Elma Kim, MD
A 45 year old female with significant past medical history of well-controlled hypertension experienced sudden painless vision loss a few days prior to presentation. On exam, the patient had a relative afferent papillary defect in the affected eye and had a normal slit lamp exam. On the dilated fundus exam, the right eye was normal except for a few drusen and a choroidal nevus. In the left eye, there were several internal hemorrhages in all four quadrants, vessel tortuosity, blurred and elevated disc margins, and retinal whitening along the superotemporal arcade. The diagnosis of a simultaneous central retinal vein occlusion (CRVO) and branch retinal artery occlusion (BRAO) was made. The diagnosis was confirmed through imaging studies. The fluorescein angiogram showed blockage of dye in the area consistent with retinal whitening on fundus exam. On OCT, there was both inner and outer OCT thickening consistent with both retinal arterial and venous occlusion, respectively.
There are several theories as to why simultaneous arterial and venous occlusions occur in the retina. The two most common theories are: 1) the resulting edema around the optic disc from a venous occlusion compresses onto a nearby artery causing an arterial occlusion, and 2) an embolic arterial blockage induces a low-flow state, which results in venous stasis and thrombosis.
An extensive work-up was done to rule out embolic sources, infectious causes, inflammatory causes, and hypercoagulable disorders. Out of these several tests, the two tests that came back positive were Factor V Leiden, which causes activated protein C resistance. Resistance to activated protein C due to the Factor V R506Q (Leiden) mutation is the most common clotting abnormality in patients with venous thromboembolism. Subsequently, we recommended that the patient see a hematologist for management and treatment of her hypercoagulable disorder.
Have a question or comment on this article? Use the "Comment" link above to leave your thoughts, and the author will respond.