Postoperative Use of Cyclosporine, Prednisolone or a Cyclosporine/Prednisolone Combination to Treat Inflammation of the Conjunctiva Following Trabeculectomy in Rabbits

Objectives: The objective of this investigation was to compare different topical treatment protocols for controlling inflammation in rabbits during the postoperative period following trabeculectomy.

Methods: Thirty rabbits had their right eyes treated with a daily eye drop of 0.03% bimatoprost for 30 days. All rabbits then underwent a trabeculectomy procedure and were divided into three groups (G1, G2 and G3). Rabbits from G1 received prednisolone acetate 1.0% four times a day, G2 received cyclosporine 0.05% twice a day and G3 received both prednisolone acetate 1.0% four times a day and cyclosporine 0.05% twice a day. Seven days after the surgery all rabbits were euthanized and enucleated. Histomorphometry was performed in HE-stained sections to evaluate epithelial thickness, blood vessel diameter and vascular area. Immunohistochemical staining using monoclonal antibodies against smooth muscle actin, factor VIII and IL-6 was performed to assessfibrosis, neovascularization and inflammatory cell infiltration, respectively.

Results: In group G3 there was a reduction in the thickness and diameter of the conjunctival epithelium and the diameter and number of blood vessels, and less inflammatory infiltrate and fibrosis.

Conclusion: This study suggests that a combination of prednisolone and cyclosporine is more effective than either of these drugs used alone to control postoperative conjunctival inflammation following trabeculectomy in rabbits.