CDOS Exam Exam Questions & Answers With Complete
Solutions
0.75mm Correct Answers minimum elevation of a lesion
above the retina and choroid to be detected with ultrasound but
ciliary body lesions will need to be even more elevated to be
detected
2mm Correct Answers height required for accurate
quantification of a lesion
4 positions to evaluate the macula Correct Answers 1.
Horizontal axial
2. Vertical transverse
3. Longitudinal
4. Vertical macula
A scan technique for RD vs PVD Correct Answers 1.Find
membrane posteriorly (100% spike)
2.Shift the probe so as to trace the membrane to its insertion
point in the periphery
3.Typically a PVD's reflectance will diminish in the periphery
and retinal will stay at 100%
acoustic hollowing Correct Answers significant internal sound
attenuation of a tumor that can produce orbital shadowing
posterior to the lesion or within it
aftermovement Correct Answers the motion of the lesion
echoes before, during, and immediately after an eye movement
,air bubbles Correct Answers focal, pointlike echo sources that
are highly reflective and appear similar to true foreign bodies
angle of sound incidence Correct Answers the angle at which
the sound beam strikes an interface
appositional choroidal detachment Correct Answers 2 large
bullous choroidal detachments that touch each other (kissing
choroidals)
Arteritic ischemic optic neuropathy (AION) Correct Answers
Insufficient blood flow to the optic nerve head resulting in a lack
of oxygen and subsequent infarction of (loss of) the nerve fibers
and loss of vision. B scan shows thickened sclera and long
scleral canals
asteroid hyalosis Correct Answers bright pointlike echoes that
may be diffuse or focal with an area of clear vitreous present
between posterior boundary of opacities and the posterior
hyaloid (present even when the hyaloid is attached)
atrophic retina Correct Answers may exhibit reflecitivity and
mobility patterns more similar to PVD
avulsion of the optic nerve Correct Answers occurs when the
optic nerve is forcibly disinserted from the
retina/choroid/vitreous and the lamina cribosa is retracted from
the scleral rim. Usually produces a hypoechoic defect in the
optic nerve and widening of the retrobulbar space. proliferative
membranes may develop later and cause the insertion of the
optic nerve to appear atypical
, basal dimensions of a tumor Correct Answers use transverse
and longitudinal dimensions. most accurate when there are
defined margins; when they have tapered edges are indistinct
bscan can be inaccurate.
Blunt trauma Correct Answers can produce marked, sudden
distortion of the globe
calcium in tumors Correct Answers most often associated with
retinoblastoma but can appear with other tumors such as
angiomas, astrocytic hamartomas, melanoma, or hemangioma.
cataractous lens Correct Answers has internal reflectivity
choroidal detachment Correct Answers usually occur in the
periphal aspects of the eye but can extend posteriorly and
usually involve the ciliary body. On bscan they are smooth,
thick, dome shaped membranes with little to no aftermovement
and insert adjacent to the optic nerve but not directly into it. can
be hemorrhagic or serous.
choroidal detachment A scan Correct Answers thick, steeply
rising 100% spike that may be double peaked with low gain
choroidal detachment in aphakic eye or limbal rupture Correct
Answers highly elevated and dome shaped choroidals that may
adhere centrally
choroidal edema Correct Answers produced by inlammation,
vascular congestion, and hypotony causing the choroid to be
Solutions
0.75mm Correct Answers minimum elevation of a lesion
above the retina and choroid to be detected with ultrasound but
ciliary body lesions will need to be even more elevated to be
detected
2mm Correct Answers height required for accurate
quantification of a lesion
4 positions to evaluate the macula Correct Answers 1.
Horizontal axial
2. Vertical transverse
3. Longitudinal
4. Vertical macula
A scan technique for RD vs PVD Correct Answers 1.Find
membrane posteriorly (100% spike)
2.Shift the probe so as to trace the membrane to its insertion
point in the periphery
3.Typically a PVD's reflectance will diminish in the periphery
and retinal will stay at 100%
acoustic hollowing Correct Answers significant internal sound
attenuation of a tumor that can produce orbital shadowing
posterior to the lesion or within it
aftermovement Correct Answers the motion of the lesion
echoes before, during, and immediately after an eye movement
,air bubbles Correct Answers focal, pointlike echo sources that
are highly reflective and appear similar to true foreign bodies
angle of sound incidence Correct Answers the angle at which
the sound beam strikes an interface
appositional choroidal detachment Correct Answers 2 large
bullous choroidal detachments that touch each other (kissing
choroidals)
Arteritic ischemic optic neuropathy (AION) Correct Answers
Insufficient blood flow to the optic nerve head resulting in a lack
of oxygen and subsequent infarction of (loss of) the nerve fibers
and loss of vision. B scan shows thickened sclera and long
scleral canals
asteroid hyalosis Correct Answers bright pointlike echoes that
may be diffuse or focal with an area of clear vitreous present
between posterior boundary of opacities and the posterior
hyaloid (present even when the hyaloid is attached)
atrophic retina Correct Answers may exhibit reflecitivity and
mobility patterns more similar to PVD
avulsion of the optic nerve Correct Answers occurs when the
optic nerve is forcibly disinserted from the
retina/choroid/vitreous and the lamina cribosa is retracted from
the scleral rim. Usually produces a hypoechoic defect in the
optic nerve and widening of the retrobulbar space. proliferative
membranes may develop later and cause the insertion of the
optic nerve to appear atypical
, basal dimensions of a tumor Correct Answers use transverse
and longitudinal dimensions. most accurate when there are
defined margins; when they have tapered edges are indistinct
bscan can be inaccurate.
Blunt trauma Correct Answers can produce marked, sudden
distortion of the globe
calcium in tumors Correct Answers most often associated with
retinoblastoma but can appear with other tumors such as
angiomas, astrocytic hamartomas, melanoma, or hemangioma.
cataractous lens Correct Answers has internal reflectivity
choroidal detachment Correct Answers usually occur in the
periphal aspects of the eye but can extend posteriorly and
usually involve the ciliary body. On bscan they are smooth,
thick, dome shaped membranes with little to no aftermovement
and insert adjacent to the optic nerve but not directly into it. can
be hemorrhagic or serous.
choroidal detachment A scan Correct Answers thick, steeply
rising 100% spike that may be double peaked with low gain
choroidal detachment in aphakic eye or limbal rupture Correct
Answers highly elevated and dome shaped choroidals that may
adhere centrally
choroidal edema Correct Answers produced by inlammation,
vascular congestion, and hypotony causing the choroid to be
