- When did you start the study?
- The first patients were operated on in autumn 2005.
- How many patients have you operated on within the study?
- 20 patients have been operated on so far.
- I am blind. Can I receive a retinal implant?
- In principle, if you suffer from retinitis pigmentosa (RP), then yes you can. However, additional prerequisites must also be fulfilled:
Regularly queried illnesses, which CANNOT be helped by a retinal implant:
- Retinitis pigmentosa, choroideremia or extensive cone-rod dystrophy
- Between 18 and 78 years of age
- Completely blind for less than 20 years, dependent on retina condition, which can be different from patient to patient.
- At least 12 years of visual experience
- Willingness to be examined repeatedly within the study period of about 12 months by the eye surgeon who will perform the implantation
- Willingness to travel to the eye hospital repeatedly for functional examinations
- glaucoma / high eye pressure
- Blindness from birth
- Blood circulation disorders in the retina
- Blindness caused by a stroke
- Blindness caused by diabetes
- Optic atrophy / damage to the optic nerve
- Age-related macular degeneration (“AMD”); not at present, as a very long-term objective at the best
- What happens to the eye – can it be damaged during the operation? How is the eye damaged?
- The insertion or removal of the implant does not cause damage. Surgery has so far been performed successfully.
- Is a second implant possible?
- It is possible, and conceivable, for the same eye to receive another implant.
- How much can one see with the implant – what have patients been able to see?
- Theoretically, 6 % acuteness of vision (sufficient to recognise faces) and a field of vision of 12 degrees are possible due to the technical properties of the chip. Previous patients have been able to locate sources of light such as windows and lamps, as well as light objects (such as crockery) against dark backgrounds. Recently, patients have been using the implant at home and at work successfully.
- Is it necessary to stay in hospital throughout the entire duration of the study?
- No. Only for one week after the operation. You are then able to stay in a holiday home or hotel room. Travel and accommodation expenses are borne by the sponsor of the study, Retina Implant AG.
- Will the health insurance companies bear the costs?
- Not to begin with. In the future, we anticipate that it will function in a similar fashion to cochlear implants.
- Can foreign patients take part in a study in Germany?
- Yes, as long as we can communicate in a language such as German, English, and French. Clinical test conditions require a good understanding of the patient's verbalized visual experiences.
- Is the implantation only performed in Tübingen?
- At the moment, yes. Soon, the implantation will be performed in several eye clinics. Contact information will be shown in due time.
- How long does the operation last?
- The implantation currently lasts about 7 hours. If required, the explantation lasts about 2 hours. As experience is gained, implantation time will be reduced substantially.
- Where is the chip implanted?
- Dependant on the patient's retina condition, the implant will be placed at the centre of the point where vision is sharpest (macula).
- Is a general anaesthetic necessary?
- Is it possible to be examined in Tübingen?
- Yes. Patients with retinitis pigmentosa (RP) should please contact Dr. Barbara Wilhelm.
- Is it possible to register in Tübingen as a potential patient?
- Yes. Patients with retinitis pigmentosa (RP) should please contact Dr. Barbara Wilhelm directly for a questionnaire. You can complete the questionnaire by yourself, or together with your eye specialist.
- What age, and in what physical condition, should patients participating in the study be?
- Between 18 and 78 years of age, and in a good general physical condition (no high blood pressure, no diabetes, suitable for anaesthetic).
- Are there any physical limitations during the test?
- Not in principle, but extreme sports should be avoided.
- Has the implantation caused inflammation or immune responses?
- The materials are very compatible with the body. This means that there are no rejections or infections. The chip is located in an area of the retina that has a very low disposition to rejections.
- Questions regarding risks?
- Questions regarding risks are answered individually by doctors.
- What is the selection procedure?
- Please contact Dr. Barbara Wilhelm directly for a questionnaire. You can complete this by yourself, or together with your eye specialist.
- Have patients had problems with the implant?
- In the initial days following the implantation, the eye was swollen and reddened, and slight pain occurred on the first day, as can be the case following operations on the retina. After this, the patients did not have any problems with the implant, and did not suffer any foreign body sensation.
- From what point is the use of an implant ethically justifiable?
- If a patient is suffering from one of the objective illnesses, is no longer independently mobile, and an implant can improve their standard of life. Another prerequisite is that the benefits prevail in a risk-benefit analysis for the patient.
- Must the “vision” be trained?
- Yes. We have determined, and also expected, that learning processes are required in order to process and use the impressions gained from “artificial” vision. It must also be taken into consideration that the patient operated on has previously had no utilisable, structured visual perceptions for several years.
- Can eyesight deteriorate again with the implant?
- We will only be able to make statements on this subject when studies have been performed with longer retention periods.
- How well can a patient with a retinal implant orientate himself/herself?
- The patients from the first studies were able to recognise and locate sources of light, such as windows or lamps. They viewed this as an important prerequisite for orientation.
- Can the retinal implant only replace the centre of the retina, and not the periphery? Is there an illustration of the maximum field of vision that a patient treated in this way can use?
- Due to the size of the chip, a 12-degree field of vision is possible. This is an enormous gain for patients with retinitis pigmentosa and similar illnesses, as they have been coping for many years with 5 degrees or less, but were still mobile and were able to read with long-distance readers, etc. To clarify: One degree of the field of vision roughly corresponds to the width of a thumb at arm’s length. Therefore, 12 degrees would be the width of 12 thumbs or the size of a CD case.
Questions on the Chip and Marketing
- How much does the implant cost?
- The retinal implant will be free for participants in clinical trial. The final price for the implant has not been determined yet.
- Expected lifetime of retinal implant
- The approved medical device will have a life expectancy of several years. This needs to be confirmed by means of comprehensive clinical tests.
- Is the chip visible from outside the eye?
- It is not visible from outside. Only the external energy patch can be visible behind the ear.
- Chip specifications
- 1500 Pixel, 3 mm x 3.5 mm size, 12° field of vision
- Does the chip require a power supply?
- Yes, the external energy pack is required for effective retinal implant function. This external energy pack is a bit larger than a cigarette box.
- Are glasses with a camera necessary for this implant?
- No, the sub-retinal implant works effectively without glasses. However, standard correction glasses might be needed to get a sharp image on the implant.
- How does the implant differ from the competition?
- For RI: The chip moves with the eye (it is not necessary to move the entire head). It has considerably more pixels (1500 instead of only 64). No spectacles are necessary.
- Who developed the chip? Did Retina Implant AG work alone?
- The chip was developed in cooperation with the "subret consortium" namely Naturwissenschaftliches und Medizinisches Institut Reutlingen (NMI), IMS Stuttgart, AMS Austria, University of Regensburg, University of Tübingen, University of Ulm.