The Effect of Intraocular Lidocaine in White Rabbit Eyes

Purpose: Recently, intraocular lidocaine anesthesia has been used in cataract surgery. We studied the toxicity of intraocular unpreserved lidocaine for corneal endothelial cell and retina using Japanese white rabbits.Methods: The rabbits were divided into two groups. One group was injected intracamerally and the other was injected intravitreally with 0.2 ml of unpreserved lidocaine of 0%, 0.02%, 0.2%, or 2% concentration. The number of corneal endothelial cells was measured 1 week after the injection. After measurements, the rabbit corneas were studied histologically. The retina was examined by electroretinogram prior to initial injection through 1 week after the injection.Results: There was no significant change in number of corneal endothelial cells after injection of 0.2% lidocaine. However, histological abnormality was seen in corneal endothelial cells after 2% lidocaine injection. There was also significant change in electroretinogram with 2% lidocaine injection. No histological abnormality was seen in the retina 1 week after the injection.Conclusion: The rabbit cornea and retina manifested no serious changes after the injection of lidocaine at less than 0.2% concentration functionally and histologically.