title: Prevalence of refractive error in Bangladeshi adults: results of the National Blindness and Low Vision Survey of Bangladesh.
abstract: OBJECTIVE
  To determine the prevalence of refractive errors and to investigate factors associated with refractive error in adults 30 years of age and older in Bangladesh.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A nationally representative sample of 12 782 adults 30 years of age and older.
  
  
  METHODS
  The sample of subjects was selected based on multistage, cluster random sampling with probability-proportional-to-size procedures. The examination protocol consisted of an interview that included measures of literacy, education, occupation, and refractive correction. Visual acuity testing (logarithm of the minimum angle of resolution [logMAR]), automated refraction, and optic disc examination were performed for all subjects. Subjects with <6/12 (0.3 logMAR) acuity in either eye were graded additionally for cataract and underwent a dilated fundal examination. Subjects for whom no refractive error was recorded (312 subjects; 2.7%) or who had undergone cataract surgery (123 subjects; 1.1%) were excluded from the analysis.
  
  
  METHODS
  Refractive error and socioeconomic variables (literacy, education, occupation).
  
  
  RESULTS
  Eleven thousand six hundred twenty-four subjects were examined (90.9% response rate; mean age+/-standard deviation, 44+/-12.6 years). Five thousand four hundred eighty-nine subjects (49.1%) were men and 5700 subjects (50.9%) were women. Mean spherical equivalent was -0.19 diopters (D; +/-1.50 D). Six thousand four hundred twelve subjects (57.3%) were emmetropic, 2469 (22.1%) were myopic (<-0.5 D), and 2308 (20.6%) were hypermetropic (>+0.5 D). Two hundred six subjects (1.8%) were highly myopic (<-5 D). Myopia was more common in men (26.3%) than in women (21.0%), whereas hyperopia was more common in women (27.4%) than in men (15.8%). Overall, myopia increased with age (17.5% of those aged 30-39 years were myopic, compared with 65.5% of those age 70 years and older). A subanalysis of subjects without cataract showed increasing hyperopia with age and an association between myopia and higher education. Myopia was more common among the employed than in unemployed subjects. Astigmatism (>0.5 D), present in 3625 subjects (32.4%), was more common among women, illiterate subjects, and unschooled subjects. Against-the-rule astigmatism was more common (58.7%) than oblique astigmatism (29.3%), which was more common than with-the-rule (WTR) astigmatism (12.1%). Against-the-rule astigmatism and oblique astigmatism increased with age, unlike WTR astigmatism. Of 830 (7.5%) subjects, women were more commonly anisometropic (>1.0 D). Anisometropia increased with age.
  
  
  CONCLUSIONS
  Refractive error data are described for a country and region that previously have lacked population-based data. Prevalence and factors associated with refractive error are presented, with a detailed comparison with other population-based surveys regionally and internationally.
authors.affiliation: Department of Epidemiology and International Eye Health, Institute of Ophthalmology, University College London & Moorfields Eye Hospital, London, United Kingdom. rupert.bourne@lshtm.ac.uk
authors.forename: Rupert R A
authors.initials: RR
authors.lastname: Bourne
authors.forename: Brendan P
authors.initials: BP
authors.lastname: Dineen
authors.forename: Syed M
authors.initials: SM
authors.lastname: Ali
authors.forename: Deen M
authors.initials: DM
authors.lastname: Noorul Huq
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Johnson
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001459:Bangladesh / Q000453:epidemiology; D001766:Blindness / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009313:National Health Programs; D015995:Prevalence; D012030:Refractive Errors / Q000453:epidemiology*; D017678:Sex Distribution; D014787:Vision Tests; D015354:Vision, Low / Q000453:epidemiology*; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*