Venous stasis retinopathy in the right eye associated with a right carotid-cavernous sinus fistula
D. Order cerebral angiography
The differential diagnosis for CME with IRHs includes retinal vein occlusion, microvascular disease (eg, diabetic retinopathy, radiation retinopathy), hyperviscosity syndrome (eg, plasma cell dyscrasias), and orbital diseases resulting in impaired venous outflow. This patient initially presented elsewhere with eye redness and decreased vision in the right eye, but by the time she presented to our institution, there was greater evidence of inadequate venous outflow (ie, unilateral proptosis, corkscrew vessels extending to the limbus, blood in Schlemm canal, IRHs, and CME). These findings can classically result from venous congestion (eg, thyroid eye disease, retrobulbar mass), arteriovenous fistulization (eg, carotid cavernous sinus fistula [CCF], Sturge-Weber syndrome), or an idiopathic disease (eg, Radius-Maumenee syndrome).1 The patient’s neuroimaging was unrevealing, but given the strong clinical suspicion for CCF, a cerebral angiogram was obtained, which revealed an indirect CCF supplied by dural branches of the right cavernous internal carotid artery. Cerebral angiography is considered to be the diagnostic standard and can detect a CCF missed by less-invasive neuroimaging methods (eg, magnetic resonance angiography). In this case, use of an antivascular endothelial growth factor agent would be inappropriate because doing so would delay the diagnosis and timely treatment of the underlying CCF. Systemic therapy with corticosteroids and a laboratory workup for uveitis are also unwarranted because there was no evidence of concurrent intraocular or orbital inflammation.