title: The morphology of the optic nerve head in the Singaporean Chinese population (the Tanjong Pagar study): part 2--Biometric and systemic associations.
abstract: OBJECTIVE
  To investigate the association of biometric and systemic variables with optic disc characteristics in Chinese Singaporean adults.
  
  
  METHODS
  Ocular, biometric and medical data including intraocular pressure, refractive error, keratometry, axial length (AL), anterior chamber depth, corneal and lens thickness as well as optic disc data (using planimetry of stereo-photographs) were obtained from 622 normal subjects aged > or = 40 years from the Tanjong Pagar glaucoma survey of Singapore.
  
  
  RESULTS
  Disc area (DA) was positively associated with AL and height but was unrelated to corneal thickness. Following adjustment for IOP and sex, DA remained positively associated with AL, height and age. Neuroretinal rim area (RA) was also significantly and positively associated with AL and also with height. RA was negatively associated with IOP and was unrelated to blood pressure, history of diabetes, myocardial infarction, stroke or migraine.
  
  
  CONCLUSIONS
  These data on a Chinese Singaporean population identify height and axial length of the globe as significantly associated with rim area of the disc. These features should be taken into account in statistical assessments of optic nerve head morphometry. This may improve the discriminative ability of image analysis to detect glaucomatous changes. In addition, we identified a statistically significant but small inverse association between rim area and IOP within the normal statistical range.
authors.affiliation: Huntingdon Glaucoma Diagnostic & Research Centre, Department Ophthalmology, Hinchingbrooke Hospital, Huntingdon PE29 6NT, UK. rupert.bourne@lshtm.ac.uk
authors.forename: R R A
authors.initials: RR
authors.lastname: Bourne
authors.forename: P J
authors.initials: PJ
authors.lastname: Foster
authors.forename: C
authors.initials: C
authors.lastname: Bunce
authors.forename: T
authors.initials: T
authors.lastname: Peto
authors.forename: R A
authors.initials: RA
authors.lastname: Hitchings
authors.forename: P T
authors.initials: PT
authors.lastname: Khaw
authors.forename: S K L
authors.initials: SK
authors.lastname: Seah
authors.forename: D F
authors.initials: DF
authors.lastname: Garway-Heath
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology; D044466:Asian People / Q000706:statistics & numerical data*; D001699:Biometry / Q000379:methods; D001827:Body Height; D019781:Corneal Topography / Q000379:methods; D003430:Cross-Sectional Studies; D005123:Eye / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000033:anatomy & histology* / Q000473:pathology; D012016:Reference Values; D012030:Refractive Errors / Q000473:pathology; D012846:Singapore