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Logo for the Journal of Rehab R&D
Volume 43 Number 5, September/October 2006
Pages 723 — 732


Abstract - Status of the feline retina 5 years after subretinal implantation

Machelle T. Pardue, PhD;1-2* Sherry L. Ball, PhD;3-4 M. Joe Phillips, BS;1 Amanda E. Faulkner, BS;1 Tiffany A. Walker, BS;1 Alan Y. Chow, MD;5 Neal S. Peachey, PhD3-4

1Atlanta Department of Veterans Affairs Medical Center (VAMC), Decatur, GA; 2Department of Ophthalmology, Emory University, Atlanta, GA; 3Cleveland VAMC, Cleveland, OH; 4Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH; 5Optobionics Corporation, Naperville, IL
Abstract — Retinal prosthetics are designed to restore functional vision to patients with photoreceptor degeneration by detecting light and stimulating the retina. Since devices are surgically implanted into the eye, long-term biocompatibility and durability are critical for viable treatment of retinal disease. To extend our previous work, which demonstrated the biocompatibility of a microphotodiode array (MPA) for 10 to 27 months in the normal feline retina, we implanted normal cats with an MPA implant backed with either an iridium oxide or platinum electrode and examined retinal function and biocompatibility for 3 to 5 years. All implants functioned throughout the study period. Retinal function remained steady and normal with a less than 15 percent decrease in electroretinogram response. The retinas had normal laminar structure with no signs of inflammation or rejection in areas adjacent to or distant from the implants. Directly over the implants, a loss of photoreceptor nuclei and remodeling of inner retinal layers existed. These results indicate that the subretinal MPA device is durable and well tolerated by the retina 5 years postimplantation.
Key words: biocompatibility, feline, GABA, glutamate, glycine, microphotodiode array, prosthetic, rehabilitation, retina, retinitis pigmentosa.

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