About Visual fields

 A patient presents with a bilateral homonymous quadranopsia involving the right upper visual field. Which of the following represents the MOST likely anatomic location of the abnormality?

• (A) Prechiasmal, right side
• (B) Optic chiasm
• (C) Postchiasmal, prethalamic, left side
• (D) Occipital lobe, right side
• (E) Occipital lobe, left side

The answer is E.

Homonymous visual field cuts imply a postchiasmal location of the abnormality because this is the first point where fibers from the same visual field of both eyes join. Fibers further divide between the thalamus and occipital lobe into upper and lower quadrant visual fields. The most common location for quadranopsia defects is the occiptal lobe. Stroke, tumor, and atypical migraine may present with quadranopsia.
Visual fields are named from the perspective of the patient, i.e., the right visual field corresponds to the left side of the retina. Therefore, a right-sided visual field cut involves the left-sided neurologic tracks.