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Klin Monbl Augenheilkd 2017; 234(04): 538-540
DOI: 10.1055/s-0042-121660
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Georg Thieme Verlag KG Stuttgart · New York

Retina-Implant Interaction after 16 Months Follow-up in a Patient with an Argus II Prosthesis

Retinaimplantatinteraktion nach 16-monatiger Nachkontrolle bei Patienten mit Argus-II-Prothese
B. K. Tran
Department of Vitreoretinal Surgery, Jules Gonin Eye Hospital, University of Lausanne, Switzerland (Chairman: Prof. T. J. Wolfensberger A. I.)
,
T. J. Wolfensberger
Department of Vitreoretinal Surgery, Jules Gonin Eye Hospital, University of Lausanne, Switzerland (Chairman: Prof. T. J. Wolfensberger A. I.)
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Publication Date:
13 February 2017 (online)

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Background

The Argus II visual prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA) can restore partial vision in patients with outer retinal degeneration such as retinitis pigmentosa (RP) [1], [2]. The perceptual threshold (stimulation energy necessary to trigger a perception) depends in theory on the distance separating the implant from the retina according to Coulombʼs law but this has been disputed by our previous report [3]. In our previous report [3], we described that perceptual threshold is unrelated to implant-retina distance whereas other authors showed that the implant position is paramount as the retinal sensitivity vary along the macula [4]. These examples show that the interaction between the implant and the retina is very complex. In vivo, many others factors may influence the perceptual threshold and some of them are still unclear. We can cite anatomical, electrical but also biological, physiological and psychological factors.

After a learning period, which last several weeks to months, the final visual performance that a patient can expect from this device will depend on all these elements. In this second report on the same patient, we follow-up the threshold map of the implant (implant sensitivity) 16 months after implantation.

 

  • References

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  • 2 Dorn JD, Ahuja AK, Caspi A. et al. The detection of motion by blind subjects with the epiretinal 60-electrode (Argus II) retinal prosthesis. JAMA Ophthalmol 2013; 131: 183-189
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  • 4 Ahuja AK, Yeoh J, Dorn JD. et al. Factors affecting perceptual threshold in Argus II retinal prosthesis subjects. Transl Vis Sci Technol 2013; 2: 1
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