Glaucoma · practice question
Diagnosis: [READINESS SEED] An adult woman has slowly progressive visual loss with…
[READINESS SEED] An adult woman has slowly progressive visual loss with optic atrophy, and abnormal vessels are seen on the optic disc that shunt blood to the retinal circulation. Imaging shows tram-track calcification around the nerve. What is the most likely diagnosis?
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Answer: A. Optic nerve sheath meningioma
Progressive visual loss with optic atrophy and optociliary shunt vessels — the Hoyt-Spencer triad — plus tram-track calcification around the nerve is an optic nerve sheath meningioma, arising from arachnoid cap cells of the nerve sheath, typically in a middle-aged woman. The shunt vessels form as the tumor obstructs the normal venous (central retinal) drainage; other causes of optociliary shunts can be recalled as "MOP'IGS" (Meningioma, Optic-nerve glioma, Papilledema, chronic central retinal vein/Occlusion, Idiopathic, Glaucoma, Sphenoid-wing lesions). A dural tail on MRI reflects reactive or invasive change in adjacent dura and is not the site of tumor origin.
Clinical pearl: The classic triad — visual loss, optic atrophy, and optociliary shunt vessels — is present in as few as 25%, so its absence does not exclude the tumor; a documented growing meningioma is managed with fractionated radiotherapy, since surgery risks blindness.