title: Corneal and conjunctival epithelial staining in hydrogel contact lens wearers.
abstract: OBJECTIVE
  The purpose of this study was to investigate the prevalence of conjunctival and corneal epithelial staining in soft contact lens wearers and to see if staining could be associated with factors such as type of lens worn, wearing time, care system, age, and sex.
  
  
  METHODS
  The records of 338 adapted hydrogel contact lens wearers were examined retrospectively.
  
  
  RESULTS
  Conjunctival staining was found to be present in 32.5% of the subjects and corneal staining was found to be present in 19.5% of subjects. None of the subjects had staining above grade 2 using the Cornea and Contact Lens Research Unit scale. Because of the low prevalence of staining, the low grading of staining found and the large variation in refractive power, lens type worn, wearing modality, and solution used statistical analysis for association between staining and different factors could only be performed for the association between sex and staining and between corneal and conjunctival staining. However, no statistical significant association could be demonstrated.
  
  
  CONCLUSIONS
  Despite the low prevalence of staining the conjunctiva and cornea should be examined carefully in contact lens wearers and prospective wearers because the conjunctival and corneal epithelium serve as protective barriers for the underlying layers of the cornea and conjunctiva. To allow comparison of data obtained in different studies assessing corneal staining, it is recommended that clinicians develop and adopt a universal standard protocol for this measure.
authors.affiliation: Unit of Optometry, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. rlb@ste.ki.se
authors.forename: Rune L
authors.initials: RL
authors.lastname: Brautaset
authors.forename: Maria
authors.initials: M
authors.lastname: Nilsson
authors.forename: Norman
authors.initials: N
authors.lastname: Leach
authors.forename: William L
authors.initials: WL
authors.lastname: Miller
authors.forename: Anisa
authors.initials: A
authors.lastname: Gire
authors.forename: Sam
authors.initials: S
authors.lastname: Quintero
authors.forename: Jan P G
authors.initials: JP
authors.lastname: Bergmanson
mesh_terms: D000328:Adult; D003228:Conjunctiva / Q000473:pathology*; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D004848:Epithelium / Q000473:pathology; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D019793:Fluorescein; D005456:Fluorescent Dyes; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D012189:Retrospective Studies; D013194:Staining and Labeling; D055815:Young Adult
chemical_list: D005456:Fluorescent Dyes; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D019793:Fluorescein