Prevalence of Thrombophilia in Patients with Retinal Vascular Occlusion

Background: Retinal vascular occlusion (RVO), both arterial (RAO) and venous (RVO) is an important cause of visual loss. Inherited and acquired thrombophilia are considered important risk factors in the development of RVO. Additionally, cardiovascular risk factors such as hypertension, diabetes, hyperlipidemia, smoking and use of female hormones may play a role.

Objective: To determine the prevalence of thrombophilia in patients with RVO.

Methods: We reviewed the medical records of all patients with documented RVO who were referred to our hematology clinic at a tertiary care center between January 2001 and June 2008 for thrombophilia evaluation. Thrombophilia evaluation included testing for factor V Leiden, prothrombin gene mutation G20210A, deficiencies in antithrombin, protein C and S, presence of antiphospholipid antibodies (aPLas), hyperhomocysteinemia and increased levels of lipoprotein (a), factor VIII, IX and XI. Serum protein electrophoresis and immunofixation were also performed. Environmental risk factors analyzed included use of female hormones, pregnancy and puerperium, smoking, hypertension, hyperlipidemia and diabetes.

Results: A total of 24 patients were identified; 10 were males and 14 females. The mean age was 62 years (range, 31 to 86 years). Seven patients had RAO and 17 RVO. Of the 24 patients, 19 (79%) had thrombophilia. Of these, 10 had only one thrombophilia and 9 had ≥2 thrombophilia. Of the 10 patients with a single thrombophilia, 3 patients had aPLas, 3 had increased lipoprotein (a) 2 had factor V Leiden, 1 hyperhomocysteinemia, and 1 had increased factor VIII level. Of the nine patients with combined thrombophilia: 3 had hyperhomocysteinemia and increase factor VIII level, 2 prothrombin gene mutation and positive lupus anticoagulant, 1 positive aPLas, hyperhomocysteinemia and a monoclonal gammopathy, 1 aPLas and increased factor VIII, 1, hyperhomocysteinemia and protein S deficiency and 1 hyperhomocysteinemia and polycythemia vera. In 5 patients, no thrombophilia was identified. Of the 24 patients, 11 had hypertension, 9 had hyperlipidemia, 3 were smokers, 3 were using female hormones and 1 was pregnant. Treatment included aspirin 81 mg (n= 9), aspirin >81 mg (n= 5), warfarin (n= 3), folic acid (n=2), aspirin and clopidogrel (n=1), clopidogrel (n=1), no treatment (n=4), and unknown (n=1).

Conclusions: Over three quarters (79%) of patients with RVO had an underlying thrombophilia with aPLas, hyperhomocysteinemia and increased factor VIII level being the most prevalent. Our findings suggest that testing for thrombophilia particularly for aPLas, homocysteine and factor VIII levels may be useful in patients with RVO