title: Couching in Nigeria: prevalence, risk factors and visual acuity outcomes.
abstract: OBJECTIVE
  Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria.
  
  
  METHODS
  Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging.
  
  
  RESULTS
  Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60).
  
  
  CONCLUSIONS
  Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country.
authors.affiliation: International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, England. clare.gilbert@Lshtm.ac.uk
authors.forename: Clare E
authors.initials: CE
authors.lastname: Gilbert
authors.forename: G V S
authors.initials: GV
authors.lastname: Murthy
authors.forename: S
authors.initials: S
authors.lastname: Sivasubramaniam
authors.forename: F
authors.initials: F
authors.lastname: Kyari
authors.forename: A
authors.initials: A
authors.lastname: Imam
authors.forename: M M
authors.initials: MM
authors.lastname: Rabiu
authors.forename: M
authors.initials: M
authors.lastname: Abdull
authors.forename: A
authors.initials: A
authors.lastname: Tafida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000453:epidemiology / Q000209:etiology; D002386:Cataract / Q000453:epidemiology*; D002387:Cataract Extraction / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D016488:Medicine, African Traditional / Q000706:statistics & numerical data*; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D016896:Treatment Outcome; D015354:Vision, Low / Q000453:epidemiology / Q000209:etiology; D014792:Visual Acuity / Q000502:physiology*