Stromal architecture and immune tolerance in additive corneal xenografts in rodents.
OBJECTIVE
To examine immune tolerance and corneal ultrastructure following additive corneal xenografts in rodents.


METHODS
We carried out surgical implantation of excised BALB/c mouse corneal tissue, either freshly isolated (n=6) or after storage at--20 degrees C for 1 week (n=7), into the corneas of Wistar rats at approximately mid-stromal depth. Corneal opacity and neovascularization were evaluated postoperatively, and stromal ultrastructure was observed by transmission electron microscopy.


RESULTS
Corneal opacification and neovascularization in the weeks after surgery were less prevalent in grafts of frozen-then-thawed tissue than in grafts of fresh tissue. In a well tolerated frozen-then-thawed xenograft, the matrix architecture was normal throughout most of the recipient and donor tissue, but pronounced fibrillar disorganization was evident adjacent to Descemet's membrane.


CONCLUSIONS
We attribute the improved tolerance of frozen-then-thawed xenografts over fresh xenografts to a reduced cellular immune response.
Quantock
Andrew J
AJ
School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.
Sano
Yoichiro
Y
Young
Robert D
RD
Kinoshita
Shigeru
S
D000818:Animals; D016510:Corneal Neovascularization; D003318:Corneal Opacity; D003319:Corneal Stroma / Q000276:immunology* / Q000601:surgery / Q000648:ultrastructure*; D016039:Corneal Transplantation / Q000276:immunology*; D015925:Cryopreservation; D007108:Immune Tolerance; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D017208:Rats, Wistar; D014183:Transplantation, Heterologous