Purpose: Vitreomacular adhesion causing vitreomacular traction is a common indication for vitrectomy. It may be avoided by using enzymatic vitreolysis. The MIVI-IIT (traction) study evaluated the ability of a single or repeated injection of microplasmin to release vitreomacular traction.
Methods: This randomized, double-masked, Phase II trial with control sham injection enrolled 60 patients. Patients in each of the 4 cohorts were randomized (4:1) to active treatment or sham injection. In the first 3 cohorts, increasing doses of microplasmin (75, 125, and 175 microg) were administered. In the fourth cohort, an initial injection of 125 microg microplasmin or sham was administered followed 1 month later by an injection of 125 microg microplasmin if no release of adhesion occurred. A third dose was injected 4 weeks later if there was still no release of adhesion.
Results: Within 28 days of sham, 75, 125, and 175 microg microplasmin administration, nonsurgical resolution of vitreomacular adhesion was observed in 8, 25, 44, and 27% of the patients, respectively. When the 125 microg dose was repeated up to 3 times, adhesion release was observed in 58% of patients 28 days after the final injection.
Conclusion: These results provide support for the potential of microplasmin as a nonsurgical treatment for vitreomacular adhesion.