Pulsatile Proptosis, Secondary to Carotid Cavernous Sinus Fistula-A Case Report

Aetiology behind unilateral proptosis can run from benign to life-threatening condition. Carotico Cavernous Sinus Fistula (CCF) is abnormal communication between Internal Carotid Artery (ICA) alone or its branches and cavernous sinus. This was a case of a 32-year-old woman presented with unilateral proptosis, diminution of vision in right eye, diplopia and unilateral headache towards right side. On ocular examination, right eye had pulsating proptosis, severe chemosis, relative afferent papillary defect, restricted ocular movements in all gazes and left eye was normal. There was no history of trauma, hypertension, diabetes mellitus, cardiovascular abnormality. Common causes of unilateral proptosis are carotid cavernous sinus fistula, orbital pseudotumour, orbital cellulitis, cavernous sinus thrombosis, or intraorbital neoplasms. Radiological investigations like Computed Tomography (CT)/Magnetic Resonance Imaging (MRI) imaging and CT/MR Angiography (MRA) is necessary to rule out the cause for proptosis. Patient presented to Ophthalmology Outpatient Department (OPD) with concern of reduced vision, redness and proptosis. Hence, MRA was advised to this patient which was suggestive of right ICA- cavernous sinus fistula. Cavernous sinus fistula can be traumatic or spontaneous and delay in diagnosis may lead to poor visual outcome.