Cornea: marginal keratitis: 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 · Cornea: marginal keratitis

Sample item

A patient with staphylococcal blepharitis has peripheral corneal infiltrates separated from the limbus by a clear zone. What is the mechanism?

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

The answer and the reasoning

C. Hypersensitivity to staphylococcal exotoxins

Marginal keratitis is an immune reaction to staphylococcal antigens, with antibody-antigen complexes deposited where limbal vessels meet the cornea. Treatment is lid hygiene and a short course of topical steroid.

Option by option

  • A. Vitamin A deficiency

    Vitamin A deficiency causes xerosis and keratomalacia.

  • B. Direct fungal invasion

    Fungal invasion would give feathery ulcers.

  • C. Hypersensitivity to staphylococcal exotoxins (correct)

    Correct. It is an immune hypersensitivity reaction.

  • D. Viral latency

    Viral latency causes herpetic 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.

More Ophthalmology questions

Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is C, Hypersensitivity to staphylococcal exotoxins. Marginal keratitis is an immune reaction to staphylococcal antigens, with antibody-antigen complexes deposited where limbal vessels meet the cornea.

Why is "Vitamin A deficiency" not the answer?

Vitamin A deficiency causes xerosis and keratomalacia.

Why is "Direct fungal invasion" not the answer?

Fungal invasion would give feathery ulcers.

Why is "Viral latency" not the answer?

Viral latency causes herpetic disease.

What concept does this question test?

It tests Cornea: marginal keratitis in Ophthalmology. Treatment is lid hygiene and a short course of topical steroid.

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 Cornea: marginal keratitis?

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.