September 2016
Volume 57, Issue 12
Open Access
ARVO Annual Meeting Abstract  |   September 2016
Preliminary Findings from the Oxford Retinal Implant Alpha AMS Trial
Author Affiliations & Notes
  • Thomas L Edwards
    Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
    Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
  • Charles L Cottriall
    Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
  • Matthew P Simunovic
    Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
    Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
  • James D Ramsden
    Department of Otolaryngology Head and Neck Surgery, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
  • Eberhart Zrenner
    Werner Reichardt Centre for Integrative Neuroscience, Tübingen, Germany
    Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
  • Robert E MacLaren
    Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
    Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
  • Footnotes
    Commercial Relationships   Thomas Edwards, None; Charles Cottriall, None; Matthew Simunovic, None; James Ramsden, None; Eberhart Zrenner, Retina Implant AG (I), Retina Implant AG (P), Retina Implant AG (R), Retina Implant AG (C); Robert MacLaren, None
  • Footnotes
    Support  Nuffield Trust
Investigative Ophthalmology & Visual Science September 2016, Vol.57, No Pagination Specified. doi:
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    • Get Citation

      Thomas L Edwards, Charles L Cottriall, Matthew P Simunovic, James D Ramsden, Eberhart Zrenner, Robert E MacLaren; Preliminary Findings from the Oxford Retinal Implant Alpha AMS Trial. Invest. Ophthalmol. Vis. Sci. 201657(12):.

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      © 2017 Association for Research in Vision and Ophthalmology.

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Abstract

Purpose : To assess the safety and efficacy of a subretinal electronic implant in end-stage retinitis pigmentosa. Visual function with the device was assessed in an ongoing prospective, participant-masked, clinical trial based at the University of Oxford.

Methods : The Retina Implant Alpha AMS (Retina Implant AG, Reutlingen, Germany) was implanted into one eye of three participants with end-stage retinitis pigmentosa. Inclusion criteria included vague non-localizing or no light perception in the eye receiving the implant, intact inner retinal function and previous reading visual acuity for a minimum of 12 years. Functional outcome measures included 1) screen-based standardized 2- or 4-alternative forced-choice tests of light perception, temporal resolution, light localization and grating acuity; 2) greyscale discrimination; 3) localization of high contrast objects; 4) full field stimulus threshold (FST) and 5) visual experiences during outdoor and daily-life activities.

Results : To date (3-6 months follow up), light perception, temporal resolution and light localization was improved by the implant in all three participants. The best grating acuity recorded for P1, P2 and P3 was 0.33, 1.0 and 0.1 cycles/degree respectively. The best recorded number of high contrast (white on black) objects correctly located on a table was 4 and 1 with implant on vs off respectively (mean value; max. 4). Similarly, for high contrast tableware the number of items located was 3.7 and 0 for implant on vs off respectively (mean value; max. 4). Two of seven greyscale values were presented side by side on a split screen. Overall discrimination between the two sides was greater with the implant on vs off. An implant-mediated FST was detected in P2 (absent with implant off) and was improved in P1 from 14.8 dB (off) to 10.1 dB (on). All three participants reported a subjective improvement in activities of daily living. These results were sustained at the most recent study visit. However, in one participant (P3) an extra-ocular component of the device eroded through conjunctiva three months post implantation and was damaged by subsequent surgical revision, with a resulting loss of function. No serious adverse events have been reported thus far in any participant.

Conclusions : Short-term results indicate that the Retina Implant Alpha AMS is reliable, well tolerated by patients and improves their visual function.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

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