title: Outcomes of cataract surgery in a rural and urban south Indian population.
abstract: OBJECTIVE
  To assess the visual outcome after cataract surgery in a south Indian population.
  
  
  METHODS
  Population-based cross-sectional study of subjects aged 40 years or more. Three thousand nine hundred and twenty-four rural subjects from 27 contiguous villages and 3850 urban subjects from five randomly selected divisions were studied. All subjects underwent a comprehensive ophthalmic examination that included visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, and dilated retinal examination.
  
  
  METHODS
  Chi square test, t test and multivariate analysis were used.
  
  
  RESULTS
  Five hundred and twenty-eight (216 males, 312 females, 781 eyes) rural subjects (13.5%, 95% confidence interval (CI) 12.4% to 14.6%) and 406 (197 males, 209 females, 604 eyes) urban subjects (10.5%, 95% CI 9.6-11.5%) had undergone cataract surgery. Outcome of cataract surgery was defined based on visual acuity. Using best-corrected visual acuity for classification, the single most important cause for visual impairment was cystoid macular edema in the aphakic group and posterior capsule opacification in the pseudophakic group. Aphakia (visual acuity of < 20/60 to <or= 20/400--odds ratio (OR) 1.8; 95% CI 1.3 to 2.6%, visual acuity of < 20/400--OR 6.2; 95% 4.0 to 9.8%), rural residence (visual acuity of < 20/60 to <or= 20/400--OR 3.2; 95% CI 2.2 to 4.5% and visual acuity of < 20/400--OR OR 3.5; 95% CI 2.3 to 5.5%) were associated with visual impairment. The urban cataract-operated population had significantly more pseudophakics ( P < 0.001), men ( P = 0.02) and literates ( P < 0.001). In the rural group the prevalence of cataract surgery (13.5% vs. 10.5%, P P < 0.001) were significantly greater. In 30% of rural and 16% of urban subjects uncorrected refraction was the cause of visual impairment.
  
  
  CONCLUSIONS
  Surgery-related complications were major causes for visual acuity of < 20/60.
authors.affiliation: Glaucoma Project, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
authors.forename: Lingam
authors.initials: L
authors.lastname: Vijaya
authors.forename: Ronnie
authors.initials: R
authors.lastname: George
authors.forename: A
authors.initials: A
authors.lastname: Rashima
authors.forename: Prema
authors.initials: P
authors.lastname: Raju
authors.forename: Hemamalini
authors.initials: H
authors.lastname: Arvind
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.forename: Ramesh S
authors.initials: RS
authors.lastname: Ve
mesh_terms: D002387:Cataract Extraction; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D012424:Rural Population; D016896:Treatment Outcome; D014505:Urban Population; D014792:Visual Acuity