Carotid-cavernous fistula (CCF) is an abnormal communication between thearterial and venous system which occurs within the cavernous sinus an categorized according to pathological, hemodynamic or angiographic criteria.1,2 Th rare condition mostly occurs after head trauma.1,2 In angiography, lesions that directly receive their flow from the internal carotid artery (ICA) (direct type of CCF) are high-flow, and those that receive their flow from dural branches of the internal or external carotid system (indirect type) are usually

low-flow fistulae.1 The size, duration, location, venous drainage pattern and collateral vascular anatomy are very important factors for the clinical manifestations. Venous drainage from the anterior region into the ophthalmic veins or posterior into the petrosal sinuses causes different symptoms in patients.1 In cases that fistula drainage takes place into the inferior petrosal sinus, the orbital sign and symptoms are less severe.3-6 The clinical manifestations are usually unilateral and ipsilateral and are often vague at the onset of occurrence.7-9 Clinical manifestations are proptosis, exophthalmia, bruit, frontal headache and orbital pain, chemosis, extraocular palsy and diplopia, loss of visual acuity, 5th cranial nerve involvement and epistaxis.10,11 The 'gold standard' method for the diagnosis of CCF is cerebral angiography which is useful in identifying the fistula, evaluating venous drainage and assessing collateral circulation.12,13 To our knowledge, there is no report of blindness without exophthalmia as the presentation of CCF in the literature or the failure of CT- angiography and MRI evaluation for the diagnosis of CCF. We report a very rar case of CCF that presented with unilateral blindnes