Evaluation of Sustained Release of PLC-Loaded Prednisolone Acetate Microfilm on Postoperative Inflammation in an Experimental Model of Glaucoma Filtration Surgery

Purpose: To evaluate the effect of a biodegradable microfilm with sustained release of prednisolone acetate (PA) on postoperative wound healing after experimental glaucoma filtration surgery (GFS). Methods: Biodegradable microfilms composed of poly (d-, L-lactide-co-caprolactone) (PLC) were fabricated and then pre-loaded PA-20% total weight. Fourteen New Zealand White rabbits were randomly divided into 3 treatment groups: GFS alone (n = 4), GFS with PLC microfilms (n = 4) and GFS with PA-loaded microfilm (n = 6). Microfilms were inserted subconjunctivally, adjacent to the filtering surgical site. We monitored all eyes with slit-lamp examination, bleb photography and anterior segment optical coherence tomography (AS-OCT). Histology with immunohistochemistry was performed to determine the presence of any inflammation. Results: Prednisolone acetate 20%-loaded microfilms exhibited steady, sustained release in vitro. Eyes implanted with PA-loaded microfilms showed a significantly better bleb survival (100% vs. 37.5%, p < 0.001) and reduced bleb vascularity (58%; 95% CI 54-62% vs. 30%; 95% CI 23-37%, p = 0.001) compared to the control at 30 days postoperatively. Histology and immunohistochemistry demonstrated less T-cell infiltration in the eye implanted with PA-loaded microfilms. Conclusion: Subconjunctival insertion of a PA-loaded biodegradeable microfilm exhibit sustained release of PA to reduce postoperative inflammation and prolong bleb survival in rabbit GFS.