title: Visual function and vision-related quality of life in presbyopic adult population of Northwestern Nigeria.
abstract: OBJECTIVE
  To determine the impact of uncorrected presbyopia on vision-related quality of life (QoL) and visual function (VF) among adults 40 years and older in Bungudu local government area (LGA) of Zamfara State, Nigeria.
  
  
  METHODS
  A population-based cross-sectional study in Bungudu LGA of Zamfara State Nigeria was conducted in 2012. Six-hundred and fifty persons at least 40 years of age were examined using a two-stage cluster random sampling-based on probability proportional to size. Presbyopia was defined as the inability to read N8 at 40 cm in an indoor illumination using LogMAR E-chart. Demographic information comprising of age, sex, occupation, and educational level among others was obtained from a pilot tested VF-14 and modified vision-related QoL questionnaire by trained interviewer.
  
  
  RESULTS
  Out Of the 650 subjects enumerated 635 were examined given a response rate of 97.7%. The mean age of participants was 53.59 years (95% confidence interval:52.75%-54.43%). The crude prevalence of presbyopia was 30.4%, (95% CI: 26.8%-34.1%). The mean VF score of persons with presbyopia was 85.09, (95% CI: 83.09%-87.09%) and being female was strongly associated with high VF scores (P = 0.003). The VFs most impaired were the ability to read, write, use mobile phones, and thread needles. The higher the degree of presbyopia the lower the mean VF score (P = 0.00).
  
  
  CONCLUSIONS
  Uncorrected presbyopia is associated with functional visual impairment and reduce QoL especially in the ability to read, write, and usage of mobile cell phones among adults 40 years and older in Bungudu District.
authors.affiliation: Department of Surgery, Ophthalmology Unit, Usmanu Danfodiyo University/Teaching Hospital, Sokoto, Nigeria.
authors.forename: Nasiru
authors.initials: N
authors.lastname: Muhammad
authors.affiliation: Department of Vitreoretina, National Eye Centre, Kaduna, Nigeria.
authors.forename: Mahmoud B
authors.initials: MB
authors.lastname: Alhassan
authors.affiliation: Department of Ophthalmology, Zamfara State Eye Care Programme, King Fahad IBN Abdul-Azeez Women and Children Hospital, Gusau, Zamfara State, Nigeria.
authors.forename: Murtala M
authors.initials: MM
authors.lastname: Umar
keywords: Ageing; Nigeria; presbyopia; quality-of-life; visual function