title: Transretinal electrical stimulation with a suprachoroidal multichannel electrode in rabbit eyes.
abstract: OBJECTIVE
  Several approaches for placing an electrode device for visual prosthesis have been previously proposed. In this study, we investigated if transretinal stimulation from the suprachoroidal space can elicit an electrical evoked potential (EEP) in albino rabbits.
  
  
  METHODS
  A flat electrode array (polyimide plate, platinum electrode) was developed and used for this study. After performing a scleral incision at 2-2.5 mm from the limbus and placing an anchoring suture, the array was inserted into the suprachoroidal space in the posterior portion of the eye by direct observation under a microscope. A platinum wire was implanted into the vitreous space as a reference electrode. For electrical stimulation, a biphasic pulse was used. When the electrode was stimulated, the EEP was recorded.
  
  
  RESULTS
  When the electrical stimulation from the suprachoroidal space was applied, the EEP could be recorded with an epidural electrode, and the threshold was 66.0 +/- 32.1 micro A (420 micro C/cm(2)) [corrected]. placement of the array and the electrical stimulation.
  
  
  CONCLUSIONS
  Transretinal electrical stimulation from the suprachoroidal space could elicit EEP, suggesting that this approach may be useful for a retinal prosthesis system.
authors.affiliation: Department of Ophthalmology, Graduate School of Medicine, Osaka University, Suita, Japan. sakaguh@ophthal.med.osaka-u.ac.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Sakaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujikado
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Fang
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kanda
authors.forename: Makoto
authors.initials: M
authors.lastname: Osanai
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nakauchi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ikuno
authors.forename: Motohiro
authors.initials: M
authors.lastname: Kamei
authors.forename: Tohru
authors.initials: T
authors.lastname: Yagi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nishimura
authors.forename: Masahito
authors.initials: M
authors.lastname: Ohji
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yagi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tano
mesh_terms: D000818:Animals; D002829:Choroid / Q000502:physiology*; D004558:Electric Stimulation / Q000295:instrumentation; D004567:Electrodes, Implanted; D004867:Equipment Design; D005071:Evoked Potentials; D005074:Evoked Potentials, Visual; D010775:Photic Stimulation / Q000379:methods; D011817:Rabbits; D012160:Retina