A 45-year-old woman has slowly progressive painless visual loss in the right eye over two years. Fundoscopy shows a pale, mildly swollen optic disc with prominent retinochoroidal collateral (optociliary shunt) vessels. MRI is most likely to show:

• A Enlarged optic nerve sheaths with empty delta sign of the cavernous sinus
• B An enhancing extra-axial mass at the tuberculum sellae
• C Periventricular white matter demyelinating plaques
• D An enhancing mass around the intraorbital optic nerve with tram-track sign ✓

Explanation

Optociliary shunt vessels divert venous blood from the retinal circulation to the choroid when the central retinal vein outflow is chronically obstructed, classically by an optic nerve sheath meningioma. On MRI this gives circumferential optic nerve enhancement with the tram-track appearance after contrast. D tuberculum sellae meningioma would cause chiasmal compression with bitemporal loss and no shunt vessels, making option B the strongest distractor.

Reference: Kanski's Clinical Ophthalmology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.