Coagulation disorders and the risk of retinal vein occlusion.

Over the past years, there has been a dramatic increase in the number of identifiable causes of thrombophilia. However, to date, there are no large, prospective studies to assess an optimal, cost-effective approach with regard to screening and case finding for thrombophilic risk factors in patients presenting with retinal vessel occlusion. Two hundred twenty-eight patients with retinal vein occlusion (RVO) and 130 age-matched healthy controls were prospectively screened for thrombophilic risk factors. Both cohorts were divided into three subgroups, depending on the patients' age at the time of the RVO or a previous thromboembolic event. Patient age < or =45 years was associated with a high prevalence of coagulation disorders (p<0.0001). Among patients < or =45 years and >45 to < or =60 years, a family history of thromboembolism was strongly associated with the presence of thrombophilic disorders. The absence of cardiovascular risk factors was found to be a strong predictor for the presence of coagulation disorders in all patient groups (< or =45 years, p=0.003; >45 to < or =60 years, p=0.0008; >60 years, p=0.001). Multivariate analysis revealed the presence of resistance to activated protein C (p=0.014), antiphospholipid antibodies (p=0.022), and deficiency of the anticoagulant proteins (p=0.05) as independent risk factors for the development of RVO among patients < or =45 years. Our results indicate that thrombophilic disorders are associated with the development of retinal vein occlusion in patients < or =45 years by the time of the RVO or a previous thromboembolic event, in patients with a family history of thromboembolism, or in patients without cardiovascular risk factors.