Abstract
Purpose: :
To investigate the effect of intracameral injection of fibrin tissue sealant on the corneal endothelium and other anterior segment structures on a rabbit model.
Methods: :
One eye of 10 rabbits received an intracameral injection of fibrin tissue sealant with thrombin concentration of 500 IU (TISSEEL, Baxter, USA), and the fellow eye received an intracameral injection of balanced salt solution as control. The rabbits were followed up with serial slit-lamp examination, serial slit-lamp photography, high resolution anterior segment optical coherence tomography scans with pachymetry measurement, and intraocular pressure (IOP) monitoring until complete dissolution of the fibrin sealant. Corneal endothelial cell viability was evaluated using live/dead cell assay. Apoptosis of the cornea and trabecular meshwork were evaluated using TUNEL assay. Ultra-structural examination of the morphology of the cornea, and trabecular meshwork were performed by electron microscopy. Histology of the trabecular meshwork and iris were analysed by light microscopy.
Results: :
The quantity of the intracameral fibrin sealant was showed to be significantly correlated with temporary increased IOP and increased pachymetry early postoperatively. Complete dissolution of the fibrin sealant occurred between 15 to 30 days. Despite the increased intraocular pressure and pachymetry, live/dead cell assays showed no difference in the viability of the corneal endothelium, and TUNEL assays showed no increase in apoptosis of the corneal epithelium, stroma and endothelium and trabecular meshwork in the eyes with the fibrin sealant compared to control eyes. Electron microscopy of the corneal endothelium showed regular cell surface, intact zonula occludens, and absence of mitosis. Light and electron microscopy of the trabecular meshwork showed normal trabecular beams and Schlemm’s canal, with absence of inflammatory cells. Normal iris architecture was seen on light microscopy.
Conclusions: :
We demonstrated the safety profile of intracameral use of fibrin glue on a rabbit model, with no evidence of long-term toxicity or structural damage to the corneal endothelium, trabecular meshwork and iris. We advocate more surgically controlled glue delivery with thinner layers of glue application and avoidance of direct injection to the drainage angle and judicious monitoring of IOP in the immediate postoperative period.
Keywords: drug toxicity/drug effects • anterior segment • clinical laboratory testing