title: Cataract prevalence, cataract surgical coverage and barriers to uptake of cataract surgical services in Pakistan: the Pakistan National Blindness and Visual Impairment Survey.
abstract: OBJECTIVE
  To estimate the prevalence of visual impairment and blindness caused by cataract, the prevalence of aphakia/pseudophakia, cataract surgical coverage (CSC) and to identify barriers to the uptake of cataract services among adults aged >or=30 years in Pakistan.
  
  
  METHODS
  Probability proportional-to-size procedures were used to select a nationally representative sample of adults. Each subject underwent interview, visual acuity measurement, autorefraction, biometry and ophthalmic examination. Those that saw <6/12 in either eye underwent a more intensive examination procedure including corrected visual acuity, slit lamp and dilated fundus examination. CSC was calculated for different levels of visual loss by person and by eye. Individuals with <6/60 in the better eye as a result of cataract were interviewed regarding barriers.
  
  
  RESULTS
  16 507 Adults were examined (95.5% response rate). The crude prevalence of blindness (presenting <3/60 in the better eye) caused by bilateral cataract was 1.75% (95% CI 1.55%, 1.96%). 1317 Participants (633 men; 684 women) had undergone cataract surgery in one or both eyes, giving a crude prevalence of 8.0% (95% CI 7.6%, 8.4%). The CSC (persons) at <3/60, <6/60 and <6/18 were 77.1%, 69.3% and 43.7%, respectively. The CSC (eyes) at <3/60, <6/60 and <6/18 were 61.4%, 52.2% and 40.7%, respectively. Cost of surgery (76.1%) was the main barrier to surgery.
  
  
  CONCLUSIONS
  Approximately 570 000 adults are estimated to be blind (<3/60) as a result of cataract in Pakistan, and 3,560000 eyes have a visual acuity of <6/60 because of cataract. Overall, the national surgical coverage is good but underserved populations have been identified.
authors.affiliation: Pakistan Institute of Community Ophthalmlogy, Kyber Institute of Ophthalmic Medical Sciences, Peshawar, Pakistan.
authors.forename: Z
authors.initials: Z
authors.lastname: Jadoon
authors.forename: S P
authors.initials: SP
authors.lastname: Shah
authors.forename: R
authors.initials: R
authors.lastname: Bourne
authors.forename: B
authors.initials: B
authors.lastname: Dineen
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.forename: C E
authors.initials: CE
authors.lastname: Gilbert
authors.forename: A
authors.initials: A
authors.lastname: Foster
authors.forename: M D
authors.initials: MD
authors.lastname: Khan
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001036:Aphakia, Postcataract / Q000453:epidemiology / Q000209:etiology; D001766:Blindness / Q000453:epidemiology / Q000209:etiology; D002386:Cataract / Q000150:complications / Q000191:economics / Q000453:epidemiology*; D002387:Cataract Extraction / Q000191:economics / Q000523:psychology; D005260:Female; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008875:Middle Aged; D010154:Pakistan / Q000453:epidemiology; D010342:Patient Acceptance of Health Care / Q000523:psychology; D015995:Prevalence; D019591:Pseudophakia / Q000453:epidemiology / Q000209:etiology; D017678:Sex Distribution; D014786:Vision Disorders / Q000453:epidemiology / Q000209:etiology