title: Obtaining Thickness Maps of Corneal Layers Using the Optimal Algorithm for Intracorneal Layer Segmentation.
abstract: Optical Coherence Tomography (OCT) is one of the most informative methodologies in ophthalmology and provides cross sectional images from anterior and posterior segments of the eye. Corneal diseases can be diagnosed by these images and corneal thickness maps can also assist in the treatment and diagnosis. The need for automatic segmentation of cross sectional images is inevitable since manual segmentation is time consuming and imprecise. In this paper, segmentation methods such as Gaussian Mixture Model (GMM), Graph Cut, and Level Set are used for automatic segmentation of three clinically important corneal layer boundaries on OCT images. Using the segmentation of the boundaries in three-dimensional corneal data, we obtained thickness maps of the layers which are created by these borders. Mean and standard deviation of the thickness values for normal subjects in epithelial, stromal, and whole cornea are calculated in central, superior, inferior, nasal, and temporal zones (centered on the center of pupil). To evaluate our approach, the automatic boundary results are compared with the boundaries segmented manually by two corneal specialists. The quantitative results show that GMM method segments the desired boundaries with the best accuracy.
authors.affiliation: Department of Bioelectrics and Biomedical Engineering, School of Advanced Technologies in Medicine, Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan 8174673461, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Rabbani
authors.affiliation: Department of Bioelectrics and Biomedical Engineering, School of Advanced Technologies in Medicine, Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan 8174673461, Iran.
authors.forename: Rahele
authors.identifier: 0000-0003-0087-9476
authors.initials: R
authors.lastname: Kafieh
authors.affiliation: Department of Bioelectrics and Biomedical Engineering, School of Advanced Technologies in Medicine, Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan 8174673461, Iran.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Kazemian Jahromi
authors.affiliation: Student Research Center, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan 8174673461, Iran.
authors.forename: Sahar
authors.initials: S
authors.lastname: Jorjandi
authors.affiliation: Department of Bioelectrics and Biomedical Engineering, School of Advanced Technologies in Medicine, Medical Image and Signal Processing Research Center, Isfahan University of Medical Sciences, Isfahan 8174673461, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Mehri Dehnavi
authors.affiliation: Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran 1968653111, Iran.
authors.forename: Fedra
authors.initials: F
authors.lastname: Hajizadeh
authors.affiliation: Isfahan University of Medical Sciences, Isfahan 817467346, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Peyman