Semi-Chronic Implantation of Artificial Retina by Suprachoroidal Transretinal Stimulation (STS) System in Dogs

Abstract

Purpose: : To study the feasibility of implantation and biostability of a suprachoroidal transretinal stimulation (STS) system consisting of a microelectrode array and an extraocular microelectric device in dogs.

Methods: : Two beagle dogs were used. Under general anesthesia, an array of 9 microelectrodes was implanted into a scleral pocket, a reference needle electrode was inserted in the vitreous through the limb of sclera and an extraocular device was placed subcutaneously on the surface of right temporalis muscle. 1 month after implantation of this system, funduscopic analysis was performed and the operation of this system was checked by measuring both the voltage of electrical circuit in an extraocular device and the electrical conduction of each electrode.

Results: : The surgical procedures for implantation of the electrode array and the extraocular device were accomplished without serious surgical complications. Both the array and the extraocular device kept a stable fixation in dogs within 1 month. 1 month after implant, funduscopy demonstrated no retinal complication over and around implants. And the system was confirmed to work properly.

Conclusions: : This study demonstrates the feasibility of a surgical procedure for safe implantation of the STS system, and this system proved to be biostable in freely-moving dogs for an observation period of 1 month.

Keywords: retina • retinitis • retinal connections, networks, circuitry