Background: The aim of this study was to investigate the therapeutic role of preservative-free artificial tears containing hyaluronic acid and high potassium ion concentration (HA/high-K artificial tears) on mechanically scraped or alkali-induced corneal epithelial defects in rats.
Methods: We created mechanically scraped epithelial defects on the corneas of 24 Sprague-Dawley (SD) rats (three groups of eight rats) and alkali-induced epithelial defects on the corneas of 27 SD rats (three groups of nine rats). Then we applied topical 0.3 per cent or 0.15 per cent HA/high-K artificial tears four times daily for 1.5 days and compared its effect with that of topical phosphate buffered saline (PBS). The fluorescein staining analysis and histological examination were performed immediately after and at 12, 24 and 36 hours after injury.
Results: In the mechanical scraping model, the areas of fluorescein staining in the eyes after topical application of 0.3 per cent HA/high-K artificial tears were significantly smaller than those after PBS treatment at 12 and 24 hours after injury. At 36 hours, the staining areas of both 0.3 per cent and 0.15 per cent HA/high-K artificial tears-treated eyes were found to be significantly smaller than those of the PBS-treated eyes. In the alkali burn model, the promotion of corneal epithelial wound healing after treatment with 0.3 per cent and 0.15 per cent HA/high-K artificial tears was not significantly different compared to that after treatment with PBS.
Conclusion: Hyaluronic acid and high potassium ion concentration artificial tears promoted corneal epithelial wound healing in the mechanical scraping model; however, in the alkali burn model, no significant beneficial effect of this treatment was observed.
Keywords: artificial tears; corneal epithelium; drugs; hyaluronic acid; potassium.
© 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.