title: Enhanced depth imaging spectral-domain optical coherence tomography of the choroid in Thai population.
abstract: OBJECTIVE
  To examine subfoveal choroidal thickness (SFCT) in Thai population using enhanced depth imaging spectral- domain optical coherence tomography (EDI-OCT) and to study its correlation with foveal retinal pigment epithelium thickness (FRPE), central neurosensory retinal thickness (CNRT), age, and refraction.
  
  
  METHODS
  Four hundred eighty eyes from 240 subjects without glaucoma, retinal, or choroidal diseases underwent scanning of the retina and choroid using EDI-OCT SFCT FRPE, and CNRT measurements were based on the 1:1 micron images and wereperformed by two independent observers. The reliability ofmeasurements between the observers was evaluated by intraclass correlation coefficient (ICC). The correlations of SFCT with FRPE, CNRT, age, and refractive error were analyzed
  
  
  RESULTS
  The mean age of the subjects was 36.22 years (range 20-81years). The means (95% reference intervals) of SFCT, CNRT andFRPE were 294.02 μm (137.14-450.90 μm), 174.22 μm (141.82-206.62 μm), and 41.94 μm (34.65-49.23 μm), respectively. SFCT and CNRThad excellent reliability between the two observers [ICC = 0.947 (95% CI, 0.918-0.963) and 0.929 (95% CI, 0.906-0.945), respectively], while FRPE showed good reliability [ICC = 0. 729 (95% CI, 0.637-0.793)]. SFCT had a low positive correlation with FRPE (r = 0.179, p<0. 0001) but not with CNRT (p = 0.317). SFCT showed a positive correlation with refraction (r = 0.338, p<0.0001) and a negative correlation with age (r = -0.166, p<0.0001). Regression analysis suggested that the SFCT decreased by 12.23 pm per one decade oflife and by 11.42 pm per one diopter of myopia.
  
  
  CONCLUSIONS
  Normal values of SFCT in Thai population were obtained SFCT significantly decreased with older age and higher myopia. SFCT was associated with FRPE, reflecting the same vascular supply of the choroid and retinal pigment epithelium. When measured with our technique based on the 1:1 micron images, the reliability ofSFCT measurement was very high despite highly morphologic inter-individual variations.
authors.forename: Nopasak
authors.initials: N
authors.lastname: Phasukkijwatana
authors.forename: Wilaipun
authors.initials: W
authors.lastname: Thaweerattanasilp
authors.forename: Sawarin
authors.initials: S
authors.lastname: Laotaweerungsawat
authors.forename: Nuttawut
authors.initials: N
authors.lastname: Rodanant
authors.forename: Apichart
authors.initials: A
authors.lastname: Singalavanija
authors.forename: Jutalai
authors.initials: J
authors.lastname: Tanterdtham
authors.forename: Chakrapong
authors.initials: C
authors.lastname: Namatra
authors.forename: Adisak
authors.initials: A
authors.lastname: Trinavarat
authors.forename: Somanus
authors.initials: S
authors.lastname: Thoongsuwan
authors.forename: Kritpol
authors.initials: K
authors.lastname: Rattanawarinchai
authors.forename: Ketwarin
authors.initials: K
authors.lastname: Thongyou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002829:Choroid / Q000033:anatomy & histology*; D005260:Female; D005584:Fovea Centralis / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology; D013785:Thailand; D041623:Tomography, Optical Coherence