Ocriplasmin (generic name for microplasmin) is a truncated form of the serine protease plasmin that has retained its enzymatic properties.
20–22 Recently approved for use in the United States and Europe, ocriplasmin is a potent collagenase activator with proteolytic activity against a range of components of the vitreoretinal interface, including fibronectin and laminin.
23 In vitro, ocriplasmin has the highest activity against fibrinogen, followed by fibronectin, gelatin, collagen type IV, and laminin (ThromboGenics, unpublished data, 2011). The proteolytic activity of ocriplasmin causes disruption of the vitreoretinal interface while preserving the morphology of the retina and the ultrastructure of the inner limiting membrane.
21,22 Previous preclinical and clinical studies have highlighted the beneficial effects of ocriplasmin in facilitating PVD. Experiments carried out in vivo and ex vivo demonstrated that intravitreal injection of ocriplasmin produced pharmacologic vitreolysis with detachment of the vitreous from the retinal surface.
20 –22 Phase 2 studies demonstrated that ocriplasmin was well tolerated and produced nonsurgical resolution of VMA and closure of FTMHs.
1,11 Results of two phase 3 clinical trials showed a statistically significant difference in favor of a single intravitreal injection of ocriplasmin 125 μg versus placebo injection for achieving the primary efficacy end point, VMA resolution at day 28, as well as the key secondary efficacy end point, total PVD at day 28.
24 Compared with placebo injection, eyes treated with ocriplasmin were more likely to have nonsurgical closure of FTMHs at day 28 (
P < 0.001), nonsurgical three-line or greater improvement in best-corrected visual acuity (BCVA) at 6 months (
P = 0.02), and a reduced need for vitrectomy at 6 months after ocriplasmin treatment (
P = 0.02) (secondary end points).
24