CERTIFIED OPHTHALMIC ASSISTANT
(COA) ADVANCED PROFICIENCY TEST
1 QUESTIONS AND ANSWERS
1. Which of the following layers of the cornea is responsible for maintaining the correct
hydration level through an active pump mechanism?
A. Bowman’s membrane
B. Endothelium
C. Stroma
D. Epithelium
Answer: B
Conceptual Explanation: The corneal endothelium contains metabolic pumps that
regulate the water content of the stroma to maintain corneal transparency.
2. A patient with a history of narrow angles is administered a mydriatic agent. What is the
most significant immediate risk?
A. Retinal detachment
B. Acute angle-closure glaucoma
,C. Cystoid macular edema
D. Corneal abrasion
Answer: B
Conceptual Explanation: Dilating a patient with narrow angles can cause the iris to bunch
up in the drainage angle, leading to a sudden spike in intraocular pressure.
3. Which visual field defect is most characteristic of a lesion at the optic chiasm, such as a
pituitary tumor?
A. Homonymous hemianopsia
B. Bitemporal hemianopsia
C. Arcuate scotoma
D. Central scotoma
Answer: B
Conceptual Explanation: A lesion at the optic chiasm interrupts the crossing nasal fibers,
resulting in loss of the temporal visual fields in both eyes.
4. What is the primary action of the Superior Oblique muscle?
A. Intorsion
B. Adduction
C. Elevation
, D. Extorsion
Answer: A
Conceptual Explanation: The superior oblique primarily intorts the eye, while also acting
to depress and abduct the globe.
5. In the context of ophthalmic pharmacology, what is the role of a ‘miotic’ drug?
A. To dilate the pupil
B. To constrict the pupil
C. To paralyze the ciliary muscle
D. To treat bacterial infection
Answer: B
Conceptual Explanation: Miotics, such as pilocarpine, cause the pupil to constrict by
stimulating the sphincter muscle of the iris.
6. Which tonometry method is considered the ‘gold standard’ for measuring intraocular
pressure but is most affected by corneal thickness?
A. Goldmann applanation tonometry
B. Tono-Pen
C. Pneumotonometry
D. Schiotz tonometry
(COA) ADVANCED PROFICIENCY TEST
1 QUESTIONS AND ANSWERS
1. Which of the following layers of the cornea is responsible for maintaining the correct
hydration level through an active pump mechanism?
A. Bowman’s membrane
B. Endothelium
C. Stroma
D. Epithelium
Answer: B
Conceptual Explanation: The corneal endothelium contains metabolic pumps that
regulate the water content of the stroma to maintain corneal transparency.
2. A patient with a history of narrow angles is administered a mydriatic agent. What is the
most significant immediate risk?
A. Retinal detachment
B. Acute angle-closure glaucoma
,C. Cystoid macular edema
D. Corneal abrasion
Answer: B
Conceptual Explanation: Dilating a patient with narrow angles can cause the iris to bunch
up in the drainage angle, leading to a sudden spike in intraocular pressure.
3. Which visual field defect is most characteristic of a lesion at the optic chiasm, such as a
pituitary tumor?
A. Homonymous hemianopsia
B. Bitemporal hemianopsia
C. Arcuate scotoma
D. Central scotoma
Answer: B
Conceptual Explanation: A lesion at the optic chiasm interrupts the crossing nasal fibers,
resulting in loss of the temporal visual fields in both eyes.
4. What is the primary action of the Superior Oblique muscle?
A. Intorsion
B. Adduction
C. Elevation
, D. Extorsion
Answer: A
Conceptual Explanation: The superior oblique primarily intorts the eye, while also acting
to depress and abduct the globe.
5. In the context of ophthalmic pharmacology, what is the role of a ‘miotic’ drug?
A. To dilate the pupil
B. To constrict the pupil
C. To paralyze the ciliary muscle
D. To treat bacterial infection
Answer: B
Conceptual Explanation: Miotics, such as pilocarpine, cause the pupil to constrict by
stimulating the sphincter muscle of the iris.
6. Which tonometry method is considered the ‘gold standard’ for measuring intraocular
pressure but is most affected by corneal thickness?
A. Goldmann applanation tonometry
B. Tono-Pen
C. Pneumotonometry
D. Schiotz tonometry
