Question 10 of 14

(demo test)

Product Demo for Part II Questions

Pituitary masses classically result in what combination of visual field defects?

A. Bilateral mostly superotemporal deficits respecting the vertical midline but extending to a complete bitemporal hemianopia late in the disease course

B. Central visual loss in one eye with a superotemporal deficit in the contralateral eye

C. A bitemporal hemianopic type defect of the central 5-10 degrees only

D. Bilateral mostly inferotemporal deficits respecting the vertical midline but extending to a complete bitemporal hemianopia late in the disease course

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Category:

Optic Nerve / Neuro-Ophthalmic Pathways

Topic:

Clinical Presentation

High Yield:

No

Your Answer:

U

Correct Answer:

A

Explanation:

Pituitary masses classically compress the middle portion of the inferior optic chiasm.  The retinal ganglion cell axons first compromised by such compression would be the inferonasal fibers supplying the superotemporal visual fieldsin both eyes.  With increasing compression, more fibers become involved and the deficits may progress to a complete hemianopia.

Please see the image below to help you visualize how enlargement of the pituituary gland (red structure) first affects the inferior portion of the optic chiasm.

(Image credit:  Wikimedia Commons; http://commons.wikimedia.org)

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