COT Ocular Motility Testing 2 — Questions and Answers
Question 1: During the alternate cover test, the examiner notes that the uncovered eye moves inward when the cover is removed. This finding indicates:
- Esophoria
- Exophoria (Correct answer)
- Hyperphoria
- Orthophoria
Correct answer: Exophoria
When the uncovered eye moves inward (nasally), it was deviated outward under the cover, indicating exophoria.
Question 2: The Hirschberg corneal light reflex test estimates approximately how many prism diopters of deviation per millimeter of decentration?
- 7 PD per mm
- 15 PD per mm
- 22 PD per mm (Correct answer)
- 30 PD per mm
Correct answer: 22 PD per mm
The Hirschberg test estimates approximately 22 prism diopters of deviation per millimeter the light reflex is decentered from the corneal center.
Question 3: Which muscle is the primary abductor of the eye?
- Medial rectus
- Lateral rectus (Correct answer)
- Superior oblique
- Inferior oblique
Correct answer: Lateral rectus
The lateral rectus muscle is the primary abductor, moving the eye outward (temporally).
Question 4: A patient with a left superior oblique palsy would show the greatest vertical deviation in which gaze position?
- Left gaze and depression
- Right gaze and depression (Correct answer)
- Left gaze and elevation
- Right gaze and elevation
Correct answer: Right gaze and depression
The left superior oblique is most active in depression and adduction (right gaze for a left eye), so the deviation is greatest in right gaze and depression.
Question 5: The Maddox rod test is primarily used to detect:
- Amblyopia
- Suppression
- Heterophoria (Correct answer)
- Cyclotropia
Correct answer: Heterophoria
The Maddox rod dissociates the two eyes to reveal a latent deviation (heterophoria) that is normally controlled by fusion.
Question 6: In a patient with a right lateral rectus palsy, the face turn would most likely be toward which direction?
- Left
- Right (Correct answer)
- Up
- Down
Correct answer: Right
Patients with a right lateral rectus palsy turn their face to the right to place the paretic muscle out of its field of action, reducing diplopia.
Question 7: The duction test measures:
- Binocular alignment
- Monocular range of movement (Correct answer)
- Fusional vergence amplitudes
- Stereoacuity at near
Correct answer: Monocular range of movement
Duction testing assesses the monocular range of eye movement with the fellow eye occluded.
COT Ocular Motility Testing 2
During the alternate cover test, the examiner notes that the uncovered eye moves inward when the cover is removed.
This finding indicates: