title: The multifocal electroretinogram (mfERG) in the pig.
abstract: OBJECTIVE
  To establish a method allowing multifocal electroretinography (mfERG) recording with simultaneous fundus monitoring on anaesthetized pigs. In addition we characterize the peaks of the porcine mfERG trace, and compare the visual streak area with the optic nerve head, a known non-response area. Finally we illustrate the feasibility of the method by performing mfERG after an induced laser burn in the visual streak.
  
  
  METHODS
  Fifteen pigs underwent mfERG recordings at baseline, and after 1 and 6 weeks of observation. One pig was evaluated before and after retinal diode laser treatment in the visual streak.
  
  
  RESULTS
  The porcine mfERG trace appears similar to the human mfERG trace, and can be described by three peaks named N1, P1 and N2. Significantly faster implicit time was found in the visual streak regarding N1 (P < 0.001) than in areas outside the visual streak. Amplitudes of all three peaks were increased in the visual streak (P < 0.005). The laser-treated area was characterized by a response similar to what is found at the location of the optic nerve head.
  
  
  CONCLUSIONS
  Porcine mfERG is similar in appearance to the human response and can be described by the same three peaks. Significantly higher amplitudes of all three peaks are found in the visual streak when compared to the optic nerve head and inferior retina. We have detected the functional deficit caused by a laser burn at the size of 3 x 3 mm.
authors.affiliation: Department of Ophthalmology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. maria_voss@dadlnet.dk
authors.forename: Maria
authors.initials: M
authors.lastname: Voss Kyhn
authors.forename: Jens F
authors.initials: JF
authors.lastname: Kiilgaard
authors.forename: Ana Garcia
authors.initials: AG
authors.lastname: Lopez
authors.forename: Erik
authors.initials: E
authors.lastname: Scherfig
authors.forename: Jan U
authors.initials: JU
authors.lastname: Prause
authors.forename: Morten
authors.initials: M
authors.lastname: la Cour
mesh_terms: D000818:Animals; D004596:Electroretinography / Q000379:methods*; D005260:Female; D017075:Laser Coagulation; D012016:Reference Values; D012160:Retina / Q000502:physiology* / Q000601:surgery; D012164:Retinal Diseases / Q000175:diagnosis*; D013552:Swine