Development of a new corneal storage medium with antimycotic tablet

Purpose: This study aimed at assessing the antimycotic activity of the new cold storage medium, Kerasave, and at evaluating the quality of donor corneas preserved in the medium at 4°C for 14 days in comparison with Optisol GS.

Material and Methods: Kerasave antimycotic activity was determined by in vitro time-kill studies using sterile porcine corneal tissues, contaminated with 10⁴ cfu/ml of C. Albicans (ATCC10231 and clinical isolate). The killing rate of the microorganisms was monitored at 4°C after 5 and 10 days of incubation in Kerasave.

Kerasave performance was assessed on 16 pairs of human corneas not suitable for transplantation, procured and evaluated according to standard procedures of Monza Eye Bank, Italy. One cornea was transferred in Kerasave and the contralateral in Optisol GS. Endothelial cell density (ECD), measured by specular microscopy (Keratoanalyzer, Konan), was evaluated pre-processing, and after 7 and 14 days of storage at 4°C. Endothelial cell morphology and mortality were determined according to Stocker method, and epithelial integrity, and corneal transparency were evaluated using a Slit lamp.

Results: In vitro time-kill studies showed a 3 to 4 log₁₀ reduction for both Candida strains within 10 days of incubation at 4°C.
Kerasave- and Optisol-GS-treated tissues showed similar ECD, mortality and endothelial morphology after 7 and 14 days of cold storage. Slit lamp analysis showed comparable corneal transparency and epithelial integrity in both groups.

Conclusions: The new cold storage medium with antimycotic tablet, Kerasave, exhibited an excellent antimycotic activity and biocompatibility with donor corneas after corneal storage at 4°C for up to 14 days.