title: Fluorophotometric determination of aqueous humor flow rates in red-tailed hawks (Buteo jamaicensis).
abstract: OBJECTIVE
  To determine aqueous humor flow rate (AHFR) in an avian species by use of anterior segment fluorophotometry.
  
  
  METHODS
  9 healthy red-tailed hawks (Buteo jamaicensis; 4 males and 5 females) that ranged from 8 months to 8 years of age.
  
  
  METHODS
  A protocol was developed for fluorophotometric determination of AHFR. Topical administration of 10% fluorescein was used to load the corneas, and corneal and aqueous humor fluorescein concentrations were measured approximately 5, 6.5, and 8 hours later. Concentration-versus-time plots were generated, and slopes and cornea-to-aqueous humor concentration ratios from these plots were used to manually calculate flow rates.
  
  
  RESULTS
  Mean ± SD AHFRs for the right eye, left eye, and both eyes were 3.17 ± 1.36 μL/min (range, 1.67 to 6.21 μL/min), 2.86 ± 0.88 μL/min (range, 2.04 to 4.30 μL/min), and 2.90 ± 0.90 μL/min (range, 1.67 to 4.42 μL/min), respectively. The AHFRs were similar for right and left eyes. These flow rates represented a mean aqueous humor transfer coefficient of 0.0082/min, which is similar to that of mammalian species.
  
  
  CONCLUSIONS
  The AHFR in red-tailed hawks was similar to that of most mammalian species, and the fractional egress was almost identical to that of other species. This information will allow a greater understanding of aqueous humor flow in avian eyes, which is crucial when evaluating diseases that affect avian eyes as well as medications that alter aqueous humor flow.
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Jones
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Ward
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000502:physiology*; D005260:Female; D019793:Fluorescein; D015590:Fluorophotometry / Q000379:methods / Q000662:veterinary*; D046428:Hawks / Q000502:physiology*; D008297:Male
chemical_list: D019793:Fluorescein