A case of carotid-cavernous fistula (CCF) with the classic corkscrew conjunctival vessels and mild chemosis 🧠👁. 📸 courtesy of Dr. Mangayarkarasi Thandampallayam Ajjeya Gowder (mangaikishore). . . A CCF is an abnormal communication between the venous cavernous sinus and the carotid artery. It may occur spontaneously but usually occurs following some sort of head trauma. There are four distinct types of fistulas (types A-D). A type A fistula is a direct, (high flow fistula) between the cavernous internal carotid artery and the cavernous sinus. It is the most common CCF following head trauma. The onset of symptoms with a Type A fistula is usually rapid and can be very dramatic. Patients with a direct Type A fistula generally present with varied complaints, including unilateral visual loss, proptosis, lid swelling, pulsatile tinnitus and/or diplopia. A triad of clinical findings has been described as exophthalmos, orbital bruit, and dilated conjunctival vessels. Once a direct CCF is ide...