title: Distribution of astigmatism among Sioux Indians in South Dakota.
abstract: BACKGROUND
  Previous studies have reported a greater prevalence of high astigmatism and vision disorders among Native Americans than occurs in the general U.S. population. The majority of these studies, however, have focused on Native American schoolchildren. This study assessed the distribution of astigmatism in a general clinic population at the Rosebud Indian Reservation in South Dakota.
  
  
  METHODS
  From examination of 174 patients, demographic information, visual acuities, refractive error, binocular vision status, and eye health were recorded.
  
  
  RESULTS
  The data showed more high astigmatism than would be expected in a general U.S. population. Three or more diopters of astigmatism were found in 9.2% of the right eyes and 10.8% of the left eyes in the study population. High astigmatism was noted less frequently among those ages 40 years and older (3.3% right eyes, 6.3% left eyes). Most of the astigmatism was with-the-rule, but a shift toward against-the-rule and oblique astigmatism was found in older individuals. No significant gender differences were noted.
  
  
  CONCLUSIONS
  The results suggest an ethnic difference in astigmatism and emphasize thee need for continued and expanded vision services for Native American populations.
authors.affiliation: University of Alabama at Birmingham, School of Optometry 36294-0010, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Pensyl
authors.forename: R A
authors.initials: RA
authors.lastname: Harrison
authors.forename: P
authors.initials: P
authors.lastname: Simpson
authors.forename: J W
authors.initials: JW
authors.lastname: Waterbor
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001251:Astigmatism / Q000208:ethnology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007198:Indians, North American; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013023:South Dakota / Q000453:epidemiology; D014481:United States; D016549:United States Indian Health Service; D014792:Visual Acuity