title: Tear film, contact lens, and patient factors associated with corneal staining.
abstract: OBJECTIVE
  The purpose of this study was to examine ocular surface and tear film, contact lens, care solution, medical, and patient-related factors that are associated with corneal staining in contact lens wearers.
  
  
  METHODS
  In this cross-sectional/nested case-control study, in addition to the assessment of corneal staining with fluorescein, a variety of tear film and ocular surface, contact lens, and patient-related factors were examined. Poisson regression models were used to examine the relation between corneal staining and these factors.
  
  
  RESULTS
  Data from 413 patients were eligible for the analyses described. The average age was 30.6 ± 11.1 years, and 277 (67.1%) of the patients were women. Several factors were shown to be related to increased corneal staining in multivariate modeling, including increased daily wearing times (P = 0.0006), lower income (P = 0.0008), lissamine green conjunctival staining (P = 0.002), contact lens deposition (P = 0.007), increased tear meniscus height (P = 0.007), and decreased hydrogel nominal water content (P = 0.02). The wearing of silicone hydrogels (as opposed to hydrogels) was protective against corneal staining (P = 0.0004). Notably, neither contact lens care solutions nor disinfectants were associated with corneal staining.
  
  
  CONCLUSIONS
  Corneal staining in contact lens wearers continues to be a frequent, but not well understood, outcome. These data suggest that contact lens factors (water content, material, wearing time, and deposition) are more generally associated with corneal staining than are contact lens care solutions or other ocular surface and tear film, demographic, or medical factors.
authors.affiliation: Ohio State University, College of Optometry, Columbus, Ohio, USA. nichols.142@osu.edu
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Nichols
authors.forename: Loraine T
authors.initials: LT
authors.lastname: Sinnott
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D018639:Contact Lens Solutions; D003261:Contact Lenses / Q000706:statistics & numerical data*; D003315:Cornea / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D019793:Fluorescein / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D012307:Risk Factors; D012923:Social Class; D013194:Staining and Labeling; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry*
chemical_list: D018639:Contact Lens Solutions; D005456:Fluorescent Dyes; D019793:Fluorescein