Innovative Cold Atmospheric Plasma (iCAP) Decreases Mucopurulent Corneal Ulcer Formation and Edema and Reduces Bacterial Load in Pseudomonas Keratitis

To evaluate the effect of application of 3% air in helium cold atmospheric plasma jet, using an inexpensive device termed iCAP, in corneal scratch wound closure and the treatment of ( ) keratitis . Thermal imaging to measure temperature of surfaces to which iCAP was applied and UV energy density delivered by iCAP were measured. Scratch wounds inflicted on cultures of a human corneal epithelial cell line were treated with iCAP and wound widths at various times post-application were measured. Rabbit eyes infected with were treated with iCAP and slit lamp biomicroscope examination conducted to determine corneal health outcomes 25h post infection. Corneal homogenates were plated on agar and viable bacterial colonies enumerated to determine the effect of iCAP on bacterial load in keratitis. iCAP was shown to operate in the non-thermal regime and also shown to deliver much lower UV energy density than that necessary to cause harmful effects on ocular tissue. iCAP treatment significantly improved the rate of scratch wound gap closure in a human corneal epithelial cell line compared to controls. , iCAP treatment of keratitis infection in the rabbit eyes (N = 20) significantly reduced the incidence of corneal ulcer (P = 0.003) and corneal edema (P = 0.011) and significantly improved total cornea health (P = 0.034) compared to untreated (N = 10). Finally, iCAP treatment of keratitis infection in the rabbit eyes (N = 19) significantly reduced bacterial loads (P = 0.012) compared to untreated (N = 9). Our results strongly suggest that iCAP treatment was effective in improving corneal epithelial defect closure , reducing ulcer formation and decreasing inflammation in infected corneas and decreasing bacterial loads in infected corneas which led to improved overall cornea health outcomes . Further studies to investigate iCAP's safety and efficacy against other infectious microbes responsible for causing ulcerative keratitis, with and without co-treatment with antimicrobial therapies are warranted.