Ischemic optic neuropathy in internal carotid artery dissection – A rare clinical presentation

Abstract

Ischaemic optic neuropathy is defined as an infarction of the retrolaminar part of optic nerve. This is caused due to hypoperfusion of optic disc leading to short posterior artery occlusion. Giant cell arteritis assumes first and foremost importance as a prominent cause of anterior ischaemic optic neuropathy. Carotid artery dissection is an uncommon aetiological factor. Carotid artery dissection presents with a constellation of ocular features like Horner’s syndrome, amaurosis fugax, hemianopia, sixth cranial nerve palsy and ischaemic optic neuropathy. Ischaemic optic neuropathy has been reported in patients who suffered from dissection of carotid artery and it could be a preliminary manifestation. Suspicion of internal carotid artery (ICA) dissection should be raised in cases of anterior ischaemic optic neuropathy (AION) associated with severe unilateral cephalic pain. Dissection of carotid artery can cause cerebral and retinal ischaemia, especially in young adults, resulting in ischaemic symptoms. An array of investigations were performed to eliminate other triggers of optic neuropathy. Carotid Doppler helps to confirm the diagnosis. This article highlights a patient with a rare presentation of anterior ischaemic optic neuropathy resulting from dissection of internal carotid artery. A high index of suspicion should be entertained by symptoms like severe unilateral headache followed by diminution of vision. Prompt diagnosis and management can prevent visual loss in the fellow eye as well as life threatening complications of ICA dissection such as stroke. Keywords: Anterior ischaemic optic neuropathy, Dissection of internal carotid artery.