<prompt> Features of carotid-cavernous fistula includeDilated superior ophthalmic vein on CT scanBlood in the Schlemms canalProptosis of contralateral eye suggests bilateral carotid-cavernous fistulaTraumatic fistula rarely close spontaneously  <response>: With anterior drainage through orbit carotid cavernous fistula produce proptosis, diplopia, glaucoma and corkscrew, aerialized conjunctival vessels carotid-cavernous fistula results from an abnormal communication between the aerial and venous systems within the cavernous sinus in the skull. It is a type of aeriovenous fistula Ref Harrison20th edition pg 2567 