Abstract
Purpose :
Fungal keratitis rates following keratoplasty in the United States are increasing, possibly due to the lack of routine antifungal coverage in commercially available corneal storage media. In this basic microbiology study, we compared the relative efficacy of three antifungal preparations of Amphotericin-B and Betadine in commercial corneal storage media as antifungal prophylaxis for stored human corneas.
Methods :
Thirty donor corneas deemed unsuitable for therapeutic transplant, donated by the Lions Eye Institute for Transplant and Research, were bathed in a suspension of Candida albicans. They were then split into three experimental arms: Kerasave media with dissolved Amphotericin-B (2.5 mcg/mL), Optisol-GS with compounded Amphotericin-B (2.5mcg/mL), and Optisol-GS with increasing concentrations of Povidone-iodone (0.25%, 0.50%, 0.75%, 1.00%). Following thermal equilibration, each cornea was swabbed, inoculated onto Sabouraud agar, and returned to its original media. Plates were then incubated, swabbed, and re-plated at 2, 4, 6, 8, 10, and 12 days to assess for C. albicans growth. Statistical analysis of colony counts was done via t-test for all days measured.
Results :
Fungal growth on donor corneas (compared to untreated storage media alone, p<0.05) was significantly reduced on Day 2 by 92% in Povidone-iodine concentrations of 0.75% and 1.00%, 82% in Kerasave with dissolved Amphotericin-B (2.5mcg/mL), and 80% in Optisol-GS with compounded Amphotericin-B (2.5mcg/mL). Povidone-iodine concentrations of 0.50% and 0.25% reduce 71% of the growth of C. albicans in Optisol-GS corneal storage media (p=0.4675 and 0.7675, respectively).
Conclusions :
Kerasave with dissolved Amphotericin-B, Optisol-GS with compounded Amphotericin-B, and povidone-iodine concentrations of 0.75% and 1.00% are potential antifungal prophylaxis options to reduce fungal growth in preserved corneas. Lower concentrations of Povidone-iodine provide less efficient antifungal coverage. While Kerasave is still undergoing FDA-approval, compounded Amphotericin-B and PpPovidone-iodine are readily available antifungal additives that could be added to existing Optisol-GS solutions with support from groups such as the Eye Bank Association of America (EBAA).
This is a 2020 ARVO Annual Meeting abstract.