title: Quo vadis older keratoconus patients? Do they die at younger ages?
abstract: OBJECTIVE
  To examine the validity of the observations made by specialist corneal surgeons that there seems to be an absence or loss of older patients with keratoconus (KC).
  
  
  METHODS
  Using a PubMed search and key words such as KC, epidemiology, mortality, mitral valve prolapse, atopy, and asthma, the literature related to this topic was reviewed. Specialist contact lens fitting practitioners were asked to supply age-related details of KC and nonkeratoconus patients within their practices.
  
  
  RESULTS
  Results suggested a marked absence or loss of older KC patients as has been observed by specialist corneal surgeons. Several possible explanations are described including increased mortality associated with mitral valve prolapse, asthma, obesity, and/or obstructive sleep apnea, for example. In addition, gender bias, the influence of progression to keratoplasty or age-related diseases, as well as difficulty in traveling to specialist practices and the need for and dependence on specialist contact lens fitting skills of KC patients were considered. The possibility that KC corneas could improve with age-related increased natural crosslinking and stiffening is discussed.
  
  
  CONCLUSIONS
  An absence or loss of older KC patients has been found in some specialist contact lens fitting practices. Notwithstanding the possible influence of numerous other issues, the absence or loss of KC patients may be because of reduced life expectancy, a topic that seems to warrant further examination. There may be implications for improving the understanding of the pathogenesis of KC if reduced life expectancy can be confirmed and the associated reasons elucidated.
authors.affiliation: School of Optometry and Vision Science, University of New South Wales, Kensington, Australia. c.mcmonnies@unsw.edu.au
authors.forename: Charles W
authors.initials: CW
authors.lastname: McMonnies
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D015897:Comorbidity; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000453:epidemiology / Q000401:mortality*; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012737:Sex Factors; D055815:Young Adult