title: The Norfolk Island Eye Study (NIES): rationale, methodology and distribution of ocular biometry (biometry of the bounty).
abstract: OBJECTIVE
  To describe the recruitment, ophthalmic examination methods and distribution of ocular biometry of participants in the Norfolk Island Eye Study, who were individuals descended from the English Bounty mutineers and their Polynesian wives.
  
  
  METHODS
  All 1,275 permanent residents of Norfolk Island aged over 15 years were invited to participate, including 602 individuals involved in a 2001 cardiovascular disease study. Participants completed a detailed questionnaire and underwent a comprehensive eye assessment including stereo disc and retinal photography, ocular coherence topography and conjunctival autofluorescence assessment. Additionally, blood or saliva was taken for DNA testing.
  
  
  RESULTS
  781 participants aged over 15 years were seen (54% female), comprising 61% of the permanent Island population. 343 people (43.9%) could trace their family history to the Pitcairn Islanders (Norfolk Island Pitcairn Pedigree). Mean anterior chamber depth was 3.32mm, mean axial length (AL) was 23.5mm, and mean central corneal thickness was 546 microns. There were no statistically significant differences in these characteristics between persons with and without Pitcairn Island ancestry. Mean intra-ocular pressure was lower in people with Pitcairn Island ancestry: 15.89mmHg compared to those without Pitcairn Island ancestry 16.49mmHg (P = .007). The mean keratometry value was lower in people with Pitcairn Island ancestry (43.22 vs. 43.52, P = .007). The corneas were flatter in people of Pitcairn ancestry but there was no corresponding difference in AL or refraction.
  
  
  CONCLUSIONS
  Our study population is highly representative of the permanent population of Norfolk Island. Ocular biometry was similar to that of other white populations. Heritability estimates, linkage analysis and genome-wide studies will further elucidate the genetic determinants of chronic ocular diseases in this genetic isolate.
authors.affiliation: Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Australia. D.Mackey@utas.edu.au
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
authors.forename: Justin C
authors.initials: JC
authors.lastname: Sherwin
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Kearns
authors.forename: Yaling
authors.initials: Y
authors.lastname: Ma
authors.forename: John
authors.initials: J
authors.lastname: Kelly
authors.forename: Byoung-Sun
authors.initials: BS
authors.lastname: Chu
authors.forename: Robert
authors.initials: R
authors.lastname: Macmillan
authors.forename: Julie M
authors.initials: JM
authors.lastname: Barbour
authors.forename: Colleen H
authors.initials: CH
authors.lastname: Wilkinson
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Matovinovic
authors.forename: Hannah C
authors.initials: HC
authors.lastname: Cox
authors.forename: Claire
authors.initials: C
authors.lastname: Bellis
authors.forename: Rod A
authors.initials: RA
authors.lastname: Lea
authors.forename: Sharon
authors.initials: S
authors.lastname: Quinlan
authors.forename: Lyn R
authors.initials: LR
authors.lastname: Griffiths
authors.forename: Alex W
authors.initials: AW
authors.lastname: Hewitt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000033:anatomy & histology; D001699:Biometry; D003315:Cornea / Q000033:anatomy & histology*; D015785:Eye Diseases, Hereditary / Q000235:genetics*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008542:Melanesia; D008875:Middle Aged; D009885:Ophthalmology; D010375:Pedigree; D010896:Pitcairn Island; D012029:Refraction, Ocular; D011795:Surveys and Questionnaires; D014065:Tonometry, Ocular; D014785:Vision, Ocular; D055815:Young Adult