title: Optic nerve head parameters of an indigenous population living within Central Australia.
abstract: OBJECTIVE
  Clinical examination of the optic disc is an essential element in the assessment of its health. Previous work has described normal optic disc appearance among different races. No such description of optic discs exists for indigenous Australians, who are at low risk of developing glaucoma. This study was designed to evaluate optic disc parameters of indigenous Australians.
  
  
  METHODS
  A sample of 208 indigenous Australians were recruited as they presented to remote clinics in Central Australia. Each subject underwent optic disc photography using a Topcon TRC-NW100 digital fundus camera. Optic discs were measured and analysed with Topcon ImageNet 2000 software.
  
  
  RESULTS
  Among other parameters, mean vertical disc diameter and disc area were 2.13 +/- 0.21 mm (mean +/- SD) and 3.13 +/- 0.57 mm2, respectively, for right eyes and 2.14 +/- 0.21 mm and 3.16 +/- 0.58 mm2 for left eyes. When compared with published studies, these parameters were significantly larger than Caucasians, but similar to African individuals.
  
  
  CONCLUSIONS
  Our results suggest that indigenous Australians have optic discs that are larger than those of Caucasians, but similar to those of Africans who are considered to at a greater risk of glaucoma. Factors other than optic disc area are likely to underlie the higher prevalence of primary open angle glaucoma among African individuals.
authors.affiliation: Department of Ophthalmology, Flinders Medical Centre, Adelaide, South Australia, Australia. john.landers@bigpond.com
authors.forename: John A
authors.initials: JA
authors.lastname: Landers
authors.forename: Tim R
authors.initials: TR
authors.lastname: Henderson
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Craig
mesh_terms: D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000208:ethnology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015876:Northern Territory / Q000453:epidemiology; D009898:Optic Disk / Q000033:anatomy & histology*; D044382:Population Groups; D012189:Retrospective Studies