Effects of air and irrigating solutions on the corneal endothelium.

It is well established that the corneal endothelium reflects the trauma it experiences by changing its morphological appearance. We have studied the effect of mild trauma to the rabbit endothelium by replacing the aqueous humor with air. After either 2 or 4 h, the air was removed and then replaced with either physiological saline or balanced salt solution (BSS). Specular microscopy was then performed for 1 week to observe endothelial changes. Various transient morphological changes observed during this period included many nonhexagonal cells, enlarged cells, and clusters of small cells. The changes produced were more dramatic for the saline replacement group than the BSS replacement group, indicating that the recovery process of the endothelium following this mild trauma depends on the material used to replace the air. The air appears to sensitize the endothelium to subsequent insult. This model can perhaps be used to evaluate the relative safety of the various solutions that are used in the anterior chamber during ocular surgery.