title: Comparison of contact lens multipurpose solutions by in vitro sodium fluorescein permeability assay.
abstract: OBJECTIVE
  This article reports the use of in vitro sodium fluorescein permeability assay to study the effects of various contact lens disinfecting solutions on the integrity of epithelium.
  
  
  METHODS
  We compared the sodium fluorescein permeability of monolayer cultures of Madin-Darby canine kidney cells (MDCK) after exposure to ReNu Multi-Purpose Solution, ReNu MultiPlus Multi-Purpose Solution, OPTIFREE Express Multi-Purpose Solution, OPTIFREE Express Solution with Aldox, SOLO-care Solution and Complete Comfort Plus Solution. Additional cell monolayer inserts were prepared for each treatment and were analyzed using a scanning electron microscope. The assay has been used to measure the potential for ocular irritancy of a test solution by evaluating its effect on the cell membranes and tight junctions of a cultured canine kidney epithelial cell monolayer.
  
  
  RESULTS
  The sodium fluorescein permeability assay and scanning electron microscopy demonstrated that the two OPTIFREE Express solutions were significantly more damaging to the MDCK epithelium than ReNu and ReNu MultiPlus multipurpose solutions (Bausch & Lomb, Rochester, NY), SOLO-care (CIBA Vision, Duluth, GA) solution, and Complete Comfort Plus (Allergan, Irvine, CA) solution. Cultures treated with the two OPTIFREE Express (Alcon, Ft. Worth, TX) solutions were more permeable to sodium fluorescein than cultures treated with the other multipurpose solutions, because of the loss of tight junctions and cell membrane damage.
  
  
  CONCLUSIONS
  This experiment demonstrates that the sodium fluorescein permeability assay can be used to determine the effect that various contact lens disinfecting products have on the integrity of an epithelium in culture.
authors.affiliation: Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, Pennsylvania 19104-4495, USA. r.tchao@usip.edu
authors.forename: Ruy
authors.initials: R
authors.lastname: Tchao
authors.forename: David J
authors.initials: DJ
authors.lastname: McCanna
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Miller
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D018639:Contact Lens Solutions / Q000633:toxicity*; D004285:Dogs; D004848:Epithelium / Q000187:drug effects* / Q000378:metabolism* / Q000648:ultrastructure; D019793:Fluorescein / Q000493:pharmacokinetics*; D007668:Kidney / Q000166:cytology; D008855:Microscopy, Electron, Scanning; D010539:Permeability
chemical_list: D018639:Contact Lens Solutions; D019793:Fluorescein