title: Prevalence of high astigmatism, eyeglass wear, and poor visual acuity among Native American grade school children.
abstract: OBJECTIVE
  The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and rate of eyeglass wear in grade school children who are members of a Native American tribe reported to have a high prevalence of large amounts of astigmatism.
  
  
  METHODS
  Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O'odham Reservation. Noncycloplegic autorefraction was conducted on the right and left eye of each child using the Nikon Retinomax K+ autorefractor, and monocular recognition acuity was tested using ETDRS logarithm of the minimum angle of resolution (logMAR) letter charts.
  
  
  RESULTS
  Tohono O'odham children had a high prevalence of high astigmatism (42% had > or = 1.00 D in the right or left eye) and the axis of astigmatism was uniformly with-the-rule. However, only a small percentage of children arrived at the vision screening wearing glasses, and the prevalence of poor visual acuity (20/40 or worse in either eye) was high (35%). There was a significant relation between amount of astigmatism and uncorrected visual acuity with each additional diopter of astigmatism resulting in an additional 1 logMAR line reduction in visual acuity.
  
  
  CONCLUSIONS
  Uncorrected astigmatism and poor visual acuity are prevalent among Tohono O'odham children. The results highlight the importance of improving glasses-wearing compliance, determining barriers to receiving eye care, and initiating public education programs regarding the importance of early identification and correction of astigmatism in Tohono O'odham children.
authors.affiliation: The University of Arizona Department of Ophthalmology and Vision Science, Tucson, Arizona 85711, USA. emharvey@u.arizona.edu
authors.forename: Erin M
authors.initials: EM
authors.lastname: Harvey
authors.forename: Velma
authors.initials: V
authors.lastname: Dobson
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D001130:Arizona / Q000453:epidemiology; D001251:Astigmatism / Q000208:ethnology* / Q000503:physiopathology / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D005139:Eyeglasses / Q000706:statistics & numerical data*; D006801:Humans; D007198:Indians, North American; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014786:Vision Disorders / Q000208:ethnology*; D014792:Visual Acuity