title: Nocturnal blood pressure reduction: effect on retrobulbar hemodynamics in glaucoma.
abstract: BACKGROUND
  Several studies suggest that nocturnal reductions in systemic blood pressure (BP) may be associated with onset or progression of glaucomatous optic neuropathy. The present study aimed to find out whether reductions in nocturnal BP are linked to retrobulbar blood flow perturbations in glaucoma patients.
  
  
  METHODS
  Fifteen patients with non-progressing glaucoma and 15 controls were studied in the evening ("baseline") and then at a point of significantly reduced arterial BP during the night. Flow velocities were measured with color Doppler imaging (CDI) in the ophthalmic, central retinal, and nasal and temporal short posterior ciliary arteries, and with transcranial Doppler (TCD) in the middle cerebral artery. BP, corrected for posture, was monitored throughout the night.
  
  
  RESULTS
  Maximal posture-corrected nocturnal BP reductions were similar in patients and controls. The reductions were about 10% for each group ( P<0.01). At baseline, patients had lower peak systolic and end-diastolic velocity ( P<0.05) in the short posterior ciliary arteries than controls. Flow velocities in these arteries remained constant in glaucoma patients, while controls showed significant declines. Patients and controls demonstrated blood flow velocities unchanged from baseline in the central retinal, ophthalmic, and middle cerebral arteries during nocturnal BP reduction.
  
  
  CONCLUSIONS
  In patients with non-progressing glaucoma there was no evidence of cerebral or retrobulbar hemodynamic abnormalities during nocturnal BP dips. Posterior ciliary arterial blood flow velocities were similar in glaucoma patients and controls during nocturnal BP dips.
authors.affiliation: Department of Ophthalmology, Indiana University School of Medicine, 702 Rotary Circle, Rm 137, Indianapolis 46202-5175, USA. alharris@indiana.edu
authors.forename: Alon
authors.initials: A
authors.lastname: Harris
authors.forename: David
authors.initials: D
authors.lastname: Evans
authors.forename: Bruce
authors.initials: B
authors.lastname: Martin
authors.forename: Miriam
authors.initials: M
authors.lastname: Zalish
authors.forename: Larry
authors.initials: L
authors.lastname: Kagemann
authors.forename: Lynne
authors.initials: L
authors.lastname: McCranor
authors.forename: Hana
authors.initials: H
authors.lastname: Garzozi
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D019842:Ciliary Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D005123:Eye / Q000098:blood supply*; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging / Q000502:physiology; D011187:Posture; D012039:Regional Blood Flow / Q000502:physiology; D012161:Retinal Artery / Q000000981:diagnostic imaging / Q000502:physiology; D018615:Ultrasonography, Doppler, Color