title: Normative database of retinal nerve fiber layer and macular retinal thickness in a Thai population.
abstract: OBJECTIVE
  To investigate the distribution of retinal nerve fiber layer (RNFL) and macular retinal thickness measured by optical coherence tomography (OCT) in a Thai population.
  
  
  METHODS
  We studied one eye each of 250 healthy subjects [age > or = 18 years; spherical refractive error within +/-6 diopters (D); astigmatism < or =3 D; no ocular pathology]. A complete eye examination, standard automated perimetry, and fast RNFL and macular thickness measurement by OCT were performed, and a disc photograph was taken. The distributions of both thicknesses, including their relationship with demographic data, were analyzed.
  
  
  RESULTS
  The mean +/- SD age of the study population was 44.7 +/- 12.2 years. The mean +/- SD RNFL thickness was 109.3 +/- 10.5 m, which was 10% thicker than that in the OCT normative database. RNFL decreased 2.3 m per decade (P < 0.001). Sex and spherical equivalent were not associated with RNFL thinning. The mean +/- SD central foveal thickness was 183.2 +/- 1.3 m. The macular thickness in the outer area was significantly thinner than that in the inner area (P < 0.001). The temporal regions were the thinnest among the four quadrants (P < 0.001). Thinning of all macular areas, except the center, was found to be associated with advancing age (P < 0.05).
  
  
  CONCLUSIONS
  RNFL thickness in the measured Thai population was about 10% thicker than that in the original normative database. Macular thickness and RNFL thickness in the superior and inferior quadrants decreased with advancing age.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. amanassa@mail.med.cmu.ac.th.
authors.forename: Anita
authors.initials: A
authors.lastname: Manassakorn
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Winai
authors.initials: W
authors.lastname: Chaidaroon
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Somsanguan
authors.initials: S
authors.lastname: Ausayakhun
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Soontaree
authors.initials: S
authors.lastname: Aupapong
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Sopa
authors.initials: S
authors.lastname: Wattananikorn
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D016208:Databases, Factual; D005260:Female; D006801:Humans; D016014:Linear Models; D008266:Macula Lutea / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000648:ultrastructure*; D012016:Reference Values; D012160:Retina / Q000648:ultrastructure*; D013785:Thailand; D041623:Tomography, Optical Coherence; D055815:Young Adult