Experimental Study On Corneal Endothelial Keratoplasty In Rabbits

Partâ… The establishment of experimental animal model for bullous keratopathyObjective: To establish model in rabbits with Permanent endothelial damage, which issuitable to evaluate the therapeutic effects of bullous keraopathy with corneal epitheliumtransplantation. Methods: A total of 48 New Zealand rabbits were assigned randomly into2 groups. Group A: a No.5 air injection needle bent 90 degrees from its 1.0mm needle tip with an obtuse angle was inserted into the anterior chamber of the right eye cornea formlmm central to the limbus, then the corneal endothelium and the Decemet's Membranewere scratched. While in the B group, only corneal endothelium was scraped off. Thecorneal turbidity and edema were assessed by slit lamp, the corneal thickness measured byVisante OCT, and the endothelium was observed and counted with specularmicroscopy.Corneal samples were examined by endothelium staining and HE staining atvarious time points.Results : In group A, the cornea remained turbidity and edema for 3months, and thecorneal thickness remained 3-4 times before mechanical injury. In groupB, the cornea became to clear in 21d after the injury, and the corneal thickness andendothelium count were close to the normal level at 3months after the injury. Conduslon:Mechanical abrasion of Desemet's membrane and endothelium could set up permanentendothelial injury in rabbits. Partâ…¡Experimental study on corneal endothelial keratoplasty in bullous keraopathyObjective:To research t corneal endothelium transplantation in BK, and to provide newmethods and evidence for the therapy of BK. Methods To arrange 40 New Zealand Whiterabbits in 3 groups:. Group A, 5 normal cornea in 5 rabbits; Group B, the contrast group ofBK in 20 rabbits; Group C, the corneal endothelium grafting with endothelium ofDescemet's membrane in 20 bullous keratopathy eyes in 20 rabbits. Right eyes were onoperation. The corneal transparency of the operation eyes of 3 groups were observed underthe slit lamp in 1 d, 3 d, 7 d, 14 d, 21 d, 28 d and 3 month after operations. And theimplants adhesiving condition of corneal endothelium, corneal thickness and complicationswere observed in group C. The endothelial cell density was measured in 21d, 28 d and 3month after corneal endothelium grafting. Corneal endothelial cells was stained withAlizarin red.The cicatrix condition of separating surfaces was assessed between the transplant and the recipient cornea in 7d, 14d ,21dand 28d after operations by histology.The morphological changes of corneas and the changes of central corneal thickness wereobserved in 3 groups for1d, 7d, 14d, 21d, 28d and 3month after operations by VisanteOCT. The cells in aqueous were observed by Wright's staining in 1d, 3d, 7d, 14d and 21dafter operations. Results The cornea of group A is transparent. The corneal edema ofgroup B was persistent to exist. The attach of graft was good in group C after surgery by7d, and the corneal transparency resumed after 14d, and corneal endothelium and receptorgrafts healed well, there was no significant scar formation between layers. Group B couldnot show corneal endothelial cell layer. Group C of corneal endothelial cells were arrangedregularly in 7d, while a small amount of corneal endothelial cell loss in 14d and cell densitywas reduction. Small number of endothelial cells continued to reduce in 21d and theendothelial cells stabilized in 28d. By the inspection of Visante OCT ,the corneal structureof group A was integrated and arranged; the corneal turbidity and loose stroma werepersistently to exist for 3 month in group B .The corneal structure of group C wasintegrated and arranged in 7d, the graft interface between the bed and graft were notobvious, cornea became thinner than the previous in 14d, reflective band of cornea couldbe seen in the cortex .The central corneal thickness stabilized in 21d. The aqueous cellscould not been checked with microscopy in group A, but more lymphocytes andmononuclear macrophages could be seen By Wright's staining in group B in 3d, and thesame time in group C ,only a small number of lymphocytes and mononuclear macrophagescould be seen. The aqueous cells could not been examined basically in 10d.ConclusionThis experimental study indicated that the direct transplantation of corneal endothelium is asimple and safe operation which has tiny injuries and slight intraocular reaction, which canprovide a new selective mode to the treatment for BK in clinic. Partâ…¢Experimental study on reservation of the Descemet's membrane in normal corneaObjective: To research the condition of corneal endothelium transplantation withDescemet's membrane reserved in normal cornea, and to study the attached conditions andmechanism of corneal endothelial transplantation. Methods To arrange 50 New ZealandWhite rabbits in 4 groups: right eyes were on operation .Group A, 5 normal cornea in 5rabbits; Group B, the contrast group of BK in 5 rabbits; Group C, the corneal endotheliumgrafting with endothelium of Descemet's membrane reserved in normal cornea in 20rabbits; Group D, the graft was torn after the corneal endothelium grafting in normalcorneal in 20 rabbits. The corneal transparency of the operation eyes in A, B and C groupswere observed under the slit lamp 1d, 3d, 7d 14d, 21d, 28d and 3month after operations.And the implants adhesiving condition of corneal endothelium, corneal thickness andcomplications were observed in group C in 1d, 3d, 7d, 14d and 21d. The cornea situation was observed after the graft was torn after transplant in 1d, 7d, 14d, 21d,28d and 3 monthin group D. The endothelial cell density was measured in 21d, 28d and 3 month aftercorneal endothelium grafting. The cicatrix condition of separating surfaces was assessedbetween the transplant and the recipient cornea in 7d, 14d and 28d after operations byhistology. The morphological change of corneas and the change of central cornealthickness were observed in 4 groups for 1d,7d, 14d, 21d, 28dand 3month after operationsby OCT and the cells in aqueous was observed by Wright's staining in 1d, 3d, 7d, 14d, 21dand 28d after operations. Results The cornea of A group is transparent. The corneal edemaof group B persistently existed. Group C after 7d attached corneal endothelial was good,and the corneal transparency resumed after 14d, and corneal endothelium and receptorgrafts healed well, there was no significant scar formation between layers. Group B couldnot show corneal endothelial cell layer. Corneal endothelial cells of group B were arrangedregularly in 7d, while a small amount of corneal endothelial cell lost in 14d and cell densitywas reduction. Small number of endothelial cells continued to reduce in 21d and theendothelial cells stabilized in 28d. Group D at the first 3d the graft could be more easilytorn off after transplantation .The graft could be completely torn off in 7d, but graft hadattached with bed, in 14d day it became difficultly to tear the graft and it had large injuryfor endothelial, and in 21d it almost could not to tear apart from the graft, when the grafthad attached closely with bed. By the inspection of OCT ,the corneal structure of group Awas integrated and arranged; the corneal turbidity and loose corneal stroma werepersistently to exist for 3 months in group B. The corneal structure of group C wasintegrated and arranged in 7d, the bed and the grafts which be seen between the graftinterface was not obvious, and the corneal edema reduced significantly in 14d, corneabecame thinner than the previous, bed and between the grafts existed less scar. The centralcorneal thickness stabilized in 21d. The graft was torn at 1d after transplantation of 3d and7d in group D,when the cornea was edema, and the thickness increased; and corneal stromawas a little loose. The corneal edema could disappear in 3d, and the corneal structure was integrityand neatly arranged in 7d.The graft was torn at 1d after transplantation of14d ,when the cornea was obviously edema and the thickness increased,and corneal stromawas a little loose, the corneal endothelium was not full. At 7d corneal edema was slightlyreduced, the endothelium became completely.The aqueous cells could not been checkedwith microscopy ingroup A, more lymphocytes and mononuclear macrophages could beseen with Wright's staining in group B in 3d, and the same time in group C only a smallnumber of lymphocytes and mononuclear macrophages could be seen, and the aqueouscells could not been examined basically in 10d.Lymphocytes and mononuclearmacrophages could be seen more after the graft was torn at 1d in group D with Wright'sstaining,and lymphocytes and mononuclear macrophages reduced after 3d, and the aqueouscells could not been examined basically in 10d.Conclusion This study showed that cornealendothelial graft could attach with the retained Descemet's membrane endothelial celllayers, and with the time it was more closely attached, and the corneal endothelium graftcould survive and exert function. The normal corneal cells were interfered by the cortex,and were gradually inactivation or apoptosis.