Abstract
Purpose:
The Factor V Leiden mutation (FV) is the most common familial thrombophilia, predominantly associated with deep venous thrombosis (DVT) and pulmonary embolus (PE). We hypothesize that ocular thrombosis [central retinal vein occlusion (CRVO), central retinal artery occlusion (CRAO), amaurosis fugax (AF)] is an uncommon but significant presenting manifestation of FV.
Methods:
We prospectively performed PCR determinations of FV in 3515 patients seen at The Jewish Hospital of Cincinnati for evaluation of thrombotic events and assessed the nature of thrombotic events in those 286 patients found to be FV heterozygotes. Evaluation of coagulation measures was accomplished via PCR assays and serology of thrombophilia and hypofibrinolysis. Comparisons were made against a group of healthy normal controls (n=105) via chi-squared and Student’s unpaired t-test analyses.
Results:
Of the 3515 patients studied, 206 females and 80 males were found to have the FV mutation (8.1% of the cohort; 279 heterozygous and seven homozygous). Of these 286 FV patients, 14 (5%; seven female and seven male; mean age 52±11) had ocular thrombosis as the presenting thrombotic event. Of these 14 patients (all non-smoking), three had CRAO, one had AF, and ten had CRVO. Two women with CRVO were taking Premarin at time of presentation. In 13 of the 14 patients, ocular thrombosis was the initial thrombotic event leading to thrombophilia screening; the other patient had a prior DVT but had not been genotyped. Two of the 14 patients later developed osteonecrosis of the hip and jaw, respectively. Other previously undiagnosed coagulation abnormalities present in the 14 patients included MTHFR C677T homozygosity or MTHFR C6767T-A1298C compound heterozygosity in seven of nine (78%) patients compared to 31 of 102 (30%) healthy normal controls (p=0.007), 4G4G homozygosity of the PAI-1 gene in seven of 13 (54%) patients compared to 26 of 100 (26%) normal controls (p=0.05), and low antithrombin III in two of eight (25%) patients compared to two of 92 (2.2%) normal controls (p=0.03).
Conclusions:
In a cohort of subjects having coagulation profiles, 8.1% were found to have FV with 5% of the subgroup having ocular thrombosis as the presenting clinical event leading to procoagulant testing. Ocular thrombosis should be considered in the broad group of thrombotic events that trigger laboratory assessment of coagulation abnormalities.
Keywords: 749 vascular occlusion/vascular occlusive disease •
572 ischemia •
467 clinical laboratory testing