title: Analysis of choriocapillaris flow patterns by continuous laser-targeted angiography in monkeys.
abstract: OBJECTIVE
  To investigate choriocapillaris flow patterns and its segmental distribution in monkeys by continuous laser-targeted angiography (LTA).
  
  
  METHODS
  A slit lamp was modified to incorporate two kinds of lasers (argon and diode). Carboxyfluorescein (CF) was encapsulated in heat-sensitive liposomes and injected intravenously. Encapsulated CF was released locally by applying a continuous heat beam provided by the diode laser (810 nm). Video angiograms were generated with excitation illumination provided by the argon laser (488 and 514 nm), to observe selective images of the choriocapillaris.
  
  
  RESULTS
  Continuous application of the diode laser disclosed three distinct phases (filling, plateau, and draining) of fluorescent images of the choriocapillaris. In the plateau phase, a cluster of lobules fed by a common arteriole was uniformly illuminated. This defined area did not change in size while a continuous diode laser was applied to the same spot. Only in posterior regions did the angiograms demonstrate that during the filling and draining phases each lobule was filled from a central spot and drained along a peripheral ring, showing honeycomb flow patterns. In peripheral regions, large choroidal vessels as well as choriocapillaris were observed.
  
  
  CONCLUSIONS
  Continuous LTA demonstrated clusters of lobules fed by a common arteriole, and each cluster was found to be functionally independent. There were regional differences in choriocapillaris flow patterns, which suggests that the choriocapillaris provides a more highly efficient system of outflow in posterior regions than in peripheral regions. This modified LTA method appears to be useful in analyzing choroidal circulation in vivo.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Hirata
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Nishiwaki
authors.forename: Shinji
authors.initials: S
authors.lastname: Miura
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ieki
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Honda
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yumikake
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugino
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Okazaki
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002196:Capillaries / Q000502:physiology; D002829:Choroid / Q000098:blood supply* / Q000473:pathology; D005451:Fluorescein Angiography / Q000379:methods*; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007834:Lasers; D008252:Macaca fascicularis; D012039:Regional Blood Flow / Q000502:physiology
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; C024098:6-carboxyfluorescein