AOC Clinical Procedures and Protocols 2 — Questions and Answers
Question 1: During the cover-uncover test, the examiner observes the uncovered eye to detect which type of deviation?
- Heterophoria
- Heterotropia (Correct answer)
- Anisometropia
- Amblyopia
Correct answer: Heterotropia
The cover-uncover test reveals heterotropia (manifest strabismus) by observing movement of the uncovered eye when the fellow eye is covered.
Question 2: What is the primary purpose of performing the alternate cover test (ACT)?
- Measure visual acuity
- Detect total deviation including phoria and tropia (Correct answer)
- Assess fusion amplitude
- Evaluate color vision
Correct answer: Detect total deviation including phoria and tropia
The alternate cover test dissociates fusion and reveals the total deviation, which includes both the phoric and tropic components.
Question 3: When using prism bars to measure a strabismic deviation, the prism is placed before which eye?
- The dominant eye only
- The deviating eye only
- Either eye, as results are equivalent by Prentice's rule (Correct answer)
- The eye with better acuity
Correct answer: Either eye, as results are equivalent by Prentice's rule
By the principle of equivalence (Prentice's rule), placing prisms before either eye yields the same measurement of the deviation.
Question 4: A patient with a left esotropia of 30 PD is being measured with prism and alternate cover test. Where is the apex of the neutralizing prism directed?
- Nasally (base out)
- Temporally (base in) (Correct answer)
- Superiorly (base down)
- Inferiorly (base up)
Correct answer: Temporally (base in)
To neutralize an esotropia, a base-in prism (apex temporal) is used, as the eye is deviated inward and the prism must redirect the visual axis.
Question 5: The Hirschberg test estimates the angle of strabismus based on the position of which clinical finding?
- The visual axis reflex
- The corneal light reflex (Correct answer)
- The red reflex
- The optic disc center
Correct answer: The corneal light reflex
The Hirschberg test uses the position of the corneal light reflex relative to the pupil center to estimate the angle of deviation.
Question 6: When performing a Worth 4-Dot test at near, a patient reports seeing two red dots only. This result indicates:
- Normal binocular single vision
- Left suppression
- Right suppression (Correct answer)
- Diplopia
Correct answer: Right suppression
Seeing only two red dots indicates suppression of the left eye, since the left eye views the green dots through the green lens filter.
Question 7: The Krimsky test is best described as a modification of which procedure?
- Maddox rod testing
- Hirschberg test using prisms (Correct answer)
- Synoptophore measurement
- Brückner transillumination
Correct answer: Hirschberg test using prisms
The Krimsky test modifies the Hirschberg technique by placing prisms before the fixating eye to center the corneal light reflex in the deviating eye.
AOC Clinical Procedures and Protocols 2
During the cover-uncover test, the examiner observes the uncovered eye to detect which type of deviation?