Abstract
Purpose: :
To evaluate endothelial cell density and viability at different time points in corneal grafts cut for endothelial keratoplasty.
Methods: :
Ten human research corneas acquired from the North Carolina Eye Bank were sectioned 300 micrometers deep using a mechanical microkeratome and stored in Optisol GS at 4°C. The cut separated endothelium and Descemets complex, similar to the intraoperative preparation of corneal tissue for use in the Descemets Stripping technique for Endothelial Keratoplasty (DSEK). Specular microscopy was used to obtain endothelial cell density pre–cut, post–cut, 24 hours post–cut, 48 hours post–cut and 72 hours post–cut. Endothelial cell damage was assessed in at least one graft from each time point using vital staining with trypan blue 0.25% and alizarin red S 0.2% and light microscopy evaluation at 100x magnification.
Results: :
The mean corneal endothelial cell density prior to tissue cut was 2780 cells/mm3 (N=10, standard deviation [SD] 348). The mean post–cut endothelial cell density was 2687 cells/mm3 (N=10, SD 493). Mean endothelial cell density at 24 hours post–cut (obtained at range 20.6 to 24.8h) was 2609 cells/mm3 (N=8, SD 487), representing a mean change of +1.4% (SD 4.6%) from post–section levels. Mean endothelial cell density at 48 hours post cut (obtained at range 46.9 to 49.3h) was 2655 cells/mm3 (N=4, SD 215), representing a mean decrease of 2.5% (SD 5.5%) from post–cut levels. A single graft was followed to the 72 hour time point with an endothelial cell density of 2219 cells/mm3, representing an 11.3% decrease from post–cut levels. Vital staining showed relative preservation of endothelial cell viability in grafts up to the 24–hour time point.
Conclusions: :
Pre–cut corneal donor tissue for endothelial keratoplasty are viable alternatives for transplantation. In this study, there did not appear to be significant endothelial cell loss within the first 24 hours post–cut. Additional validation of these results with further studies will be useful to delineate the quantity and pattern of endothelial cell loss.
Keywords: cornea: endothelium • anterior segment • transplantation