The effect of topical cyclosporin A on the rabbit cornea. A clinical and electron microscopic study

To investigate the effect of topical cyclosporin A (CSA) on the rabbit cornea, both eyes of 80 animals were treated with CSA 2% eye drops over a 3-week period under various conditions. CSA was dissolved in castor oil or ethanol 13.8 vol. %. Slit-lamp, scanning and transmission electron microscopic examinations were performed. CSA 2% in castor oil given 5 times daily showed no damage to either the corneal epithelium or endothelium. In contrast the solutions containing ethanol revealed considerable epithelial cell damage.