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Washing to Dilute May be the Answer to Eliminate Fungus from Donor Corneal Tissue
Roheena M. Kamyar, MD
Julia D. Shatten, MD, M.Ed
Deepinder K. Dhaliwal, MD, L.Ac
Michelle K. Rhee, MD
Alex Mammen, MD
Gaurav Prakash, MD
Vishal Jhanji, MD
Regis P. Kowalski, M(ASCP) MS
Fungus elimination; donor corneal tissue; optisol antifungal supplementation; antifungal synergistic drugs; antiseptic fungal decontamination
Purpose: Fungal contamination can be a problem for refrigerated corneal tissue stored in Optisol-GS. We developed methods to test the elimination of fungi on donor corneal tissue.
Methods: Three yeast and two mold isolates were tested at different fungal loads with three antifungal regimens to eliminate fungi from corneoscleral tissue. In regimen 1 (antifungals), the corneoscleral rims were placed in Optisol with and without amphotericin B 2.5 μg/ml (AmpB), clotrimazole 10 μg/ml, and an antifungal synergistic mixture (ASD), respectively. In regimen 2 (antiseptics), rims were treated topically with 5% povidone iodine (PI) or 0.01% hypochlorous acid (HOCL) and placed in Optisol. Another rim set was treated with PI and placed in Optisol plus AmpB. In regimen 3 (wash-dilute), the rims underwent a wash, topical PI, wash, rest period, topical PI, wash, and placement in Optisol supplemented with ASD or AmpB. All rims were refrigerated at 6O C for 48 hours. All corneal rims were cultured and monitored for viable fungi for 7 days. The objective was 100% elimination of fungi from donor corneal tissue.
Results: Regimens 1 and 2 were not fully effective for eliminating fungi. However, the wash-dilute regimen only produced yeast growth in the ASD supplemented Optisol at 1000 cfu, and mold growth in the AmpB supplemented Optisol at 100 cfu.
Discussion: Optisol supplemented with antifungals or topical antiseptics alone did not consistently eliminate fungal growth. The wash-dilute method which is a complementation of antifungals, antiseptics, and washing was best for eliminating fungi from rim tissue.