Abstract
Purpose: :
Intracorneal rings and segments are an alternative of surgical correction of myopia and an alternative in the care of corneal disorders like keratoconus. The purpose of this research is to evaluate, in an experimental animal model in hen, the outcome of intracorneal segments with clinical and cell biology parameters.
Methods: :
PMMA segments (Ferrara Rings) were implanted in 24 Lohmann Classic hens, closely mimic the human technique. Animals were evaluated at several time–points (4h, 12h, 24h, day 3, 7, 15, 30 and 60) for clinical signs and histology. Clinical reaction (conjunctiva redness and corneal transparency) were evaluated under surgical microscope on a scale previous described. Corneas were extracted after appropriate euthanasia and tissue were processed for light microscopy, Tunnel procedure for apoptosis study, Brdu inmunostaining for cell proliferation and actine staining for myofibroblast characterization.
Results: :
Intracorneal segments were well tolerated with minimal conjunctival redness and preserving corneal transparency. Apoptotic keratocytes were found in the border of the stromal tunnel with the peak at 12 h and progressive disappearance at the 3rd day. Proliferation of keratocytes were progressive detected arising from the limbus to cover the injury zone at day 3. Also a proliferative reaction was detected at the corneal epithelium immediately superior to the top of the segment. Myofibroblast were present surrounding the segments with a peak at 15 days and progressive reduction and disappearance at day 60.
Conclusions: :
An animal model of corneal wound healing after intracorneal segment implantation was developed. Segments were well tolerated from the clinical point of view and there were an active wound healing reaction with apoptosis, proliferation and myofibrobast formation similar to other corneal refractive surgery procedures that we previous described
Keywords: cornea: stroma and keratocytes • refractive surgery: other technologies • pathology: experimental