title: Angiography and multifocal electroretinography show that blood supply to the pig retina may be both ipsilateral and contralateral.
abstract: OBJECTIVE
  We recently presented a transfemoral endovascular coiling technique for inducing experimental retinal ischemia in pigs. Substantial variation was seen in the degree of ischemia. It was hypothesized that the blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries and that there may be an interconnecting artery between the eyes.
  
  
  METHODS
  The external carotid system of 6 pigs was catheterized using a fluoroscopy-monitored, transfemoral, endovascular approach. Vascular occlusion was achieved in the ophthalmic artery using coils. The effect of occlusion was examined using angiography and multifocal electroretinography (mfERG).
  
  
  RESULTS
  During angiography of the ophthalmic artery on one side, contrast filling was seen in the retinas on both sides, suggesting that the ophthalmic artery on one side may supply both retinas. A blood vessel connecting the eyes was visualized. The mfERG recordings indicated that the use of coiling to occlude the ophthalmic artery had greater ischemic effects in eyes that may depend mainly on the ipsilateral ophthalmic artery for blood supply and had smaller ischemic effects in retinas that received blood from both the ipsilateral and contralateral ophthalmic arteries via the interconnecting vessel.
  
  
  CONCLUSIONS
  The blood supply to the retina may originate from both the ipsilateral and contralateral ophthalmic arteries in the pig. There is an interindividual variability in the ischemic effect of occlusion depending on the architecture of the vasculature. These findings may be important in the development of new animal models of experimental retinal ischemia because arterial occlusion in one eye may affect the blood supply to the contralateral eye.
authors.affiliation: Department of Ophthalmology, Lund University, and Skåne University Hospital, 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 / Q000379:methods*; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D008297:Male; D009880:Ophthalmic Artery / Q000473:pathology / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000502:physiology*; D015203:Reproducibility of Results; D012160:Retina / Q000473:pathology* / Q000503:physiopathology; D012164:Retinal Diseases / Q000175:diagnosis* / Q000503:physiopathology; D013552:Swine
keywords: animal model; electroretinography; intra-arterial coiling; retinal ischemia; retinal vasculature