Evidences of new risk factors for retinal vein thrombosis

Purpose: Hypercoagulability and hypofibrinolysis have been implicated in RVO pathogenesis, with possible differences in central and branch RVO. RVO patients have higher Endogenous Thrombin Potential ETP (thus hypercoagulability) and/or higher Clot Lysis Time (thus lower plasma fibrinolytic potential). Methods: We performed a retrospective and a prospective study on RVO patients referred to our Ophthalmology Unit and Coagulation and Atherosclerotic Diseases Unit. In the retrospective study, we analyzed blood chemistry and thrombophilic factors in 276 consecutive patients. Consequently, we tested these factors in a prospective study involving 127 consecutive patients at RVO diagnosis. Results: Retrospective study: we found higher ETP in CRVO patients (OR 2.13, 95% CI 1.66–3.06, p < 0.01) and lower fibrinolysis in RVO (OR 1.99, 95% CI 1.23–2.83, p < 0.01). Patients older than 50 (no gender differences) showed positive isolated lupus anticoagulant (LAC), a hypercoagulant factor (OR 1.69, 95% CI 1.19–2.47, p < 0.05) and a strong association with monoclonal gammopathy (OR 2.13, 95% CI 1.59–3.19, p < 0.01), IgG or IgM, 94% of which were λ chains. Prospective study: 56% of our patients were positive for both LAC+ and monoclonal gammopathy at diagnosis (OR 4.45, 95% CI 3.37–5.98 p < 0.001). No association with LAC+ or monoclonal gammopathy alone was found. Conclusions: In our cohort of RVO patients, the association of isolated LAC+ and monoclonal gammopathy appears to be a specific risk pattern. The putative trigger for LAC+ in monoclonal gammopathy may be immunomodulatory dysregulation. Thus, we may consider screening all RVO patients for gamma‐globulin disorders and LAC+. If the prospective study, which is still ongoing, confirms these data, we may consider starting specific antithrombotic therapy in patients with monoclonal gammopathy and LAC+.