Preservative-free artificial tear preparations. Assessment of corneal epithelial toxic effects.
Scanning electron microscopy was used to evaluate the corneal epithelium of rabbit eyes after administration of two preservative-free ocular lubricants, preservative-free artificial tear-1 (Hypotears PF) and preservative-free artificial tear-2 (Refresh), and 0.02% benzalkonium chloride. Animals were randomly assigned to either mild or exaggerated use regimens. A quantitative rating system was used to assess epithelial damage. With mild use, scanning electron microscopy revealed normal epithelial morphologic characteristics for both preservative-free artificial tear solutions (mean relative damage score, solution 1, 0.75 +/- 0.16; solution 2, 1.02 +/- 0.23), which were not significantly different from eyes treated with phosphate-buffered saline (1.38 +/- 0.38) or a mild dosage regimen of 0.02% benzalkonium chloride (1.20 +/- 0.12). Exaggerated use with preservative-free artificial tear solutions (solution 1, 1.31 +/- 0.21; solution 2, 1.35 +/- 0.08) induced minimal damage that was not different from control eyes treated with phosphate-buffered saline (1.26 +/- 0.13). Compared with an exaggerated use of 0.02% benzalkonium chloride (4.0 +/- 0.16), both preservative-free artificial tear solutions induced significantly less epithelial damage (P = .0001). These results suggest that with frequent-dosage regimens, preservation-free artificial tear solutions-1 and -2 are free of the toxic effects associated with preserved solutions.
Berdy
G J
GJ
Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston.
Abelson
M B
MB
Smith
L M
LM
George
M A
MA
D000818:Animals; D001548:Benzalkonium Compounds / Q000633:toxicity; D003315:Cornea / Q000187:drug effects* / Q000648:ultrastructure; D003316:Corneal Diseases / Q000139:chemically induced / Q000473:pathology; D004311:Double-Blind Method; D004848:Epithelium / Q000187:drug effects / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D011206:Povidone-Iodine / Q000633:toxicity*; D011310:Preservatives, Pharmaceutical / Q000633:toxicity*; D011817:Rabbits; D011897:Random Allocation
D001548:Benzalkonium Compounds; D011310:Preservatives, Pharmaceutical; D011206:Povidone-Iodine