title: Peripapillary choroidal thickness assessed using automated choroidal segmentation software in an Asian population.
abstract: OBJECTIVE
  To objectively quantify the thickness of peripapillary choroid using spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) followed by a novel automated choroidal segmentation software in Asian eyes and to evaluate its systemic and ocular determinants.
  
  
  METHODS
  We recruited 520 subjects (1040 eyes) from the Singapore Malay Eye Study, a cross-sectional population-based study. Subjects underwent standardised detailed ophthalmic examination including SD-OCT (Spectralis) with EDI for measurement of peripapillary choroidal thickness (PPCT).
  
  
  RESULTS
  The mean age of the subjects was 66.7±10.4 years (range 47-88 years) and the mean spherical equivalent was -0.01±2.28 D (range -18.50 to +7.00 D). The intra-session repeatability of PPCT measurements at four quadrants using automated choroidal segmentation software was excellent (intraclass correlation coefficient 0.9998-0.9999). The overall mean PPCT was 136.2±56.8 µm. Peripapillary choroid showed geographical differences among the four quadrants, being thickest in the superior quadrant (150.5±59.6 µm), followed by the nasal (143.5±58.4 µm) and temporal quadrants (139.4±68.9 µm), and thinnest in the inferior quadrant (111.3±51.7 µm). Among the range of ocular and systemic factors studied, shorter axial length (p=0.002), younger age (p=0.018), lower triglyceride level (p=0.015) and the presence of diabetes (p=0.036) were the only significant predictors of thicker peripapillary choroid.
  
  
  CONCLUSIONS
  Using novel automated choroidal segmentation software, we provide reliable objective measurements of PPCT in a population-based setting. Shorter axial length, younger age, lower triglyceride levels and the presence of diabetes are the factors independently associated with thicker PPCT. These factors should be taken into consideration when interpreting Spectralis EDI SD-OCT-based PPCT measurements in clinics.
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
authors.forename: Preeti
authors.initials: P
authors.lastname: Gupta
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
authors.forename: Tian
authors.initials: T
authors.lastname: Jing
authors.affiliation: School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
authors.forename: Pina
authors.initials: P
authors.lastname: Marziliano
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Mani
authors.initials: M
authors.lastname: Baskaran
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Gemmy C M
authors.initials: GC
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Ecosse L
authors.initials: EL
authors.lastname: Lamoureux
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, Singapore.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Cheng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D058452:Axial Length, Eye / Q000033:anatomy & histology; D002829:Choroid / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D048909:Diabetes Complications; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000033:anatomy & histology; D015203:Reproducibility of Results; D012846:Singapore / Q000453:epidemiology; D012984:Software; D041623:Tomography, Optical Coherence / Q000379:methods*; D014280:Triglycerides / Q000097:blood
chemical_list: D014280:Triglycerides
keywords: Epidemiology; Imaging