CO Neuro-Ophthalmic Disorders & Visual Function Testing 3 — Questions and Answers
Question 1: A 70-year-old presents with sudden painless vision loss in one eye described as a 'curtain coming down.' The most likely diagnosis is:
- Central retinal vein occlusion
- Anterior ischemic optic neuropathy
- Central retinal artery occlusion (Correct answer)
- Optic neuritis
Correct answer: Central retinal artery occlusion
Sudden, painless, profound unilateral vision loss like a descending curtain is classic for central retinal artery occlusion.
Question 2: The Pulfrich phenomenon is a visual illusion resulting from:
- Binocular color rivalry
- Asymmetric optic nerve conduction velocity causing stereoscopic depth illusion (Correct answer)
- Monocular diplopia from lens changes
- Oscillopsia from nystagmus
Correct answer: Asymmetric optic nerve conduction velocity causing stereoscopic depth illusion
The Pulfrich phenomenon occurs when asymmetric optic nerve conduction (e.g., from optic neuritis) causes a pendulum to appear to swing in an ellipse.
Question 3: Which pattern of optic disc appearance is expected in a patient with longstanding increased intracranial pressure?
- Disc pallor with cupping
- Bilateral disc edema (papilledema) (Correct answer)
- Tilted discs
- Morning glory disc anomaly
Correct answer: Bilateral disc edema (papilledema)
Papilledema—bilateral optic disc swelling—is the hallmark of raised intracranial pressure transmitted along the optic nerve sheaths.
Question 4: The Humphrey 24-2 visual field test uses a grid of test points separated by:
- 1 degree
- 3 degrees
- 6 degrees (Correct answer)
- 10 degrees
Correct answer: 6 degrees
The Humphrey 24-2 test pattern places test points on a 6-degree grid within the central 24 degrees of the visual field.
Question 5: Foster Kennedy syndrome consists of:
- Bilateral papilledema with bilateral central scotomas
- Ipsilateral optic atrophy and contralateral papilledema from a frontal mass (Correct answer)
- Bilateral optic atrophy with absent pupillary reflexes
- Unilateral papilledema with a contralateral CN VI palsy
Correct answer: Ipsilateral optic atrophy and contralateral papilledema from a frontal mass
Foster Kennedy syndrome is caused by a frontal lobe or olfactory groove mass that directly compresses the ipsilateral optic nerve (causing atrophy) while raising ICP (causing contralateral papilledema).
Question 6: In testing color vision with Ishihara plates, which type of color deficiency is most commonly detected?
- Tritanopia (blue-yellow)
- Acquired optic nerve disease
- Protan and deutan (red-green) deficiencies (Correct answer)
- Achromatopsia
Correct answer: Protan and deutan (red-green) deficiencies
Ishihara plates are specifically designed to detect congenital red-green color deficiencies (protan and deutan types).
Question 7: A patient with myasthenia gravis is most likely to show which ocular motility pattern?
- Fixed, symmetric esotropia
- Pupil-involving ptosis and ophthalmoplegia
- Variable ptosis and ocular misalignment that worsens with fatigue (Correct answer)
- Internuclear ophthalmoplegia
Correct answer: Variable ptosis and ocular misalignment that worsens with fatigue
Myasthenia gravis causes fatigable ptosis and variable ocular motility deficits that worsen with sustained effort due to acetylcholine receptor antibodies.
CO Neuro-Ophthalmic Disorders & Visual Function Testing 3
A 70-year-old presents with sudden painless vision loss in one eye described as a 'curtain coming down.' The most likely diagnosis is: