Abstract
Purpose: :
To quantitatively assess through calcein AM staining the endothelial cell damage to pre-cut corneal grafts deemed unsuitable by standard eye bank techniques of slit lamp and specular microscopy
Methods: :
Specular and slit-lamp microscopies were utilized to determine suitability for EK preparation and subsequent transplantation according to Eye Bank Association of America standards. These evaluations were preformed on corneas pre and post EK preparation with a microkeratome. During the time period of October 2011 to November 2011 there were two corneas that were deemed not suitable for transplantation due to difficulty visualizing cells and atypical appearance of cell morphology upon specular and slit-lamp exam. The unsuitable corneas and a sampling of suitable corneas (n=6) were trephinated and stained with calcein AM, images were captured with florescent microscope and endothelial cell loss (ECL) was calculated using Adobe Photoshop. Mean ECL was compared between groups using Mann Whitney U-test in SPSS v. 19.
Results: :
Cell viability staining demonstrated 10% ECL at an average of 5 days post-processing for tissues deemed unsuitable for transplantation compared to 13% ECL in the control group sample. This difference was not statistically significant (p=0.505).
Conclusions: :
We have demonstrated that grafts deemed unsuitable by traditional methods of exclusion (specular and slit lamp evaluation) may have minimal endothelial cell damage and could still be used for transplantation. Viability staining of the entire graft after processing could be helpful in determining suitability for transplantation and avoid unnecessary tissue wastage. Further investigations regarding long-term viability of this endothelium with atypical appearance upon slit-lamp and specular microscopy is warranted.
Keywords: cornea: endothelium • transplantation • imaging/image analysis: clinical