title: Effect of the use of artificial tears on the size of squamous cells of the rabbit corneal epithelium evaluated by scanning electron microscopy.
abstract: Female pigmented rabbits (2 to 2.3 kg) received 2 drops of a chlorobutanol 0.5%-preserved, polyvinyl alcohol-based artificial tear at 21.00 h and 09.00 h for 1, 2, 3, 6, or 12 days. The animals were euthanized at 15.00 h and the corneas fixed with 2.0% glutaraldehyde in 80 mM cacodylate buffer. Scanning electron micrographs were taken close to the corneal center at 500 x magnification and normal to the epithelial surface. The surface areas of the squamous cells were measured with a digitizer pad. As a result of the treatment, up to 9% of the cells were observed to be in the process of exfoliation with the effect being greatest after 3 days. Control (nontreated) corneas showed only 0.44% exfoliating cells. Over this time period there was a progressive shift of cell sizes to larger values followed by recovery back to control values by 12 days. The results confirm the lack of gross cytotoxic effect of chlorobutanol-preserved artificial tears and indicate that the corneal epithelium can adapt to the use of a polymer-containing artificial tear.
authors.affiliation: School of Optometry, University of Waterloo, Ontario, Canada.
authors.forename: M J
authors.initials: MJ
authors.lastname: Doughty
mesh_terms: D000818:Animals; D002724:Chlorobutanol / Q000633:toxicity; D003315:Cornea / Q000187:drug effects* / Q000648:ultrastructure; D004848:Epithelium / Q000187:drug effects / Q000648:ultrastructure; D005260:Female; D007091:Image Processing, Computer-Assisted; D008855:Microscopy, Electron, Scanning; D009883:Ophthalmic Solutions / Q000633:toxicity*; D011310:Preservatives, Pharmaceutical / Q000633:toxicity; D011817:Rabbits
chemical_list: D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D002724:Chlorobutanol