Vision maintenance and retinal apoptosis reduction in RCS rats with Okayama University-type retinal prosthesis (OUReP™) implantation

J Artif Organs. 2015 Sep;18(3):264-71. doi: 10.1007/s10047-015-0825-1. Epub 2015 Mar 3.

Abstract

Photoelectric dye-coupled polyethylene film, designated Okayama University-type retinal prosthesis or OUReP™, generates light-evoked surface electric potentials and stimulates neurons. In this study, the vision was assessed by behavior tests in aged hereditary retinal dystrophic RCS rats with OUReP™, retinal apoptosis and electroretinographic responses were measured in dystrophic eyes with OUReP™. The dye-coupled films, or plain films as a control, were implanted in subretinal space of RCS rats. On behavior tests, RCS rats with dye-coupled films, implanted at the old age of 14 weeks, showed the larger number of head-turning, consistent with clockwise and anticlockwise rotation of a surrounding black-and-white-striped drum, compared with rats with plain films, under the dim (50 lux) and bright (150 lux) conditions in the observation period until the age of 22 weeks (n = 5, P < 0.05, repeated-measure ANOVA). The number of apoptotic cells in retinal sections at the site of dye-coupled film implantation was significantly smaller, compared with the other retinal sites, neighboring the film, or opposite to the film, 5 months after film implantation at the age of 6 weeks (P = 0.0021, Friedman test). The dystrophic eyes of RCS rats with dye-coupled films showed positive responses to maximal light stimulus at a significantly higher rate, compared with the eyes with no treatment (P < 0.05, Chi-square test). Electroretinograms in normal eyes of Wistar rats with dye-coupled or plain films showed significantly decreased amplitudes (n = 14, P < 0.05, repeated-measure ANOVA). In conclusions, vision was maintained in RCS rats with dye-coupled films implanted at the old age. The dystrophic eyes with dye-coupled films showed electroretinographic responses. Five-month film implantation caused no additional retinal changes.

MeSH terms

  • Aniline Compounds*
  • Animals
  • Apoptosis
  • Disease Models, Animal
  • Electroretinography
  • Male
  • Polyethylene*
  • Rats
  • Rats, Wistar
  • Retinal Dystrophies / pathology
  • Retinal Dystrophies / therapy*
  • Thiazoles*
  • Visual Prosthesis*

Substances

  • 2-(2-(4-(dibutylamino)phenyl)ethenyl)-3-carboxymethylbenzothiazolium
  • Aniline Compounds
  • Thiazoles
  • Polyethylene