Retina: cilioretinal artery and artery occlusion: 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.

Try it

Ophthalmology · Retina: cilioretinal artery and artery occlusion

Sample item

A 60-year-old man has sudden loss of vision in one eye from central retinal artery occlusion. Despite a diffusely pale retina, a tongue of normal-coloured retina and good central vision persists between the disc and the macula. What explains this?

APreserved supply from the long posterior ciliary artery to the retinaBA cilioretinal artery supplied from the choroidal circulationCCollateral flow from the vortex veinsDUnusually thick retinal pigment epithelium

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

The answer and the reasoning

B. A cilioretinal artery supplied from the choroidal circulation

About a fifth of eyes have a cilioretinal artery arising from the ciliary circulation, which is independent of the central retinal artery. When the central artery is blocked, the territory supplied by this vessel stays perfused and the macula may be spared. Visual acuity can then remain good.

Option by option

A. Preserved supply from the long posterior ciliary artery to the retina
The long posterior ciliary arteries supply the anterior segment and are not the source of this sparing.
B. A cilioretinal artery supplied from the choroidal circulation (correct)
Correct. A cilioretinal artery from the ciliary circulation keeps its territory perfused.
C. Collateral flow from the vortex veins
The vortex veins drain the choroid and do not supply the inner retina.
D. Unusually thick retinal pigment epithelium
The pigment epithelium does not alter perfusion of the inner retina.

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 B, A cilioretinal artery supplied from the choroidal circulation. About a fifth of eyes have a cilioretinal artery arising from the ciliary circulation, which is independent of the central retinal artery.

Why is "Preserved supply from the long posterior ciliary artery to the retina" not the answer?

The long posterior ciliary arteries supply the anterior segment and are not the source of this sparing.

Why is "Collateral flow from the vortex veins" not the answer?

The vortex veins drain the choroid and do not supply the inner retina.

Why is "Unusually thick retinal pigment epithelium" not the answer?

The pigment epithelium does not alter perfusion of the inner retina.

What concept does this question test?

It tests Retina: cilioretinal artery and artery occlusion in Ophthalmology. When the central artery is blocked, the territory supplied by this vessel stays perfused and the macula may be spared. Visual acuity can then remain good.

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 Retina: cilioretinal artery and artery occlusion?

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.