Extraction of a Chronically Implanted, Microfabricated, Subretinal Electrode ArrayChen J. · Shah H.A. · Herbert C. · Loewenstein J.I. · Rizzo, III J.F.
aDepartment of Ophthalmology, Harvard Medical School and the Massachusetts Eye and Ear Infirmary, and bCenter for Innovative Visual Rehabilitation, VA Boston Healthcare System, Boston, Mass., USA
Purpose: To assess the feasibility of extraction of a chronically implanted subretinal electrode array. Methods: Inactive, polyimide strips (10 mm × 1.5 mm × 15 μm) were surgically implanted into the subretinal space of 8 rabbits using a mostly ab externo approach. Pre- and postoperative clinical examinations, electroretinography and in some cases optical coherence tomography were performed to follow the course of the eyes. Two months after implantation, the polyimide strips were extracted from 5 eyes; 2 animals kept the implants and served as controls. All animals were then sacrificed and eyes enucleated for histological examination. Results: All 8 surgeries yielded successful placement of the arrays into the subretinal space. All 5 extraction surgeries were performed without obvious complications. Clinical examinations and electroretinography did not reveal any significant abnormalities. The histological examinations showed alterations from normal anatomy in all animals; the anatomical changes in the explanted animals were relatively mild and confined to the area of the surgery. Conclusions: Successful extraction of electrode arrays from the subretinal space of rabbits can be reliably performed 2 months after implantation, which is beyond the time period when postoperative scarring would be most intense.
Dr. Joseph Rizzo
Massachusetts Eye and Ear Infirmary, 243 Charles St.
Boston, MA 02114 (USA)
Received: June 17, 2008
Accepted after revision: September 16, 2008
Published online: July 4, 2009
Number of Print Pages : 10
Number of Figures : 7, Number of Tables : 1, Number of References : 38
Additional supplementary material is available online - Number of Parts : 1
Ophthalmic Research (Journal for Research in Experimental and Clinical Ophthalmology)
Vol. 42, No. 3, Year 2009 (Cover Date: November 2009)
Journal Editor: Pleyer U. (Berlin)
ISSN: 0030-3747 (Print), eISSN: 1423-0259 (Online)
For additional information: http://www.karger.com/ORE