This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Visual field defect in pituitary tumour with suprasellar extension is: 
Select and explain. 
A. Visual field defect in pituitary tumour with suprasellar extension is:, B. Binasal hemianopia, C. Homonymous hemianopia, D. Pie in the sky vision
A: Visual field defect in pituitary tumour with suprasellar extension is:
Answer: A: Visual field defect in pituitary tumour with suprasellar extension is: 
Explanation: A chiasmatic lesion (often owing to a pituitary tumor or a lesion around the sella turcica) can injure the decussating axons of retinal ganglion cells within the optic chiasm. These axons originate in the nasal halves of the two retinas. Thus, this type of lesion produces bitemporal hemianopsia, characterized by blindness in the lateral or temporal half of the visual field for each eye. Ref: Waxman S.G. (2010). Chapter 15. The Visual System. In S.G. Waxman (Ed), Clinical Neuroanatomy, 26e.