title: Measurement of choroidal thickness in normal eyes using 3D OCT-1000 spectral domain optical coherence tomography.
abstract: OBJECTIVE
  To study choroidal thickness and its topographic profile in normal eyes using 3D OCT-1000 spectral domain optical coherence tomography and the correlation with age and refractive error.
  
  
  METHODS
  Fifty-seven eyes (45 individuals) with no visual complaints or ocular disease underwent horizontal and vertical line scanning using 3D OCT-1000. The definition of choroidal thickness was the vertical distance between the posterior edge of the hyper-reflective retinal pigment epithelium and the choroid/sclera junction. Choroidal thickness was measured in the subfoveal area at 500 µm intervals from the fovea to 2,500 µm in the nasal, temporal, superior, and inferior regions. The spherical equivalent refractive error was measured by autorefractometry. Statistical analysis was used to confirm the correlations of choroidal thickness with age and refraction error.
  
  
  RESULTS
  The mean age of the 45 participants (57 eyes) was 45.28 years. Detailed visualization of the choroid for measuring its thickness was possible in 63.3% of eyes. The mean subfoveal choroidal thickness was found to be 270.8 µm (standard deviation [SD], ±51 µm), in horizontal scanning and 275.0 µm (SD, ±49 µm) in vertical scanning. The temporal choroidal thickness was greater than any 500 µm interval in corresponding locations, and there was no significant difference between the superior and inferior choroid as far as 2,000 µm from the fovea. Age and refractive error were associated with subfoveal choroidal thickness in terms of regression (p < 0.05).
  
  
  CONCLUSIONS
  Choroidal thickness in normal Korean eyes can be measured using 3D OCT-1000 with high resolution line scanning. The topographical profile of choroidal thickness varies depending on its location. Age and refractive error are essential factors for interpretation of choroidal thickness.
authors.affiliation: Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Joong Won
authors.initials: JW
authors.lastname: Shin
authors.forename: Yong Un
authors.initials: YU
authors.lastname: Shin
authors.forename: Hee Yoon
authors.initials: HY
authors.lastname: Cho
authors.forename: Byung Ro
authors.initials: BR
authors.lastname: Lee
mesh_terms: D044466:Asian People; D002829:Choroid / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012016:Reference Values; D012030:Refractive Errors; D056910:Republic of Korea; D041623:Tomography, Optical Coherence / Q000379:methods*