Abstract
Purpose :
Fungal keratitis is serious ocular infection caused by any of the fungi species. It is treated with antifungal medications, in worst scenario with cornea transplantation. The therapy is still challenging due to poor drug penetration into the cornea. Cold plasma, produced by ionization of argon gas, contains especially reactive species but also UV radiation which damage microorganisms. The aim of this study is to determine the effect of cold plasma on human corneal epithelial cells (HCE), corneal tissue and multiple pathogen microorganisms to assess the opportunity of cold plasma treatment for fungal keratitis.
Methods :
The effect of cold plasma (0.5, 1, 2, 5 and 10 min) on in vitro HCE and ex vivo donor corneas obtained from the Cornea Eye Bank (DGFG) (Ethic Committee No. A2020-0108) was analyzed by light microscopy, Live/Dead assay, metabolic activity assay, and immunohistochemistry. Disinfecting potential was analyzed by plating prevalent yeasts (C. albicans, C. krusei, C. parapsilosis, C. glabrata) on agar plates and treated with cold plasma for 2, 5, 7 and 10 minutes. Plasma treatment (1, 2 and 5 min) of infected human donor corneas with C. albicans was determined by measurement of optical density of liquid culture.
Results :
Treatment of HCE by cold plasma led to the change of the morphology, significantly lower viability, metabolic activity and proliferation of the cells. The damage of the epithelium and basement membrane in corneas was detected only with longer cold plasma applications. Yeast strains were significantly eradicated completely after 5 min of cold plasma treatment (P ≤ 0.001). Cold plasma therapy of the infected human donor corneas showed the decrease of the infection in all tested time intervals with statistical significance (P ≤ 0.01, P < 0.05 and P ≤ 0.001 respectively for 1, 2 and 5 min treatment).
Conclusions :
Cold plasma treatment showed negative impact on the HCE cell cultures, but not in corneas if shorter time of application was used. Moreover, a significant reduction of CFU was observed in all examined microorganisms and significant decrease of infection was determined in infected corneas. Therefore, the cold plasma technology has a potential to be an novel effective treatment for fungal keratitis.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.