What causes pie in the sky visual field defect?

Left Superior Homonymous Quadrantanopia: This visual defect is often referred to as pie in the sky. This visual defect happens when the inferior optic radiating fibers (Meyer’s loop) are damaged in the temporal lobe of the brain. Strokes involving the middle cerebral artery (MCA) can result in this presentation.

What causes pie on the floor visual field defect?

A superior quadrantanopia results from an insult to the optic radiation inferiorly in the temporal lobe, resulting in a ‘pie in the sky’ type of visual field defect (Figure 1d), while an inferior quadrantanopia is caused by damage to the parietal lobe optic radiation (Figure 1e).

What causes right temporal hemianopia?

What causes homonymous hemianopsia? The most common cause of this type of vision loss is stroke. However, any disorder that affects the brain — including tumors, inflammation and injuries — can be a cause.

What happens if you have a temporal lobe lesion?

Temporal lobe lesions may cause you to be unable to see one area in your field of vision (this is called a visual field defect). Your visual fields will therefore also be tested.

Where does loss of visual field lead to?

* Altitudinal (Eg. NAION) Retrochiasmal lesions produce homonymous hemianopic VF defects. Complete hemianopias can be anywhere on the retrochiasmal pathway even if they are congruous. Loss of TEMPORAL field leads to Atrophy of NASAL & TEMPORAL disc (TNT). Inferior fibres loop anteriorly and downward through the temporal lobes (Meyer loop).

How are hemianopias related to loss of temporal field?

Retrochiasmal lesions produce homonymous hemianopic VF defects. Complete hemianopias can be anywhere on the retrochiasmal pathway even if they are congruous. Loss of TEMPORAL field leads to Atrophy of NASAL & TEMPORAL disc (TNT). Inferior fibres loop anteriorly and downward through the temporal lobes (Meyer loop).

What are visual field defects and visual pathway lesions?

Lesions of the visual pathway and their respective visual field defects. The visual pathway comprises the retina, optic nerve, optic chiasm, optic radiations, and the visual centre in the occipital lobe. Optic nerve lesions tend to cause ipsilateral monocular blindness.