title: Detection of Zinn-Haller arterial ring in highly myopic eyes by simultaneous indocyanine green angiography and optical coherence tomography.
abstract: OBJECTIVE
  To determine the intrascleral location of the circle of Zinn-Haller by simultaneous indocyanine green (ICG) angiography and enhanced-depth imaging optical coherence tomography (EDI-OCT) in highly myopic eyes.
  
  
  METHODS
  Retrospective, consecutive, observational case series.
  
  
  METHODS
  Ninety-four eyes of 67 consecutive patients with pathologic myopia who underwent simultaneous ICG angiography and EDI-OCT examinations by Spectralis HRA-OCT, and whose Zinn-Haller ring was observed within the area of myopic conus by ICG angiography, were studied. The definition of pathologic myopia was a refractive error (spherical equivalent) <-8.00 diopters (D) or an axial length >26.5 mm.
  
  
  RESULTS
  The EDI-OCT images showed cross-sections of the vessels that were identified in the ICG images as the circle of Zinn-Haller. The vessels were seen as a hyporeflective circle within the peripapillary sclera. An intrascleral course of the Zinn-Haller ring was clearly observed in adjacent serial OCT sections. The filling of the Zinn-Haller ring was from the short posterior ciliary arteries, and OCT also showed a continuous pathway from the retrobulbar short posterior ciliary arteries to the circle of Zinn-Haller. Centripetal branches were seen to run toward the optic nerve from the Zinn-Haller ring in 20 eyes by ICG and were confirmed by OCT in 4 eyes.
  
  
  CONCLUSIONS
  The HRA-OCT images confirmed that the vascular structure surrounding the optic disc observed by ICG angiography had topographic features specific to the Zinn-Haller arterial ring by OCT. The in situ observation of the circle of Zinn-Haller by simultaneous ICG angiography and OCT is a useful method to examine the Zinn-Haller ring in eyes with pathologic myopia.
authors: Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, Japan. k.ohno.oph@tmd.ac.jp
authors: Kyoko
authors: K
authors: Ohno-Matsui
authors: Kaori
authors: K
authors: Kasahara
authors: Muka
authors: M
authors: Moriyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019842:Ciliary Arteries / Q000473:pathology*; D004396:Coloring Agents; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000473:pathology*; D009898:Optic Disk / Q000098:blood supply* / Q000473:pathology; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green