title: Development of surgical techniques for implantation of a wireless intraocular epiretinal retina implant in Göttingen minipigs.
abstract: BACKGROUND
  The aim of this study was to develop surgical methods for the implantation of a wireless intraocular epiretinal retina implant (EPI RET3) in Göttingen minipigs. This animal model resembles closely the anatomical conditions in humans, and is thus suitable for investigating the EPI RET3 implant as designed for the application in humans.
  
  
  METHODS
  Phacoemulsification and vitrectomy was performed on the right eye of 16 Göttingen minipigs under general anesthesia. The implants, consisting of a receiver module and an electrode array connected via a flexible micro cable, were inserted through a corneoscleral incision. The receiver module was placed into the sulcus ciliaris and the electrode array was fixed onto the retina temporal to the optic disc with a retinal tack. Minipigs were monitored for intra- and postoperative ocular complications. Follow-up times were 3 (seven minipigs) and 12 weeks (nine minipigs).
  
  
  RESULTS
  Implantation was successfully performed in all 16 minipigs. The complete implantation surgery required on average 2 hours. Intraoperative findings were a minor hemorrhage of the anterior chamber angle in two eyes, one minor iris hemorrhage, and one minor punctiform retinal hemorrhage, which were all reversible. Postoperatively, the corneoscleral incision showed good wound healing in all eyes. Intraocular reactions included mainly fibrin exudation (six eyes) and formation of iris synechiae with the receiver module of the implants (three eyes).
  
  
  CONCLUSIONS
  The performed implantation procedures of the intraocular EPI RET3 implant are feasible and reproducible within an acceptable surgical time. The development of inflammatory responses is a specific predisposition of the minipig following any intraocular intervention; nevertheless, the surgical techniques should be further improved to minimize procedure-related reactions. Our results provide a step towards the application of the EPI RET3 system in clinical studies.
authors.affiliation: Department of Ophthalmology, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany. thomas.laube@uni-due.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Laube
authors.forename: Claudia
authors.initials: C
authors.lastname: Brockmann
authors.forename: Gernot
authors.initials: G
authors.lastname: Roessler
authors.forename: Peter
authors.initials: P
authors.lastname: Walter
authors.forename: Christine
authors.initials: C
authors.lastname: Krueger
authors.forename: Michael
authors.initials: M
authors.lastname: Goertz
authors.forename: Susanne
authors.initials: S
authors.lastname: Klauke
authors.forename: Norbert
authors.initials: N
authors.lastname: Bornfeld
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004596:Electroretinography; D005240:Feasibility Studies; D005451:Fluorescein Angiography; D008839:Microelectrodes; D013508:Ophthalmologic Surgical Procedures; D018918:Phacoemulsification; D011446:Prospective Studies; D019919:Prosthesis Implantation; D012160:Retina / Q000601:surgery*; D013552:Swine; D013556:Swine, Miniature; D014821:Vitrectomy