Carotid cavernous sinus fistula presenting with pulsating exophthalmos and secondary glaucoma

Carotid cavernous sinus fistula is abnormal communications between the carotid arterial system and the venous cavernous sinus. Carotid cavernous sinus fistula can develop either because of trauma or spontaneous causes. Spontaneous carotid cavernous sinus fistula is often associated with a pre-existing aneurysm in the intracavernous portion of internal carotid artery. However, these fistulas may be congenital arteriovenous connections that open spontaneously in the settings of collagen vascular disease, atherosclerosis, hypertension, or may develop in females during peripartum period. A case of spontaneous carotid cavernous sinus fistula in a young adult male who presented with pulsating exophthalmos and secondary glaucoma is presented. Characteristic features of arteriovenous fistula--bruit, thrill, corkscrew episcleral vessels were present. Radiological investigations were done to confirm the diagnosis. Transvenous embolisation was done to close the fistula.