[Corneal preservation at 31 degrees C--experimental study]

To study the cornea, specially the corneal endothelium in preservation media for different periods of time, trying to assess the best period of preservation. To evaluate the endothelial cell loss during preservation, trying to assess the endothelial cell minimum density for a cornea able to be preserved.

We studied 7 human corneas and 15 pig corneas. We used the inverted specular microscope, Axiovert 100. We used the soft KS 400 for image processing. We used to preservation medium: Inosol-like. We made an initial examination, then after 1,4,7,10 and 14 days.

In human corneas the mean cell loss(%) was 4.1% from initial cell density after 4 days of preservation, 14.7% after 7 days, 18.6% after 10 days and 23.4% after 14 days. In pig corneas the mean cell loss (%) was 2.3% from initial cell density after 4 days of preservation, 8.8% after 7 days, 14.9% after 10 days and 23% after 14 days.

The best period of preservation in Inosol-like medium is 7-10 days. This period may be extended to 14 days. During preservation there is an endothelial cell loss which after 14 days is about 23% from initial endothelial cell density (about 550 cell/mm2). The minimum initial endothelial cell density for a cornea to be able to be preserved is 2400 cell/mm2.