title: Implantation of stimulation electrodes in the subretinal space to demonstrate cortical responses in Yucatan minipig in the course of visual prosthesis development.
abstract: OBJECTIVE
  During the course of the development of visual prostheses, subretinal stimulation films were implanted in micropigs in order to prove the feasibility of subretinal electrical stimulation with subsequent cortical response. One aim was to demonstrate that epidural recording of visual evoked potentials is possible in the micropig.
  
  
  METHODS
  Film-bound stimulation electrode arrays were placed in the subretinal space of micropigs. This enabled the retina to be stimulated subretinally. Since conventional visual evoked potential (VEP) measuring is virtually impossible in the pig from the neurosurgical point of view, epidural recording electrode arrays were positioned over the visual cortex as permanent electrodes.
  
  
  RESULTS
  The feasibility of temporary implantation of film-bound stimulation electrode arrays was successfully demonstrated in the micropig model. On stimulation with monopolar voltage pulses (1000 to 3000 mV), reproducible epidural VEP measurements (5 to 10 micronV) were detected.
  
  
  CONCLUSIONS
  The feasibility of subretinal stimulation of the retina was demonstrated in a retinal model that is similar to the human retina. This animal model therefore offers a suitable means of studying the tolerability of stimulation situations in the course of visual prosthesis development.
authors.affiliation: University Eye Clinic, Regensburg - Germany.
authors.forename: H G
authors.initials: HG
authors.lastname: Sachs
authors.forename: F
authors.initials: F
authors.lastname: Gekeler
authors.forename: H
authors.initials: H
authors.lastname: Schwahn
authors.forename: W
authors.initials: W
authors.lastname: Jakob
authors.forename: M
authors.initials: M
authors.lastname: Kohler
authors.forename: F
authors.initials: F
authors.lastname: Schulmeyer
authors.forename: J
authors.initials: J
authors.lastname: Marienhagen
authors.forename: U
authors.initials: U
authors.lastname: Brunner
authors.forename: C
authors.initials: C
authors.lastname: Framme