AOC Patient Assessment and Evaluation 3 — Questions and Answers
Question 1: What is the primary purpose of performing a cycloplegic refraction in children compared to a manifest refraction?
- To measure the actual working distance of the patient
- To eliminate the effect of accommodation on the refractive measurement (Correct answer)
- To assess the amplitude of accommodation
- To determine the add power for bifocals
Correct answer: To eliminate the effect of accommodation on the refractive measurement
Cycloplegia paralyzes the ciliary muscle, preventing accommodation and revealing the full latent hyperopia that would otherwise be masked.
Question 2: A 7-year-old presents with a right esotropia. The alternate cover test shows a greater deviation than the unilateral cover test. This difference indicates the presence of:
- Convergence spasm
- Fusional convergence controlling part of the deviation (Correct answer)
- Divergence excess
- Monofixation syndrome
Correct answer: Fusional convergence controlling part of the deviation
The difference between the alternate cover test (total deviation) and the unilateral cover test (manifest deviation) reflects the amount of fusional vergence holding the eyes aligned.
Question 3: In assessing a child for amblyopia, the crowding phenomenon refers to:
- Better visual acuity with isolated optotypes than with line charts
- Reduced visual acuity when targets are surrounded by contours (Correct answer)
- Overcrowding of fixation targets during near vision testing
- Inability to identify letters when presented rapidly
Correct answer: Reduced visual acuity when targets are surrounded by contours
Crowding phenomenon in amblyopia describes reduced visual acuity when optotypes are surrounded by closely spaced contours, making line acuity worse than single-letter acuity.
Question 4: The Randot Preschool Stereoacuity test is preferred over the Titmus fly test for young children primarily because:
- It uses larger stereoscopic targets easier to hold
- It eliminates monocular cues that allow guessing (Correct answer)
- It tests a wider range of stereoacuity levels
- It requires no polarized glasses
Correct answer: It eliminates monocular cues that allow guessing
The Randot test uses random-dot patterns that eliminate monocular contour cues, providing a purer measure of stereopsis compared to the contour-based Titmus fly.
Question 5: During sensorimotor evaluation, the Maddox rod test is MOST useful for measuring:
- Magnitude of a tropia in primary position
- Phoria by dissociating binocular fusion (Correct answer)
- Stereoacuity at near fixation
- Suppression depth in strabismic patients
Correct answer: Phoria by dissociating binocular fusion
The Maddox rod dissociates the eyes by converting one eye's point light source into a streak, allowing measurement of the underlying phoria.
Question 6: Which finding on the Hess screen test suggests a right lateral rectus palsy?
- Underaction in the left field of the left eye
- Contraction of the right field of the right eye with expansion of the left field (Correct answer)
- Symmetric fields with central displacement only
- Expansion of the right field of the right eye
Correct answer: Contraction of the right field of the right eye with expansion of the left field
In a right lateral rectus palsy, the right eye shows a contracted field (underaction in abduction), while the left eye compensates with an expanded field due to Hering's law.
Question 7: A patient with a left cranial nerve III palsy would be expected to show which combination of findings?
- Left exotropia, ptosis, and mydriasis (Correct answer)
- Left esotropia, ptosis, and miosis
- Left hypotropia, ptosis, and normal pupil
- Left exotropia, normal lid, and mydriasis
Correct answer: Left exotropia, ptosis, and mydriasis
CN III innervates the medial rectus, superior rectus, inferior rectus, inferior oblique, levator palpebrae, and pupillary sphincter; palsy causes exotropia (lateral rectus unopposed), ptosis, and mydriasis.
AOC Patient Assessment and Evaluation 3
What is the primary purpose of performing a cycloplegic refraction in children compared to a manifest refraction?