title: Exogenous oestrogen exposure, female reproductive factors and the long-term incidence of cataract: the Blue Mountains Eye Study.
abstract: OBJECTIVE
  To assess the association between exogenous oestrogen exposure, female reproductive factors and the long-term incidence of cataract.
  
  
  METHODS
  People aged 49+ years living in a defined geographic region were invited to participate in this prospective population-based survey. Of 2072 women (83% of those eligible) who were examined during 1992-1994 at baseline, around 75% of survivors were re-examined at 5- and 10-year follow-up visits. Lens photographs were assessed using the Wisconsin Cataract Grading System by masked graders. An interviewer-administered questionnaire was used at each visit to collect information on female reproductive factors and the use of the oral contraceptive pill and postmenopausal hormone replacement therapy.
  
  
  RESULTS
  After adjusting for age, smoking, socioeconomic status, steroid use, hypertension and diabetes, ever having used the oral contraceptive pill had a mild protective effect against incident cortical cataract (odds ratio 0.70, 95% confidence interval 0.50-0.98). However, hormone replacement therapy, age at menarche, age at menopause, duration of exposure to endogenous oestrogen, parity and type of menopause were not found to have significant associations with the incidence of any type of cataract or cataract surgery.
  
  
  CONCLUSIONS
  Apart from a weak protective association of oral contraceptive pill use and the development of cortical cataract, we found no significant longitudinal associations between exogenous oestrogen exposure, female reproductive factors and the long-term incidence of cataract in this older population-based cohort.
authors.affiliation: Centre for Vision Research, Department of Ophthalmology, Westmead Millennium Institute, University of Sydney, Australia.
authors.forename: Gowri L
authors.initials: GL
authors.lastname: Kanthan
authors.forename: Jie Jin
authors.initials: JJ
authors.lastname: Wang
authors.forename: George
authors.initials: G
authors.lastname: Burlutsky
authors.forename: Elena
authors.initials: E
authors.lastname: Rochtchina
authors.forename: Robert G
authors.initials: RG
authors.lastname: Cumming
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000367:Age Factors; D000368:Aged; D001315:Australia / Q000453:epidemiology; D002386:Cataract / Q000453:epidemiology* / Q000517:prevention & control; D015331:Cohort Studies; D003276:Contraceptives, Oral / Q000494:pharmacology*; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007904:Lens Cortex, Crystalline / Q000187:drug effects*; D008572:Menarche; D008593:Menopause; D008875:Middle Aged; D016037:Single-Blind Method
chemical_list: D003276:Contraceptives, Oral; D004967:Estrogens