A placebo-controlled trial of microplasmin intravitreous injection to facilitate posterior vitreous detachment before vitrectomy.

PURPOSE To evaluate the safety and efficacy of a preoperative intravitreous injection of microplasmin in patients scheduled for vitreous surgery. DESIGN Phase 2, multicenter, placebo-controlled, double-masked, parallel-group, dose-ranging clinical trial. PARTICIPANTS One hundred twenty-five patients scheduled for pars plana vitrectomy (PPV), primarily for treatment of either vitreomacular traction or macular hole. INTERVENTION A single intravitreous injection of either microplasmin at 1 of 3 doses (25 microg, 75 microg, or 125 microg in 100 microl) or placebo injection administered 7 days before PPV. MAIN OUTCOME MEASURES Presence or absence of posterior vitreous detachment (PVD) at the time of PPV, progression of PVD, and resolution of vitreomacular interface abnormality precluding the need for PPV. RESULTS Rates of total PVD at the time of surgery were 10%, 14%, 18%, and 31% in the placebo group (n = 30), 25-microg (n = 29), 75-microg (n = 33), and 125-microg microplasmin groups (n = 32), respectively. The secondary end point resolution of vitreomacular interface abnormality precluding the need for vitrectomy at the 35-day time point was observed at rates of 3%, 10%, 15%, and 31% in the placebo, and the 25-microg, the 75-microg, and the 125-microg microplasmin groups, respectively. At the 180-day time point, the equivalent rates were 3%, 7%, 15%, and 28%, respectively. CONCLUSIONS Microplasmin injection at a dose of 125 microg led to a greater likelihood of induction and progression of PVD than placebo injection. Patients receiving microplasmin were significantly more likely not to require vitrectomy surgery. More definitive evaluation in phase 3 clinical trials therefore is warranted. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.