July 2019
Volume 60, Issue 9
Open Access
ARVO Annual Meeting Abstract  |   July 2019
Implant size matters for visual field and consecutive orientation. Large scale subretinal implant surgery for blind RP patients
Author Affiliations & Notes
  • Helmut G Sachs
    Eye Clinic, Klinikum Dresden, Dresden, Germany
  • Ursula F Brunner
    Eye Clinic, Klinikum Dresden, Dresden, Germany
  • Footnotes
    Commercial Relationships   Helmut Sachs, Alcon (C), Allergan (C), Bayer (C), Novartis (C), Retina Implant AG (C), Retina Implant AG (R), Retina Implant AG (P); Ursula Brunner, None
  • Footnotes
    Support  none
Investigative Ophthalmology & Visual Science July 2019, Vol.60, 4974. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Helmut G Sachs, Ursula F Brunner; Implant size matters for visual field and consecutive orientation. Large scale subretinal implant surgery for blind RP patients. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4974.

      Download citation file:

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

  • Supplements

Purpose : Currently the size of the retinal implants in use to improve vision in blind patients is limited due to surgical reasons. Hence the size of the visual field is small in terms of orientation. Both the epiretinal and the subretinal implants show this restriction. Even with an acceptable resolution when implanting foveally the orientation capabilities lack due to the visual field problem. This results in scanning maneuvers of the patient in form of head movement caused by this centralized visual field. Subretinal implantation proved to be save for an implantation area that is 5 times the size of the active chip in use. The subretinal cable path is not used to elicit sensations. So this area is lost for stimulation. This area of subretinal implantation could be used to enhance the visual field when equipped with stimulation chips.

Methods : A redistribution of the active and passive subretinal implantation areas is reconsidered. We modifiy the established procedure using the well-known safe components of the surgery like entry size into the eye and evaluated material properties. Thus the resulting visual field is enlarged 2 to 3 fold. Using porcine cadaver eyes we demonstrate the surgical feasibility to implant the modified carrier structures transchoroidally for the chips. The new procedure and the changed implant geometry allow a visual field up to theoretically approx. 30 deg.

Results : The implantation is technically manageable without major changes to procedure which is already established in human eyes . A save surgical access is demonstrated in 12 cadaver eyes and results in a stable p.o. situation. The large scale implants show a stable position without any damage to the retina covering the complete macular area. Retina was p.o. comlpletely reattched. All the used components are proved either in human implantation or in prior published animal research so that animal reseach at that point was not necessary.

Conclusions : Most of the progress since the first human subretinal implantation was dedicated to technical features like biostability of the implant. However one of the main goals of the implant namely orientation was out of focus and not reached sufficiently. We learned from the implanted patients that orientation is still difficult with all the implants currently in use. Great progress in this field is not visible due to comercialized driven research.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.


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.