Hypercoagulable states in patients with retinal venous occlusion

Background and purpose: The pathogenesis of thrombus formation in the retin al vein resulting in retinal vein occlusion is not well understood. This st udy was carried out to ascertain the role of hypercoagulable states in pati ents with retinal vein occlusion. Methods: Fifty seven consecutive patients with acute retinal vein occlusion (mean age 48 +/- 11.5 years) were invest igated for possible hypercoagulable states. Levels of antithrombin III (AT III), protein C (PC), Protein S (PS), factor XII, and fibrinogen as well as the presence of antiphospholipid antibodies (APAs) were investigated. The APAs and fibrinogen results obtained in these patients were compared to tho se of healthy controls. Results: We detected APAs in 15 out of 57 patients compared to 3 out of 74 controls (p = 0.0002). Fibrinogen levels were signi ficantly higher in patients compared with the controls (p < 0.001). Deficie ncies in the naturally occurring anticoagulant proteins including AT III (4 out of 54 patients tested), PC (8 out of 42 patients tested), and PS (12 o ut of 56 patients tested) were detected. Seven patients out of 32 patients tested had reduced levels of factor XII. Subgroup analysis of the thromboph ilic differences between patients who aged 45 years or less and older patie nts and patients with major trunk vein occlusion and patients with branch v ein occlusion revealed no significant differences. Conclusion: Hypercoagula ble states are common in patients with retinal vein occlusion and may contr ibute to the etiology of the disease.