Expanded fluorocarbon for keratoprosthesis cellular ingrowth and transparency

The development of a synthetic material allowing increased cellular adhesion and ingrowth would improve keratoprosthetic devices and requires an understanding of cell colonization processes. Interlamellar implantation of hydrophobic synthetic material may lead to poor corneal nutrition with subsequent necrosis. The probability of necrosis increases with material which is more impermeable, larger in diameter and more anterior in its placement. In this study we demonstrated the importance of pore diameter in the rate and density of cell colonization. We demonstrated that an opaque hydrophobic material may become translucent and wettable with very low perturbation of flow through the cornea. We used an expanded polytetrafluoroethylene with either 20 microns or 50 microns pore diameter. Cellular ingrowth was significantly greater in the material with 50 microns pores, resulting in collagen deposition within the pores without corneal vascularization at 6 months follow-up. Immunohistochemical study with monoclonal antibody AE5 revealed normal epithelial differentiation on the surface of the cornea over the implanted polymer.