AOC Patient Assessment and Evaluation 2 — Questions and Answers
Question 1: When performing the Hirschberg corneal reflex test, a reflex displaced 1 mm temporal to center on the right eye corresponds to approximately how many prism diopters of esotropia?
- 7 prism diopters
- 15 prism diopters (Correct answer)
- 22 prism diopters
- 30 prism diopters
Correct answer: 15 prism diopters
Each 1 mm of corneal reflex displacement corresponds to approximately 15 prism diopters of deviation.
Question 2: Which test best differentiates a true fusion response from monocular cues in a patient with suspected monofixation syndrome?
- Bagolini striated lens test
- Worth 4-dot test at distance
- 4-prism diopter base-out test (Correct answer)
- Titmus stereo test
Correct answer: 4-prism diopter base-out test
The 4 prism diopter base-out test detects the small scotoma characteristic of monofixation syndrome by assessing whether the eye makes a fusional vergence movement.
Question 3: A child's cycloplegic refraction shows +4.00 D OD and +0.50 D OS. This significant anisometropia places the child at risk primarily for:
- Convergence insufficiency
- Anisometropic amblyopia (Correct answer)
- Accommodative esotropia
- Intermittent exotropia
Correct answer: Anisometropic amblyopia
Anisometropia of 1.50 D or more is a leading cause of amblyopia due to unequal retinal image quality between the two eyes.
Question 4: During a sensory evaluation, a patient with longstanding esotropia reports diplopia only after the deviation is surgically corrected. This phenomenon is best described as:
- Suppression scotoma
- Anomalous retinal correspondence
- Paradoxical diplopia (Correct answer)
- Horror fusionis
Correct answer: Paradoxical diplopia
Paradoxical diplopia occurs after strabismus surgery when a patient who previously suppressed suddenly experiences diplopia because the sensory adaptation has not resolved.
Question 5: The Lancaster red-green test is most useful in assessing patients with:
- Childhood-onset comitant strabismus
- Amblyopia with eccentric fixation
- Incomitant strabismus with normal retinal correspondence (Correct answer)
- Intermittent exotropia with microtropia
Correct answer: Incomitant strabismus with normal retinal correspondence
The Lancaster test requires normal retinal correspondence and is ideal for incomitant deviations such as paralytic strabismus, plotting the field of binocular single vision.
Question 6: When recording a prism and cover test measurement, a notation of '25 PD ET at distance, 18 PD ET at near' most likely suggests:
- Convergence excess esotropia
- Convergence insufficiency
- Divergence excess esotropia (Correct answer)
- Basic esotropia
Correct answer: Divergence excess esotropia
Divergence excess is characterized by a larger deviation at distance than at near, indicating the distance deviation exceeds the near deviation.
Question 7: When evaluating ocular motility, which finding is most consistent with a left superior oblique palsy?
- Left hypotropia worse in right gaze
- Left hypertropia worse in right gaze with excyclotorsion (Correct answer)
- Left hypertropia worse in left gaze with incyclotorsion
- Left hypotropia worse in down gaze
Correct answer: Left hypertropia worse in right gaze with excyclotorsion
A left superior oblique palsy produces a left hypertropia that increases in right gaze (contralateral field) and in left head tilt, often with subjective excyclotorsion.
AOC Patient Assessment and Evaluation 2
When performing the Hirschberg corneal reflex test, a reflex displaced 1 mm temporal to center on the right eye corresponds to approximately how many prism diopters of esotropia?