title: Differences in Ocular Blood Flow Between People of African and European Descent With Healthy Eyes.
abstract: To investigate differences in ocular blood flow between people of African descent (AD) and European descent (ED) with healthy eyes.
  
  
  
  Retrobulbar and retinal capillary blood flow was assessed in 1 eye of 58 participants (24 AD, 34 ED) with healthy eyes with systemic blood pressure lower than 140/90. Retrobulbar blood flow was measured in the ophthalmic artery (OA), central retinal artery (CRA), nasal posterior ciliary artery (NPCA) and temporal posterior ciliary artery (TPCA). Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive index (RI) were assessed. Retinal capillary blood flow was assessed using mean retinal flow and avascular space defined as the percent of area measured with no blood flow. Groups were compared using t tests and Pearson correlations were compared using Fisher r-to-z transformation.
  
  
  
  Compared with people of ED, people of AD had significantly lower EDV in the NPCA (P=0.01), and higher RI in the CRA (P=0.04) and TPCA (P=0.01). No significant differences were observed in mean retinal capillary flow or avascular area. In the CRA, a significant negative correlation was observed between pattern standard deviation and peak systolic velocity (P=0.02) in the AD group and this correlation was significantly different from that observed in the ED group (P=0.01). A significant correlation was also observed between pattern standard deviation and EDV (0.04) in the AD group.
  
  
  
  This study suggests that retrobulbar blood flow is lower in healthy eyes in persons of AD compared with ED. This may provide a mechanism through which people of AD are at increased risk for ophthalmic diseases such as glaucoma.
authors: Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN.
authors: Betül
authors: B
authors: Kaskan
authors: Koosha
authors: K
authors: Ramezani
authors: Alon
authors: A
authors: Harris
authors: Brent
authors: B
authors: Siesky
authors: Carine
authors: C
authors: Olinde
authors: Darrell
authors: D
authors: WuDunn
authors: Jennifer
authors: J
authors: Eikenberry
authors: Leslie A
authors: LA
authors: Tobe
authors: Lyne
authors: L
authors: Racette
mesh_terms: D001741:Black or African American; D001783:Blood Flow Velocity / Q000502:physiology; D019842:Ciliary Arteries / Q000502:physiology*; D005060:Europe; D005123:Eye / Q000098:blood supply; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology*; D012161:Retinal Artery / Q000502:physiology*; D018615:Ultrasonography, Doppler, Color; D014481:United States; D044465:White People