Recurrent Branch Retinal Arterial Occlusions Associated With Plasminogen Activator Inhibitor-1 Mutation - Recurrent Branch Retinal Arterial Occlusions Associated With Plasminogen Activator Inhibitor-1 Mutation - Open Access Pub

A 57-year-old Hispanic female presented with 3 days of blurry vision in the left eye. Eight years prior, she had a branch retinal artery occlusion in the right eye and a hematologic work-up revealed a 4G/4G polymorphism in plasminogen activator inhibitor-1. With the current episode, she was found to have bilateral branch retinal artery occlusions and mild vitritis in the left eye, simulating a toxoplasma infection. An infectious and inflammatory work up, however, was negative and the vitritis resolved after a short course of steroids. Plasminogen activator inhibitor-1 mutations may be associated with an increased risk of retinal vascular occlusions. DOI 10.14302/issn.2470-0436.jos-17-1721 Retinal vascular occlusions are caused by three primary mechanisms: hematologic abnormalities, vessel wall changes, or perivascular abnormalities, such as sclerosis or a common adventitia. Abnormal hematologic factors can produce increased thrombosis, which is thought to account for 15-28% of unexplained systemic vascular thrombosis in young patients.1 The primary fibrinolytic enzyme in humans is plasmin, which is derived from the inactive precursor plasminogen. The two primary plasminogen activators are urokinase plasminogen activator (uPA) and tissue plasminogen activator (tPA). Plasminogen activator inhibitors neutralize plasminogen activators and have been classified as several distinct inhibitors, the most important of which is plasminogen activator inhibitor-1 (PAI-1), which is the primary inhibitor of tPA.1 In contrast to the systemic circulation where fibrinolytic activity is primarily found in the endothelium of veins and capillaries, high fibrinolytic activity is localized to the endothelium of both arteries and veins within the retinal circulation.2 While mutations in plasminogen activator inhibitor-1 have been associated with an increased risk of systemic thrombosis, the embolic effects of the mutation in the eye have not been well documented and ocular sequelae of PAI-1 inhibitor mutation is not well understood. In this case report, we describe a patient with recurrent branch retinal artery occlusions associated with PAI-1 inhibitor mutation. A 57-year-old Hispanic female was referred to our clinic with decreased vision in the left eye of two months duration. Past medical history included hypothyroidism. Additionally, eight years prior, she experienced a branch retinal artery occlusion (BRAO) in the right eye. At that time an extensive work-up was performed, including a hematologic evaluation, which was found to be normal for lupus anticoagulant, factor