Toxicity of xylocaine to rabbit corneal endothelium

Purpose: To assess the toxicity of lidocaine hydrochloride (Xylocaine(R)) to the corneal endothelium. Setting: Department of Ophthalmology, Hotel-Dieu Hospital, Paris, France. Methods: Rabbit corneas were excised and the endothelium was exposed to balanced salt solution (BSS(R)), Xylocaine 1%, or Xylocaine 5% (5 corneas/group) for 20 minutes. The endothelium was then stained with trypan blue and alizarin red, and 5 photomicrographs were taken of each cornea at a standard magnification and analyzed with a digital imaging system (Biocom 200). Results: Xylocaine solutions produced changes in endothelial cell morphology, but there was no cell staining with trypan blue. Corneas exposed to Xylocaine 5% had more marked cell alterations. Small areas of cells were lost from all 15 corneas, mainly at the periphery, but the difference among the 3 groups of corneas were not significant. Conclusion: Exposure of rabbit corneal endothelium to Xylocaine solutions in vitro was not associated with trypan blue staining of endothelial cells.