Clinical trial NCT00427180: IRIS PILOT - Extended Pilot Study With a Retinal Implant System
Official title: Extended Pilot Study to Evaluate Pattern Recognition With a Chronic Retinal Implant System
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Retinitis Pigmentosa
Cone-Rod Dystrophy
Choroideremia
Keywords: Visual Perception
Retina
Light
Retinitis Pigmentosa
Visual acuity
Retinal Implant
Electrical stimulation
Lead sponsor: Intelligent Medical Implants GmbH
Sponsor class: INDUSTRY
First posted: 2007-01-26
Enrollment: 20
Sex: ALL
Minimum age (years): 30
Maximum age (years): 79
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: Investigate whether blind subjects that fulfil the patient criteria provided with a Retinal Implant are able to differentiate between simple patterns like horizontal bar, vertical bar and cross.

Detailed description: The Retinal Implant System consists of three main components, the Retinal Stimulator, which is the component actually implanted into the eye, the visual interface, and the Pocket Processor The Retinal Stimulator will be implanted into the eye of a blind subject during a surgical operation. However, the external components are activated only during the test sessions under the control of the investigator team. In a first step of the investigation a software controlled system on a PC which is connected to the Pocket Processor via Ethernet interface, will generate the defined stimulation patterns (bars, crosses, cubes). During the test session, the blind subject is exposed to a series of these stimulation patterns and he / she has to describe the visual perceptions. Based on his descriptions and in an interactive way, the stimulation signal is subsequently be modulated by changing parameters like amplitude, duration of impulse, polarity, number of repetitions or pulse frequency on the PC.

In a second step the visual interface is equipped with a camera which presents realtime images to the subject. Data obtained from the investigation with computer generated patterns in the first step are used in the second step to improve the fitting software for the use in the camera supported system.

Finally the system should enable the subject to recognize simple images supported from the camera.

Eligibility criteria: Inclusion Criteria

* Age between 30 and 79 years at the date of enrollment
* Normal hearing and linguistic understanding (with hearing aids if - necessary and in the language of the hospital or in English)
* Ability to understand the study and procedures involved
* Willingness to participate and comply with follow-up procedures
* Good general health based on investigator's opinion
* Ability to undergo surgery using general anaesthesia
* Signed informed consent
* RP, choroideremia, or rod cone dystrophy
* Visual field less than 40 ° (if measurable)
* Visual acuity not better than (1/50), (logMAR≥1.7)
* Visual function stable for a duration of at least one year (according to subject statement)
* Normal eye pressure (9-21 mmHg)
* Bulbus length (AP) between 21 and 25 mm

Exclusion Criteria

* Allergic response to multiple antibiotics
* Known allergies to materials of the implant
* Known carrier of multi-resistant organisms
* Pregnancy or lactating
* History of epileptic seizures
* Having active implantable devices (or need within the next 3 years)
* Patients with cancer or patients received cancer therapy within the last 2 years
* Currently undergoing psychiatric treatment without expert opinion approving participation on the study
* Patients having insufficient mental capacity
* Neurological diseases, in particular those affecting nerve conduction velocities
* Patients currently taking medications affecting brain function
* Immunosuppressive subjects

Primary outcomes:
measure: Investigate whether blind subjects that fulfill the patient criteria provided with a Retinal Implant are able to differentiate between simple patterns like horizontal bar, vertical bar and cross.
timeFrame: 18 months
Secondary outcomes:
measure: Secondary goals of this study phase are: Further evaluation of stimulation parameters, Light localization with use of camera, Safety verification of stimulation parameters
timeFrame: 18 months
Other outcomes:
Locations:
Study officials:
affiliation: Klinik und Poliklinik für Augenheilkunde Hamburg-Eppendorf
name: Gisbert Richard, Prof.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Hornig R, Laube T, Walter P, Velikay-Parel M, Bornfeld N, Feucht M, Akguel H, Rossler G, Alteheld N, Lutke Notarp D, Wyatt J, Richard G. A method and technical equipment for an acute human trial to evaluate retinal implant technology. J Neural Eng. 2005 Mar;2(1):S129-34. doi: 10.1088/1741-2560/2/1/014. Epub 2005 Feb 22.