Ocriplasmin (Jetrea®) is a recombinant protease used to treat vitreomacular traction. To gain insight into vitreoretinal observations reported after ocriplasmin treatment, we have developed an in vivo porcine ocriplasmin-induced posterior vitreous detachment (PVD) model in which we investigated vitreoretinal tissues by optical coherence tomography, histology, and cytokine profiling. Eight weeks postinjection, ocriplasmin yielded PVD in 82% of eyes. Subretinal fluid (85%) and vitreous hyperreflective spots (45%) were resolved by week 3. Histological analysis of extracellular matrix (ECM) proteins such as laminin, fibronectin, and collagen IV indicated no retinal ocriplasmin-induced ECM distribution changes. Retinal morphology was unaffected in all eyes. Cytokine profiles of ocriplasmin-treated eyes were not different from vehicle. In cell-based electrical resistance assays, blood-retinal barrier permeability was altered by ocriplasmin concentrations of 6 μg/mL and higher, with all effects being nontoxic, cell-type specific, and reversible. Ocriplasmin was actively taken up by RPE and Müller cells, and our data suggest both lysosomal and transcellular clearance routes for ocriplasmin. In conclusion, transient hyperreflective spots and fluid in a porcine ocriplasmin-induced PVD model did not correlate with retinal ECM rearrangement nor inflammation. Reversible in vitro effects on blood-retinal barrier permeability provide grounds for a hypothesis on the mechanisms behind transient subretinal fluid observed in ocriplasmin-treated patients.

PurposeRetinal cells participate in the transport and clearance of therapeutics. In this study, we used in vitro retinal cell models to investigate the uptake and transport of ocriplasmin, a protease used for the treatment of vitreomacular traction.MethodsCultures of primary porcine Müller and human ARPE‐19 cells were incubated with Alexa488‐labeled ocriplasmin or its inactive form for up to 3 h. Spatial distribution and colocalization with vesicle transport proteins were assessed at several time points.ResultsOcriplasmin was rapidly detected in Müller and RPE cells. Uptake was observed as cytoplasmic foci and confirmed by confocal microscopy. In contrast, enzymatically inactive ocriplasmin was taken up at a significantly slower rate. Given its focal cytoplasmic distribution, we investigated whether ocriplasmin was present in cellular transport organelles. In Müller cells, ocriplasmin colocalized partly with Rab5‐positive early endosomes and Rab7‐positive lysosomes but with very few Rab11‐positive recycling endosomes. In RPE cells, ocriplasmin also colocalized in part with early endosomes and lysosomes, but to a larger extent with recycling endosomes.ConclusionsTaken together, our data indicate that ocriplasmin can be taken up by Müller and RPE cells and that this uptake depends in part on its enzymatic activity. Ocriplasmin was found in transport vesicles, indicating active transport mainly through the degradation pathway in Müller cells whereas in RPE cells, outward transport is preferred. It is described that RPE cells transport anti‐VEGFs which emphasizes their role in retinal drug clearance. Our study suggests that retinal cells might participate in ocriplasmin drug clearance. Further in vivo studies will need to assess the ocriplasmin transport in the retina as well as the impact of uptake on ocriplasmin activity.