<prompt> Anterior ischaemic optic neuropathy is characterized by:Centrocaecal scotomaAltitudinal hemianopiaRing scotomaIncreased blood supply  <response>: Altitudinal hemianopia 335-Parson 20thAnterior ischaemic optic neuropathy AION - refers to the segmental or generalized infarction of anterior part of the optic nerve.Clinical features - Visual loss is usually marked and sudden Pale or hyperaemic disc, with splinter haemorrhage Visual field shows typical altitudinal hemianopia. Confirmation of the diagnosis - Temporal artery biopsy Annular or ring shaped scotoma are seen in Retinitis pigmentosa. 