Is Activated Factor Vii Associated with Retinal Vein Occlusion?

Abstract

Aim-To determine whether a newly identified thrombophilia factor, activated factor VII (FVIIa), is associated with retinal vein occlusion (RVO). Methods-54 consecutive cases with RVO seen between March and September 1999 were included in the study. 22 cases had central retinal vein occlusion (CRVO) and 32 had branch retinal vein occlusion (BRVO). Ophthalmoscopic examination with detailed medical history was followed by blood analyses for liver and renal functions, cholesterol, triglycerides, complete blood count, and coagulation factors including protein C activity, free protein S, antithrombin III, fibrinogen, and factor VIIa (FVIIa). Data were compared with those of the control group, composed of 19 cases under ophthalmological follow up for refractive errors, presbyopia, or senile cataract. Results-Hypertension was highly prevalent in cases with BRVO. Complete blood count, and liver and kidney function tests were within normal limits in the study group. Two cases had low protein C activity, and one had low free protein S. FVIIa levels were significantly higher in the RVO group than in the control group (p=0.0004). There was no significant difference in FVIIa levels between the CRVO and BRVO groups (p=0.51). Conclusion-No haematological parameter except FVIIa differed significantly from that of the control group. Elevation of FVIIa level may play a part in the pathophysiology of both CRVO and BRVO.