Effect of Surgical Adhesives on the Corneal Endothelium

Robin, Jeffrey

Abstract

The corneal endothelium is the monolayer of cells that is responsible for keeping the stroma relatively deturgesced, thus ensuring corneal clarity. In humans, these cells are not capable of regenerating. Despite advances in eye banking, the availability of transplantable corneas remains a problem. Several experimental attempts have been made to transplant only the endothelial layer of the cornea. One recurring problem has been the quality of the adhesion of cells to stroma. Additionally, the seeding of cells to autologous stroma would require excessive time with the eye open, thus necessitating the use of gelatin membranes or homologous stroma. The use of surgical adhesives may provide answers to these problems. To date, adhesives have not been thoroughly evaluated in corneal endothelial transplantation. Before any investigation of adhesive efficacy in endothelial cell transplantation, it is necessary to evaluate the interaction of these agents with the cells.
The specific aim of this pilot research project is to determine whether three adhesive substances affect the growth and morphology of corneal endothelial cells in culture. The results will provide preliminary data for a future R01 application designed to evaluate the efficacy of adhesives in endothelial transplantation. The long- term hypothesis is that adhesives can facilitate corneal endothelial transplantation to autologous stroma, thus allowing the development of this technique for clinical use. The adhesives to be investigated in this study include; butyl-2- cyanoacrylate, a fibrin adhesive derived from human serum, and a repeating decapeptide polymer derived from molluscs. Endothelial cells will be taken from rabbit, bovine and human eyes. Standard endothelial cell culturing techniques will be used. Cell growth will be assessed (1) after addition of the adhesive to the growth media, and 2) following inoculation of cells onto well plates that have been previously coated with adhesives. Five concentrations of adhesives will be added to the growth media; at least five concentrations of adhesive will be used to coat the well plates. Cell population determination will be performed using both Coulter Counter and tritiated thymidine incorporation. Cell morphology experiments will involve growing the endothelial cells on plastic coverslips. Similarly, assessments will be performed following either addition of adhesives to the growth media or growing of cells on coverslips that have been previously coated with adhesives. At various time points, cells will be examined using vital stains (trypan blue and alizarin red) and transmission electron microscopy. All experiments will be repeated 3 times.