The effects of the presence of the corneal epithelium and supplemental hydrocortisone on β-glucuronidase levels with corneal preservation

PURPOSE: To analyze the levels of β-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. β-glucuronidase activity levels were measured at the end of this period. RESULTS: β-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, β-glucuronidase, during preservation. The addition of 10(−4) M HCT decreases the production of β-glucuronidase during corneal preservation in this model.