title: The effects of six months of contact lens wear on the tear film, ocular surfaces, and symptoms of presbyopes.
abstract: OBJECTIVE
  To assess the tear film, ocular surfaces, and symptoms of ocular discomfort in a presbyopic population before and after contact lens wear.
  
  
  METHODS
  A total of 150 presbyopes (49% were previous soft contact lens wearers) participated in a clinical trial in which they wore either monovision (single vision Acuvue lenses) or Acuvue Bifocal contact lenses. Clinical measurements of tear film, biomicroscopy, and corneal sensitivity as well as subjective ratings using the Dry Eye Questionnaire were collected at the initial visit and repeated after 6 months. Comparisons were made between age groups (40 to 51 years and 52 to 71 years) and genders before and after contact lens wear. Associations between objective and subjective tests were sought.
  
  
  RESULTS
  After 6 months of contact lens wear, clinical signs had worsened by less than one-half of a grade, and tear break up time (TBUT) worsened by 3 s. Only TBUT was lower for the older age group. Females had less bulbar hyperemia, more sensitive eyes, more lissamine green staining, and lower TBUT and phenol red thread measurements (all p < 0.04). Twenty-eight percent experienced dryness before contact lens wear, but this figure increased to 68% when wearing contact lenses. There were no age differences, but almost twice as many females as males reported dryness. Reporting symptoms of dryness was associated with gender, corneal sensitivity, and type of corneal staining.
  
  
  CONCLUSIONS
  These results provide a representation of the ocular surface condition and symptoms of ocular discomfort in the middle-aged population and seem similar to reports of younger populations. Wearing contact lenses seems to influence dry eye symptoms more than age or gender. Therefore, presbyopes should not be excluded from consideration for contact lens fitting.
authors.affiliation: Centre for Contact Lens Research, University of Waterloo, Ontario, Canada. r.dutoit@cclru.unsw.edu.au
authors.forename: R
authors.initials: R
authors.lastname: du Toit
authors.forename: P
authors.initials: P
authors.lastname: Situ
authors.forename: T
authors.initials: T
authors.lastname: Simpson
authors.forename: D
authors.initials: D
authors.lastname: Fonn
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D000818:Animals; D003261:Contact Lenses; D003315:Cornea / Q000502:physiology*; D015352:Dry Eye Syndromes / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D013666:Tears / Q000502:physiology*; D013997:Time Factors