title: Hormone replacement therapy and cataract: a population-based case-control study.
abstract: OBJECTIVE
  Laboratory studies have suggested that hormone replacement therapy (HRT) may protect against the development of cataract, but epidemiological studies in humans have thus far been inconclusive. The aim of this study was to assess the association between hormone replacement therapy and cataract.
  
  
  METHODS
  Population-based case-control study using data from the General Practice Research Database in the UK. Participants were 10 000 women aged 45 years and over with diagnosed cataract and 10 000 controls matched on age, general practice, and calendar period.
  
  
  RESULTS
  The crude odds ratio for the association between cataract and ever-use of oestrogen-only hormone replacement therapy was 1.13 (95% CI 0.99-1.29). This reduced to 0.81 (95% CI 0.71-0.94) after adjustment for consultation rate. Similarly, the crude odds ratio for the association between cataract and ever-use of a formulation containing oestrogen and progestogen was 1.18 (95% CI 1.01-1.39), reducing to 0.86 (95% CI 0.72-1.02) after adjustment for consultation rate.
  
  
  CONCLUSIONS
  Oestrogen-only and oestrogen-progestogen hormone replacement therapies are associated with a small reduced risk of cataract. This data adds to the growing body of evidence on the effects of HRT on health. All potential benefits and risks of this therapy should be taken into account when considering its use.
authors.affiliation: Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK.
authors.forename: F O
authors.initials: FO
authors.lastname: Aina
authors.forename: L
authors.initials: L
authors.lastname: Smeeth
authors.forename: R
authors.initials: R
authors.lastname: Hubbard
authors.forename: L S
authors.initials: LS
authors.lastname: Hurt
authors.forename: A E
authors.initials: AE
authors.lastname: Fletcher
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002386:Cataract / Q000453:epidemiology / Q000517:prevention & control*; D015914:Estrogen Replacement Therapy / Q000706:statistics & numerical data; D004967:Estrogens; D005194:Family Practice; D005260:Female; D006801:Humans; D008875:Middle Aged; D011372:Progestins; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D004967:Estrogens; D011372:Progestins