title: Effect of trabeculectomy on ocular blood flow.
abstract: OBJECTIVE
  Current evidence suggests that vascular insufficiencies in the optic nerve head play an important part in the pathogenesis of glaucomatous optic neuropathy. Trabeculectomy is the most common operative procedure for the treatment of medically uncontrolled glaucoma. This study was conducted to investigate whether trabeculectomy may improve ocular haemodynamics.
  
  
  METHODS
  30 patients with primary open angle glaucoma about to undergo trabeculectomy were included in the study. Patients were evaluated before surgery and at 2 and 10 weeks after trabeculectomy. Optic nerve head blood flow (OnhBF) was assessed with scanning laser Doppler flowmetry. Fundus pulsation amplitude (FPA) measurements were obtained with laser interferometry.
  
  
  RESULTS
  Because of the decrease in intraocular pressure there was a significant increase in ocular perfusion pressure (OPP) following trabeculectomy (18.5% (SD 12.0%) and 19.0% (17.1%) at 2 and 10 weeks postoperatively; p <0.001). A significant increase in OnhBF was observed after trabeculectomy (11.6% (16.4%) and 16.2% (20.2%) for each postoperative visit, respectively; p <0.001). FPA was also significantly higher compared with baseline values (17.2% (17.3%) and 17.4% (16.3%), respectively; p <0.001). A significant association between the increase in OPP and the increase in OnhBF and FPA was observed 10 weeks after surgery (r = 0.47; p = 0.009, and r = 0.50; p = 0.005, respectively).
  
  
  CONCLUSIONS
  The results of this study suggest that trabeculectomy improves ocular blood flow in patients with chronic open angle glaucoma.
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Allgemeines Krankenhaus Wien, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
authors.forename: F
authors.initials: F
authors.lastname: Berisha
authors.forename: K
authors.initials: K
authors.lastname: Schmetterer
authors.forename: C
authors.initials: C
authors.lastname: Vass
authors.forename: S
authors.initials: S
authors.lastname: Dallinger
authors.forename: G
authors.initials: G
authors.lastname: Rainer
authors.forename: O
authors.initials: O
authors.lastname: Findl
authors.forename: B
authors.initials: B
authors.lastname: Kiss
authors.forename: L
authors.initials: L
authors.lastname: Schmetterer
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D005654:Fundus Oculi; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007368:Interferometry / Q000379:methods; D007429:Intraocular Pressure / Q000502:physiology; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply*; D014130:Trabeculectomy / Q000379:methods*; D016896:Treatment Outcome