Low-flow carotid-cavernous fistula associated with cavernous sinus thrombosis: An ophthalmic presentation.

A 70-year-old woman presented with 20 days of painless left-sided proptosis and ocular discomfort, without infectious symptoms. Examination revealed conjunctival chemosis and hyperemia, painless proptosis, ocular hypertension (intraocular pressure, 35mmHg), and mild limitation of abduction and elevation. Contrast-enhanced computed tomography and venous computed tomography angiography demonstrated left cavernous sinus thrombosis with proptosis and dilation of the superior ophthalmic vein. Dynamic magnetic resonance angiography suggested a low-flow carotid-cavernous fistula with partial cavernous sinus thrombosis and orbital venous hypertension. Orbital ultrasonography showed an arterialized superior ophthalmic vein with reversed flow. Conservative management with topical hypotensive agents and oral acetazolamide resulted in progressive clinical improvement. The 4-month follow-up magnetic resonance imaging demonstrated complete spontaneous resolution of the fistula and orbital venous congestion, with full clinical recovery.