Effect of carbachol on rabbit corneal endothelium.

We investigated the current reformulation of the commercially available intraocular preparation of carbachol for its effect on corneal thickness and endothelial cell ultrastructure. A 15-minute perfusion in the specular microscope with 0.01% carbachol caused a significant increase in the corneal swelling rate, which returned to control values after 75 minutes of reperfusion with Krebs Ringer bicarbonate solution. Continued reperfusion with Krebs Ringer bicarbonate solution led to the final average corneal swelling rate being statistically similar to that of controls over the entire 180-minute perfusion period. Transmission and scanning electron microscopy demonstrated no changes in endothelial cell ultrastructure.