Branch Retinal Artery Occlusion in a Patient with Patent Foramen Ovale

To report branch retinal artery occlusion (BRAO) in a patient with patent foramen ovale (PFO). Case Report: A 29-year-old female patient was referred for sudden onset superior visual field defect in her left eye. Ocular examination revealed visual acuity of 20/32 in the affected eye along with a positive relative afferent pupillary defect. A calcified white embolus was noted at the first bifurcation of the inferior temporal artery in her left eye together with mild retinal edema. With a diagnosis of BRAO, the patient received oral acetazolamide, topical timolol, ocular massage and anterior chamber paracentesis. The visual field defect partially recovered and the embolus moved to the third bifurcation level as revealed by fundus examination. An extensive workup, including neurology, rheumatology, cardiology and hematology consultation, carotid ultrasonography, transthoracic/transesophageal echocardiography and laboratory testing was performed. All results were within normal limits except for a small-sized PFO detected by transesophageal echocardiography. Low-dose aspirin therapy was initiated and over the subsequent two years, no other embolic event occurred. The association between PFO and BRAO has not yet been reported. Intracardiac right-to-left shunting through a PFO, accentuated by Valsalva maneuver, may predispose to embolic events while the source of initial thrombosis remains unknown.