Autologous Plasmin and Fibrinolytic System in Diabetic Retinopathy

The purpose of this study is to evaluate in a prospective study the efficacy of intravitreal autologous plasmin enzyme in macular edema and to analyze the fibrinolytic system in vitreous body.

Autologous plasmin enzyme has been used to liquefy the gel structure of the vitreous body and to decrease the adherence of the posterior vitreous cortex to the inner limiting membrane in clinical studies. The investigators performed intravitreal autologous plasmin enzyme for macular edema. in addition, the investigators collected vitreous body in macular edema and analyzed fibrinolytic system.

autologous plasmin was prepared in the operation department. Samples (3.5 mL) of autologous whole blood, collected by sterile vacuum blood collection tubes, were obtained from a peripheral vein. The blood was centrifuged at 4,000 rounds per minute for 15 minutes to obtain complete sedimentation of the cells; 1.5 mL of the plasma was aspirated and transferred under sterile conditions in a vial of urokinase(10,000 IU) that had been incubated for 15 minutes at 37°C. By gently moving the vial for 5 minutes, the solution was incubated for 15 minutes at 37°C; 0.2 mL of the obtained solution was used for intravitreal injection.

Inclusion Criteria: eyes with macular edema those who showed poor outcomes in visual acuity or macular thickness after grid laser,triamcinolone,or bevacizumab therapy or a combination of these treatments. Exclusion Criteria: uncontrolled blood pressure (systolic and diastolic blood pressure greater than 150 and 90 mm Hg, respectively) renal insufficiency intraocular surgery or any intravitreal treatment during the previous 3 months history of ocular hypertension and/or glaucoma