title: Tear film evaporation--effect of age and gender.
abstract: OBJECTIVE
  Dry eye is more prevalent in older patients and among them more marked in women than men. The increase in dry eye with aging is traditionally thought to be associated with a decrease in tear production enhanced by hormonal changes. Clinical evidence of an abnormal lipid production system in older patients, in particular women is established. It is therefore postulated that the greater prevalence of dry eye problems in an older population has an evaporative component.
  
  
  METHODS
  Tear film evaporation was measured with the Oregon Health Sciences University Evaporimeter at 30% and 40% humidity.
  
  
  RESULTS
  160 subjects less than 45 years old and 57 subjects aged 45 years or more formed the study population. The results revealed a significant effect of age (p < 0.001), gender (p < 0.001) and their interaction (p < 0.001): (i) the rate of evaporation was higher in the older age group at both humidities; (ii) the rate of evaporation was overall higher for women; and (iii) the synergic effect of age and gender was very marked: the rate of evaporation of older women was 34-80% higher than that of older men and 36-69% than younger women.
  
  
  CONCLUSIONS
  Aging of the tear film includes a significant evaporative component characterised by higher tear film evaporation for the over 45 compared to younger people. Further, in the over 45 years of age, a significantly greater tear film evaporation was recorded in women than men. The findings have significant implications for the management of presbyopic dry eye sufferers.
authors.affiliation: OTG Research & Consultancy, London, UK.
authors.forename: Michel
authors.initials: M
authors.lastname: Guillon
authors.forename: Cécile
authors.initials: C
authors.lastname: Maïssa
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D018450:Disease Progression; D015352:Dry Eye Syndromes / Q000453:epidemiology / Q000209:etiology* / Q000378:metabolism; D004739:England / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006813:Humidity; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012737:Sex Factors; D013666:Tears / Q000378:metabolism*; D013997:Time Factors; D014835:Volatilization; D055815:Young Adult