Deep Lamellar Endothelial Keratoplasty For Bullous Keratopathy In Rabbit

Objectives1. To establish a rabbit model with permanent endothelial damage, which is suitable to evaluate the therapeutic effects of corneal transplantation.2. To perform the deep lamellar endothelial keratoplasty (DLEK) through a scleraocorneal pocket incision on the rabbit model with self-made surgical instruments, and to assess the feasibility, therapeutic effect and complications of this transplantation method.3. To observe the corneal topography changes of the early stage after small-incision DLEK.Methods1. A total of 24 adult rabbits were assigned randomly into 2 groups. In one group (group Endo), a 30 gauge air injection cannula was inserted into the anterior chamber of the right eye viathe cornea, lmm central to the limbus, then the corneal endothelium were scratched while in the other group ( group DM+Endo), both the corneal endothelium and the Descmet's membrane was scraped off. The corneal cloudiness and edema were assessed by slit lamp, the corneal thickness measured by ultrasound biomicroscopy, and the endothelium observed and counted with specular microscopy. Corneal samples were examined by endothelium staining and HE staining at various time points. 2. Thirty-two rabbits with Bullous keratopathy (BK) wererandomly divided into two groups. In one group (group DLEK), a lamellar pocket was created through a superior limbus incision, a self-made specialized trephine was centered within the lamellar pocket, and a 7-mm trephination of the posterior stroma and endothelial tissue was performed, then a 7.25mm donor disk with healthy DM and endothelium was placed in the recipient bed. In the other group (group PK), standard penetrating keratoplasty (PK) was performed. Corneal clarity, central corneal thickness and endothelium density were evaluated.3. Twenty rabbits without eye diseases were randomized to two groups. In one group (group sDLEK), DLEK was performed through a 4.0-5.0mm scleral incision 1.0mm peripheral to the limbus; in the other group (group PK), PK was performed. Corneal power, astigmatism, corneal uniform index; corneal unspherical index and visual acuity were assessed by corneal topography.Results1. In group DM+Endo, the cornea remained cloudy and edematous for 6 months, and the magnitude of corneal thickness remained 3-4 times of that before the mechanical injury; In group Endo, the cornea became to clear by 1 month after the injury, and the corneal thickness and endothelium count was close to the normal level by 3 months after the injury.2. In group DLEK, the cornea began clearing at 2 weeks after the surgery in 14 of the 16 eyes, the corneal thickness became close to the normal level 3 months after surgery. The graft endothelial cell count at 6 months remained at normal range. The operation failed in 2 eyes, one because of the lamellar perforation, the other of anterior synechia. Fourteen of the 16 corneas also began clear at 2 weeks after surgery, two failed because of...