title: Central corneal thickness in Northwestern American Indians/Alaskan Natives and comparison with White and African-American persons.
abstract: OBJECTIVE
  To determine the demographic factors associated with central corneal thickness (CCT) in Northwestern American Indians/Alaskan Natives (AI/ANs) and to compare these CCT measurements with those of White and African-American persons.
  
  
  METHODS
  Cross-sectional comparative, observational study.
  
  
  METHODS
  We performed ultrasonic pachymetry (DGH-500 Pachette; DGH Technologies, Exton, Pennsylvania, USA) on a random sample of AI/AN subjects from three randomly selected AI/AN tribes in the Northwest United States (n = 429). Pachymetry also was performed on a convenience sample of White (n = 46) and African-American (n = 33) persons. Our main outcome measure was the average of right and left eye CCT.
  
  
  RESULTS
  Average AI/AN CCT was 554.8 +/- 33.9 microm. AI/AN CCT was found to be thicker than that of African Americans (528.5 +/- 33.2 microm) but similar to that of White persons (551.9 +/- 28.3 microm). CCT was greater in AI/AN females than in AI/AN males (557.6 +/- 33.3 microm vs 550.1 +/- 34.5 microm; P = .03). We found no difference in CCT based on percent AI/AN heritage, age, and keratometry readings. We found no significant differences in mean CCT between AI/ANs with glaucoma (556.2 microm) and those who did not have glaucoma (556.6 microm).
  
  
  CONCLUSIONS
  CCT measurements for the Northwest AI/AN population are similar to those of White persons but thicker than those of African-American persons. Although glaucoma is common in AI/ANs, we did not find an association with thin CCT. We need future studies to explore the risk factors for glaucoma in AI/ANs.
authors.affiliation: Devers Eye Institute/Discoveries In Sight, Legacy Health System, Portland, Oregon 97210, USA.
authors.forename: Rodrigo J
authors.initials: RJ
authors.lastname: Torres
authors.forename: Emily
authors.initials: E
authors.lastname: Jones
authors.forename: Beth
authors.initials: B
authors.lastname: Edmunds
authors.forename: Thomas
authors.initials: T
authors.lastname: Becker
authors.forename: George A
authors.initials: GA
authors.lastname: Cioffi
authors.forename: Steven L
authors.initials: SL
authors.lastname: Mansberger
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D000413:Alaska / Q000208:ethnology; D044467:American Indian or Alaska Native; D003315:Cornea / Q000000981:diagnostic imaging*; D003431:Cross-Cultural Comparison; D005260:Female; D006801:Humans; D007198:Indians, North American; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000208:ethnology; D014463:Ultrasonography; D044465:White People