Altitudinal visual field defect is seen in ?

Ans. is 'c' i.e., Anterior ischemic neuropathy Anterior ischemic optic neuropathv (AION) It is a condition of local anoxia of the anterior region of the optic nerve. It is due to the involvement of posterior ciliary aery and may be central retinal aery causing infarct of the anterior pa of the optic nerve and retina. It occurs commonly in neglected acute attack of closed angle glaucoma, severe anemia, after a massive haemorrhage, and temporal aeritis. There is sudden loss of vision. On examination there is swelling of the disc resulting in optic atrophy. Permanent altitudinal visual field defects are present. These involve two quadrants of either the superior or inferior visual field.