinoblastoma will typically follow either an endophytic or exophytic growth pattern (Figure 11.1). Other growth patterns
including mixed and diffuse infiltrative forms (Figure
11.2
) are less commonly observed. Necrosis may be a
significant component of the tumor. Endophytic retinoblastomas grow from the retina inward towards the vitreous cavity. Vitreous seeding from these friable tumors as
well as anterior chamber involvement can simulate endophthalmitis and other inflammatory conditions. In contrast, exophytic retinoblastomas grow from the retina
outward into the subretinal space and can cause exudative
retinal detachment, sometimes displacing the retina
anteriorly behind the lens. Advanced retinoblastoma
can present with neovascular glaucoma, corneal edema,
spontaneous hyphema, vitreous hemorrhage, pseudohypopyon, and vitreitis.
Diagnostic evaluation
Ultrasonography is helpful in confirming the diagnosis of
retinoblastoma and in differentiating the disease from
other causes of leukocoria. This is particularly valuable
when funduscopic examination is limited in advanced
cases. On A-scan, the internal reflectivity of these lesions
varies in accordance to the degree of calcification within
the tumor. Non-calcified tumors exhibit low to medium
111
Ophthalmic Ultrasonography
11
A
C
Figure 11.1 Classic presentation of retinoblastoma. External photograph showing right-sided leukocoria (A), slit lamp photograph (B), B-scan revealing an
intraocular calcified mass (C), gross photograph of globe with retinoblastoma (D).
internal reflectivity, whereas calcified lesions demonstrate
B
D
Salient diagnostic findings
high internal reflectivity. When a significant degree of
calcification is present, shadowing of the adjacent sclera
and orbit occurs. B-scan ultrasonography typically displays a rounded or irregular intraocular mass. It should
be noted that mildly elevated and diffuse lesions have
also been reported.
2,3
Other associated ultrasonographic
findings may include retinal detachment and vitreous
opacities. When extraocular extension is present in cases
of retinoblastoma, invasion of the optic nerve is the most
The diagnosis of retinoblastoma can generally be suspected based upon the clinical findings observed in a
complete ophthalmic examination in the office or an
examination performed under anesthesia. The most commonly observed finding is an elevated intraocular mass
with characteristic calcification demonstrating either an
endophytic or exophytic growth pattern. Other causes of
intraocular calcification are listed in Box 11.1.
common route. In cases where extensive calcification is
present, tumor involvement of the optic nerve and
extraocular extension can be difficult to detect secondary
to the shadowing effect. CT and MRI imaging of the orbits
should be used in combination with ultrasonography
when optic nerve or extraocular invasion is suspected
(Figure 11.2). MRI of the optic nerve, orbits, and brain
is preferred as this modality offers superior soft tissue
resolution and avoids potentially harmful exposure to
radiation.
Differential diagnosis
There are several pediatric ocular conditions that can
cause leukocoria and should be considered in the
differential diagnosis of retinoblastoma. The conditions
that most commonly present a diagnostic challenge
include retinopathy of prematurity (ROP), persistent
fetal vasculature (PFV), Coats’ disease, toxocariasis, and
medulloepithelioma (Table 11.1).
112
Intraocular Tumors
11
A
C
Figure 11.2 Diffuse variant of retinoblastoma. External photograph demonstrating the appearance of diffuse retinoblastoma (A), B-scan ultrasonography
revealed irregularly thickened retinal detachment with vitreous cells (B). Typical features of retinoblastoma including intraocular mass and intraocular
calcification were not present. Magnetic resonance imaging confirmed enhancing thickened retina (C). Enucleated globe with diffuse infiltrating
retinoblastoma (D).
B
D
Retinopathy of prematurity
Box 11.1 Conditions associated with intraocular calcification
Retinal and retinal pigment epithelium (RPE) lesions
• Retinoblastoma
• Astrocytic hamartoma
• Chronic retinal detachment
• RPE metaplasia
• Cysticercosis
Choroidal lesions
• Choroidal osteoma
• Sclerochoroidal calcification
• Choroidal granuloma
Others
• Optic nerve head drusen
• Scleral calcification (Cogan’s plaque)
• Phthisis bulbi
ROP occurs in the setting of known risk factors including:
prematurity, low birth weight, and exposure to supplemental oxygenation in the neonatal period. While both
ROP and retinoblastoma can present with leukocoria, in
ROP the absence of the red reflex is caused by retinal
dragging toward fibrovascular tissue in the retinal
periphery. Eyes that develop retinoblastoma are usually
of normal axial length. In contrast, in ROP it is more
common for eyes to have some degree of the axial length
shortening. Additionally, ROP is typically a bilateral condition whereas retinoblastoma can be either unilateral or
bilateral. In the most advanced cases of ROP, the retina
is detached in a funnel-like configuration, resulting in a
hyper-reflective retrolental membrane on B-scan. The
peripheral retina frequently exhibits a loop or trough-like
appearance as a result of traction by the retrolental membrane (Figure 11.3).
113
Ophthalmic Ultrasonography
11
Table 11.1 Differential diagnosis of retinoblastoma.
Condition Age of presentation Risk factors Laterality Axial
length
Retinoblastoma 90% <3 years old Family history Unilateral
or bilateral
ROP Days to months after
birth
PFV Days to weeks after birth Unilateral Short Vitreous band from lens to optic nerve
Coats’ disease 4–10 years of age Male gender Unilateral Normal Exudative RD
Toxocariasis Variable Contact with dogs Unilateral Normal Peripheral mass, vitreoretinal band, traction RD
Medulloepithelioma First decade of life Unilateral Normal Ciliary body mass with cyst
USG: ultrasonography, ROP: retinopathy of prematurity, RD: retinal detachment, PFV: persistent fetal vasculature
Prematurity; oxygen
supplementation
Bilateral Short RD with retinal bands
Normal Intraretinal/subretinal mass with calcification
USG
Subretinal hyper-reflective particles
Figure 11.3 Retinopathy of prematurity. Longitudinal B-scan demonstrates
a highly reflective, closed funnel-shaped retinal detachment (arrows)
inserting into the disk.
AD. Intraocular tumors. Ultrasound Clin 2008; 3:229–244.
Reproduced with permission from: Fu EX, Hayden BC, Singh
Persistent fetal vasculature
PFV, formerly known as persistent hyperplastic primary
vitreous (PHPV), is a congenital condition that usually
presents during the first few days to weeks of life. In contrast, retinoblastoma typically presents months to years
after birth. In nearly all cases, PFV is a unilateral condition that occurs in association with a number of other
congenital ocular anomalies including: microphthalmos,
a shallow or flat anterior chamber, a hypoplastic iris with
prominent blood vessels, and a retrolental fibrovascular
mass that causes the ciliary body processes to rotate
inwards. On ophthalmic examination, a stalk-like structure connecting the optic nerve to the posterior lens
capsule may be visualized. Ultrasonography can be used
to confirm the diagnosis. On B-scan, persistent hyaloid
remnants arising from the optic nerve are observed. The
vitreous band may be extremely thin, and its entire course
may not be visualized. Some vitreous bands can be
A
B
Figure 11.4 Persistent fetal vasculature (PFV). Fundus photograph (A).
Longitudinal B-scan demonstrates taut, thickened vitreous band adherent to
the slightly elevated optic disc (B, arrow).
EX, Hayden BC, Singh AD. Intraocular tumors. Ultrasound Clin 2008; 3:229–244.
Reproduced with permission from: Fu
extremely thick simulating a tightly closed, funnel-shaped
retinal detachment.
The lens is often thin with irregularities in the posterior
capsule (Figure 11.4). Eyes usually have some degree
of axial length shortening. Calcification may be present,
114
11
however in contrast to retinoblastoma, there is no discrete
mass visualized clinically or with ultrasonography.
Coats’ disease
Coats’ disease is a retinal vascular disorder characterized
by telangiectasia, intraretinal exudation, and exudative
retinal detachment. Although Coats’ disease can present
at any age, it usually is diagnosed in young males between
4 and 10 years of age.4 It is most commonly a unilateral
disease process. In the early stages of Coats’ disease, localized, shallow retinal detachments may occur. In more
advanced cases, total exudative detachments secondary to
leakage from aneurysmal blood vessels are observed. This
exudative process results in yellow cholesterol crystal
deposition in the subretinal space that can be observed
clinically as refractile bodies. These particles are much less
reflective than the calcium particles in retinoblastoma.
Ultrasonography is helpful in differentiating the two entities, in that in retinoblastoma a distinct tumor can be
detected beneath the retinal detachment, whereas no distinct mass is seen in Coats’ disease (Figure 11.5).
Intraocular Tumors
A
Toxocariasis
Toxocariasis is caused by ocular infestation by Toxocara
canis. It typically occurs in older children with a history
of soil ingestion or exposure to dogs. Clinically, ocular
toxocariasis may present as a large retinal inflammatory
mass with diffuse vitreitis. The appearance can simulate
endophytic retinoblastoma, or if ocular toxocariasis
presents with a solitary subretinal granuloma with little
vitreous inflammation, the lesion can resemble exophytic
retinoblastoma. In toxocariasis, the chorioretinal mass is
most commonly located in the peripheral fundus and
produce vitreoretinal bands that can extend to the optic
disc. Contraction of these vitreoretinal membranes result
in tractional retinal detachment. In contrast, tractional
retinal detachments are extremely rare in retinoblastoma.
Ultrasonography is useful in differentiating the two diseases, because vitreous traction bands and tractional
retinal folds or detachments are characteristic of ocular
toxocariasis. Additionally, the calcification which would
be expected to be seen in retinoblastoma is absent in
ocular toxocariasis.
Medulloepithelioma
Medulloepithelioma is a congenital neuroepithelial
tumor that typically manifests during the first decade of
life. It most commonly arises from the ciliary body,
however involvement of the iris and optic nerve has also
been reported.
appears as a lightly pigmented or amelanotic cystic mass.
Large cysts may break off from the main tumor and float
5–10
On ophthalmic examination, the tumor
B
C
Figure 11.5 Coats’ disease. Clinical photograph showing lipid exudation
(A). B-scan demonstrating exudative retinal detachment (B, arrow) and
vitreous band (B, arrowhead) and A-scan with high internal reflectivity (C).
freely in the anterior chamber or vitreous cavity. Because
of their appearance and because medulloepithelioma
may present with leukocoria, these tumors are an
important consideration in the differential diagnosis
of retinoblastoma. A-scan of medulloepithelioma shows
mainly high internal reflectivity with a medium spike
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