Comparative outcomes of penetrating and component endothelial cell corneal allografts in outbred sheep
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Date
2012-12-04
Authors
Mills, Richard Arthur
Klebe, Sonja
Coster, Douglas John
Williams, Keryn Anne
Journal Title
Journal ISSN
Volume Title
Publisher
Cognizant Communication Corporation
Rights
© 2012 Cognizant Communication Corporation
Rights Holder
Cognizant Communication Corporation
Abstract
Lamellar (component-cell) corneal transplantation is replacing penetrating keratoplasty
for some corneal disorders in humans; but the relative risks of immunological graft
rejection for the two procedures are uncertain. A model of component endothelial cell
keratoplasty (endokeratoplasty) was developed in the outbred sheep. Clinical and
histological graft outcomes after endokeratoplasty were then compared with
contemporaneous penetrating corneal allografts. No topical or systemic
immunosuppression was administered to any recipient sheep. Endothelial cell allografts
(n = 10) took significantly longer to achieve perfect transparency following surgery than
did penetrating corneal grafts (n = 7) (day 10 versus day 4; p = 0.003; two-tailed Mann-
Whitney U-test). The median day to rejection of penetrating grafts was post-operative
day 18; and of endothelial cell grafts was day 48 (p = 0.04; two-tailed Mann-Whitney
U-test). The clinical courses of the two procedures were quite different. Penetrating
grafts gained clarity quickly but exhibited rapid graft neovascularization. Clinical
rejection was preceded by inflammation in the anterior segment. Endothelial cell grafts
exhibited a fluctuating; more indolent course of opacification; although all did
eventually fail. Histological analysis confirmed immunological rejection in all failed
grafts; but with different patterns of leukocytic infiltration in endokeratoplasties
compared with penetrating keratoplasties. Inflammatory cells in endothelial cell grafts
were generally fewer in number and were more often found in the posterior stroma. We
conclude that in the absence of immunosuppression; all endothelial cell allografts do
undergo immunological rejection; albeit at a slower tempo than penetrating grafts.
Description
Keywords
Opthalmology, Corneal grafting
Citation
Mills, R.A.D., Klebe, S., Coster, D.J. and Williams, K.A., 2012. Comparative outcomes of penetrating and component endothelial cell corneal allografts in outbred sheep. Cell Transplantation, 2012 Dec 4 [Epub ahead of print PMID: 23211557].