title: Measurement of retinal blood flow in normal Chinese-American subjects by Doppler Fourier-domain optical coherence tomography.
abstract: OBJECTIVE
  To measure total retinal blood flow (TRBF) in normal, healthy Chinese Americans by using semi-automated analysis of Doppler Fourier-domain optical coherence tomography (FD-OCT) scans.
  
  
  METHODS
  Two hundred sixty-six normal, healthy Chinese-American participants (266 eyes) were enrolled from The Chinese American Eye Study. All participants underwent complete ophthalmic examination, including best-corrected visual acuity, indirect ophthalmoscopy, and Doppler FD-OCT imaging, using the circumpapillary double circular scan protocol. Total retinal blood flow and other vascular parameters (e.g., venous and arterial cross-sectional area and their velocities) were calculated by using Doppler OCT of Retinal Circulation software. Associations between TRBF and other clinical parameters were assessed by using bivariate correlations and linear regression.
  
  
  RESULTS
  The mean age of study participants was 57.40 ± 5.60 (range, 50-82) years. The mean TRBF was 49.34 ± 10.08 (range, 27.17-78.08, 95% confidence interval: 25.98-69.10) μL/min. The mean venous area was 0.0548 (±0.0084) mm(2). Superior retinal hemispheric blood flow (25.50 ± 6.62 μL/min) was slightly greater than inferior retinal hemispheric blood flow (23.84 ± 7.19 μL/min, P = 0.008). The mean flow velocity was 15.16 ± 3.12 mm/s. There was a weak but significant negative correlation between TRBF and age (r = -0.15, P = 0.012). No significant correlation was found between TRBF and axial length (r = 0.11, P = 0.08). Retinal blood flow was not significantly correlated with any other clinical parameters, including body mass index, systolic blood pressure, diastolic blood pressure, and intraocular pressure.
  
  
  CONCLUSIONS
  Normal Doppler OCT-derived total retinal blood values in a Chinese-American population showed considerable variability, some of which was explained by age. These observations should help design future studies evaluating TRBF in populations with eye disease.
authors: Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States.
authors: Sowmya
authors: S
authors: Srinivas
authors: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States.
authors: Ou
authors: O
authors: Tan
authors: Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States.
authors: Shuang
authors: S
authors: Wu
authors: Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States.
authors: Muneeswar Gupta
authors: MG
authors: Nittala
authors: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States.
authors: David
authors: D
authors: Huang
authors: Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States.
authors: Rohit
authors: R
authors: Varma
authors: Doppler OCT Reading Center, Doheny Eye Institute, Los Angeles, California, United States Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, United States.
authors: SriniVas R
authors: SR
authors: Sadda
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001213:Asian; D001783:Blood Flow Velocity / Q000502:physiology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D012171:Retinal Vessels / Q000502:physiology*; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Doppler OCT; age; retinal blood flow