Clinical and Pathological Outcome of New Materials for Corneal Additive Surgery

Abstract

Purpose: : To evaluate the clinical and histological outcome of new materials for additive corneal surgery (intra corneal ring and segments) in an experimental animal model.

Methods: : In an experimental animal model (Gallus domesticus) of intra stromal ring-segment implantation (ferrara technique) previously described by us, prosthesis of different materials were implanted.The outcome measured was clinical (time of epithelial closure, infection, haze and inflammation) and histopathological (classic light histology, apoptosis with tunnel, proliferation with Brdu and cell differentiation to myofibroblast with anti SMA staining).Twenty four hens were divided in 4 groups of four animals that underwent surgery and ring segment implantation of A. Classic PMMA segment. B. Silicon hydrogel segment. C. Acrylic copolymer segments D. No segment (only intrastromal channel).At one and three months three hens of each group were sacrificed, afterwards corneas were removed and fixed for histopathology analysis.

Results: : All the segments from different materials were well tolerated after stromal implantation with no central clinical haze, no infections and epithelial closure of the corneal wound in 2 days. Histopathological study showed no significant statistical differences among the groups of animals with the different segment implanted for the parameters evaluated: apoptosis, proliferation and myofibroblast formation, but much less reaction was detected for this 3 parameters in the group that underwent stromal surgery with no segment implantation (P<0.05)

Conclusions: : Classic PMMA, acrylic copolymers and hydrogel segments are well tolerated after intra-stromal implantation with good clinical and histopathological outcome.

Keywords: refractive surgery: other technologies • cornea: clinical science • keratoprostheses