title: Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion.
abstract: OBJECTIVE
  To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.
  
  
  METHODS
  Experimental BRVO was induced by diathermy close to the optic disc. RPO(2) was measured with an oxygen-sensitive electrode 0.5 mm above the BRVO-affected area, which was compared to the retinal areas not affected by BRVO. In one group of five pigs, RPO(2) was measured at baseline, 1 and 3 hours after BRVO, and after intravenous injection of 500 mg dorzolamide. In a second group of five pigs, RPO(2) was measured 1 week after the BRVO, both before and after intravenous injection of 500 mg dorzolamide.
  
  
  RESULTS
  The average baseline RPO(2) was 2.64 +/- 0.09 kPa (mean +/- SD). In the BRVO-affected areas, RPO(2) decreased significantly (by 0.67 +/- 0.29 and 0.94 +/- 0.13 kPa) at 1 hour and 3 hours after BRVO induction. In the non-BRVO areas RPO(2) increased significantly (by 0.51 +/- 0.14 kPa) 1 hour after BRVO induction, but subsequently decreased and reached baseline 3 hours after BRVO induction. One week after BRVO induction, RPO(2) was 0.67 +/- 0.29 kPa lower in affected areas when compared with the non-BRVO areas. In the BRVO-affected areas, dorzolamide increased RPO(2) significantly (by 0.36 +/- 0.21 kPa at 3 to 4 hours and by 0.67 +/- 0.40 kPa) 1 week after BRVO induction.
  
  
  CONCLUSIONS
  Retinal hypoxia induced by experimental BRVO remained significant 1 week after BRVO. Dorzolamide increased retinal oxygen tension in the BRVO-affected areas both at 4 hours and 1 week after experimental BRVO in pigs.
authors.affiliation: Department of Ophthalmology, Rigshospitalet, Copenhagen, Denmark. hovemichael@yahoo.com
authors.forename: Michael Hove
authors.initials: MH
authors.lastname: Noergaard
authors.forename: Daniella
authors.initials: D
authors.lastname: Bach-Holm
authors.forename: Erik
authors.initials: E
authors.lastname: Scherfig
authors.forename: Kurt
authors.initials: K
authors.lastname: Bang
authors.forename: Peter Koch
authors.initials: PK
authors.lastname: Jensen
authors.forename: Jens Folke
authors.initials: JF
authors.lastname: Kiilgaard
authors.forename: Einar
authors.initials: E
authors.lastname: Stefánsson
authors.forename: Morten
authors.initials: M
authors.lastname: la Cour
mesh_terms: D000818:Animals; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage*; D004195:Disease Models, Animal; D005451:Fluorescein Angiography; D000860:Hypoxia / Q000378:metabolism; D007275:Injections, Intravenous; D017736:Ion-Selective Electrodes; D007511:Ischemia / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010313:Partial Pressure; D012160:Retina / Q000378:metabolism; D012170:Retinal Vein Occlusion / Q000378:metabolism*; D013449:Sulfonamides / Q000008:administration & dosage*; D013552:Swine; D013876:Thiophenes / Q000008:administration & dosage*
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D013449:Sulfonamides; D013876:Thiophenes; C062765:dorzolamide; D010100:Oxygen