Branch retinal vein occlusion (BRVO) is the second most common vascular disorder of the eye. Intravitreal injections of anti-VEGF agents and corticosteroids have proven efficacy. Posterior vitreous cortex (PVC) adhesion has been shown to support the development of retinal vein occlusion. The induction of a complete posterior vitreous detachment (PVD) is of benefit to BRVO-affected eyes. If intravitreal plasminogen is present in eyes with BRVO, then intravitreally applied tissue Plasminogen activator (t-PA) will activate plasminogen into the active enzyme plasmin, thus facilitating PVD development. In this study, vitreous taps were taken from central vitreous body and plasminogen was functionally determined in a p-nitroanilide reaction after activation with streptokinase (100% of normal, %N = functional plasminogen in pooled normal citrated plasma). Intravitreal functional plasminogen was detected in all analysed samples (n=30) and mean plasminogen activities were found to be 0.97±1.06%N (range: 0.03-3.9%N). The study concluded that intravitreal functional plasminogen is significantly elevated in eyes with BRVO and intravitreal t-PA should be further explored to induce PVD.