title: Distribution and determinants of choroidal thickness and volume using automated segmentation software in a population-based study.
abstract: OBJECTIVE
  To objectively quantify choroidal thickness and choroidal volume using fully automated choroidal segmentation software applied to images obtained from enhanced depth imaging spectral-domain optical coherence tomography (EDI SD OCT) in a population-based study; and evaluate the ocular and systemic determinants of choroidal thickness and choroidal volume.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  Participants ranging in age from 45 to 85 years were recruited from the Singapore Malay Eye Study-2 (SiMES-2), a follow-up population-based study. All participants (n = 540) underwent a detailed ophthalmic examination, including EDI SD OCT for measurements of thickness and volume of the choroid.
  
  
  RESULTS
  The intrasession repeatability of choroidal thickness at 5 measured horizontal locations and macular choroidal volume using automated choroidal segmentation software was excellent (intraclass correlation coefficient, 0.97-0.99). Choroid was significantly thicker under the fovea (242.28 ± 97.58 μm), followed by 3 mm temporal (207.65 ± 80.98 μm), and was thinnest at 3 mm nasal (142.44 ± 79.19 μm) location. The mean choroidal volume at central macular region (within a circle of 1 mm diameter) was 0.185 ± 0.69 mm(3). Among the range of ocular and systemic factors studied, age, sex, and axial length were the only significant predictors of choroidal thickness and choroidal volume (all P < .05).
  
  
  CONCLUSIONS
  Using a new automated choroidal segmentation software, we provide fast, reliable, and objective measurements of choroidal thickness and volume in a population-based sample. Male sex, younger age, and shorter axial length are the factors independently associated with thicker choroid and larger choroidal volume. These factors should be taken into consideration when interpreting EDI SD OCT-based choroidal thickness measurements in clinics.
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore.
authors.forename: Preeti
authors.initials: P
authors.lastname: Gupta
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore.
authors.forename: Tian
authors.initials: T
authors.lastname: Jing
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore.
authors.forename: Pina
authors.initials: P
authors.lastname: Marziliano
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Ecosse L
authors.initials: EL
authors.lastname: Lamoureux
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore.
authors.forename: Chui Ming Gemmy
authors.initials: CM
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore. Electronic address: ching-yu_cheng@nuhs.edu.sg.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Cheng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D002829:Choroid / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011446:Prospective Studies; D015203:Reproducibility of Results; D012984:Software; D041623:Tomography, Optical Coherence / Q000379:methods*