title: Thickness mapping of eleven retinal layers segmented using the diffusion maps method in normal eyes.
abstract: This study was conducted to determine the thickness map of eleven retinal layers in normal subjects by spectral domain optical coherence tomography (SD-OCT) and evaluate their association with sex and age. Mean regional retinal thickness of 11 retinal layers was obtained by automatic three-dimensional diffusion map based method in 112 normal eyes of 76 Iranian subjects. We applied our previously reported 3D intraretinal fast layer segmentation which does not require edge-based image information but rather relies on regional image texture. The thickness maps are compared among 9 macular sectors within 3 concentric circles as defined by ETDRS. The thickness map of central foveal area in layers 1, 3, and 4 displayed the minimum thickness. Maximum thickness was observed in nasal to the fovea of layer 1 and in a circular pattern in the parafoveal retinal area of layers 2, 3, and 4 and in central foveal area of layer 6. Temporal and inferior quadrants of the total retinal thickness and most of other quadrants of layer 1 were significantly greater in the men than in the women. Surrounding eight sectors of total retinal thickness and a limited number of sectors in layers 1 and 4 significantly correlated with age.
authors.affiliation: Biomedical Engineering Department, Medical Image & Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan 81745, Iran ; Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey.
authors.forename: Raheleh
authors.initials: R
authors.lastname: Kafieh
authors.affiliation: Biomedical Engineering Department, Medical Image & Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan 81745, Iran ; The Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Hossein
authors.initials: H
authors.lastname: Rabbani
authors.affiliation: Noor Ophthalmology Research Center, Tehran 1968653111, Iran.
authors.forename: Fedra
authors.identifier: 0000-0002-2661-5439
authors.initials: F
authors.lastname: Hajizadeh
authors.affiliation: Department of Ophthalmology & Visual Science, The University of Iowa, Iowa City, IA 52242, USA ; VA Medical Center, Iowa City, IA 52246, USA.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Abramoff
authors.affiliation: The Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, IA 52242, USA ; Department of Electrical & Computer Engineering, The University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka