Effect of topical anesthetic agents and ethanol on corneoepithelial wound healing in an ex vivo whole-globe porcine model

PurposeTo assess the impact of topical anesthetic agents and ethanol on ocular surface wound healing using an ex vivo whole-globe porcine model.SettingDepartment of Ophthalmology, Inselspital, University of Bern, Bern, Switzerland.DesignExperimental study.MethodsStandardized corneoepithelial lesions (5.0 mm diameter, 40 μm depth) were created with excimer laser light in freshly enucleated porcine eyes. The globes (6 per group) were exposed to different concentrations of ethanol (2.0% to 99.0%), cocaine (2.0% to 10.0%), procaine hydrochloride (0.4%), tetracaine (0.5% to 1.0%), or lidocaine (2.0%), 3 drops/hour for 3 hours. Control solutions were physiologic saline, balanced salt solution, and tissue-culture medium. After 20 to 26 hours, wound-healing response was compared by measuring the diameter of each corneoepithelial lesion.ResultsThe mean diameter of corneoepithelial lesions exposed to physiologic saline decreased from 4.78 mm ± 0.19 (SD) to 4.44 ± 0.17 mm between 20 and 26 hours. After 24 hours, the mean lesion size, compared with physiological saline, was larger after cocaine 5.0% (5.20 ± 0.26 mm) and 10.0% (5.39 ± 0.12 mm), tetracaine 0.5% (5.59 ± 0.35 mm) and 1.0% (5.55 ± 0.27 mm), and procaine hydrochloride 0.4% (5.76 ± 0.12 mm), but not after lidocaine 2.0% (5.01 ± 0.17 mm). Balanced salt solution, tissue-culture medium, ethanol 2.0% to 99.0%, and cocaine 2.0% did not inhibit the wound-healing response.ConclusionsIn an ex vivo whole-globe porcine model, lidocaine 2.0% and cocaine 2.0% were the least toxic anesthetic agents. At all concentrations, ethanol had no impact on wound healing.Financial DisclosureNo author has a financial or proprietary interest in any material or method mentioned.