title: Primary open-angle glaucoma vs normal-tension glaucoma: the vascular perspective.
abstract: OBJECTIVE
  To compare and contrast the presence of ocular and systemic vascular function in patients with newly diagnosed and previously untreated primary open-angle glaucoma (POAG) vs those with normal-tension glaucoma (NTG) and comparable early-stage, functional loss.
  
  
  METHODS
  The systemic vascular function of 19 patients with POAG, 19 patients with NTG, and 20 healthy individuals serving as controls was assessed using 24-hour ambulatory blood pressure monitoring, peripheral pulse-wave analysis, and carotid intima-media thickness. Retinal vascular reactivity to flicker light was assessed using dynamic retinal vessel analysis (Imedos, GmbH).
  
  
  RESULTS
  Compared with controls, patients with POAG and those with NTG exhibited similarly increased nocturnal systemic blood pressure variability (P = .01), peripheral arterial stiffness (P = .02), carotid intima-media thickness (P = .04), and reduced ocular perfusion pressure (P < .001). Furthermore, on dynamic retinal vessel analysis, both glaucoma groups exhibited steeper retinal arterial constriction slopes after cessation of flicker (P = .007) and a similarly increased fluctuation in arterial and venous baseline diameter (P = .008 and P = .009, respectively) compared with controls.
  
  
  CONCLUSIONS
  Patients with POAG or NTG exhibit similar alterations in ocular and systemic circulation in the early stages of their disease process. This finding highlights the importance of considering vascular risk factors in both conditions and raises questions about the current separation of the two conditions into distinct clinical entities.
authors.affiliation: Vascular Research Laboratory, Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham, England.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Mroczkowska
authors.forename: Alexandra
authors.initials: A
authors.lastname: Benavente-Perez
authors.forename: Anil
authors.initials: A
authors.lastname: Negi
authors.forename: Velota
authors.initials: V
authors.lastname: Sung
authors.forename: Sunni R
authors.initials: SR
authors.lastname: Patel
authors.forename: Doina
authors.initials: D
authors.lastname: Gherghel
mesh_terms: D000368:Aged; D001775:Blood Circulation / Q000502:physiology; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D001824:Body Constitution; D059168:Carotid Intima-Media Thickness; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008027:Light; D057066:Low Tension Glaucoma / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012171:Retinal Vessels / Q000502:physiology* / Q000528:radiation effects; D014065:Tonometry, Ocular