Clinical and histopathological analysis of intrastromal segment explantation in normal and complicated corneas in an experimental animal model

Poster Details

First Author: L.Ibares-Fr SPAIN

Co Author(s):    C. Martinez Garc   P. Gallego   R. Cantalapiedra Rodriguez   M. Avella   J. Merayo Lloves  

Abstract Details

Purpose:

To determine, in an experimental animal model, the relationship between the clinical and histological findings in the cornea after Intrastromal Ring explantation and the electronic microscopic findings on the Segment surface after this explantation of the segments.

Setting:

Cell Biology, Histology and Pharmacology Department. University of Valladolid.

Methods:

As an animal experimental model we used the hen. Animals were cared for following the guidelines of the ARVO Statement for the use of Animals in Ophthalmic and Vision Research. The segments were implanted in both eyes at 70-80% corneal thickness (250-300 micrometers) closely mimiking the human manual technique (Ferrara Technique). The segments were Ferrara Segments. (Ferrararing®). On time proposed, Segments were explanted from 6 eyes. In three eyes the segments were explanted by complications (neovascularization and risk of extrusion) and in the other 3, used as a control (without complications) the segments were explanted 3 months after implantation. Later, the segments were placed in a fixation solution of Palay during 2 hours and then they were moved to a solution of Phosphate tampon. Later, they were watched in a electronic microscope at Low Vacuum Mode. At time proposed, hens were euthanized and clinical analysis of the eyes were made too. The corneas were fixed and stained for histological analysis with hematoxilin-eosin.

Results:

On the explanted segments of corneas with complications we could see under Electronic Microscopy analysis, biodeposits of extracelular matrix, cells (epithelial cells , macrophages and limphocites) and collagen fibers. They were found predominantly on the proximal end of the segment, next to the incision.All this findings could be related with clinical and histological findings. On the explanted segments, used as a control we only could see deposits of extracellular matrix and collagen, and cells which appeared to be keratocytes This findings were predominantly found along the inner radius of the ring segments. We did not find any inflamatory cell. Those findings could be related with the deposits shown in clinical analysis. As regards histological analysis this findings could be related with deposits of keratocytes along the inner radius of the segments.

Conclusions:

In cases of segment complications we confirmed inflamatory reaction. The absence of inflamatory reaction in normal clinical follow-up segments support that the Intrastromal Ring Segments are well tolerated. We believe that this is the first study which compare clinical, histologic and electron-microscopic findings after explantation of intrastromal ring segments in an experimental animal model. FINANCIAL DISCLOSURE?: No