title: Retinal blood flow in response to an intravitreal injection of ranibizumab for neovascular age-related macular degeneration.
abstract: OBJECTIVE
  To assess the hemodynamic response of retinal arterioles and venules following a single intravitreal injection of ranibizumab in neovascular age-related macular degeneration (NV-AMD) patients and to assess the influence of the number of prior injections on this response.
  
  
  METHODS
  Fifteen NV-AMD patients were prospectively recruited and grouped according to the dosage of ranibizumab previously received. Group 1 NV-AMD patients (n = 7) had previously received 1.50 mg or less, and group 2 patients (n = 8) had received more than 1.50 mg in the study eye. A group of 12 non-NV AMD patients were also recruited for control comparison. Vessel diameter, centreline blood velocity and blood flow were assessed with the Canon Laser Blood Flowmeter immediately prior to an injection and at a mean follow-up of 37.7 and 36.7 days for group 1 and group 2 patients, respectively.
  
  
  RESULTS
  The NV-AMD patients as a whole and the group 1 cohort had a significantly greater arteriolar diameter at baseline than the non-NV AMD patients. There was a significant reduction in arteriolar diameter, velocity and blood flow in group 1 but not in group 2 NV-AMD patients at follow-up. There was only an insignificant decrease in measured parameters of the retinal venules. At follow-up, there was no difference in the diameter, velocity or flow between AMD patients.
  
  
  CONCLUSIONS
  Intravitreal ranibizumab treatment for NV-AMD induces a reduction in arteriolar diameter, velocity, and blood flow in patients who have received <1.50 mg of ranibizumab.
authors.affiliation: Retina Research Group, Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Micieli
authors.forename: Edmund
authors.initials: E
authors.lastname: Tsui
authors.forename: Wai-Ching
authors.initials: WC
authors.lastname: Lam
authors.forename: Michael H
authors.initials: MH
authors.lastname: Brent
authors.forename: Robert G
authors.initials: RG
authors.lastname: Devenyi
authors.forename: Chris
authors.initials: C
authors.lastname: Hudson
mesh_terms: D000368:Aged; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D058449:Intravitreal Injections; D017078:Laser-Doppler Flowmetry; D011446:Prospective Studies; D000069579:Ranibizumab; D012039:Regional Blood Flow; D012171:Retinal Vessels / Q000502:physiology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D057135:Wet Macular Degeneration / Q000188:drug therapy* / Q000503:physiopathology*
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; D000069579:Ranibizumab