White light confocal microscopy of preserved human corneas from an eye bank

To verify the possibility of using a commercially available ophthalmologic white light confocal microscope for imaging optical sections of donated corneas preserved at 4 degrees C, especially for endothelial evaluation.

Sixteen corneas donated to the Warsaw Eye Bank but excluded from use in surgery for serological or morphologic reasons were examined using a ConfoScan 3 confocal scanning microscope (Nidek Technologies, Padova, Italy) and a Konan Eye Bank KeratoAnalyzer specular microscope (Konan Medical, Inc.; Hyogo, Japan). Images of corneal structures were obtained, including epithelium, corneal nerves, stroma, and endothelium. The endothelial cell density was calculated for both microscopes, and the results were compared.

For images obtained with the specular microscope, mean (+/- SD) endothelial cell density was 2168.6 +/- 404.0 cells/mm; for confocal microscope images, mean +/- SD was 2090.9 +/- 369.1 cells/mm. There was no significant difference between the methods.

White light confocal microscopy can be used for high-magnification imaging of corneas preserved in an eye bank with the 4 degrees C method, and images obtained permit evaluation of endothelium. Although the quality of confocal microscopy images of eye bank corneas is generally lower than that achieved with in vivo examinations, and although technical adaptations are needed for easier and safer application to corneas intended for transplantation, confocal microscopy is a promising new tool for evaluation of collected corneas.