Pilotstudie zur Messung der Fibrinolytikakonzentrationen der Vorderkammer- und Glaskörperflüssigkeit des Auges bei Patienten mit einem Zentralvenen- (ZVV) oder Venenastverschluss (VAV)

Retinal vein occlusions (RVO) are common reasons for visual loss and blindness. The prevalence is about 80 per 100.000 for central retinal vein occlusion (CRVO) and 442 per 100.000 for branch retinal vein occlusion (BRVO). In consequence of RVO the development of hemorrhages, ischaemia and cystoid macula edema (CME) may substantially decrease visual acuity. There is an obvious impact of vitreous adhesion status and pathophysiology and prognosis of RVO. An attached posterior vitreous cortex is a risk factor for the development of CRVO and BRCO, for neovascularisation as well as for chronic CME. The induction of a posterior vitreous detachment is in focus of current studies. Besides pars plana vitrectomy, enzymatic vitreolysis with recombinant tissue plasminogen activator (rt-PA) might be an option. The purpose of this study is the detection of components of the fibrinolytic cascade, which are precondition for the effect of rt-PA. 47 eyes were enrolled in this survey, comprising 14 eyes with CRVO, 22 with BRVO and 11 in the control group. Fluid from the vitreous was obtained by core pars plana vitrectomy and was frozen immediately. For the purpose of this investigation we stabilized these samples with an innovative method for determining plasminogen, VEGF, plasmin-α2-antiplasmin-complex (PAP) and D-dimer activities and/or concentrations. Intravitreal activities and concentrations in the CRVO/BRVO/control group were 2,07±1,87%N/1,24±1,12%N/0,38±0,63%N for plasminogen, 1268,71±1318,46pg/ml/527,77±543,28pg/ml/104,91±115,92pg/ml for VEGF, 8,14±7,07ng/ml/6,96±4,8ng/ml/9,74±10,98ng/ml for PAP and 60,94±150,4ng/ml/68,83±94,75ng/ml/9,34±14,48ng/ml for D-dimer. Significant differences of intravitreal plasminogen (p=<0,001) and VEGF (p=0,001) between the groups were analysed. Intravitreal plasminogen correlated with intravitreal VEGF (r = 0,476, p = 0,001), the latter being a biomarker for blood-retina barrier (BRB) breakdown. Intraocular plasminogen activity was detected for the first time with an innovative analysis method at patients with CRVO or BRVO. The activity correlates positively with the severity of BRB breakdown. More components of the fibrinolytic cascade and the efficacy of rt-PA treatment for posterior vitreous detachment (PVD) induction should be explored in further investigations.