Quantitative evaluation of the effects of a bicarbonate and glucose-free balanced salt solution on rabbit corneal endothelium in vitro.

Whole corneas from 2- to 2.5-kg albino rabbits were perfused in vitro at 35 to 36 degrees C with a commercial balanced salt solution (BSS) that lacks bicarbonate and glucose. The corneas swelled at an average rate of 45 +/- 11 microns/h. Evaluation of the corneal endothelium by scanning electron microscopy revealed no obvious cytotoxic effect beyond the occasional small area affected by air bubble damage. Morphometric analysis of the central corneal endothelium revealed no significant differences between the endothelial mosaic of perfused corneas, when compared to freshly fixed corneas, in terms of percentage 6-sided cells (pleomorphism) and variance in cell areas (polymegethism). In this example, therefore, a corneal swelling induced by a bicarbonate and glucose-free BSS does not appear to be due to either obvious endothelial cytotoxic effects or significant morphological alteration of the endothelial mosaic.