Intravitreal functional plasminogen in eyes with branch retinal vein occlusion.

PURPOSE: To evaluate whether intravitreal functional plasminogen is elevated in eyes with branch retinal vein occlusion (BRVO) and to discover whether intravitreal plasminogen activities are correlated with the extent of blood-retina barrier (BRB) breakdown. METHODS: Our study is a prospective case series of 20 consecutive patients with BRVO and 10 consecutive patients serving as controls. Vitreous taps were extracted from the central vitreous body and plasminogen was functionally determined in an innovative, ultrasensitive p-nitroanilide reaction after activation with streptokinase (100% of normal, %N = functional plasminogen in pooled normal citrated plasma). Intravitreal VEGF levels were assayed to estimate BRB breakdown. RESULTS: Intravitreal functional plasminogen was detected in all analyzed samples (n = 30) and mean (±SD) plasminogen activities were found to be 0.97 ± 1.06%N (range: 0.03-3.9%N). Patients suffering from BRVO exhibited significantly higher intravitreal plasminogen (1.35 ± 1.11%N) in comparison with controls (0.20 ± 0.21%N, p < 0.001). Intravitreal VEGF concentrations in the BRVO group (576 ± 547 pg/ml) were significantly higher than these in controls (111 ± 120 pg/ml, p = 0.003). There was a significant correlation between intravitreal functional plasminogen and intravitreal VEGF levels (r = 0.519, p = 0.003). CONCLUSIONS: Intravitreal functional plasminogen is significantly elevated in eyes suffering from BRVO and correlates with the extent of BRB breakdown. The induction of posterior vitreous detachment by using intravitreally administered recombinant tissue plasminogen activator (enzymatic vitreolysis) should be explored in further investigations.

Intravitreal functional plasminogen is elevated in central retinal vein occlusion.

PURPOSE: To detect intravitreal functional plasminogen in vitreous samples of patients with recent onset of central retinal vein occlusion (CRVO) and to demonstrate significantly higher intravitreal plasminogen in CRVO patients in comparison to controls. METHODS: Prospective clinical case series of 13 consecutive patients with recent onset of CRVO scheduled for core pars plana vitrectomy and 10 consecutive patients undergoing standard pars plana vitrectomy for routine macular surgery or vitreal floater removal. In all 23 cases, vitreous taps were extracted from the central vitreous body, and plasminogen was functionally determined in a new ultrasensitive p-nitroanilide reaction after activation with streptokinase (100% of normal, %N = functional plasminogen in pooled normal citrated plasma). RESULTS: Plasminogen was detected in all analyzed samples (n = 23), and mean plasminogen was revealed to be 1.33 ± 1.73% (mean ± SD), with a range of 0.03-7.8%N. Patients with recent onset of CRVO exhibited significantly higher intravitreal plasminogen (2.19 ± 1.89%N) in comparison to controls (0.20 ± 0.21%N; p < 0.001, Mann-Whitney U test). CONCLUSION: Due to significantly increased intravitreal plasminogen in patients with recent onset of CRVO, intravitreally administered tissue plasminogen activator might be an option to induce posterior vitreous detachment (enzymatic vitreolysis) in CRVO patients.