title: Automated segmentation of the cup and rim from spectral domain OCT of the optic nerve head.
abstract: OBJECTIVE
  To evaluate the performance of an automated algorithm for determination of the cup and rim from close-to-isotropic spectral domain (SD) OCT images of the optic nerve head (ONH) and compare to the cup and rim as determined by glaucoma experts from stereo color photographs of the same eye.
  
  
  METHODS
  Thirty-four consecutive patients with glaucoma were included in the study, and the ONH in the left eye was imaged with SD-OCT and stereo color photography on the same day. The cup and rim were segmented in all ONH OCT volumes by a novel voxel column classification algorithm, and linear cup-to-disc (c/d) ratio was determined. Three fellowship-trained glaucoma specialists performed planimetry on the stereo color photographs, and c/d was also determined. The primary outcome measure was the correlation between algorithm-determined c/d and planimetry-derived c/d.
  
  
  RESULTS
  The correlation of algorithm c/d to experts 1, 2, and 3 was 0.90, 0.87, and 0.93, respectively. The c/d correlation of expert 1 to 2, 1 to 3, and 2 to 3, were 0.89, 0.93, and 0.88, respectively.
  
  
  CONCLUSIONS
  In this preliminary study, we have developed a novel algorithm to determine the cup and rim in close-to-isotropic SD-OCT images of the ONH and have shown that its performance for determination of the cup and rim from SD-OCT images is similar to that of planimetry by glaucoma experts. Validation on a larger glaucoma sample as well as normal controls is warranted.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA. michael-abramoff@uiowa.edu
authors.forename: Michael D
authors.initials: MD
authors.lastname: Abràmoff
authors.forename: Kyungmoo
authors.initials: K
authors.lastname: Lee
authors.forename: Meindert
authors.initials: M
authors.lastname: Niemeijer
authors.forename: Wallace L M
authors.initials: WL
authors.lastname: Alward
authors.forename: Emily C
authors.initials: EC
authors.lastname: Greenlee
authors.forename: Mona K
authors.initials: MK
authors.lastname: Garvin
authors.forename: Milan
authors.initials: M
authors.lastname: Sonka
authors.forename: Young H
authors.initials: YH
authors.lastname: Kwon
mesh_terms: D000368:Aged; D000465:Algorithms; D001331:Automation; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000145:classification / Q000175:diagnosis*; D005902:Glaucoma, Open-Angle / Q000145:classification / Q000175:diagnosis*; D006801:Humans; D008297:Male; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000145:classification / Q000175:diagnosis*; D010781:Photography / Q000379:methods; D041623:Tomography, Optical Coherence / Q000379:methods*