Purpose: To assess the endothelial toxicity and the microbiological efficacy of voriconazole (100 microg/mL) as an antimicrobial additive to Optisol GS.
Methods: A total of 533 donor rims were studied. One half of each donor rim was placed in standard Optisol GS and the other half rim in Optisol GS fortified with voriconazole (100 microg/mL). All rims were refrigerated for 24 hours at 3 degrees C and placed in thioglycolate broth and incubated at 37 degrees C for 7 days. A pair of donor buttons not used in transplantation was stored for 2 days in each solution and examined for endothelial changes with electron microscopy (EM). A second pair of cornea buttons was examined for toxicity by endothelial staining with 0.3% trypan blue and 0.2% alizarin red.
Results: Seven of 533 corneal rim cultures were positive for fungal organisms in the Optisol GS group. No rims were positive for fungal growth in the voriconazole-fortified Optisol GS medium. The difference was statistically significant (P = 0.015; Fisher exact test). There was no difference in the cellular morphology of the button stored in voriconazole fortified Optisol GS compared with Optisol GS using EM. In the bioassay, the percentage of nonviable cells in the voriconazole-fortified medium compared with the control medium was nonsignificant (P < 0.05, Student t test).
Conclusions: Voriconazole seems to be safe as a fortifying agent for cornea storage medium. It significantly reduces the rate of positive fungal rim cultures and shows no signs of endothelial cytotoxicity as viewed by EM and by a bioassay of trypan blue and alizarin red.