title: A patient questionnaire approach to estimating the prevalence of dry eye symptoms in patients presenting to optometric practices across Canada.
abstract: OBJECTIVE
  To collect questionnaire data from patients in a large clinical population that would allow for an estimate of the prevalence of self-reported symptoms of dry eyes.
  
  
  METHODS
  A 13-point questionnaire (The Canada Dry Eye Epidemiology Study, CANDEES) was mailed to all optometric practices in Canada in October 1994, with the request that it be completed by 30 successive nonselected patients.
  
  
  RESULTS
  Four hundred fifty sets of questionnaires (total, 13,517) were analyzed (a 15.7% return rate) from patients aged from < 10 years to > 80 years; 55% were in the 21- to 50-year age group; 60.7% were female; and 24.3% were contact lens wearers. A total of 28.7% reported dry eye symptoms, of whom 24.2% reported concurrent dry mouth, 24.5% had worse symptoms in the morning, 30.3% reported concurrent lid problems, and 35.7% reported a history of allergies. Of the 3716 patients reporting symptoms, 62 (1.6%) were in the "severe" category and 290 (7.8%) were in the "constant but moderate" category. Contact lens wear, concurrent allergies, dry mouth, lid problems, or use of medications increased the chance of a patient reporting dry eye symptoms.
  
  
  CONCLUSIONS
  The prevalence of patients reporting any level of symptoms of dry eyes was approximately 1 in 4; severe symptoms were reported by 1 in 225 patients.
authors.affiliation: Centre for Contact Lens Research, School of Optometry, University of Waterloo, Ontario, Canada.
authors.forename: M J
authors.initials: MJ
authors.lastname: Doughty
authors.forename: D
authors.initials: D
authors.lastname: Fonn
authors.forename: D
authors.initials: D
authors.lastname: Richter
authors.forename: T
authors.initials: T
authors.lastname: Simpson
authors.forename: B
authors.initials: B
authors.lastname: Caffery
authors.forename: K
authors.initials: K
authors.lastname: Gordon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015352:Dry Eye Syndromes / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009907:Optometry / Q000706:statistics & numerical data*; D015995:Prevalence; D011364:Professional Practice / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires