title: Choroidal analysis in healthy eyes using swept-source optical coherence tomography compared to spectral domain optical coherence tomography.
abstract: OBJECTIVE
  To compare analyses of choroidal thickness and volume in healthy eyes measured concurrently with prototype long-wavelength swept-source optical coherence tomography (OCT) and commercially available spectral-domain optical coherence tomography (OCT) with and without enhanced depth imaging (EDI).
  
  
  METHODS
  Prospective cross sectional study.
  
  
  METHODS
  The study included 19 healthy subjects (19 eyes), who were prospectively recruited to undergo 2 consecutive imaging sessions on the same randomly selected eye using spectral domain OCT and a prototype long-wavelength swept-source OCT. On spectral domain OCT, 2 line scans, 1 with and 1 without EDI, and 1 volumetric scan were obtained. On swept-source OCT, 1 line scan and 1 volumetric scan were obtained. Scan patterns on swept-source OCT were created to simulate those available on Cirrus HD-OCT to keep the time of image acquisition constant. Swept-source OCT volumetric scans were motion corrected using a novel registration algorithm. Choroidal thickness and volume were analyzed.
  
  
  RESULTS
  The choroidoscleral interface was clearly visualized in 19/19 (100%) of eyes imaged by swept-source OCT, compared to 14/19 (73.6%) and 13/19 (68.4%) eyes imaged by spectral domain OCT, with and without EDI, respectively. There was no significant difference in choroidal thickness measurements on the line scans obtained on either system (P = 0.10). Choroidal volume could not be assessed on volumetric scans from spectral domain OCT. Mean choroidal volume from swept-source OCT volumetric scans was 11.77 ± 3.13 mm(3) (6.43 mm(3)-17.15 mm(3)).
  
  
  CONCLUSIONS
  This is the first study that compares simultaneously a prototype long-wavelength swept-source OCT to a commercially available spectral domain OCT for a detailed analysis of choroid in healthy eyes. Swept-source OCT shows potential for better choroidal analysis. Studies using swept-source OCT in diseased eyes will further define this new technology's utility in chorioretinal diseases.
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Mehreen
authors.initials: M
authors.lastname: Adhi
authors.affiliation: Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Liu
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Ahmed H
authors.initials: AH
authors.lastname: Qavi
authors.affiliation: Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: Ireneusz
authors.initials: I
authors.lastname: Grulkowski
authors.affiliation: Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: Chen D
authors.initials: CD
authors.lastname: Lu
authors.affiliation: Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: Kathrin J
authors.initials: KJ
authors.lastname: Mohler
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Daniela
authors.initials: D
authors.lastname: Ferrara
authors.affiliation: Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts; Pattern Recognition Lab and School of Advanced Optical Technologies (SAOT), University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Martin F
authors.initials: MF
authors.lastname: Kraus
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Caroline R
authors.initials: CR
authors.lastname: Baumal
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Andre J
authors.initials: AJ
authors.lastname: Witkin
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Nadia K
authors.initials: NK
authors.lastname: Waheed
authors.affiliation: Pattern Recognition Lab and School of Advanced Optical Technologies (SAOT), University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Hornegger
authors.affiliation: Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: James G
authors.initials: JG
authors.lastname: Fujimoto
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts. Electronic address: Jduker@tuftsmedicalcenter.org.
authors.forename: Jay S
authors.initials: JS
authors.lastname: Duker
mesh_terms: D000328:Adult; D002829:Choroid / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D015588:Observer Variation; D009929:Organ Size; D011446:Prospective Studies; D012590:Sclera / Q000033:anatomy & histology; D041623:Tomography, Optical Coherence / Q000295:instrumentation*; D014792:Visual Acuity; D055815:Young Adult