Abstract
Purpose:
Amniotic membrane (AM) transplantation is the gold standard for ocular surface reconstruction. However, keratin films (KF),was proposed as an alternative carrier and showed to be suitable for corneal epithelial cell expansion. Aim of this study was to evaluate the biocompatibility of KFs with different aqueous and alkaline dialysate ratios (100, 90.10, 80.20) in a rabbit model.
Methods:
In accordance with ARVO statement for the use of animals in ophthalmic research, 30 New Zealand white rabbits underwent manual dissection of a corneal intrastromal pocket in which a 4mm implant of AM or KF (100, 90.10, 80.20, each n = 6) was placed; in 6 control animals no implant was placed (C). In each group half of the animals received steroids twice daily for 10 days, while the other half was left without any steroid eye drops. At the end of the follow-up slit lamp examination was performed to grade corneal transparency, neovascularization and epithelial integrity. The corneal scleral button was processed for histology.
Results:
In the groups left without steroids, slit lamp examination showed a transparent cornea in all control and AM eyes while transparency was reduced in 5 out of 9 eyes with a KF implant. In the group treated with steroids the cornea was transparent in all control while transparency was reduced in 2 out of 9 eyes with KF implant and in 1 out of 3 eyes grafted with AM. Neovascularization was observed in 1 out of 9 eyes grafted with KF in the steroid group and epithelial defects were detected in 1out of 9 eyes grafted with KF in the non-steroid group. Histological examination revealed eosinophilic cells and macrophage stromal infiltration in all KF groups treated without steroids. Dexamethasone prevented any inflammatory response in eyes with KF implants.
Conclusions:
Keratin film based matrices can be successfully implanted into a corneal stromal pocket in vivo. They induce a mild inflammatory response which can be controlled with low dose topical steroids. Further experiments have to evaluate long-term biocompatibility and KF feasibility as graft material in ocular surface reconstruction.
Keywords: 479 cornea: clinical science •
765 wound healing