title: Aqueous Flow Measured by Fluorophotometry in the Mouse.
abstract: OBJECTIVE
  A fluorophotometer designed to measure aqueous flow in murine eyes was tested with artificial fluorescein chambers and in live mice with different anesthesia regimens, aqueous flow suppressants, and an anterior chamber cannulation method.
  
  
  METHODS
  Two hours following topical fluorescein application, one group of CD-1 mice was anesthetized with ketamine/xylazine, 2,2,2-tribromoethanol, or ketamine alone. Cornea and anterior chamber fluorescein concentrations were measured periodically for 60 to 90 minutes by fluorophotometric scans to calculate aqueous flow. Later, a subgroup of mice underwent aqueous flow measurement by anterior chamber cannulation. A third group was treated with timolol, dorzolamide, and vehicle in a crossover manner 1 hour prior to fluorophotometric scans.
  
  
  RESULTS
  Aqueous flow with ketamine/xylazine anesthesia (0.09 ± 0.05 μL/min, mean ± SD, n = 24) was slower than with tribromoethanol or ketamine alone (P < 0.001). Timolol reduced aqueous flow from 0.20 ± 0.07 μL/min to 0.07 ± 0.03 μL/min (P = 0.001) under tribromoethanol anesthesia and from 0.14 ± 0.03 μL/min to 0.10 ± 0.02 μL/min (P = 0.004) under ketamine anesthesia but not under ketamine/xylazine anesthesia. Dorzolamide reduced aqueous flow from 0.09 ± 0.03 to 0.06 ± 0.03 μL/min (P = 0.04) under ketamine/xylazine anesthesia. Aqueous flow by anterior chamber cannulation (0.20 ± 0.13 μL/min) was greater (P = 0.05) than by fluorophotometry (0.09 ± 0.07 μL/min).
  
  
  CONCLUSIONS
  A new noninvasive fluorophotometric method detected effects of general anesthesia and known aqueous suppressants on aqueous flow in mice. Aqueous flow measured by fluorophotometry was slower than by cannulation, and was technically easier with less variability. The mouse fluorophotometer is useful for repeated measurements of aqueous flow in the murine eye making crossover and longitudinal studies possible.
authors.affiliation: Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center, Omaha, Nebraska, United States 2Case Western Reserve University, Cleveland, Ohio, United States.
authors.forename: Carol B
authors.initials: CB
authors.lastname: Toris
authors.affiliation: Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center, Omaha, Nebraska, United States.
authors.forename: Shan
authors.initials: S
authors.lastname: Fan
authors.affiliation: Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center, Omaha, Nebraska, United States 3Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, United States.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Johnson
authors.affiliation: Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center, Omaha, Nebraska, United States.
authors.forename: Lucinda J
authors.initials: LJ
authors.lastname: Camras
authors.affiliation: Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center, Omaha, Nebraska, United States.
authors.forename: Cassandra L
authors.initials: CL
authors.lastname: Hays
authors.affiliation: Department of Ophthalmology and Visual Sciences University of Nebraska Medical Center, Omaha, Nebraska, United States.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.affiliation: OcuMetrics, Inc., Mountain View, California, United States.
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Ishimoto
mesh_terms: D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000778:Anesthetics, Dissociative / Q000494:pharmacology; D000818:Animals; D000867:Anterior Chamber / Q000033:anatomy & histology; D001082:Aqueous Humor / Q000502:physiology*; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology; D003315:Cornea / Q000033:anatomy & histology; D000431:Ethanol / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D019793:Fluorescein / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D015590:Fluorophotometry / Q000295:instrumentation; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007649:Ketamine / Q000494:pharmacology; D008297:Male; D051379:Mice; D009929:Organ Size; D013449:Sulfonamides / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D013999:Timolol / Q000494:pharmacology; D014991:Xylazine / Q000494:pharmacology
chemical_list: D000319:Adrenergic beta-Antagonists; D000778:Anesthetics, Dissociative; D002257:Carbonic Anhydrase Inhibitors; D005456:Fluorescent Dyes; D006993:Hypnotics and Sedatives; D013449:Sulfonamides; D013876:Thiophenes; C062527:tribromoethanol; D014991:Xylazine; D000431:Ethanol; D007649:Ketamine; D013999:Timolol; C062765:dorzolamide; D019793:Fluorescein