Patients » Frequently Asked Questions

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?
7 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:
  • Retinitis pigmentosa, choroideremia or extensive cone-rod dystrophy
  • Between 25 and 75 years of age
  • Completely blind for less than 5 years
  • At least 12 years of visual experience
  • Willingness to be examined twice within a period of about 3 months by the eye surgeon who will perform the implantation and explantation in Regensburg
  • Willingness to travel to Tübingen about six times for functional examinations
Regularly queried illnesses, which CANNOT be helped by a retinal implant:
  • Cataract / glaucoma / high eye pressure
  • Blindness from birth
  • Blood circulation disorders in the retina
  • Blindness caused by a stroke
  • Changes to the retina 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
Why is the implant removed after 4 months?
Clinical routine replacements are not yet authorised. Removing the implant and performing detailed examinations can enable us to discover important information for further improvements.
Is it really impossible to keep the implant if it enables you to see something?
Each patient has the right to decline the removal (explantation). However, the patient then bears the risks. For this reason, we strongly advise against declining the explantation.
What happens to the eye – can it be damaged during the operation or explantation? How is the eye damaged?
The removal of the implant does not cause damage. Removals have so far been performed without problems.
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. However, they have not yet really been able to recognise what the objects are. We are dealing with “artificial vision”.
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?
Not in the first study, unless they have a perfect knowledge of German. This is because oral communication and understanding is essential during a study with blind persons. However, the next study will be performed in several countries (e.g. France and USA).
How many patients are required for 2007?
6-10.
Is the implantation only performed in Tübingen?
At the moment, yes. For the next study, the implantation will be performed in several eye clinics, including abroad.
How long does the operation last?
The implantation currently lasts about 7 hours, the explantation about 1.5 hours. As experience is gained, this time will be reduced.
Where is the chip implanted?
Near the centre of the point where vision is sharpest.
Is a general anaesthetic necessary?
Yes.
Are further studies planned?
Yes.
  1. The pilot study will continue.
  2. Following this, a larger study is planned in several countries, with various ophthalmic clinics. In this study, the patients will retain the implant for at least 1 year.
Is it possible to be examined in Tübingen?
Yes. Patients with retinitis pigmentosa (RP) should please contact Frau Dr. Barbara Wilhelm.
Is it possible to register in Tübingen as a potential patient (e.g. for subsequent studies with longer retention periods)?
Yes. Patients with retinitis pigmentosa (RP) should please contact Frau Dr. Barbara Wilhelm.
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. Only for great physical efforts and extreme sports.
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 Frau Dr. Barbara Wilhlem 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 ethnically 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 are 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.

Questions on the Chip and Marketing

How much does the implant cost?
Nothing during research studies. Subsequently, it will cost ¤ 25,000 plus operation costs. A guide dog also costs approximately ¤ 25,000, and can be prescribed by an eye specialist.
Product life of the end product?
The approved medical product will have a product life of several years. Confirmation by means of comprehensive clinical tests is still to be acquired.
Is the chip visible from outside the eye?
It is not visible from outside. In the pilot study, only a thin wire is visible behind the ear.
Chip specifications
1500 Pixel, 3x3 mm size, 12° field of vision
Does the chip require a power supply?
Yes. The human eye is more sensitive than a semi-conductor chip. Batteries (larger than a cigarette packet) supply energy via inductors to the eye.
Are glasses with a camera necessary for this implant?
No. This is not the case with the sub-retinal implant developed in Tübingen. There is another research project in Germany. Spectacles with a camera are required for this implant (epiret).
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 NMI and the IMS.