EMAIL THIS PAGE TO A FRIEND

PloS one

Chronic electrical stimulation with a suprachoroidal retinal prosthesis: a preclinical safety and efficacy study.


PMID 24853376

Abstract

To assess the safety and efficacy of chronic electrical stimulation of the retina with a suprachoroidal visual prosthesis. Seven normally-sighted feline subjects were implanted for 96-143 days with a suprachoroidal electrode array and six were chronically stimulated for 70-105 days at levels that activated the visual cortex. Charge balanced, biphasic, current pulses were delivered to platinum electrodes in a monopolar stimulation mode. Retinal integrity/function and the mechanical stability of the implant were assessed monthly using electroretinography (ERG), optical coherence tomography (OCT) and fundus photography. Electrode impedances were measured weekly and electrically-evoked visual cortex potentials (eEVCPs) were measured monthly to verify that chronic stimuli were suprathreshold. At the end of the chronic stimulation period, thresholds were confirmed with multi-unit recordings from the visual cortex. Randomized, blinded histological assessments were performed by two pathologists to compare the stimulated and non-stimulated retina and adjacent tissue. All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. After an initial post-operative settling period, electrode arrays were mechanically stable. Mean electrode impedances were stable between 11-15 kΩ during the implantation period. Visually-evoked ERGs & OCT were normal, and mean eEVCP thresholds did not substantially differ over time. In 81 of 84 electrode-adjacent tissue samples examined, there were no discernible histopathological differences between stimulated and unstimulated tissue. In the remaining three tissue samples there were minor focal fibroblastic and acute inflammatory responses. Chronic suprathreshold electrical stimulation of the retina using a suprachoroidal electrode array evoked a minimal tissue response and no adverse clinical or histological findings. Moreover, thresholds and electrode impedance remained stable for stimulation durations of up to 15 weeks. This study has demonstrated the safety and efficacy of suprachoroidal stimulation with charge balanced stimulus currents.

Related Materials

Product #

Image

Description

Molecular Formula

Add to Cart

AB5804
Anti-Glial Fibrillary Acidic Protein (GFAP) Antibody, 50 µL, Anti-Glial Fibrillary Acidic Protein (GFAP) Antibody is an antibody against Glial Fibrillary Acidic Protein (GFAP) for use in IC, IH, IH(P) with more than 65 product citations.
MAB302
Anti-Glutamine Synthetase Antibody, clone GS-6, 100 µg, Detect Glutamine Synthetase using this Anti-Glutamine Synthetase Antibody, clone GS-6 validated for use in ELISA, IH, IH(P) & WB with more than 45 product citations.
SAB2500462
Anti-GFAP antibody produced in goat, affinity isolated antibody, buffered aqueous solution
SAB1405864
Anti-GFAP antibody produced in mouse, purified immunoglobulin, buffered aqueous solution
SAB4300647
Anti-GFAP antibody produced in rabbit, affinity isolated antibody
HPA056030
Anti-GFAP antibody produced in rabbit, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution
SAB2107063
Anti-GFAP antibody produced in rabbit, affinity isolated antibody
SAB2701668
Anti-glul antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution
SAB2701726
Anti-glul antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution
HPA007316
Anti-GLUL antibody produced in rabbit, Ab1, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution
HPA007571
Anti-GLUL antibody produced in rabbit, Ab2, Prestige Antibodies® Powered by Atlas Antibodies, affinity isolated antibody, buffered aqueous glycerol solution
SAB1408580
Anti-GLUL antibody produced in rabbit, purified immunoglobulin, buffered aqueous solution
G2781
Anti-Glutamine Synthetase antibody produced in rabbit, IgG fraction of antiserum, buffered aqueous solution
SAB4200705
Anti-Neurofilament 200 (Phos and Non-Phos) antibody, Mouse monoclonal, clone N52, purified from hybridoma cell culture
Y0000858 Isoflurane, European Pharmacopoeia (EP) Reference Standard
C3H2ClF5O
WH0002752M1
Monoclonal Anti-GLUL antibody produced in mouse, clone 2B12, purified immunoglobulin, buffered aqueous solution