Aachen-Keratoprosthesis as temporary implant. Case report on first clinical application

The Aachen-Keratoprosthesis was designed to serve as a permanent keratoprosthesis, modeling natural corneal physical properties as closely as possible. Prior to permanent application in patients, keratoprostheses are commonly tested in animal models to assess biochemical and biomechanical compatibility. However, immune and inflammatory responses acquired through animal experimentation are difficult to extrapolate in order to develop a predictable and generalized outcome in humans. Therefore, this preliminary report includes results following a temporary implantation of the Aachen-Keratoprosthesis in a patient during vitreoretinal surgery to assess the long-term prospect of application as a permanent artificial cornea.

A 43 year old man presented with a ruptured right eye resulting in an opaque cornea and retinal detachment. A soft silicone rubber keratoprosthesis, the Aachen-Keratoprosthesis, was temporarily implanted. Subretinal membranes were removed and the total retinal detachment was reattached. Liquid perfluorocarbon and silicone oil were used. The temporary keratoprosthesis was replaced by a 7 mm corneal graft after completion of surgery.

The Aachen-Keratoprosthesis was securely positioned into the trephined hole. It allowed complete visualisation of vitreous, retina and thus controlled manipulations in the vitreous cavity up to the extreme periphery. Leakage across the trephination-prosthesis interface was minimal.

We report the first temporary application of an innovative keratoprosthesis. Its flexibility and good optical qualities allow visualisation and control of intraoperative procedures. This temporary pilot study of the Aachen KPro encourages further investigation of the Aachen KPro as a permanent replacement for a diseased cornea.