Transretinal electrical stimulation with a suprachoroidal multichannel electrode in rabbit eyes.
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.
Sakaguchi
Hirokazu
H
Department of Ophthalmology, Graduate School of Medicine, Osaka University, Suita, Japan. sakaguh@ophthal.med.osaka-u.ac.jp
Fujikado
Takashi
T
Fang
Xiaoyun
X
Kanda
Hiroyuki
H
Osanai
Makoto
M
Nakauchi
Kazuaki
K
Ikuno
Yasushi
Y
Kamei
Motohiro
M
Yagi
Tohru
T
Nishimura
Shigeru
S
Ohji
Masahito
M
Yagi
Tetsuya
T
Tano
Yasuo
Y
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