Repetitive magnetic stimulation protects corneal epithelium in a rabbit model of short-term exposure keratopathy

Ocul Surf. 2020 Jan;18(1):64-73. doi: 10.1016/j.jtos.2019.09.009. Epub 2019 Sep 28.

Abstract

Purpose: To investigate the effect of repetitive magnetic stimulation (RMS) on corneal epithelial permeability in a rabbit model of exposure keratopathy.

Methods: 61 female New Zealand White (NZW) rabbits were treated on one eye with repetitive magnetic stimulation (RMS) at a frequency of 20 Hz for 15 min. The other eye was untreated. Rabbit eyes were kept open for 2 h to induce acute corneal desiccation. The extent of fluorescein corneal staining was evaluated using EpiView software and the concentration of fluorescein in the anterior chamber was determined by a fluorometer. Safety was evaluated by electroretinogram, spectral domain optical coherence tomography (SD-OCT) and histopathology. Expression pattern of corneal cell markers was determined by immunofluorescence.

Results: A significant decrease in fluorescein concentration in the anterior chamber (54 ± 8.4 ng/ml vs. 146.5 ± 18.6 ng/ml, p = 0.000001) and in corneal surface fluorescein staining score (1.7 ± 0.2 vs. 4.6 ± 0.6, p = 0.00001) was obtained in RMS-treated eyes compared with control eyes, respectively. RMS treatment reduced by nearly 4 fold the percentage of corneal area with epithelial erosions by anterior segment SD-OCT. The therapeutic effect was maintained for at least 3 months. Increased expression of epithelial tight junction protein Zo-1 was observed in treated eyes. SD-OCT and histopathology analysis revealed no pathological changes in the treated or non-treated eyes.

Conclusions: RMS treatment decreases epithelial corneal erosions in a rabbit model of exposure keratopathy, with no indication of pathological changes. RMS may present a novel treatment for protection of corneal epithelium from desiccation.

Keywords: Corneal defects; Epithelial erosions; Exposure keratopathy; Fluorescein; Magnetic stimulation; RMS; SD-OCT; TMS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cornea
  • Epithelium, Corneal*
  • Female
  • Keratoconjunctivitis*
  • Magnetic Phenomena
  • Rabbits
  • Tomography, Optical Coherence