Safety and Efficacy of Subretinal Implants for Partial Restoration of Vision in Blind Patients


Patients suffering from hereditary retinal degeneration receive a retinal implant to restore sight. Subretinal implant "ON" results in significant visual acuity improvement, when compared to "OFF" condition.

Full Title of Study: “Safety and Efficacy of Subretinal Implants for Partial Restoration of Vision in Blind Patients: A Prospective Multicenter Clinical Study Based on Randomized Intra-individual Implant Activation in Patients With Degenerative Retinal Diseases”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: Single (Participant)
  • Study Primary Completion Date: April 2017


  • Device: Device name: “Retina Implant model Alpha”. Surgical implantation of medical device into eye
    • Surgical implantation of medical device named “Retina Implant” into eye to restore vision partially. Randomized intra-individual implant activation in patient under test conditions such as: FrACT, BaLM, BaGA, maze, ADL.

Clinical Trial Outcome Measures

Primary Measures

  • Activities of daily living and mobility significantly improve with implant-ON shown via activities of daily living tasks, recognition tasks, mobility, or a combination thereof.
    • Time Frame: every 3 months for a period of one year

Secondary Measures

  • Visual acuity/light-perception and/or object-recognition are significantly improved with implant-ON versus OFF as shown via: FrACT/BaLM/BaGA/VFQ-25 or a combination thereof.
    • Time Frame: every 3 months for a period of one year
  • Patient long term safety and stability of implant function
    • Time Frame: every 3 months for a period of one year

Participating in This Clinical Trial

Inclusion Criteria

  • Hereditary retinal degeneration of the outer retinal layers i.e. photoreceptor rods & cones. – Pseudophakia – Angiography shows retinal vessels adequately perfused, despite pathological RP condition. – Age between 18 and 78 years. – Blindness (at least monocular) i.e. visual functions not appropriate for localization of objects, self sustained navigation and orientation. – Ability to read normal print in earlier life, optically corrected without magnifying glass. – Willing and able to give written informed consent in accordance to EN ISO 14155 (section 6.7) and local legislation prior to participation in the study. Able to perform the study during the full time period of one year for Module-2. Exclusion Criteria:

  • Period of appropriate visual functions approx. 12 years / lifetime. – Optical Coherence Tomography (OCT) shows significant retina edema &/or scar tissue within target region for implant. – Retina detected as too thin to expect required rest-functionality of inner retina as shown via Optical Coherence Tomography (OCT). – Lack of inner-retinal function, as determined by Electrically Evoked Phosphenes (EEP). – Heavy clumped pigmentation at posterior pole – Any other ophthalmologic disease with relevant effect upon visual function (e.g. glaucoma, optic neuropathies, trauma, diabetic retinopathy, retinal detachment). – Amblyopia reported earlier in life on eye to be implanted – Systemic diseases that might imply considerable risks with regard to the surgical interventions and anaesthesia (e.g. cardiovascular/ pulmonary diseases, severe metabolic diseases). – Neurological and/or psychiatric diseases (e.g. M. Parkinson, epilepsy, depression). – Hyperthyroidism or hypersensitivity to iodine – Women who are pregnant or nursing, or women of childbearing potential who are not willing to use a medically acceptable means of birth control for the duration of the study, or women unwilling to perform a pregnancy test before entering the study. – Participation in another interventional clinical trial within the past 30 days.

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 78 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Retina Implant AG
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Eberhart Zrenner, Prof. MD, Study Chair, Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tuebingen, Germany
    • Karl-Ulrich Bartz-Schmidt, Prof. MD, Principal Investigator, University Eye Hospital Tuebingen, Germany
    • Timothy L Jackson, PhD FRCOphth, Principal Investigator, King’s College Hospital NHS Trust
    • János Németh, Prof. MD PhD, Principal Investigator, Department of Ophthalmology Semmelweis University Budapest
    • Robert E MacLaren, Prof. DPhil, Principal Investigator, Department of Ophthalmology, John Radcliffe Hospital, Oxford, UK
    • Johann Roider, Prof. MD, Principal Investigator, University Eye Hospital, Kiel, Germany
    • Helmut Sachs, PD, MD, Principal Investigator, Eye Hospital Dresden-Friedrichstadt, Germany


Koitschev A, Stingl K, Bartz-Schmidt KU, Braun A, Gekeler F, Greppmaier U, Sachs H, Peters T, Wilhelm B, Zrenner E, Besch D. Extraocular Surgical Approach for Placement of Subretinal Implants in Blind Patients: Lessons from Cochlear-Implants. J Ophthalmol. 2015;2015:842518. doi: 10.1155/2015/842518. Epub 2015 Dec 10.

Hafed ZM, Stingl K, Bartz-Schmidt KU, Gekeler F, Zrenner E. Oculomotor behavior of blind patients seeing with a subretinal visual implant. Vision Res. 2016 Jan;118:119-31. doi: 10.1016/j.visres.2015.04.006. Epub 2015 Apr 20.

Stingl K, Gekeler F, Bartz-Schmidt KU, Kögel A, Zrenner E, Gelisken F. Fluorescein angiographic findings in eyes of patients with a subretinal electronic implant. Curr Eye Res. 2013 May;38(5):588-96. doi: 10.3109/02713683.2013.767349. Epub 2013 Feb 14.

Stingl K, Bartz-Schmidt KU, Besch D, Braun A, Bruckmann A, Gekeler F, Greppmaier U, Hipp S, Hörtdörfer G, Kernstock C, Koitschev A, Kusnyerik A, Sachs H, Schatz A, Stingl KT, Peters T, Wilhelm B, Zrenner E. Artificial vision with wirelessly powered subretinal electronic implant alpha-IMS. Proc Biol Sci. 2013 Feb 20;280(1757):20130077. doi: 10.1098/rspb.2013.0077. Print 2013 Apr 22.

Citations Reporting on Results

Stingl K, Bartz-Schmidt KU, Besch D, Chee CK, Cottriall CL, Gekeler F, Groppe M, Jackson TL, MacLaren RE, Koitschev A, Kusnyerik A, Neffendorf J, Nemeth J, Naeem MA, Peters T, Ramsden JD, Sachs H, Simpson A, Singh MS, Wilhelm B, Wong D, Zrenner E. Subretinal Visual Implant Alpha IMS–Clinical trial interim report. Vision Res. 2015 Jun;111(Pt B):149-60. doi: 10.1016/j.visres.2015.03.001. Epub 2015 Mar 23.

Kitiratschky VB, Stingl K, Wilhelm B, Peters T, Besch D, Sachs H, Gekeler F, Bartz-Schmidt KU, Zrenner E. Safety evaluation of "retina implant alpha IMS"–a prospective clinical trial. Graefes Arch Clin Exp Ophthalmol. 2015 Mar;253(3):381-7. doi: 10.1007/s00417-014-2797-x. Epub 2014 Sep 16.

Stingl K, Bartz-Schmidt KU, Gekeler F, Kusnyerik A, Sachs H, Zrenner E. Functional outcome in subretinal electronic implants depends on foveal eccentricity. Invest Ophthalmol Vis Sci. 2013 Nov 19;54(12):7658-65. doi: 10.1167/iovs.13-12835.

Stingl K, Schippert R, Bartz-Schmidt KU, Besch D, Cottriall CL, Edwards TL, Gekeler F, Greppmaier U, Kiel K, Koitschev A, Kühlewein L, MacLaren RE, Ramsden JD, Roider J, Rothermel A, Sachs H, Schröder GS, Tode J, Troelenberg N, Zrenner E. Interim Results of a Multicenter Trial with the New Electronic Subretinal Implant Alpha AMS in 15 Patients Blind from Inherited Retinal Degenerations. Front Neurosci. 2017 Aug 23;11:445. doi: 10.3389/fnins.2017.00445. eCollection 2017.

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