title: Select Features of Diabetic Retinopathy on Swept-Source Optical Coherence Tomographic Angiography Compared With Fluorescein Angiography and Normal Eyes.
abstract: OBJECTIVE
  Optical coherence tomographic angiography (OCTA) is a recently developed noninvasive imaging technique that can visualize the retinal and choroidal microvasculature without the injection of exogenous dyes.
  
  
  OBJECTIVE
  To evaluate the potential clinical utility of OCTA using a prototype swept-source OCT (SS-OCT) device and compare it with fluorescein angiography (FA) for analysis of the retinal microvasculature in diabetic retinopathy.
  
  
  METHODS
  Prospective, observational cross-sectional study conducted at a tertiary care academic retina practice from November 2013 through November 2014. A cohort of diabetic and normal control eyes were imaged with a prototype SS-OCT system. The stage of diabetic retinopathy was determined by clinical examination. Imaging was performed using angiographic 3 × 3-mm and 6 × 6-mm SS-OCT scans to generate 3-dimensional en-face OCT angiograms for each eye. Two trained Boston Image Reading Center readers reviewed and graded FA and OCTA images independently.
  
  
  METHODS
  The size of the foveal nonflow zone and the perifoveal intercapillary area on OCTA were measured in both normal and diabetic eyes using Boston Image Reading Center image analysis software.
  
  
  RESULTS
  The study included 30 patients with diabetes (mean [SD] age, 55.7 [10] years) and 6 control individuals (mean [SD] age, 55.1 [6.4] years). A total of 43 diabetic and 11 normal control eyes were evaluated with OCTA. Fluorescein angiography was performed in 17 of 43 diabetic eyes within 8 weeks of the OCTA. Optical coherence tomographic angiography was able to identify a mean (SD) of 6.4 (4.0) microaneurysms (95% CI, 4.4-8.5), while FA identified a mean (SD) of 10 (6.9) microaneurysms (95% CI, 6.4-13.5). The exact intraretinal depth of microaneurysms on OCTA was localized in all cases (100%). The sensitivity of OCTA in detecting microaneuryms when compared with FA was 85% (95% CI, 53-97), while the specificity was 75% (95% CI, 21-98). The positive predictive value and the negative predictive value were 91% (95% CI, 59-99) and 60% (95% CI, 17-92), respectively.
  
  
  CONCLUSIONS
  Optical coherence tomographic angiography enables noninvasive visualization of macular microvascular pathology in eyes with diabetic retinopathy. It identified fewer microaneurysms than FA, but located their exact intraretinal depth. Optical coherence tomographic angiography also allowed the precise and reproducible delineation of the foveal nonflow zone and perifoveal intercapillary area. Evaluation of OCTA may be of clinical utility in the evaluation and grading of diabetic eye disease.
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: David A
authors.initials: DA
authors.lastname: Salz
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts2Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge3Research Laboratory of Electronics, Massachusetts Institute of Technology, Camb.
authors.forename: Talisa E
authors.initials: TE
authors.lastname: de Carlo
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts2Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge3Research Laboratory of Electronics, Massachusetts Institute of Technology, Camb.
authors.forename: Mehreen
authors.initials: M
authors.lastname: Adhi
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge3Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge.
authors.forename: Eric
authors.initials: E
authors.lastname: Moult
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge3Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge.
authors.forename: WhooJhon
authors.initials: W
authors.lastname: Choi
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: Jay S
authors.initials: JS
authors.lastname: Duker
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge3Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge.
authors.forename: James G
authors.initials: JG
authors.lastname: Fujimoto
authors.affiliation: New England Eye Center, Tufts Medical Center, Boston, Massachusetts.
authors.forename: Nadia K
authors.initials: NK
authors.lastname: Waheed
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D005451:Fluorescein Angiography; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012171:Retinal Vessels / Q000473:pathology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence