Master Visual Field Defects - Left Upper Quadrantic Anopia with Picmonic for Medicine

This anopia consists a partial loss of vision in both eyes.

A quarter of the same visual field is lost in the superior portion of each eye, giving the vision loss an appearance of a slice of “pie in the sky.”

Meyer's loop is the ventral part of the pathway that carries information to the visual cortex. It wraps around the inferior horn of the lateral ventricle. Lesion of the loop on one side leads to vision loss in the contralateral upper quarters of both eyes.

The temporal lobe houses Meyer’s loop and lesions of the right loop leads to left upper quadrantic anopia. Traumatic injuries to the right temporal lobe are a common cause.

Meyer’s loop runs from the lateral geniculate nucleus to the primary visual cortex. The middle cerebral artery supplies the LGN, and an infarct in this artery would lead to ischemia of the LGN. Ischemia of the right LGN can cause a lesion of the right pathway and consequently left upper quadrantic anopia.