title: Trabeculectomy Improves Vessel Response Measured by Dynamic Vessel Analysis (DVA) in Glaucoma Patients.
abstract: OBJECTIVE
  To determine the effects of surgical IOP reduction (trabeculectomy) on retinal blood flow parameters in glaucoma patients using Dynamic Vessel Analysis (DVA).
  
  
  METHODS
  26 eyes of 26 patients with progressive primary open-angle glaucoma (POAG) despite maximal topical therapy were examined before and after trabeculectomy. The responses of the retinal vessels to flickering light provocation were measured with DVA the day before surgery and 4 to 6 weeks after trabeculectomy. Between 3 and 4 weeks before surgery all local therapies were stopped and a systemic therapy with acetazolamide and conservative free topic steroidal eye drops was started.
  
  
  RESULTS
  In 19 patients (73%), an inadequate response to the flicker stimulation was measured preoperatively. In these patients, the maximum dilation of arteries and veins was reduced significantly as compared to healthy eyes. In this group, the maximum dilation of the arteries following the flicker provocation improved from 1.4% before to 3.8% following trabeculectomy (p<0.01). In retinal veins, this parameter increased from 3.1% to 4.6% (p<0.05). In the 7 patients whose arterial and venous reactions to flickering light provocation preoperatively did not differ from healthy eyes, there was no significant change after surgery. The initial baseline values of arteries and veins (MU) did not deviate significantly in both groups.
  
  
  CONCLUSIONS
  POAG patients with progressive disease and impaired vascular regulation profit from IOP lowering trabeculectomy concerning vascular reactivity and dilative reserve, indicating a possible improvement of retinal perfusion following effective IOP control. Future studies with long-term follow-up must determine the clinical importance of these findings for the treatment of glaucoma patients.
authors.affiliation: Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany ; Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors.forename: Michael Selbach
authors.initials: MS
authors.lastname: J
authors.affiliation: Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors.forename: Maurice
authors.initials: M
authors.lastname: Schallenberg
authors.affiliation: Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kramer
authors.affiliation: Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany ; Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Anastassiou
authors.affiliation: Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Steuhl
authors.affiliation: Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Gustav-Kirchhoff-Str.2, Germany ; Imedos Systems UG, Jena, Am Naßtal 4, Germany.
authors.forename: Walthard
authors.initials: W
authors.lastname: Vilser
authors.affiliation: Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany ; Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kremmer
keywords: Dynamic vessel analyzer (DVA); IOP; glaucoma; retinal autoregulation; trabeculectomy; vascular dysregulation.