title: Change in retinal blood flow and retinal arterial diameter after intraocular pressure reduction in glaucomatous eyes.
abstract: OBJECTIVE
  To study retinal blood flow and vessel diameter after intra-ocular pressure (IOP) reduction in high- and low-pressure glaucomas, that is, exfoliation glaucoma (ExG) and normal-tension glaucoma (NTG).
  
  
  METHODS
  The study included 17 eyes with ExG and 20 with NTG. A minimum of 25% IOP reduction was achieved by deep sclerectomy. Blood flow in the temporal peripapillary retina was measured with scanning laser Doppler flowmetry (Heidelberg Retina Flowmeter, HRF), and retinal vessel diameters were evaluated with the retinal vessel analyser (RVA). Examinations were carried out before and 3 months after the operation.
  
  
  RESULTS
  Pre-operative IOP was significantly higher in ExG than in NTG (median 26 mmHg, range 20-33 mmHg versus 15 mmHg, 12-20; p < 0.001). Surgery reduced IOP significantly both in ExG eyes (postoperative IOP 13 mmHg, 5-17; p < 0.001) and NTG eyes (9 mmHg, 3-13; p < 0.001). After the operation, systolic retinal flow was significantly reduced in ExG eyes, whereas in NTG, HRF parameters remained unchanged. Pre-operatively, the central retinal artery equivalent (CRAE) and arteriovenous ratio (AVR) were higher in ExG than in NTG eyes. After IOP reduction, both CRAE and AVR were reduced in ExG eyes, but remained unchanged in NTG.
  
  
  CONCLUSIONS
  The study showed that before IOP reduction, arterial diameter was larger in ExG eyes than in NTG eyes. IOP reduction resulted in vasoconstriction and reduction of flow in ExG, whereas in NTG, both vessel diameter and retinal flow remained unchanged.
authors.affiliation: Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Kurvinen
authors.forename: Janne P
authors.initials: JP
authors.lastname: Kytö
authors.forename: Paula
authors.initials: P
authors.lastname: Summanen
authors.forename: Eija
authors.initials: E
authors.lastname: Vesti
authors.forename: Mika
authors.initials: M
authors.lastname: Harju
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D017889:Exfoliation Syndrome / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D017078:Laser-Doppler Flowmetry; D057066:Low Tension Glaucoma / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology; D012171:Retinal Vessels / Q000503:physiopathology*; D012599:Sclerostomy; D014065:Tonometry, Ocular
keywords: Heidelberg Retina Flowmeter; retinal blood flow; retinal vessel analyser; retinal vessel diameter