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Epiretinale Sehprothesen

Epiretinal visual prostheses

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Zusammenfassung

Epiretinale Implantate bestehen aus einem Kamerachip, der die Umgebung abbildet, einem Sehprozessor, der die Bildinformation in netzhautspezifische Pulssequenzen umrechnet, einem Sendesystem für Energie und Daten und dem eigentlichen Implantat. Dieses besteht aus einem Empfangsmodul, das in eine Intraokularlinse integriert ist, einem Mikrokabel und dem eigentlichen Netzhautstimulator. Dieser ist mit seinen Reizelektroden auf der Netzhaut fixiert, wobei Netzhautnägel eingesetzt werden. Tierexperimente haben gezeigt, dass die verwendeten Materialien auch über einen längeren Zeitraum im Auge vertragen werden, dass die chronische Energieübertragung keine schädlichen Effekte hat und dass das Implantat sich mit einem Nagel fixieren lässt. Es konnte gezeigt werden, dass die elektrische Stimulation der inneren Netzhautoberfläche zu einer Aktivierung topografisch korrekt zugeordneter kortikaler Areale im primären Sehfeld führt. Erste Untersuchungen am Menschen zeigten, dass selbst nach einer langen Anamnese vollständiger Erblindung durch die elektrische Reizung Sehwahrnehmungen ausgelöst werden können.

Abstract

Epiretinal implants consist of a camera chip capturing the scene, a visual processor calculating retina-specific pulse sequences, a transponder for data and energy, and the implant itself. The implant consists of a receiver integrated into a posterior chamber lens, a microcable, and the retina stimulator. The stimulator is fixated onto the retinal surface using retinal tacks. In animal experiments it was shown that the materials being used were tolerated, the data and energy stream did not induce any adverse events, and that the fixation was feasible using retinal tacks. Stimulation of the inner retinal surface yielded a topographically correct activation of visual cortical areas. Even after a long history of blindness, tests in humans disclosed visual percepts.

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Authors and Affiliations

  1. Universitätsaugenklinik, RWTH, Aachen

    P. Walter

  2. Institut für Werkstoffe der Elektrotechnik I, RWTH, Aachen

    W. Mokwa

  3. Universitätsaugenklinik, RWTH, Pauwelsstraße 30, 52074 , Aachen

    P. Walter

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Correspondence to P. Walter.

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Walter, P., Mokwa, W. Epiretinale Sehprothesen. Ophthalmologe 102, 933–940 (2005). https://doi.org/10.1007/s00347-005-1250-2

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  • DOI: https://doi.org/10.1007/s00347-005-1250-2

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