Neuro-ophthalmology and pupils: traumatic optic neuropathy: 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 · Neuro-ophthalmology and pupils: traumatic optic neuropathy

Sample item

An unconscious man after a road accident with a brow injury has a normal-looking fundus. Which sign most strongly suggests an indirect optic nerve injury?

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

The answer and the reasoning

B. Relative afferent pupillary defect

In traumatic optic neuropathy the disc appears normal at first, and pallor develops after weeks. An afferent pupillary defect is the key early sign, especially when the patient cannot be tested for vision. Proptosis and ptosis point to orbital or third nerve injury.

Option by option

  • A. Disc pallor on first examination

    Disc pallor appears only weeks later.

  • B. Relative afferent pupillary defect (correct)

    Correct. A relative afferent defect shows optic nerve dysfunction when the disc looks normal.

  • C. Ptosis

    Ptosis suggests a third nerve or levator injury.

  • D. Proptosis

    Proptosis suggests orbital haemorrhage or fracture, not the nerve injury itself.

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.

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Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is B, Relative afferent pupillary defect. In traumatic optic neuropathy the disc appears normal at first, and pallor develops after weeks.

Why is "Disc pallor on first examination" not the answer?

Disc pallor appears only weeks later.

Why is "Ptosis" not the answer?

Ptosis suggests a third nerve or levator injury.

Why is "Proptosis" not the answer?

Proptosis suggests orbital haemorrhage or fracture, not the nerve injury itself.

What concept does this question test?

It tests Neuro-ophthalmology and pupils: traumatic optic neuropathy in Ophthalmology. An afferent pupillary defect is the key early sign, especially when the patient cannot be tested for vision. Proptosis and ptosis point to orbital or third nerve injury.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Neuro-ophthalmology and pupils: traumatic optic neuropathy?

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.