Histological and confocal changes in rabbit cornea produced by an intrastromal inlay made of hexafocon A

The aim of this study was to evaluate biocompatibility of a newly proposed intrastromal inlay in rabbit corneas.

Eighteen eyes of 9 New Zealand rabbits were included in this prospective study. An intrastromal pocket was created in both eyes using Melles instruments. Annular intracorneal inlays made of hexafocon A were implanted randomly into the stromal pocket of one eye of each rabbit. Confocal microscopy was performed at each visit during 6-month follow-up. After 6 months, the rabbits were killed and corneal tissues of both eyes were sent for light microscopic studies.

Mild stromal edema was present during the first few days and disappeared afterward with mild haze around the tunnel site in all cases. Deposits around the lamellar channel developed in 3 implanted eyes and in none of the pocket-only eyes. No neovascularization or epithelial downgrowth was present at the incision site in any case. All inlays remained centered and optically clear. In confocal imaging, we observed no significant difference in keratocyte cell density and inflammatory cells between the control pocket-only group and inlay group. In pathological evaluation, there was no difference in the average epithelial thickness between both groups. Descemet membrane and endothelium appeared normal in both groups.

This study revealed safety and biocompatibility of hexafocon A as an intracorneal inlay in rabbits.