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.