Innovative cold atmospheric plasma (iCAP) decreases corneal ulcer formation and bacterial loads and improves anterior chamber health in methicillin resistant Staphylococcus aureus keratitis

Abstract

Bacterial keratitis is a vision-threatening infection of the cornea that is typically treated with antibiotics. However, antibiotics sometimes fail to eradicate the infection and do not prevent or repair the damage caused directly by the bacteria or the host immune response to the infection. Our group previously demonstrated that treatment of Pseudomonas aeruginosa keratitis in rabbits with innovative cold atmospheric plasma (iCAP) resulted in reduced edema, ulcer formation, and bacterial load. In this study, we investigated the efficacy of iCAP treatment in methicillin-resistant Staphylococcus aureus (MRSA). New Zealand white rabbits were infected intrastromally with MRSA then treated with iCAP, moxifloxacin, vancomycin, or combination of iCAP with each antibiotic to assess the safety and efficacy of iCAP treatment compared to untreated controls and antibiotics. iCAP treatment significantly reduced bacterial loads and inflammation, improved anterior chamber clarity, and prevented corneal ulceration compared to untreated controls and antibiotic treatment. Safety assessments of grimace test scores and tear production showed that iCAP was not significantly different from either antibiotic treatment in terms of distress or tear production. Combination iCAP/antibiotic treatment did not appear to provide significant added benefit over iCAP alone. Our findings suggest that the addition of iCAP may be a viable tool in reducing damage to the cornea and anterior chamber of the eye following S. aureus keratitis.