Wound healing and refractive changes after inverted and normal implantation of intrastromal ring segments in an experimental animal model

Poster Details

First Author: L.Ibares-FrÄ·as SPAIN

Co Author(s):                  

Abstract Details

Purpose:

To evaluate stromal wound healing, clinical follow-up, complications and refractive changes in an animal model after normal and inverted intrastromal ring implantation.

Setting:

Cell Biology, Histology and Pharmacology Department. University of Valladolid

Methods:

As an animal 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. We performed surgery for this study on 48 hens (96 eyes) and implanted one segment in each eye. The size of the segments was 150 micrometres , 90 degrees in arch and the shape was triangular (FerrararingĀ®). The eyes after surgery were divided into 2 groups as regards intrastromal ring implantation inverted or normal. We did clinical follow-up under surgery microscope, refractive measurements with a special device and histological analysis with hematoxilin-eosin stain.

Results:

9 rings were implanted in an inverted way and 87 correctly. All the segments normally implanted were well clinically tolerated. In 3 segments inverselly implanted, we found complications (extrusion and neovascularization). We did not find statistically significant differences between both groups in the clinical follow-up in normal corneas. As regards histological analisis, in the group with the inverted implanted ring with a normal follow-up, we noticed less epithelial hipoplasia over the segment and hipercellularity around the segment. However, we observed more oedema in posterior stroma in this group. The refractive change after inverted implantation was smaller than in the group in which we implanted the segment in a normal way.

Conclusions:

The inverted implantation was not quite well tolerated in our animal model. However, in normal follow-up corneas of both groups we did not find statistical clinical differences with normal implantation.The wound healing response evidenced that the epithelial hipoplasia is directly related to the apex of the triangular ring and the hipercelullarity could be related to the tension strengths due to the shape and disposition of the rings in the stroma. FINANCIAL DISCLOSURE?: No