Anatomy and physiology of the eye: acquired colour vision defect: practice question

A Ophthalmology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Ophthalmology · Anatomy and physiology of the eye: acquired colour vision defect

Sample item

A 28-year-old woman with painful loss of vision in one eye and a relative afferent pupillary defect also notes that red objects look washed out. Which pattern of colour defect is typical of her condition?

AComplete achromatopsiaBNormal colour perceptionCRed-green dyschromatopsiaDBlue-yellow dyschromatopsia

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Red-green dyschromatopsia

Optic nerve disorders such as optic neuritis typically cause red-green defects with red desaturation, whereas outer retinal and many macular disorders cause blue-yellow defects (Kollner rule). Glaucoma and dominant optic atrophy are well-known exceptions.

Option by option

A. Complete achromatopsia
Complete achromatopsia is a congenital cone disorder with poor acuity and nystagmus.
B. Normal colour perception
Colour perception is usually clearly abnormal in optic neuritis.
C. Red-green dyschromatopsia (correct)
Correct. Optic neuritis characteristically produces red-green loss with red desaturation.
D. Blue-yellow dyschromatopsia
Blue-yellow loss is the usual pattern in outer retinal and macular disease.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is C, Red-green dyschromatopsia. Optic nerve disorders such as optic neuritis typically cause red-green defects with red desaturation, whereas outer retinal and many macular disorders cause blue-yellow defects (Kollner rule).

Why is "Complete achromatopsia" not the answer?

Complete achromatopsia is a congenital cone disorder with poor acuity and nystagmus.

Why is "Normal colour perception" not the answer?

Colour perception is usually clearly abnormal in optic neuritis.

Why is "Blue-yellow dyschromatopsia" not the answer?

Blue-yellow loss is the usual pattern in outer retinal and macular disease.

What concept does this question test?

It tests Anatomy and physiology of the eye: acquired colour vision defect in Ophthalmology. Glaucoma and dominant optic atrophy are well-known exceptions.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Anatomy and physiology of the eye: acquired colour vision defect?

Group the red eye by what to examine and what the pupil does. Then use the flashcards and the other Ophthalmology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.