title: Cataract surgery is associated with a reduced risk of dementia: a nationwide population-based cohort study.
abstract: OBJECTIVE
  Our purpose was to determine the association of cataract surgery with subsequent development of dementia in older adults with newly diagnosed cataract.
  
  
  METHODS
  By using data from Taiwan National Health Insurance Research Database (NHIRD), a population-based cohort study including 491 226 subjects aged 70 or older with first-time diagnosis of cataract coded from 2000 to 2009 was conducted. After matching cataract patients receiving cataract surgery with cataract patients without receiving cataract surgery for age, sex, index date, Charlson Comorbidity Index score, interval between first coding of cataract diagnosis and index date, hypertension and diabetes mellitus, 113 123 patients in each cohort were enrolled. The main outcome measure was newly diagnosed dementia coded by neurologists or psychiatrists more than 365 days after cataract surgery. Incidence rate and hazard ratio of dementia were compared between the cataract surgery and cataract diagnosis cohorts.
  
  
  RESULTS
  The incidence rate of dementia was 22.40 per 1000 person-years in the cataract surgery cohort and 28.87 per 1000 person-years in the cataract diagnosis cohort. The rate of dementia was significantly lower in the cataract surgery group (hazard ratio 0.77, 95% confidence interval 0.75-0.79, P < 0.001). Female gender (P < 0.001) and a shorter interval between the date of first coding of a cataract diagnosis and the date of cataract surgery (P = 0.009) were significantly associated with a lower incidence rate of dementia.
  
  
  CONCLUSIONS
  In an NHIRD cohort of Taiwanese aged 70 years and older with a diagnosis of cataract, patients undergoing cataract surgery were associated with a reduced risk of subsequent dementia compared with those without cataract surgery.
authors.affiliation: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: W-K
authors.initials: WK
authors.lastname: Yu
authors.affiliation: Department of Medicine, Taipei City Hospital Heping Fuyou Branch, Taipei, Taiwan.|Faculty of Medicine, National Yang Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Y-T
authors.initials: YT
authors.lastname: Chen
authors.affiliation: Faculty of Medicine, National Yang Ming University School of Medicine, Taipei, Taiwan.|Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.|Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: S-J
authors.initials: SJ
authors.lastname: Wang
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.|National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan.
authors.forename: S-C
authors.initials: SC
authors.lastname: Kuo
authors.affiliation: Graduate School of Business Administration, Fu Jen Catholic University, Taipei, Taiwan.|Department of Statistics and Information Science and Applied Statistics, Fu Jen Catholic University, Taipei, Taiwan.
authors.forename: B-C
authors.initials: BC
authors.lastname: Shia
authors.affiliation: Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine, National Yang Ming University School of Medicine, Taipei, Taiwan.
authors.forename: C J-L
authors.initials: CJ
authors.lastname: Liu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000175:diagnosis / Q000453:epidemiology*; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D015331:Cohort Studies; D016208:Databases, Factual / Q000706:statistics & numerical data; D003704:Dementia / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009313:National Health Programs / Q000706:statistics & numerical data; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors
keywords: cataract; cataract surgery; dementia