title: Social Determinants and Their Impact on Visual Impairment in Southern Mexico.
abstract: OBJECTIVE
  Visual impairment in disadvantaged populations in Mexico has been scarcely reported. We compared the prevalence of visual impairment and its associated risk factors in populations in rural compared to urban areas of the Mexican southern state of Chiapas.
  
  
  METHODS
  In a population-based study, the prevalence of visual impairment in rural and urban areas of Comitan, Chiapas, was estimated. All eligible individuals aged ≥20 years living in rural areas were invited to participate; persons from urban areas were chosen randomly. Individuals were considered of indigenous (IND) origin either by self-report or if they spoke an IND language. Visual acuity (VA) and pinhole VA were measured using a tumbling E chart. VA was defined as normal (better than or equal to 20/60), moderate impairment (worse than 20/60 but better than or equal to 20/200), severe impairment (worse than 20/200 but better than or equal to 20/400), or blindness (worse than 20/400).
  
  
  RESULTS
  Data on VA were obtained from 969 persons (610 rural, 359 urban) whose mean age was 43.3 years (standard deviation 15.6 years). Prevalence of moderate visual impairment was higher in rural (10.2%, 95% confidence interval, CI, 7.2-14.2%) than urban (3.9%, 95% CI 1.9-7.9%) areas (p < 0.001). Persons with moderate visual impairment were older and less educated (both p < 0.001). Rural individuals aged 50 years and older had 4.4 times (95% CI 1.8-11.3, p = 0.002) the likelihood of having moderate visual impairment compared with urban persons.
  
  
  CONCLUSIONS
  Unfavorable socioeconomic conditions were associated with higher prevalence of moderate visual impairment in rural compared with urban populations in Mexico.
authors.affiliation: a Diabetes and Cardiovascular Risk Research Unit, Health Population Research Center, National Institute of Public Health , Cuernavaca , Morelos , Mexico .
authors.forename: Aida
authors.initials: A
authors.lastname: Jimenez-Corona
authors.affiliation: b Biologics and Reagents Laboratories of Mexico , BIRMEX, Mexico City , Mexico , and.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Jimenez-Corona
authors.affiliation: b Biologics and Reagents Laboratories of Mexico , BIRMEX, Mexico City , Mexico , and.
authors.forename: Samuel
authors.initials: S
authors.lastname: Ponce-de-Leon
authors.affiliation: b Biologics and Reagents Laboratories of Mexico , BIRMEX, Mexico City , Mexico , and.
authors.forename: Mariela
authors.initials: M
authors.lastname: Chavez-Rodriguez
authors.affiliation: c Department of Cornea and Refractive Surgery , Instituto de Oftalmologia Conde de Valenciana , Mexico D.F. , Mexico.
authors.forename: Enrique O
authors.initials: EO
authors.lastname: Graue-Hernandez
mesh_terms: D000328:Adult; D000368:Aged; D001766:Blindness / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D064890:Social Determinants of Health / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*; D015354:Vision, Low / Q000453:epidemiology*; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*
keywords: Indigenous; prevalence; rural and urban areas; survey; visual impairment