title: No Evidence for Retinal Damage Evolving from Reduced Retinal Blood Flow in Carotid Artery Disease.
abstract: BACKGROUND
  Carotid artery disease (CAD) comprising high-grade internal carotid artery stenosis (CAS) or carotid artery occlusion (CAO) may lead to ipsilateral impaired cerebral blood flow and reduced retinal blood supply.
  
  
  OBJECTIVE
  To examine the influence of chronic CAD on retinal blood flow, retinal morphology, and visual function.
  
  
  METHODS
  Patients with unilateral CAS ≥ 50% (ECST criteria) or CAO were grouped according to the grade of the stenosis and to the flow direction of the ophthalmic artery (OA). Retinal perfusion was measured by transorbital duplex ultrasound, assessing central retinal artery (CRA) blood flow velocities. In addition, optic nerve and optic nerve sheath diameter were measured. Optical coherence tomography (OCT) was performed to study retinal morphology. Visual function was assessed using high- and low-contrast visual paradigms.
  
  
  RESULTS
  Twenty-seven patients were enrolled. Eyes with CAS ≥ 80%/CAO and retrograde OA blood flow showed a significant reduction in CRA peak systolic velocity (no-CAD side: 0.130 ± 0.035 m/s, CAS/CAO side: 0.098 ± 0.028; p = 0.005; n = 12). OCT, optic nerve thicknesses, and visual functional parameters did not show a significant difference.
  
  
  CONCLUSIONS
  Despite assessable hemodynamic effects, chronic high-grade CAD does not lead to gaugeable morphological or functional changes of the retina.
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Heßler
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Hanna
authors.initials: H
authors.lastname: Zimmermann
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: Oberwahrenbrock
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Ella Maria
authors.initials: EM
authors.lastname: Kadas
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Janine
authors.initials: J
authors.lastname: Mikolajczak
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Alexander U
authors.initials: AU
authors.lastname: Brandt
authors.affiliation: Department of Neurology, Königin-Elisabeth-Herzberge Hospital, 10365 Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kauert
authors.affiliation: NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany ; Department of Neurology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Friedemann
authors.initials: F
authors.lastname: Paul
authors.affiliation: Department of Neurology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany.
authors.forename: Stephan J
authors.initials: SJ
authors.lastname: Schreiber
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002340:Carotid Artery Diseases / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology*; D012160:Retina / Q000503:physiopathology*; D012161:Retinal Artery / Q000503:physiopathology; D012164:Retinal Diseases / Q000503:physiopathology*; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods