What is the typical appearance of the optic disc in the equine fundus?

• A. Pink and circular
• B. Red and oval
• C. Blue and square
• D. White and triangular

Answer: (A)

The main idea is that the optic disc in the equine fundus is pink and round. The optic disc is the exit point of retinal nerve fibers as the optic nerve enters the eye, and in horses its margins are well defined and its color is a pale pink due to the exposure of nerve tissue with underlying choroidal blood supply. This combination—pink, circular appearance—is the typical description you’ll see for an equine optic disc. The other descriptions don’t fit normal anatomy: a blue or white color isn’t characteristic, and a triangular or highly elongated shape isn’t how the disc usually presents.