TECHNICAL REALISATION OF THE AACHEN KERATOPROSTHESIS - FIRST INTRAOPERATIVE APPLICATIONS
N.F. Schrage, S. Langefeld, T. v. Fischern, C.J. Numan, L. Yuan, S. Kompa, N. Völcker, M. Reim, B. Kirchhof
Introduction: Design and product development of the Aachen-Keratoprosthesis are established. In cell culture experiments the efficacy of the chemical surface modification on haptic and optical part could be demonstrated. Now the final technical realisation of the prosthesis before implantation must be realised. The authorisation of ethical commission for first human application has been received recently.
Materials and methods: The problem of finding a recombinant fibronectin- analogon for surface modification had to be solved. Sterilisation of the modified haptic surface without loss of the protein activity had to be tested. Intraocular pressure measurements were tested and references to applanatory measurements had to be found. Additionally two different designs of the prosthesis were produced for short term implantation during vitreoretinal surgery and for long term implantation for example in surgery of eye burns.
Results: A recombinant fibronectin-fragment has been found, that still enhances cell adhesion on the haptic even after gamma-sterilisation. Reference measurements for applanatory intraocular pressure evaluation were established. A video about how to measure intraocular pressure on the Aachen-Keratoprosthesis will enable any ophthalmologist to perform intraocular pressure controls. First implantations in vitreoretinal surgery were successful (video).
Conclusion: The Aachen-Keratoprosthesis does not show any foreign body reaction during the first application in patients. The intraoperative handling of the prosthesis is comfortable. The surface modification enhances the wetting of the prosthesis surface during surgery improving intraoperative visibility.
Dept. of Ophthalmology, Technical University Aachen, Pauwelsstr. 30, D-52074 Aachen
IZKF "Biomat.", Technical University Aachen, Pauwelsstr. 30, D-52074 Aachen
Institute of Textile and Macromolecular Chemistry, Technical University Aachen, Veltmanplatz, D-52062 Aachen