<prompt> AION is seen in which of the following conditionsChronic simple glaucomaGaint cell aeritisChronic iridocyclitisSarcoidosis  <response>: ANTERIOR ISCHAEMIC OPTIC NEUROPATHYAION refers to ischaemic damage to the optic nerve head from occlusion of the sho posterior ciliary aeries. It is of two types : Aeretic AION - results from inflammatory and thrombotic occlusion of sho posterior ciliary aeries caused by Giant Cell Aeritis GCA , usually occurs in older patients mean age 70 yrs and accounts for only 5-10 cases of AION. Non aeretic AION - accounts for 90 - 95 cases of AION. Exact etiology of occlusion of posterior ciliary aeries causing infarction of the retrolaminar poion of the disc is not known. Risk factors include cataract surgery , HTN, diabetes , drugs sildenafil. Ref: khurana 6th edition page no.318 