title: Optical coherence tomography angiography of optic disc perfusion in glaucoma.
abstract: OBJECTIVE
  To compare optic disc perfusion between normal subjects and subjects with glaucoma using optical coherence tomography (OCT) angiography and to detect optic disc perfusion changes in glaucoma.
  
  
  METHODS
  Observational, cross-sectional study.
  
  
  METHODS
  Twenty-four normal subjects and 11 patients with glaucoma were included.
  
  
  METHODS
  One eye of each subject was scanned by a high-speed 1050-nm-wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to compute 3-dimensional optic disc angiography. A disc flow index was computed from 4 registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc (C/D) ratios. Wide-field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness.
  
  
  METHODS
  Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations among disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression.
  
  
  RESULTS
  In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in subjects with glaucoma. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV, respectively. The disc flow index was reduced by 25% in the glaucoma group (P = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R(2) = 0.752, P = 0.001). These correlations were significant even after accounting for age, C/D area ratio, NFL, and rim area.
  
  
  CONCLUSIONS
  Optical coherence tomography angiography, generated by the new SSADA, repeatably measures optic disc perfusion and may be useful in the evaluation of glaucoma and glaucoma progression.
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Yali
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Eric
authors.initials: E
authors.lastname: Wei
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Xinbo
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: John C
authors.initials: JC
authors.lastname: Morrison
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Mansi
authors.initials: M
authors.lastname: Parikh
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Lori H
authors.initials: LH
authors.lastname: Lombardi
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Devin M
authors.initials: DM
authors.lastname: Gattey
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Armour
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Beth
authors.initials: B
authors.lastname: Edmunds
authors.affiliation: Pattern Recognition Lab and School of Advanced Optical Technologies, University Erlangen-Nuremberg, Erlangen, Germany; Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: Martin F
authors.initials: MF
authors.lastname: Kraus
authors.affiliation: Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts.
authors.forename: James G
authors.initials: JG
authors.lastname: Fujimoto
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon. Electronic address: davidhuang@alum.mit.edu.
authors.forename: David
authors.initials: D
authors.lastname: Huang
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003430:Cross-Sectional Studies; D005260:Female; D005451:Fluorescein Angiography; D005901:Glaucoma / Q000145:classification / Q000503:physiopathology*; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional; D007429:Intraocular Pressure; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000098:blood supply*; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology; D012171:Retinal Vessels / Q000502:physiology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence; D058609:Visual Field Tests; D014794:Visual Fields