Abstract
Purpose:
To demonstrate the feasibility of a new form of penetrating keratoplasty with a lamellar component in an experimental animal and human cadaver eyes. Graft dislocation test and bursting pressure were used to evaluate stability.
Methods:
25 freshly enucleated sheep cadaver eyes and 4 human cadaver eyes not suitable for corneal transplantation were used in the study. A divergent angle trephination (from surface to endothelium) using the Intralase FS (Abbot Medical Optics, IL, USA) was planned. Eyes were placed in a special holder and bursting pressure after transplantation was measured using Tonopen (Reichert, Depew, NY). Donor corneas measured 7.3 mm, recipients 7.0 mm. After mechanical tests, globes were fixated in formalin for HE and PAS staining.
Results:
No major difficulties were observed during the procedure. The insertion of the donor discs was relatively straightforward, through the planned self-sealing incisions of 4 mm. Total pressure resisted after bursting pressure tests was above 75 mmHg in all cases. With manipulation of the graft with cyclodialysis spatula, donors were easily centered in recipient beds. At histology, selected eyes showed a good apposition of the wound, despite some graft shrinkage in some areas induced by the fixation process. A 45 degree cut angle was confirmed in pathology slides. Endothelial cells looked favorably healthy in the animal eyes evaluated.
Conclusions:
A potential new method for corneal transplantation preserving an intact corneal surface was demonstrated. Graft stability and wound apposition seemed acceptable in our model. Although an ex vivo study cannot demonstrate the events occurring in real patients, the biomechanical feasibility of the procedure seems to be proven with this study.
Keywords: 479 cornea: clinical science •
741 transplantation •
467 clinical laboratory testing