title: Laser cyclophotocoagulation enhances the regulative capacity of retinal vessels in glaucoma.
abstract: OBJECTIVE
  To determine the effects of laser surgical IOP reduction by means of transscleral cyclophotocoagulation (CPC) on retinal blood flow parameters in glaucoma patients using Dynamic Vessel Analysis (DVA).
  
  
  METHODS
  26 patients (average age: 70 years) with a long history of primary open angle glaucoma underwent CPC. The effect on the reactive capacity of retinal vessels was assessed before and 6-8 weeks after CPC by means of the Dynamic Vessel Analyzer (DVA) using flicker light provocation.
  
  
  RESULTS
  In our group of POAG patients, IOP was significantly reduced about approximately 20% by CPC while systemic blood pressure and heart rate were not changed. The most obvious differences between the pre- and postoperative DVA measurements could be observed in the maximal dilation of the retinal arteries which increased from 0.75 % (+/- 0.6) to 3.17 % (+/- 0.5) with an average increase of 2.4 % (p<0.01). In addition, the ability of the arteries for constriction improved significantly (p<0.05) while the dynamic responses of the veins and the initial baseline values (MU) of the vessel diameters did not change.
  
  
  CONCLUSIONS
  Our results of DVA measurements after an IOP-lowering laser surgical intervention (CPC) reveal a significant recovery of the regulative capacity of retinal arteries in glaucoma patients that has up to now neither been properly documented nor appreciated. Future studies with long-term follow-up must determine the clinical importance of these findings for the treatment of glaucoma patients.
authors: Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany ; Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors: Stephan
authors: S
authors: Kremmer
authors: Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany ; Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors: Gerasimos
authors: G
authors: Anastassiou
authors: Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors: Maurice
authors: M
authors: Schallenberg
authors: Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors: Klaus-Peter
authors: KP
authors: Steuhl
authors: Institut of Biomedical Engineering and Informatics, Ilmenau University of Technology, Ilmenau, Gustav-Kirchhoff-Str.2, Germany ; Imedos Systems UG, Jena, Am Naßtal 4, Germany.
authors: Vilser
authors: V
authors: W
authors: Department of Ophthalmology, Evangelische Kliniken Gelsenkirchen, Munckelstr. 27, 45879 Gelsenkirchen, Germany ; Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45122 Essen, Germany.
authors: Michael Selbach
authors: MS
authors: J
keywords: Cyclophotocoagulation (CPC); IOP; dynamic vessel analyzer (DVA); glaucoma; retinal vessel autoregulation; vascular dysregulation.