gms | German Medical Science

27th International Congress of German Ophthalmic Surgeons

15. to 17.05.2014, Nürnberg

Clinical Trial Results. Update from the Argus® II Retinal Prosthesis System (P2, I)

Meeting Abstract

  • Gregoire Cosendai - Second Sight Medical Products, Lausanne, Switzerland
  • Lyndon da Cruz - Moorfields Eye Hospital, London, Vereinigtes Königreich
  • José-Alain Sahel - Center Hospitalier National d’Ophtalmologie des Quinze-Vingt, Paris, France
  • Paulo Stanga - Manchester Royal Eye Hospital, Manchester, Vereinigtes Königreich
  • Farhad Hafezi - Hôpitaux Universitaires de Genève, Geneva, Switzerland
  • Robert Greenberg - Second Sight Medical Products, Inc., Sylmar, Vereinigte Staaten von Amerika
  • Argus II Study Group - Second Sight Medical Products, Inc., Sylmar, Vereinigte Staaten von Amerika

27. Internationaler Kongress der Deutschen Ophthalmochirurgen. Nürnberg, 15.-17.05.2014. Düsseldorf: German Medical Science GMS Publishing House; 2014. DocWK 5.12

doi: 10.3205/14doc148, urn:nbn:de:0183-14doc1480

Published: May 5, 2014

© 2014 Cosendai et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Purpose: The Argus II clinical trial is the largest trial of a retinal prosthesis in the world. Its subjects are constantly followed for safety and performance. There are 10 implanting centers involved in the clinical trial in the US, UK, France, and Switzerland. Before implantation, all 30 subjects enrolled ( NCT00407602) were suffering from severe outer retinal degeneration that brought them to have bare light perception or worse in both eyes.

Methods: Safety is evaluated by recording the number, type, and severity of adverse events. Visual function is evaluated by high-contrast computer tests such as Square Localization, Direction of Motion, and Grating Visual Acuity. Functional Vision is evaluated with Orientation and Mobility tests and the Functional Low-vision Observer Rated Assessment (FLORA). In order to compare Argus II performance against subjects’ residual vision, all assessments are performed with the System ON and OFF.

Results: To date, this trial has gathered 160 subject-years of data. As of February 20, 2014, 25 subjects remain implanted with functioning Argus II implants. There have been three explants, two of which were elective, and two device failures (i.e., a failure to maintain communications link). On average, these 25 subjects have been implanted for 5.6 years (range of 4.5–6.7 years). The long-term safety profile remains very good; there was only one new non-serious adverse event (related to the device or the procedure) among all subjects in the last year. Performance on all assessments shows better function with the System ON than OFF, sustained beyond 5 years of use.

Conclusions: The Argus II Retinal Prosthesis System confirms in these latest results its long term safety and benefits as previously reported. The Argus II is commercially available in the US, Europe, and the Middle East.