CO Neuro-Ophthalmic Disorders & Visual Function Testing 2 — Questions and Answers
Question 1: A patient with a right homonymous hemianopia has damage in which location?
- Right optic nerve
- Optic chiasm
- Left optic tract or cortex (Correct answer)
- Right lateral geniculate nucleus
Correct answer: Left optic tract or cortex
Right homonymous hemianopia results from a lesion of the left visual pathway posterior to the chiasm (optic tract, LGN, or cortex).
Question 2: Which cranial nerve palsy causes an eye that is 'down and out' with a dilated, non-reactive pupil?
- CN IV palsy
- CN VI palsy
- CN III palsy (Correct answer)
- Horner syndrome
Correct answer: CN III palsy
A complete CN III palsy causes ptosis, an eye deviated down and out, and a dilated non-reactive pupil due to parasympathetic involvement.
Question 3: The swinging flashlight test is primarily used to detect which condition?
- Accommodative esotropia
- Relative afferent pupillary defect (RAPD) (Correct answer)
- Horner syndrome
- Argyll Robertson pupil
Correct answer: Relative afferent pupillary defect (RAPD)
The swinging flashlight test reveals an RAPD by comparing the consensual and direct responses between the two eyes.
Question 4: In internuclear ophthalmoplegia (INO), which eye movement finding is characteristic?
- Ipsilateral abduction failure with nystagmus of the adducting eye
- Failure of adduction ipsilateral to the lesion with nystagmus of the abducting eye (Correct answer)
- Bilateral gaze palsy
- Alternating skew deviation
Correct answer: Failure of adduction ipsilateral to the lesion with nystagmus of the abducting eye
INO is characterized by impaired adduction of the eye ipsilateral to the MLF lesion and nystagmus of the abducting (contralateral) eye.
Question 5: A bitemporal hemianopia with a central scotoma in one eye suggests which lesion?
- Lateral geniculate body lesion
- Occipital lobe infarction
- Junctional scotoma from anterior chiasmal lesion (Correct answer)
- Dorsal midbrain syndrome
Correct answer: Junctional scotoma from anterior chiasmal lesion
A junctional scotoma (one central scotoma + contralateral superior temporal defect) indicates a lesion at the junction of the optic nerve and chiasm.
Question 6: Which visual field defect pattern is most consistent with an occipital lobe lesion?
- Altitudinal defect
- Congruous homonymous hemianopia with macular sparing (Correct answer)
- Nasal step
- Centrocecal scotoma
Correct answer: Congruous homonymous hemianopia with macular sparing
Occipital lobe lesions produce highly congruous homonymous hemianopias, often with macular sparing due to the dual blood supply of the occipital pole.
Question 7: Parinaud syndrome (dorsal midbrain syndrome) is characterized by all of the following EXCEPT:
- Light-near dissociation
- Convergence-retraction nystagmus
- Paralysis of upgaze
- Absence of the pupillary light reflex with a large, reactive pupil (Correct answer)
Correct answer: Absence of the pupillary light reflex with a large, reactive pupil
In Parinaud syndrome, pupils are mid-dilated with light-near dissociation (react to near, not light) and upgaze palsy; pupils are not large and reactive.
CO Neuro-Ophthalmic Disorders & Visual Function Testing 2
A patient with a right homonymous hemianopia has damage in which location?