title: Posterior Eye Shape Measurement With Retinal OCT Compared to MRI.
abstract: Posterior eye shape assessment by magnetic resonance imaging (MRI) is used to study myopia. We tested the hypothesis that optical coherence tomography (OCT), as an alternative, could measure posterior eye shape similarly to MRI.
  
  
  
  Macular spectral-domain OCT and brain MRI images previously acquired as part of the Singapore Epidemiology of Eye Diseases study were analyzed. The right eye in the MRI and OCT images was automatically segmented. Optical coherence tomography segmentations were corrected for optical and display distortions requiring biometry data. The segmentations were fitted to spheres and ellipsoids to obtain the posterior eye radius of curvature (Rc) and asphericity (Qxz). The differences in Rc and Qxz measured by MRI and OCT were tested using paired t-tests. Categorical assignments of prolateness or oblateness using Qxz were compared.
  
  
  
  Fifty-two subjects (67.8 ± 5.6 years old) with spherical equivalent refraction from +0.50 to -5.38 were included. The mean paired difference between MRI and original OCT posterior eye Rc was 24.03 ± 46.49 mm (P = 0.0005). For corrected OCT images, the difference in Rc decreased to -0.23 ± 2.47 mm (P = 0.51). The difference between MRI and OCT asphericity, Qxz, was -0.052 ± 0.343 (P = 0.28). However, categorical agreement was only moderate (κ = 0.50).
  
  
  
  Distortion-corrected OCT measurements of Rc and Qxz were not statistically significantly different from MRI, although the moderate categorical agreement suggests that individual differences remained. This study provides evidence that with distortion correction, noninvasive office-based OCT could potentially be used instead of MRI for the study of posterior eye shape.
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States.
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Kuo
authors.affiliation: Singapore Eye Research Institute, The Academia, Singapore.
authors.forename: Pavan K
authors.initials: PK
authors.lastname: Verkicharla
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: McNabb
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
authors.affiliation: Memory Aging & Cognition Centre and Department of Pharmacology, National University of Singapore, Singapore.
authors.forename: Saima
authors.initials: S
authors.lastname: Hilal
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States 5Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States.
authors.forename: Sina
authors.initials: S
authors.lastname: Farsiu
authors.affiliation: Memory Aging & Cognition Centre and Department of Pharmacology, National University of Singapore, Singapore.
authors.forename: Christopher
authors.initials: C
authors.lastname: Chen
authors.affiliation: Singapore Eye Research Institute, The Academia, Singapore 6Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore 7Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Tien Y
authors.initials: TY
authors.lastname: Wong
authors.affiliation: Memory Aging & Cognition Centre and Department of Pharmacology, National University of Singapore, Singapore 8Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: M Kamran
authors.initials: MK
authors.lastname: Ikram
authors.affiliation: Singapore Eye Research Institute, The Academia, Singapore 6Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore.
authors.forename: Ching Y
authors.initials: CY
authors.lastname: Cheng
authors.affiliation: Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore 9University of Wisconsin-Madison, Department of Ophthalmology and Visual Sciences, Madison, Wisconsin, United States.
authors.forename: Terri L
authors.initials: TL
authors.lastname: Young
authors.affiliation: Singapore Eye Research Institute, The Academia, Singapore 6Duke-National University of Singapore (NUS) Graduate Medical School, Singapore, Singapore.
authors.forename: Seang M
authors.initials: SM
authors.lastname: Saw
authors.affiliation: Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States 5Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Izatt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry; D005260:Female; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D057972:Posterior Eye Segment / Q000473:pathology*; D012160:Retina / Q000473:pathology; D012846:Singapore / Q000453:epidemiology; D041623:Tomography, Optical Coherence / Q000379:methods*