Morphological changes in rabbit cornea after implantation of a new keratoprosthesis supporting plate

Abstract

To evaluate biocompatibility of the new keratoprosthesis supporting plates (KSP) in rabbits in vivo. The study included 15 chinchilla rabbits. In the first group (5 rabbit eyes) KSP made of hydrophobic acryl with square penetrating holes of 220×220 micron (model 1) were inserted into rabbits' corneas. In the second group (5 eyes), KSP made of hydrophobic acryl were used that had trapezoidal fenestrations with size (from 170×130 micron to 180×70 microns) gradually changing from periphery to the center of KSP (model 2). The control group rabbits (5 eyes) had 1/2 of Fyodorov-Zuev KSP made of titanium implanted. All animals were observed for up to 3 months with biomicroscopy and optical coherence tomography of the anterior segment. The animals were then euthanized and had their corneo-scleral discs excised and then examined with optical microscopy and scanning electron microscopy (SEM). After 3 months, there was only one case of KSP protrusion in the first group. In the second group, thinning of the corneal layers above the central part of KSP occurred in one case. The presence of polymer KSP (of both models) in the corneal stroma was found not to cause formation of rough fibrotic tissue. At the same time, adhered cellular and fibrous elements were discovered on the surface and inside the holes of the polymer KSP, while on the surface of the titanium plate cellular elements were absent. Supporting plates made of hydrophobic acrylic material can potentially serve as a foundation for the new keratoprosthesis design.