This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of the Optic Nerve, Subject name: Ophthalmology
Which amongst the following is associated with Altitudinal visual field defect: 
Select and explain. 
A. Optic neuritis, B. AION (Anterior Ischemic Optic Neuropathy), C. Intracranial tumor, D. Papillitis
B: AION (Anterior Ischemic Optic Neuropathy)
Answer: B: AION (Anterior Ischemic Optic Neuropathy) 
Explanation: Ans. (b) AION (Anterior Ischemic Optic Neuropathy)Ref: Harrison's 19th ed. / 202* Anterior Ischemic Optic Neuropathy refers to a segmental or generalized infarction of anterior part of the optic nerve* It occurs due to occlusion of the short posterior ciliary arteries* Visual field defects show typically altitudinal hemianopia involving the inferior (commonly) or superior half.