Abstract
Abstract: :
Purpose: To determine the prevalence of inherited and acquired thrombophilia in all patients that presented with a new diagnosis of retinal vein occlusion from March to December 2001 at our Retina and Vitreous Service. Methods:Fifty-three patients that presented with a new diagnosis of acute (no more than six months of history) retinal vein occlusion (RVO) were submitted to a complete ophthalmological examination, including fluorescein angiography. Screening for thrombophilias was performed in blood samples from all patients. The screening protocol included: complete hematological counts, anticardiolipin-antibodies, lupus anticoagulant, fibrinogen, protein C and protein S levels, antithrombin levels, Leiden V factor mutation, MTHFR 677 mutation related to hyperhomocysteinaemia and G20210A prothrombin mutation. The results obtained from the RVO patients were compared with values from a data bank based on blood samples from 400 normal individuals. Results:Diagnosis of antiphospholipid syndrome was established on 34% of patients: 11 patients had positive anticardiolipin-antibodies, 3 patients had lupus anticoagulant antibodies and 4 patients had elevated levels of both antibodies. The prevalence of Protein S deficiency was significantly higher in patients with RVO (5,7%) when compared to the normal population (0,03-0,13%). G20210A mutation and Leiden V factor were present on 3,8% of patients with RVO, a prevalence slightly higher than controls (1,3% and 2,6%, respectively). MTHFR mutation was present on 47,2% of cases, accordingly to its polymorphism and high prevalence on general population (52%). Elevated levels of fibrinogen (>400 mg/dl) were present on 37,7% of patients. Conclusions: Excluding MTHFR mutation, that is highly prevalent also in the normal population, sixty percent of the patients enrolled in the study presented at least one risk factor for thrombophilia, proving its importance on RVO etiology. Antiphospholipid antibodies and protein S deficiency are important predisposing factors to RVO.
Keywords: retina • clinical laboratory testing • clinical (human) or epidemiologic studies: ris