title: The impact of intraocular pressure reduction on retrobulbar hemodynamic parameters in patients with open-angle glaucoma.
abstract: OBJECTIVE
  To assess the retrobulbar hemodynamic parameters in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCA) after decreasing elevated intraocular pressure (IOP) in patients with open-angle glaucoma (OAG) by using color Doppler imaging.
  
  
  METHODS
  A total of 46 eyes from 46 patients with OAG, with elevated IOP, were consecutively included in this prospective study. Peak-systolic velocity, end-diastolic velocity, and Pourcelot resistivity index were assessed in the OA, CRA, and PCA. The IOP was measured with Goldmann applanation tonometer (GAT) and the dynamic contour tonometer (DCT), 3 times respectively. Ocular pulse amplitude (OPA) appeared during the DCT measurement.
  
  
  RESULTS
  After decreasing the elevated IOP, measured with both GAT and DCT, the retrobulbar parameters showed no differences as compared with baseline measurements. After Bonferroni correction (p ≤ 0.0042, alpha/12), statistical significance appeared in retrobulbar hemodynamics only in DCT (29.3 ± 6.4 vs 15.5 ± 4.2 mmHg), GAT (33.0 ± 8.3 vs 15.8 ± 7.0 mmHg), and OPA measurements (4.1 ± 1.3 vs 2.7 ± 1.4 mmHg), in comparison to baseline. There was no correlation between the changes in IOP measured with either DCT or GAT and the changes in the retrobulbar hemodynamic parameters (p>0.05 for all).
  
  
  CONCLUSIONS
  The results of our study suggested a lack of correlation between the changes in IOP, measured with either DCT or GAT, and the changes in the retrobulbar hemodynamic parameters. The results of our study might suggest that the blood flow disturbances found in glaucoma patients are independent of the IOP.
authors.affiliation: Glaucoma Department, University Eye Clinic, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Marjanovic
authors.forename: Natasa
authors.initials: N
authors.lastname: Milic
authors.forename: Antonio
authors.initials: A
authors.lastname: Martinez
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D019842:Ciliary Arteries / Q000502:physiology*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000502:physiology*; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D012161:Retinal Artery / Q000502:physiology*; D014065:Tonometry, Ocular; D018615:Ultrasonography, Doppler, Color