A comparison of two preservation media (CSM and K-Sol) by scanning electron microscopy of preserved corneal endothelium.

We compared by scanning electron microscopy the structural preservation of the endothelium of three groups of human corneas after 14 days of refrigerated storage in media, with one eye in K-Sol and the fellow eye in CSM. Each group used a different production lot of CSM and K-Sol. Group 1 comprised ten corneal pairs, and groups 2 and 3 each comprised six corneal pairs. In group 1, K-Sol provided better preservation for each of the ten corneal pairs, but CSM was equal or possibly superior to K-Sol in groups 2 and 3. Variation between different lots from the same manufacturer probably explains the results, which emphasizes the need for consistency in the composition of these preservative media. Large areas of endothelial cell disruption were found in the periphery of the majority of the corneas. Seven of the 44 corneas had no viable endothelial cells. As storage times increase, methods are needed to detect corneas that are not well preserved. We found no consistent differences in the efficacy of corneal preservation between CSM and K-Sol.