title: Choroidal Thickness and Choroidal Vessel Density in Nonexudative Age-Related Macular Degeneration Using Swept-Source Optical Coherence Tomography Imaging.
abstract: To analyze the relationship between choroidal thickness and the distribution of choroidal blood vessels in eyes with nonexudative AMD.
  
  
  
  Eyes with a diagnosis of nonexudative AMD were imaged using a prototype 100-kHz swept-source (SS) optical coherence tomography (OCT) instrument (Carl Zeiss Meditec, Dublin, CA, USA) with a central wavelength of 1050 nm. We used an OCT cube scan pattern consisting of 512 × 512 A-scans over a 12 × 12 mm retinal area. The eyes were partitioned into two groups based on the presence or absence of reticular pseudodrusen (RPD). All scans were segmented using an automated algorithm. In addition, five eyes from each of the two groups were randomly chosen for manual segmentation. Binary choroidal vessels maps were generated from suitable OCT choroidal slabs, and the relationship between the density of large choroidal vessels and choroidal thickness was analyzed using an Early Treatment Diabetic Retinopathy Study-like target centered on the fovea.
  
  
  
  Twenty-five eyes were enrolled in each group. The automated algorithm produced accurate choroidal thickness maps with an average difference between the manual and automated segmentations of 13.7 μm. There was a significant and stable correlation between choroidal thickness and choroidal vessel density across the two groups. Both average choroidal thickness and vessel density were significantly lower in eyes with RPD.
  
  
  
  Our fully automated choroidal segmentation algorithm was able to capture the different patterns of choroidal thickness over a wide area. Choroidal thickness has a clear relationship with the density of large choroid vessels in our sample, irrespective of the presence or absence of RPD.
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States 2Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zheng
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gregori
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Karen B
authors.initials: KB
authors.lastname: Schaal
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Legarreta
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Miller
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Luiz
authors.initials: L
authors.lastname: Roisman
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: William J
authors.initials: WJ
authors.lastname: Feuer
authors.affiliation: Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Rosenfeld
mesh_terms: D000368:Aged; D000465:Algorithms; D002829:Choroid / Q000098:blood supply* / Q000473:pathology*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D008268:Macular Degeneration / Q000175:diagnosis*; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D012171:Retinal Vessels / Q000000981:diagnostic imaging*; D041623:Tomography, Optical Coherence / Q000295:instrumentation*