title: Endovascular coiling of the ophthalmic artery in pigs to induce retinal ischemia.
abstract: OBJECTIVE
  The authors recently showed that the retinal circulation can be accessed by transfemoral endovascular catheterization. The purpose of this study was to examine whether endovascular coiling can be used to induce different degrees of ischemic injury. The possibility of creating occlusions at different sites in the vasculature to cause retinal ischemia with different degrees of severity was investigated.
  
  
  METHODS
  The ophthalmic artery was catheterized through the external carotid system using a fluoroscopy-monitored, transfemoral, endovascular approach in 12 pigs (mean weight, 70 kg). The effects were evaluated using angiography and multifocal electroretinography.
  
  
  RESULTS
  Occlusion of arteries supplying the retina was established using endovascular coiling. Coiling in the proximal part of the ophthalmic artery caused no or little ischemia, presumably because of collateral blood supply. Coiling in the distal part of the ophthalmic artery, over the branching of the main ciliary artery, caused more severe retinal ischemia. Multifocal electroretinography recordings, which reflect retinal function in an area close to the visual streak, showed decreased amplitudes and increased implicit times after distal occlusion, but not after proximal occlusion of the ophthalmic artery. The responses were similar 1 hour and 72 hours after coiling, indicating that a permanent ischemic injury was established.
  
  
  CONCLUSIONS
  The porcine ophthalmic artery can be occluded using an endovascular coiling technique. This provides an experimental animal model of retinal ischemia in which occlusion at different sites of the vasculature produces different degrees of severity of the ischemic damage.
authors.affiliation: Department of Ophthalmology, Lund University, Lund, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Morén
authors.forename: Bodil
authors.initials: B
authors.lastname: Gesslein
authors.forename: Per
authors.initials: P
authors.lastname: Undrén
authors.forename: Sten
authors.initials: S
authors.lastname: Andreasson
authors.forename: Malin
authors.initials: M
authors.lastname: Malmsjö
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004596:Electroretinography; D004621:Embolization, Therapeutic / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D007511:Ischemia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D009880:Ophthalmic Artery / Q000601:surgery*; D012039:Regional Blood Flow; D012160:Retina / Q000473:pathology*; D015356:Retinal Artery Occlusion / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013552:Swine