Fibrinolytic activity in retinal vein occlusion

Purpose: Impaired fibrinolytic function is a common finding in patients wit h thrombotic disease. The present study was initiated to evaluate the fibri nolytic response to a venous occlusion test (VOT) in patients with retinal vein occlusion. Methods: Euglobulin clot lysis time (ECLT), tissue plasmino gen activator (t-PA) activity, and plasminogen activator inhibitor (PAI) ac tivity were measured before and after VOT in a group of 26 consecutive pati ents presenting with retinal vein occlusion and in 15 healthy age- and sex- matched controls. Results: Before VOT (baseline), a higher proportion of pa tients (54%) had an ECLT of more than 5 h compared with controls (6.7%) (p = 0.0027) indicating decreased overall fibrinolytic activity. Patients had non-significantly lower t-PA and higher PAI activities compared with contro ls. After VOT, a higher proportion of patients (34.6%) had an ECLT of more than 5 h compared with controls (6.7%) (p = 0.05). Patients had significant ly lower t-PA activity (p = 0.0232) and significantly higher PAI activity ( p = 0.0292). Subgroup analysis revealed that patients with an ECLT of more than 5 h had significantly higher levels of PAT activity at baseline (p = 0 .0326) and after VOT (p = 0.0184) compared with patients with an ECLT of le ss than 5 h. However, t-PA activity was significantly higher (p = 0.0153) a t baseline, and non-significantly higher after VOT in patients with an ECLT of more than 5 h when compared with patients with an ECLT of less than 5 h . Conclusions: These findings suggest that impaired fibrinolysis due to inc reased PAT activity may play a role in the pathogenesis of retinal vein occ lusion.