Central Retinal Artery Occlusion Secondary to Patent Foramen Ovale: The Unexpected Journey of a Paradoxical Embolus.

Central retinal artery occlusion (CRAO) represents one of the most devastating ophthalmic emergencies, since the inner two-thirds of the retina lose their blood supply. The acute obstruction of the central retinal artery is characterized by severe, sudden and unilateral painless visual loss and usually occurs secondary to an embolus of cardiovascular origin. A paradoxical thromboembolic event of the central retinal artery through patent foramen ovale is an exceptionally unusual clinical entity as well as a great diagnostic challenge since the source of initial thrombus formation requires extensive investigation. Herein, we aim to describe a patient with no significant comorbidities who experienced a paradoxical thromboembolic episode of central retinal artery associated with patent foramen ovale.