[Damage to the corneal endothelium following exposure to sulfur hexafluoride gas]

Damage to the corneal endothelium caused by sulfur hexafluoride was analyzed in 14 rabbits. Fourteen eyes were used for testing, while the other 14 served as controls. Three stages of endothelial reaction resulting from long-term contact with sulfur hexafluoride were established by morphologic and morphometric analyses. The first stage - acute necrosis of the endothelial cells - covers all stages of destruction up to total obliteration in the exposed area of the endothelium, which is clearly demarcated from the rest of the endothelium. The second, repair stage, begins as early as 24 hours after the operation and includes the diverse forms of endothelial cell spread, transformations of the hexagonal endothelial cells, and endothelial cell migration with polymorphia and formation of rosettes. The third, proliferative phase of the endothelial cell reaction follows directly after the second phase and is characterized by the production of more giant cells, the production of giant rosettes, compaction of cell membranes and filling of the intercellular space with amorphous substances. The results of this research are of major practical relevance, since they show that a 40/60% sulfur hexafluoride/air mixture cannot be regarded as inert.