Autologous plasmin for pharmacologic vitreolysis prepared 1 hour before surgery

PURPOSE: To evaluate the safety and efficacy of intravitreal injection of autologous plasmin enzyme (APE) in inducing a posterior vitreous detachment (PVD). APE was obtained by a modified method 1 hour before surgery. METHODS: APE was obtained by centrifugation of autologous whole blood from the patients 1 hour before surgery and by incubation with streptokinase. APE was injected in the vitreous cavity 20 minutes before surgery. This procedure was applied for 20 patients who underwent vitrectomy for macular pucker, macular hole, and macular edema due to vitreoretinal traction. The status of PVD was graded intraoperatively. The plasmin concentration obtained by this method and the plasminogen titer of the plasma from each patient were compared. Activated partial thromboplastin time was controlled before surgery and 1, 6, 12, and 24 hours after surgery to evaluate alteration of the coagulation due to systemic absorption of the plasmin. RESULTS: Preparation of APE was easy and took on average 45 minutes for all patients. A PVD with an evident Weiss ring was observed during surgery in 17 eyes (85%). The average plasmin activity was 0.26 IU/0.2 mL activated plasma. The partial thromboplastin time did not show any alteration in any of the patients with respect to preoperative values. CONCLUSION: APE obtained by this method can lead to a PVD and facilitate the complete remotion of vitreous cortex. The intravitreal injection does not lead to alteration of systemic blood coagulation. Copyright © by Ophthalmic Communications Society, Inc.