Endothelium of the human organ cultured cornea: an electron microscopic study

Utilizing transmission electron microscopy (TEM) and scanning electron microscopy (SEM) six pairs of human corneas were studied as to the effect of moist chamber storage vs varying lengths of time in organ culture (up to 3 weeks) on the ultrastructure and surface morphology of the endothelial cells. The length of moist chamber storage time was proportional to the area and severity of cell damage. The fellow cornea in organ culture 21 days demonstrated covering of the defect left by these damaged cells by a dynamic process of endothelial cell enlargement and thinning, thereby spreading to cover these defects. Although these cells appeared to maintain ultrastructural integrity, they were extremely thin (<1μ) and contained few mitochondria. Corneas kept in moist chambers no longer than 12 hours and stored from 10 to 21 days did not demonstrate this endothelial cell thinning and enlargement. These cells also maintained ultrastructural integrity although in some the mitochondrial population was decreased. Round cells, that may represent dividing cells, were seen on the endothelial surface of organ cultured corneas where moist chamber storage was prolonged or the culture medium may have been infected.