title: Cataract, visual impairment and long-term mortality in a rural cohort in India: the Andhra Pradesh Eye Disease Study.
abstract: BACKGROUND
  A large-scale prevalence survey of blindness and visual impairment (The Andhra Pradesh Eye Diseases Study [APEDS1]) was conducted between 1996-2000 on 10,293 individuals of all ages in three rural and one urban clusters in Andhra Pradesh, Southern India. More than a decade later (June 2009-March 2010), APEDS1 participants in rural clusters were traced (termed APEDS2) to determine ocular risk factors for mortality in this longitudinal cohort.
  
  
  RESULTS
  Mortality hazard ratio (HR) analysis was performed for those aged >30 years at APEDS1, using Cox proportional hazard regression models to identify associations between ocular exposures and risk of mortality. Blindness and visual impairment (VI) were defined using Indian definitions. 799/4,188 (19.1%) participants had died and 308 (7.3%) had migrated. Mortality was higher in males than females (p<0.001). In multivariable analysis, after adjusting for age, gender, diabetes, hypertension, body mass index, smoking and education status the mortality HR was 1.9 (95% CI: 1.5-2.5) for blindness; 1.4 (95% CI: 1.2-1.7) for VI; 1.8 (95% CI: 1.4-2.3) for pure nuclear cataract, 1.5 (95% CI: 1.1-2.1) for pure cortical cataract; 1.96 (95% CI: 1.6-2.4) for mixed cataract, 2.0 (95% CI: 1.4-2.9) for history of cataract surgery, and 1.58 (95% CI: 1.3-1.9) for any cataract. When all these factors were included in the model, the HRs were attenuated, being 1.5 (95% CI: 1.1-2.0) for blindness and 1.2 (95% CI: 0.9-1.5) for VI. For lens type, the HRs were as follows: pure nuclear cataract, 1.6 (95% CI: 1.3-2.1); pure cortical cataract, 1.5 (95% CI: 1.1-2.1); mixed cataract, 1.8 (95% CI: 1.4-2.2), and history of previous cataract surgery, 1.8 (95% CI: 1.3-2.6).
  
  
  CONCLUSIONS
  All types of cataract, history of cataract surgery and VI had an increased risk of mortality that further suggests that these could be potential markers of ageing.
authors.affiliation: Allen Foster Research Centre for Community Eye Health, International Centre for Advancement of Rural Eye care, L V Prasad Eye Institute, Hyderabad, India ; Brien Holden Eye Research Centre, L.V. Prasad Eye Institute, Hyderabad, India.
authors.forename: Rohit C
authors.initials: RC
authors.lastname: Khanna
authors.forename: Gudlavalleti V S
authors.initials: GV
authors.lastname: Murthy
authors.forename: Pyda
authors.initials: P
authors.lastname: Giridhar
authors.forename: Sannapaneni
authors.initials: S
authors.lastname: Krishnaiah
authors.forename: Hira B
authors.initials: HB
authors.lastname: Pant
authors.forename: Ghanshyam
authors.initials: G
authors.lastname: Palamaner Subash Shantha
authors.forename: Subhabrata
authors.initials: S
authors.lastname: Chakrabarti
authors.forename: Clare
authors.initials: C
authors.lastname: Gilbert
authors.forename: Gullapalli N
authors.initials: GN
authors.lastname: Rao
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D002386:Cataract / Q000401:mortality*; D002387:Cataract Extraction; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016016:Proportional Hazards Models; D012307:Risk Factors; D012424:Rural Population; D017678:Sex Distribution; D016019:Survival Analysis; D014786:Vision Disorders / Q000401:mortality* / Q000601:surgery