Thomas Mauger, Eric QuartettiHavener Eye Institute, Department of Ophthalmology, The Ohio State University, OH, USAPurpose: To analyze the levels of ß-glucuronidase during prolonged (14 day) corneal preservation with epithelialized (EPI) and deepithelialized (DEP) corneas and the effect of supplemental hydrocortisone (HCT) on these levels.Methods: Thirty-six freshly excised bovine corneas were preserved in Optisol solution (4°C) for 14 days with the following conditions EPI/no supplemental HCT, DEP no supplemental HCT, EPI/10-8 M HCT, and EPI 10-4 M HCT. ß-glucuronidase activity levels were measured at the end of this period.Results: ß-glucuronidase levels (nmol/mL/h) for each group were found to be: EPI – No HCT: 4.302, SEM 0.586; DEP – No HCT: 2.178, SEM 0.271; EPI – 10-8 M HCT: 4.472, SEM 0.435; EPI – 10-4 M HCT: 2.072, SEM 0.437. The EPI – No HCT and EPI – 10-8 M HCT were not significantly different as were the DEP – No HCT and EPI – 10-4 M HCT groups. The EPI – No HCT group and the EPI – 10-8 M HCT group were independently significantly different from the DEP – No HCT and the EPI – 10-4 M HCT groups.Conclusions: The corneal epithelium contributes significantly to the formation of the lysosomal enzyme, ß-glucuronidase, during preservation. The addition of 10-4 M HCT decreases the production of ß-glucuronidase during corneal preservation in this model.Keywords: ß-glucuronidase, preservation&nbsp