Microbiological contamination in donor corneas preserved for medium-term

Abstract

To evaluate the characteristics of microbiological contamination in donor corneas preserved for medium-term. A total of 82 donated corneas from June 1, 2014 to November 30, 2014 were retrospectively analyzed. The corneas were preserved in cornea chambers medium-term solution at 4-8°C for keratoplasty. After removal of the central corneas for transplantation, the corneoscleral rims were put back into the medium for 1month at room temperature (20-25°C). The suspicious contaminated storage solutions indicated with transparency or color change were examined with bacteria and fungi cultivation for strain identification. The data collected included gender, age, procurement site and causes of death of donors, and follow-up of recipients. Statistical analysis was performed using Microsoft Excel and SPSS 24.0. Significance level was set at a P value<0.05. The overall pathogen positive rate was 9.8% (n = 8), including 7 (87.5%) fungi and 1 (12.5%) bacteria. They were 2 (2.44%) Fusarium, 2 (2.44%) Chromomycosis, 1 (1.22%) Candida albicans, 1 (1.22%) Aspergillus versicolor, 1 (1.22%) Acremonium species, and 1 (1.22%) Enterococcus. 5 contaminated corneas were used for penetrating keratoplasty; although four out of five (80%) had not been given antifungal drugs during more than 6months following-up period, none of the recipients was infected with a graft. Donor age (P = 0.839), gender (P = 0.062), procurement sites (P = 0.713) and cause of death (P = 0.711) had no statistically significant influence on the contamination rate. All donor corneas have a possibility of microbiological contamination. Strict tissue preservation protocol but not antifungal drugs following keratoplasty seems necessary to prevent graft infection.