Effects of In-vivo Application of Cold Atmospheric Plasma on Corneal Wound Healing in New Zealand White Rabbits

Cold Atmospheric Plasma (CAP) has been shown to influence tissue wound healing but little is known about the impact of CAP on healthy corneal tissues and their ability to respond to injuries. The objective of this study is to examine the effect of CAP on wound healing after corneal epithelial and basement membrane ablation in New Zealand white rabbits. The rabbits were assigned into three groups. Ten Rabbits from two groups underwent a 6 mm corneal ablation to the right eyes. After ablation, five rabbits in group (A) received 2 minutes of CAP whereas the other five rabbits (B) were not treated with CAP. A third group (C) included two rabbits and received CAP without ablation. Eyes monitored for corneal haze,
epithelial healing, lens clarity and any signs of inflammation. At 24 hours, two rabbits from group A and two from group B were sacrificed to harvest the corneas. Twenty days, all remaining rabbits in groups A, B, and C were sacrificed and corneas were harvested. Corneas were fixed in formalin and stained with H&E or used for immunofluorescence microscopy to assess scar formation using antibodies against fibronectin and a-smooth muscle actin. At 24 hours, corneas from group A had average epithelial defect
of 9.25 mm2 on day 1 whereas those from group B had average defect of 12.05 mm2, a difference of 2.8 mm2 (P=0.57). H & E stained corneal sections didn’t show abnormal responses to injury at 24 hours and 20 days. Epithelial thickness and stromal cell counts 20 days after injury showed no significant differences. Analysis of immunofluorescence microscopy images showed no differences between all groups. In conclusion, CAP application to cornea doesn’t appear to have obvious adverse effects. CAP
does not interfere with rate of wound closure or induce increased inflammation. CAP did not have an effect on corneal wound healing or lead to scar formation.