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


Patients who are legally blind, caused by retinal degeneration of photoreceptor rods & cones (e.g. Retinitis pigmentosa), receive a subretinal implant to restore vision partially.

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

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: Single (Participant)
  • Study Primary Completion Date: January 2014


  • Procedure: surgical implantation of subretinal device
    • surgical implantation of subretinal device
  • Procedure: surgical implantation of subretinal device
    • intra-individual implant OFF

Arms, Groups and Cohorts

  • Experimental: intra-individual implant ON
    • intra-individual implant activation
  • Placebo Comparator: intra-individual implant OFF
    • intra-individual implant deactivation

Clinical Trial Outcome Measures

Primary Measures

  • Safety
    • Time Frame: 1 year
    • treatment shows no permanent damage of function and structures that have been functional before surgery and no permanent damage to health and/or well being of patients
  • Efficacy
    • Time Frame: 1 year
    • Activities of Daily Living & Mobility are significantly improved with implant-ON versus OFF, as shown via tests: Activities of Daily Living tasks or Recognition tasks or Mobility or a combination of the above

Secondary Measures

  • Safety
    • Time Frame: 1 year
    • Patient long term safety: stability of implant function stability of body structure & function related to implant system
  • Efficacy
    • Time Frame: 1 year
    • Visual Acuity / Light-perception and/or Object-recognition are significantly improved with implant-ON versus OFF as shown via: FrACT or BaLM or Grating test (e.g. BaGA) and/or Quality of life Quality of life (questionnaire) or a combination of the above

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 (impaired light localization or worse). – 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 Exclusion Criteria:

  • Period of appropriate visual functions < 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)
    • David Wong, Prof., MD, Principal Investigator, Chair Professor in Ophthalmology Eye Institute

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.

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