Thrombophilic mutations and risk of retinal vein occlusion.

PURPOSE The association of retinal vein occlusion and hereditary thrombophilia abnormalities is not established, with controversial results in the literature. This study investigates the association between retinal vein occlusion and three thrombophilic mutations: factor V 1691A (factor V Leiden), prothrombin 20210A (PT 20210A) and homozygous methylenetetrahydrofolate reductase 677T (MTHFR 677TT). METHODS 55 consecutive retinal vein occlusion patients and 55 controls matched by age, gender and race, were tested for the presence of the following mutations: factor V Leiden, PT 20210A and MTHFR 677TT. The frequencies of the three mutations in cases and controls were compared. RESULTS Factor V Leiden was found in 3.6% of patients and in 0% of controls; PT 20210A was found in 1.8% of patients and 3.6% of controls, (matched-pair odds ratio, 0.5; 95% confidence interval, 0.04 to 5.51); MTHFR 677TT was found in 9% of patients and 9% of controls (matched-pair odds ratio, 1; 95% confidence interval, 0.92 to 3.45). Arterial hypertension was more frequent in patients than controls (matched-pair odds ratio, 3.4; 95% confidence interval, 1.25 to 9.21). CONCLUSIONS This study suggests that thrombophilic mutations are not risk factors for RVO. Routine investigation of hereditary thrombophilia in these patients is not justified.