Second Sight: Vision Restoration Devices
Companies around the world are working on innovative new devices for people blinded by degenerative conditions. Chris Lo talks to Nano Retina's managing director Ra'anan Gefen about the in-development Bio-Retina implant, which the company believes could take a patient from blindness to watching television after a 30-minute procedure.
The sophistication of modern technology is moving on at such a pace that concepts previously confined to the realms of science fiction are now spilling over into real life. Nowhere is this more evident than in the field of medical science, where robots are being designed to aid surgeons in complex procedures and nanotechnology is beginning to unlock the world of the micro.
One particularly evocative concept is the ability to restore sight to the blind; several innovative biotechnology companies around the world are now hard at work to convert this idea into workable technology within the next few years. The devices being developed are targeting degenerative eye conditions like age-related macular degeneration (AMD), diabetic retinopathy and glaucoma that are gradually robbing millions of people of their sight. According to the National Federation of the Blind, there are around 3.6 million legally blind people over 40 in the US alone.
This technology is generally based on tiny chips that will replace damaged photo-receptors in the eye, translating light into electrical signals to stimulate the neurons and send pictures to the brain. These devices are powered by external wireless batteries placed on special eyeglasses.
In the US, Second Sight is currently trialling the Argus II Retinal Prosthesis System. In Germany, Retina Implant last year reported positive trial results of its subretinal microchip system in 11 patients rendered blind by retinitis pigmentosa, which allowed patients to make out letters and identify foreign objects.
Nano Retina, an Israel-based technology company, is currently developing its own retinal implant device, Bio-Retina, in conjunction with domestic and international partners like Swiss technology developer CSEM. We talked to Nano Retina's managing director Ra'anan Gefen, who believes that Bio-Retina will restore sight to patients with a whole new level of clarity, with plans for 600 pixel, grey-scale vision in the first generation implant, moving up to 5,000 pixels in the second generation. All of this, if the company is successful, will be possible after a 30-minute procedure under local anaesthetic.
Chris Lo: Could you give some background about the design of the Bio-Retina device and how it will be implanted?
Ra'anan Gefen: What we have in mind is for the device to be easy for the doctor to implant. It can be implanted in a minimally invasive surgery under local anaesthesia in about 30 minutes. The implantation includes making a small incision on the eyeball, and gluing the implant to the back of the eye, to the macula. It's a quite short recovery for the patient; they can go home the same day and start seeing. So going from being blind to being able to see with minimally invasive surgery is the concept, and our target is that the level of vision will be high, so that people will be able to read, watch TV and function in daily life.
From the functionality point of view, the device receives the optical image through the eye optic and an internal imager translates it into neuron language. On the back of the implant, there is a connection to the eye neurons on the retina and it will transmit the information received from the imager to the neurons on the back of the implant.
CL: How far along is the device in development?
RG: At the moment, we are in the middle of development. The specifications are done already and we are developing the different elements. We intend to have the main element at hand later this year, and to incorporate them together and tune them and demonstrate that all these concepts can work together. That's the plan.
Next year, we intend go to pre-clinical trials with a functional implant, and we plan to conduct clinical trials in 2013. I believe a couple of years after clinical trials, it can be available in Europe.
We shall see about the US FDA regulations and processes; I hope they can be short enough. I think we have reason to believe that it won't be too long.
CL: Why did you choose CSEM to develop the Bio-Retina chip?
RG: I would like to emphasise that our operation is very international. Our closest ally is Zyvex Labs in Dallas, Texas. They are doing nano-mechanics on the device, and that's a very important part of the design and production. This work is being done at their site and elsewhere in the US and outside the US.
We are collaborating with CSEM as well. We contracted CSEM to design and implement the electrical part of the implant. As with any part of the project, we were looking for skilful people who have experience in this specific field and can be responsive, and that's what we found in CSEM, as well as in Zyvex. In addition, we have other collaborations. We are working with the Paris Vision Institute, Tel Aviv University facilities and CSEM's design will be manufactured at Tower Semiconductor here in Israel. So it's all over, really.
CL: What plans do you have to improve the resolution of vision from the implant?
RG: As you say, I think resolution and field-of-view are the critical elements of vision, and we intend to improve them. We intend to get to a higher count of pixels, and smaller distances so you can get a bigger field-of-view and better resolution. If you can accomplish a very high quality device from the start, then later the sky's the limit.
CL: Patients with the Bio-Retina implant will see in grey-scale. What are the issues with restoring sight in colour?
RG: Colour is challenging. I'm not sure at this stage we understand how we perceive colour. So we have to improve this understanding first, and that's going back to more research and implementation.
CL: What are the advantages of Bio-Retina over other sight-restoring devices being developed around the world?
RG: First of all, it's the ease of surgery. That will open it up to a bigger population; other options need general anaesthesia. Many of the patients are not so young, so there are risks with a full operation. Most importantly, it's the level of vision. We're talking about, as basic for our first generation, about 600 pixels. This level of vision is enough to function normally, to recognise faces and so on. It's an order of magnitude better than the alternatives.
CL: Once the device is available, what will the cost be and will it be too expensive to be affordable for patients in developing countries?
RG: I think in the developing world, the problem of degenerative vision is a little bit different. First of all, the biggest problem is cataracts and the solution is easy and much less expensive, but it's still not available to the population. I think a lot of effort is being made to make treatment more accessible to the population. Even corrective glasses are hard to find in a lot of places. I know the World Health Organisation has put together the Vision 2020 programme to improve vision, and it focuses on the developing world and the cases there.
Our device is more expensive, and much more directed at the developed world. Also, as the population is older in the developed world, a lot of the conditions that Bio-Retina could be used to treat are much more common there.
CL: How do you think retinal implant devices will improve in the next 10-15 years?
RG: I think the demand is obvious. I'm getting daily letters from patients and families who are desperate for a solution. I think we have a really big challenge to overcome in providing retinal implants that can work, that can restore vision. That will be a huge step forward. We are putting in a lot of effort, here and all over the world, to accomplish this. What will be next? It can go to colour, as you said; it can go to improving the interface. It won't stay on the eye only, it can go anywhere. I think once we overcome the problem of interfacing with the neuron, which is just around the corner, you can connect to the brain and after that, the possibilities are endless.