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Certified Diagnostic Ophthalmic Sonographer (CDOS)
Exam | Latest Verified Questions and Detailed Answers
OVERVIEW DESCRIPTION
This comprehensive set of multiple-choice questions is designed for the Certified
Diagnostic Ophthalmic Sonographer (CDOS) exam, an advanced specialty credential
administered by the International Joint Commission on Allied Health Personnel in
Ophthalmology (IJCAHPO). The questions are organized according to the exam’s job
task analysis content outline, covering pathology, examination techniques, ultrasound
physics, anatomy and physiology of the eye and orbit, biometry, and instrumentation.
They assess the ability to safely and accurately perform specialized B-scan ultrasound
examinations and biometry, with a strong emphasis on identifying vitreoretinal,
choroidal, optic nerve, and orbital disorders; applying proper scanning protocols;
understanding ultrasound physics and safety; and maintaining diagnostic equipment.
Pathology
QUESTION 1
A 65-year-old patient presents with sudden onset of flashes and floaters. B-scan
ultrasonography reveals a thin, continuous, moderately reflective membrane that
undulates with eye movement and inserts at the optic nerve head and ora serrata. What
is the most likely diagnosis?
A. Posterior vitreous detachment
B. Rhegmatogenous retinal detachment
C. Exudative retinal detachment
D. Vitreous hemorrhage
CORRECT ANSWER: B
EXPERT RATIONALE: A rhegmatogenous retinal detachment appears as a mobile,
continuous membrane with insertion at the optic disc and ora serrata; posterior vitreous
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detachment does not anchor at the optic nerve. Undulating movement with eye motion
is a classic dynamic finding.
QUESTION 2
Which B-scan feature best differentiates a tractional retinal detachment from a
rhegmatogenous detachment?
A. After-movement of the membrane
B. Insertion into the optic nerve head
C. Convex shape with a narrow base and tented configuration
D. High reflectivity on A-scan overlay
CORRECT ANSWER: C
EXPERT RATIONALE: Tractional detachments exhibit a concave or tented shape due to
vitreoretinal traction bands, often with a narrow base. Rhegmatogenous detachments
are typically mobile and convex with insertion at the disc.
QUESTION 3
A patient with diabetes has a vitreous hemorrhage. B-scan shows a moderately
reflective, thick membrane with restricted motion that connects to fibrovascular stalks at
the posterior pole. What is the most probable underlying pathology?
A. Posterior vitreous detachment
B. Tractional retinal detachment
C. Retinoschisis
D. Choroidal melanoma
CORRECT ANSWER: B
EXPERT RATIONALE: Diabetic tractional detachment appears as a thick, tethered
membrane anchored by fibrovascular proliferations, showing reduced mobility and a
concave configuration.
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QUESTION 4
Which echographic characteristic is most suggestive of an exudative retinal detachment?
A. Kissing configuration in a V-shape
B. Shifting fluid with gravity-dependent position change
C. Hyperechoic membrane fixed at the optic disc
D. Absence of subretinal fluid on kinetic B-scan
CORRECT ANSWER: B
EXPERT RATIONALE: Exudative detachments show shifting subretinal fluid that moves
with patient positioning; they lack a retinal break and the membrane is smooth and
non-mobile.
QUESTION 5
A patient has a dome-shaped, choroidal mass with a smooth surface, medium-to-low
internal reflectivity on A-scan, and an excavated base on B-scan. These findings are most
consistent with:
A. Choroidal hemangioma
B. Choroidal melanoma
C. Metastatic choroidal tumor
D. Choroidal nevus
CORRECT ANSWER: B
EXPERT RATIONALE: Choroidal melanoma typically appears as a dome or mushroom-
shaped mass with low to medium internal reflectivity and choroidal excavation, whereas
hemangioma shows high internal reflectivity.
QUESTION 6
Which of the following is a characteristic B-scan feature of a choroidal hemangioma?
A. Mushroom shape with collar button
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B. High internal reflectivity with a smooth, dome-shaped elevation
C. Irregular surface with calcified plaques
D. Retinal detachment with homogeneous subretinal echoes
CORRECT ANSWER: B
EXPERT RATIONALE: Choroidal hemangiomas are typically dome-shaped, echodense
masses with high internal reflectivity due to numerous blood-filled channels, and they
lack choroidal excavation.
QUESTION 7
A patient with known lung cancer presents with decreased vision. B-scan reveals a
shallow, irregular, and moderately reflective choroidal lesion with associated serous
retinal detachment. What is the most likely diagnosis?
A. Choroidal osteoma
B. Choroidal metastasis
C. Melanoma
D. Choroidal nevus
CORRECT ANSWER: B
EXPERT RATIONALE: Choroidal metastases are typically flat, irregular, moderately
reflective lesions often accompanied by serous retinal detachment; history of primary
malignancy is key.
QUESTION 8
On B-scan, a “collar button” shaped mass is observed protruding through Bruch’s
membrane. This pathognomonic shape is most often associated with:
A. Choroidal hemangioma
B. Choroidal melanoma
C. Retinoblastoma
Certified Diagnostic Ophthalmic Sonographer (CDOS)
Exam | Latest Verified Questions and Detailed Answers
OVERVIEW DESCRIPTION
This comprehensive set of multiple-choice questions is designed for the Certified
Diagnostic Ophthalmic Sonographer (CDOS) exam, an advanced specialty credential
administered by the International Joint Commission on Allied Health Personnel in
Ophthalmology (IJCAHPO). The questions are organized according to the exam’s job
task analysis content outline, covering pathology, examination techniques, ultrasound
physics, anatomy and physiology of the eye and orbit, biometry, and instrumentation.
They assess the ability to safely and accurately perform specialized B-scan ultrasound
examinations and biometry, with a strong emphasis on identifying vitreoretinal,
choroidal, optic nerve, and orbital disorders; applying proper scanning protocols;
understanding ultrasound physics and safety; and maintaining diagnostic equipment.
Pathology
QUESTION 1
A 65-year-old patient presents with sudden onset of flashes and floaters. B-scan
ultrasonography reveals a thin, continuous, moderately reflective membrane that
undulates with eye movement and inserts at the optic nerve head and ora serrata. What
is the most likely diagnosis?
A. Posterior vitreous detachment
B. Rhegmatogenous retinal detachment
C. Exudative retinal detachment
D. Vitreous hemorrhage
CORRECT ANSWER: B
EXPERT RATIONALE: A rhegmatogenous retinal detachment appears as a mobile,
continuous membrane with insertion at the optic disc and ora serrata; posterior vitreous
,2|Page
detachment does not anchor at the optic nerve. Undulating movement with eye motion
is a classic dynamic finding.
QUESTION 2
Which B-scan feature best differentiates a tractional retinal detachment from a
rhegmatogenous detachment?
A. After-movement of the membrane
B. Insertion into the optic nerve head
C. Convex shape with a narrow base and tented configuration
D. High reflectivity on A-scan overlay
CORRECT ANSWER: C
EXPERT RATIONALE: Tractional detachments exhibit a concave or tented shape due to
vitreoretinal traction bands, often with a narrow base. Rhegmatogenous detachments
are typically mobile and convex with insertion at the disc.
QUESTION 3
A patient with diabetes has a vitreous hemorrhage. B-scan shows a moderately
reflective, thick membrane with restricted motion that connects to fibrovascular stalks at
the posterior pole. What is the most probable underlying pathology?
A. Posterior vitreous detachment
B. Tractional retinal detachment
C. Retinoschisis
D. Choroidal melanoma
CORRECT ANSWER: B
EXPERT RATIONALE: Diabetic tractional detachment appears as a thick, tethered
membrane anchored by fibrovascular proliferations, showing reduced mobility and a
concave configuration.
,3|Page
QUESTION 4
Which echographic characteristic is most suggestive of an exudative retinal detachment?
A. Kissing configuration in a V-shape
B. Shifting fluid with gravity-dependent position change
C. Hyperechoic membrane fixed at the optic disc
D. Absence of subretinal fluid on kinetic B-scan
CORRECT ANSWER: B
EXPERT RATIONALE: Exudative detachments show shifting subretinal fluid that moves
with patient positioning; they lack a retinal break and the membrane is smooth and
non-mobile.
QUESTION 5
A patient has a dome-shaped, choroidal mass with a smooth surface, medium-to-low
internal reflectivity on A-scan, and an excavated base on B-scan. These findings are most
consistent with:
A. Choroidal hemangioma
B. Choroidal melanoma
C. Metastatic choroidal tumor
D. Choroidal nevus
CORRECT ANSWER: B
EXPERT RATIONALE: Choroidal melanoma typically appears as a dome or mushroom-
shaped mass with low to medium internal reflectivity and choroidal excavation, whereas
hemangioma shows high internal reflectivity.
QUESTION 6
Which of the following is a characteristic B-scan feature of a choroidal hemangioma?
A. Mushroom shape with collar button
, 4|Page
B. High internal reflectivity with a smooth, dome-shaped elevation
C. Irregular surface with calcified plaques
D. Retinal detachment with homogeneous subretinal echoes
CORRECT ANSWER: B
EXPERT RATIONALE: Choroidal hemangiomas are typically dome-shaped, echodense
masses with high internal reflectivity due to numerous blood-filled channels, and they
lack choroidal excavation.
QUESTION 7
A patient with known lung cancer presents with decreased vision. B-scan reveals a
shallow, irregular, and moderately reflective choroidal lesion with associated serous
retinal detachment. What is the most likely diagnosis?
A. Choroidal osteoma
B. Choroidal metastasis
C. Melanoma
D. Choroidal nevus
CORRECT ANSWER: B
EXPERT RATIONALE: Choroidal metastases are typically flat, irregular, moderately
reflective lesions often accompanied by serous retinal detachment; history of primary
malignancy is key.
QUESTION 8
On B-scan, a “collar button” shaped mass is observed protruding through Bruch’s
membrane. This pathognomonic shape is most often associated with:
A. Choroidal hemangioma
B. Choroidal melanoma
C. Retinoblastoma
