Specular microscopic appearance of damaged and dead endothelial cells in corneas following short-term storage

Specular microscopic evaluation of rabbit, pig, and cat corneas was performed after storage in a moist chamber in McCarey-Kaufman (M-K) medium or in tissue culture medium 199. Irrespective of the storage method, cooling at 4 degrees C resulted in a deterioration of the specular microscopic image. Most of the changes proved to be reversible if the tissue was quickly rewarmed to 35 degrees C and maintained at that temperature for 20 minutes. One change, dark areas larger than a single cell, was not reversible and increased in prevalence with increased storage time. Trypan blue staining revealed that the dark areas seen with the specular microscope contained damaged endothelial cells. Deep corneal striae tended to increase as the storage interval increased, and considerable cell damage occurred in the endothelium covering these folds. Storage in M-K medium was the most effective of the three methods in preventing deep corneal folds and endothelial damage.