gms | German Medical Science

24th Annual Meeting of the German Retina Society

German Retina Society

17.06. - 18.06.2011, Aachen

Biochemically modified surfaces as a fixation concept for epiretinal stimulator arrays: First results of in-vivo implantation in rabbits

Meeting Abstract

  • Gernot Rössler - Universitäts-Augenklinik der RWTH Aachen
  • S. Kaempf - Universitäts-Augenklinik der RWTH Aachen
  • D. Klee - Institut für textile und makromolekulare Chemie der RWTH Aachen
  • W. Mokwa - Institut für Werkstoffe in der Elektrotechnik der RWTH Aachen
  • C. Koch - Institut für Werkstoffe in der Elektrotechnik der RWTH Aachen
  • B. Sellhaus - Institut für Neuropathologie am Universitätsklinikum Aachen
  • B. Mazinani - Universitäts-Augenklinik der RWTH Aachen
  • G. Thumann - Universitäts-Augenklinik der RWTH Aachen
  • P. Walter - Universitäts-Augenklinik der RWTH Aachen

German Retina Society. 24th Annual Conference of the German Retina Society. Aachen, 17.-18.06.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11rg61

doi: 10.3205/11rg61, urn:nbn:de:0183-11rg619

This is the translated version of the article.
The original version can be found at:

Published: June 15, 2011

© 2011 Rössler et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Purpose: To develop an alternative fixation procedure for epiretinal stimulators as an alternative to the conventional fixation using retinal tacks.

Methods: Polyimide microstructures were coated with different protein configurations by immobilizing laminin peptide composites onto the surface. Implantation was performed in rabbits including vitrectomy and the positioning of the structures onto the retinal surface. After an observation period of three months the eyes were enucleated for histopathological examination.

Results: Using one additional retinal tack at one edge of the microstructures led to tight connection of the entire dummy microstructures at the posterior pole of the rabbits’ eyes. In cases where the positioning was performed without an additional tack fixation the dummy structures did not remain at the posterior pole. In one case with additional tack fixation the microstructure showed tight contact although the tack was not detectable at the fixation site during the follow-up examinations.

Conclusions: Our first results of in-vivo implantation show that basically a tight contact of the modified microstructures with the retinal surface could be achieved. However, the necessity of a temporary additional tack fixation implies that a certain period of time needs to be bypassed until the biochemical fixation takes effect completely. Moreover, experiments in animal models which a more similar to the human eye could be helpful to investigate the relevance of this problem while the design of an entirely implanted prosthesis including the transscleral fixation of the receiver and the built-in stress of the stimulator cable may provide a certain temporary fixation.