Central retinal vein occlusion (CRVO) can be associated with ocular and systemic conditions, including glaucoma, hypertension, diabetes mellitus, hyperlipidemia, hypercoagulable states, collagen vascular disease, type II familial hyperlipoproteinemia, trauma, AIDS, anatomic abnormalities (eg, optic nerve drusen), and other conditions (1).

Hypercoagulable states associated with CRVO include primary hypercoagulable states with a defect in the physiological anticoagulation mechanism, such as

• protein C deficiency, protein S deficiency, activated protein C resistance
• antithrombin (also known as antithrombin III) deficiency
• hyperlipoproteinemia (a)
• abnormal platelet function
• beta-thromboglobulin abnormalities
• homocystinuria and hyperhomocysteinemia

AND

secondary hypercoagulable states, which are conditions associated with an increased risk of thrombosis, such as

• hyperviscosity syndromes (eg, polycythemia, essential thrombocythemia, leukemia, multiple myeloma, paraproteinemia)
• malignancy (eg, lung cancer)
• the presence of lupus anticoagulant
• the use of oral contraceptives.