The effect of vancomycin on the corneal endothelium

Possible toxic effects of vancomycin on the corneal endothelium were assessed in rabbit eyes and subsequently in corneal transplant recipients. Fifteen New Zealand White rabbits were divided into five groups of three rabbits each. A paracentesis was performed on right eyes only. One hundred microliters of aqueous humor was removed followed by anterior chamber injection of 100 mu l of balanced salt solution (BSS) or varying concentrations of vancomycin (150, 750, 1,875, 7,500 mu g/ml). Left eyes served as untreated controls. Endothelial cell morphology and density were assessed by contact specular microscopy 48 h postinjection. There was no statistically significant difference in endothelial cell density between left (control) or right (treated) eyes receiving either BSS or varying concentrations of vancomycin. Transmission electron microscopy of rabbit corneal endothelium exposed to varying concentrations of vancomycin (150, 750, 1,875, 7,500 mu g/ml) showed no toxic effects. Six patients undergoing penetrating keratoplasty (PKP) received donor corneas stored in Optisol containing gentamicin to which vancomycin was added to make a final concentration of 150 mu g/ml. Eight patients undergoing PKP received corneas stored in Optisol alone. Specular microscopy was performed preoperatively and 3, 6, and 12 months postoperatively. No statistically significant difference in mean endothelial cell change was observed (Wilcoxon signed-rank test) at any time point postoperatively. Endothelial cell morphology and function are not adversely affected by therapeutic doses of vancomycin.