title: Relationship of ocular and systemic factors to the visibility of choroidal-scleral interface using spectral domain optical coherence tomography.
abstract: OBJECTIVE
  To assess the visibility of the choroidal-scleral interface (CSI) from spectral domain optical coherence tomography (SD-OCT) and evaluate the ocular and systemic factors influencing the visibility of CSI in healthy eyes from population-based Malay sample.
  
  
  METHODS
  Participants were consecutively recruited from the population-based Singapore Malay Eye Study-2 (SiMES-2). SD-OCT images were obtained by Spectralis OCT with enhanced depth imaging (EDI) mode. Visibility of CSI was assessed by a grading system ranging from 0 to 2 scores. The reliability of choroidal thickness measurement in different grades of CSI visibility was assessed using intraclass correlation coefficient. Ordinal regression analyses were performed to evaluate a range of ocular and systemic factors influencing the visibility of CSI.
  
  
  RESULTS
  A total of 176 healthy eyes were analysed, and 59.1% of our subjects had well-defined CSI (score 2), 8.5% had poorly defined CSI (score 0), and 32.4% had CSI between well and poorly defined (score 1). The reliability of subfoveal choroidal thickness measurement decreased with each grade of CSI visibility score. Decreased axial length (AL) (estimate of ordinal regression [OR] = 0.465, p = 0.003), thicker retinal thickness (estimate of OR = -0.030, p = 0.004), younger age (estimate of OR = 0.045, p = 0.030) and diabetes (estimate of OR = -0.746, p = 0.004) were associated with lower CSI visibility score.
  
  
  CONCLUSIONS
  Only 60% of normal healthy eyes had well-defined CSI from SD-OCT images. Our data suggest that choroidal thickness measurements can be substantially affected by the visibility of CSI. The visibility of CSI varies with AL, retinal thickness, age and diabetes.
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: 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.|Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore.|Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Cheng
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.|Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Chui Ming Gemmy
authors.initials: CM
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore.|Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Hla Myint
authors.initials: HM
authors.lastname: Htoon
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Yingfeng
authors.initials: Y
authors.lastname: Zheng
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.|Office of Clinical Sciences, 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.|Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.|Office of Clinical Sciences, 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.|Office of Clinical Sciences, 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.|Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, Singapore.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000033:anatomy & histology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D012590:Sclera / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence
keywords: EDI SD-OCT; choroid-scleral interface; choroidal thickness; visibility of choroid-scleral interface