Artificial Corneal Implant

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Summary   Artificial corneal implants (keratoprosthesis) have great potential to benefit millions in the U.S. and worldwide with corneal disease. Nearly 10 million people worldwide are blind due to corneal disease and current corneal implants have not been adopted because of complications such as infection and peripheral tissue necrosis. Stanford University scientists developed a novel corneal prosthesis based on an interpenetrating double network hydrogel of poly(ethylene glycol) (PEG) and poly(acrylic acid) (PAA). Both PEG and PAA are biocompatible and are used widely in ophthalmic, biomedical, and commercial applications. The hydrogel has high mechanical strength (estimated to be 1.1 MPa) in the context of high water content (~80%), while possesing a Dk value of 90. This indicates that the membrane will be easy to implant and durable, while possessing the ability to facilitate high permeability of oxygen and nutrients to pass through the hydrogel. The scientists also developed a method for the fabrication of the full-thickness artificial using this hydrogel. This fabrication is done in a sequential manner without the need for fusion or gluing of two separate core and skirt pieces. The present device overcomes the limitations of many other devices due to dissimilar material properties, weakness at the core-skirt junction, or general weakness of the skirt itself. The core-and-skirt construct consists of a optically clear central component and a porous periphery with pores sized for host tissue integration, i.e. to adhere and enable migration of stromal cells. Collagen can be covalently linked to the surface of the artificial cornea to promote adhesion, proliferation, and migration on cells over the surface of the prosthesis for full integration into the eye. This technology could be a practical alternative to current methods for replacing diseased corneas.