June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
Estimation of the reliability of a subretinal implant using systematic statistical evaluation of clinical results and developing a laboratory model
Author Affiliations & Notes
  • Renate Daschner
    Retina Implant AG, Reutlingen, Germany
  • Martin Kokelmann
    Retina Implant AG, Reutlingen, Germany
  • Udo Greppmaier
    Retina Implant AG, Reutlingen, Germany
  • Ralf Rudorf
    Retina Implant AG, Reutlingen, Germany
  • Sandra Rudorf
    Retina Implant AG, Reutlingen, Germany
  • Footnotes
    Commercial Relationships   Renate Daschner, Retina Implant AG (E); Martin Kokelmann, Retina Implant AG (E); Udo Greppmaier, Retina Implant AG (E); Ralf Rudorf, Retina Implant AG (E); Sandra Rudorf, Retina Implant AG (E)
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 4199. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Renate Daschner, Martin Kokelmann, Udo Greppmaier, Ralf Rudorf, Sandra Rudorf; Estimation of the reliability of a subretinal implant using systematic statistical evaluation of clinical results and developing a laboratory model. Invest. Ophthalmol. Vis. Sci. 2017;58(8):4199.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Purpose : As there are no therapies available yet to cure Retinitis Pigmentosa, several approaches of retinal implants are under development that might allow patients to retrieve some kind of visual sensations. A critical issue thereof is the functional life of these devices, because sensitive electronic components must continuously withstand the environment of the body. A first estimation of the reliability of the two implant systems Retina Implant Alpha IMS and Retina Implant Alpha AMS is given.

Methods : The subretinal implant Alpha IMS has been part of a clinical trial consisting of 29 patients (www.clinicaltrials.gov, NCT01024803). This part of the trial is already finished allowing us to statistically evaluate the reliability of the retinal implant. An exponential model is used to calculate the system lifetime. Additionally the reliability of the implant is simulated in a laboratory environment. Here all critical components of the implant system are tested under accelerated ageing conditions. The total system lifetime is predicted from the components using a competing risk analysis. The advanced implant system Alpha AMS is part of an ongoing clinical trial. For that reason only a first estimate of the reliability can be given using the same evaluation models and assumptions that have been developed for Alpha IMS.

Results : Using an exponential model to calculate the reliability of the Alpha IMS system a median device lifetime of 0.6 years is determined. Failure mechanisms that occurred during the clinical trial could be reproduced in our laboratory accelerated aging tests. Also the estimated median device lifetime of 0.7 years from laboratory experiments is in good agreement with the clinical result showing that our experiments are suitable to model clinical usage of the system. Therefore we use the same model to estimate the laboratory and clinical reliability of the newer system Alpha AMS where only few clinical data exist up to now. Already now it can be shown, that for a confidence level of 75% the median device lifetime of Alpha AMS is expected to be at least four times the system lifetime of Alpha IMS.

Conclusions : A laboratory model is developed which gives a reliable estimation of the device lifetime of the subretinal implants Alpha IMS and Alpha AMS showing good agreement with the predicted clinical reliability based on recent clinical data.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.


This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.