COA - Certified Ophthalmic Assistant Ocular Motility and Alignment Questions and Answers 1 — Questions and Answers
Question 1: A patient's left eye turns inward toward their nose when the right eye is covered. What is the term for this misalignment?
- Exotropia
- Esotropia (Correct answer)
- Hypertropia
- Hypotropia
Correct answer: Esotropia
Esotropia is the term for an inward turning of the eye. Exotropia is an outward turning, while hypertropia and hypotropia refer to vertical misalignments (upward and downward, respectively).
Question 2: Which cranial nerve is responsible for innervating the lateral rectus muscle, which abducts the eye?
- Cranial Nerve III (Oculomotor)
- Cranial Nerve IV (Trochlear)
- Cranial Nerve VI (Abducens) (Correct answer)
- Cranial Nerve V (Trigeminal)
Correct answer: Cranial Nerve VI (Abducens)
Cranial Nerve VI, the abducens nerve, innervates the lateral rectus muscle. Its function is to abduct the eye (move it outward). Cranial Nerve III (Oculomotor) innervates the majority of the other extraocular muscles, and Cranial Nerve IV (Trochlear) innervates the superior oblique muscle.
Question 3: During a cover-uncover test, the examiner notes that the uncovered eye moves outward to pick up fixation when the other eye is covered. This movement is only observed during the test. This finding is indicative of a(n):
- Esotropia
- Exophoria
- Esophoria (Correct answer)
- Exotropia
Correct answer: Esophoria
A phoria is a latent deviation that is only present when binocular vision is interrupted, such as by covering an eye. Since the eye was turned inward (eso-) under the cover and moves outward to fixate when uncovered, this indicates an esophoria. A tropia is a manifest deviation that is always present.
Question 4: Which of the following tests is used to evaluate ocular alignment by observing the location of the corneal light reflex?
- Cover-Uncover Test
- Worth 4-Dot Test
- Titmus Test
- Hirschberg Test (Correct answer)
Correct answer: Hirschberg Test
The Hirschberg test assesses ocular alignment by observing the reflection of a light source on the corneas. In a properly aligned patient, the reflection should be centered in both pupils. An asymmetric reflex indicates a possible strabismus.
Question 5: To best isolate and evaluate the action of the right superior rectus muscle, in which of the six cardinal positions of gaze should the patient be directed to look?
- Up and to the left
- Straight up
- Down and to the right
- Up and to the right (Correct answer)
Correct answer: Up and to the right
The six cardinal positions of gaze are used to isolate the primary action of specific extraocular muscles. To test the right superior rectus, the eye must first be abducted (turned out). Therefore, having the patient look up and to the right isolates the elevating action of the right superior rectus muscle.
Question 6: A 5-year-old child presents for an eye exam. The ophthalmic assistant observes that the child's right eye is deviated upwards compared to the left eye. This condition is best described as a:
- Right Exotropia
- Right Hypertropia (Correct answer)
- Left Hypotropia
- Left Esotropia
Correct answer: Right Hypertropia
Hypertropia refers to a vertical misalignment where one eye is deviated upward relative to the other. Since the right eye is higher, it is termed a right hypertropia. Alternatively, this could be described as a left hypotropia (the left eye being lower), but Right Hypertropia is the more direct description based on the observation.
COA - Certified Ophthalmic Assistant Ocular Motility and Alignment Questions and Answers 1
A patient's left eye turns inward toward their nose when the right eye is covered.
What is the term for this misalignment?