Activated protein C resistance is a risk factor for central retinal vein occlusion

Central retinal vein occlusion is one of the most common retinal vascular disorders. Few and contrasting data are available on the prevalence of hemostatic risk factors in patients with central retinal vein occlusion. The aim of this study was to investigate the most common hemostasis-related inherited risk factors for venous thrombosis in a group of 53 central retinal vein occlusion patients (median age 59 years, range 18-77 years) and in 53 comparable control subjects (median age 57 years, range 22-84 years). No difference was found in antithrombin III, protein C and protein S plasma levels between patients and controls. At univariate analysis, activated protein C resistance (odds ratio 5.8) and factor V Leiden (odds ratio 4.4) were significantly associated with central retinal vein occlusion whereas G20210A polymorphism of the prothrombin gene was not. After adjustment for sex, age, and the other classic vascular risk factors (hypertension, diabetes, hypercholesterolemia, smoking) activated protein C resistance remained the only independent risk factor for central retinal vein occlusion (odds ratio 11.5). These data indicate that activated protein C resistance may play a role in the pathophysiology of central retinal vein occlusion.