Corneal epithelial wound healing in rabbit eyes in response to an externally applied electric field.

Abstract

Abstract: : Purpose: Electric fields (EF) are generated in the vicinity of wounded cornea epithelium. Tissue cultured keratinocytes and epithelial cells, when subjected to EFs, have been shown to reorient perpendicularly and migrate cathodally. The purpose of the present study is to analyze the effects of corneal epithelial wound healing in the presence of an electric field in organ culture Methods: Two alcohol induced circular epithelial defects (3mm diameter) were placed on rabbit corneas placed in Tyron’s solution modified with HEPES. Utilizing a platinum circular electrode (4 mm diameter) with a cathode centrally, a radial electric field was established directed towards the center. The circular electrode was placed to encompass the epithelial defect and the ground placed in the center of the defect. The second, identically created, defect but without an EF was used as a control on the same cornea. Ag:Cl microelectrodes at the wound junctions were used to measure the electric field strength. Voltage potential and applied current were also measured to determine the dynamic resistance of the wound. Serial time–lapse digital photographs were taken to assess the epithelial migration. The corneas were then harvested for histology. Results: Enhancement in the rate of epithelial wound healing with an externally applied DC electric field was observed that varied with the field strength (voltage and current). Applied field strengths of 100 mV/mm induced the optimal migratory rates. A cell speed of 25um/hr was observed compared with 15um/hr in a normal rabbit epithelium. Dynamic resistance on the order of 225K ohms was measured in the healing corneal epithelium. Conclusion:Electric fields play an important role in the wound healing process. When external EFs are applied exogenously, epithelial cell migration and would healing are enhanced in rabbit eyes. Potential clinical applications (contact lens with embedded electrodes) may help in patients with recurrent and non– healing corneal epithelial defects. Supported in part by NEI #5P30EYO1867, Research to Prevent Blindness (to Asbell and Department).

Keywords: cornea: epithelium