Engineering Bio-Medical Marvels : Dr. Rajat Aggarwal, Implants, University of Southern California

Dr. Rajat Aggarwal
MD, Assistant professor of ophthalmology and co-director of Intraocular Implants, University of Southern California

In addition to the routine clinical work, Dr. Agarwal is involved in the Artificial Retinal Implant project, being carried out in collaboration with Texas Instruments, which aims at developing a complex artificial epiretinal device in patients with advanced retinitis pigmentosa and age-related macular degeneration, which will help these patients see again. He is also involved in developing techniques for using stem cells in retinal degenerative disorders and development of nano-drug delivery devices.

Q. Would you kindly elaborate on the research areas that you are working on in the biomedical area, most specifically the work on ‘Bionic Eye’?

Dr. Agarwal: The work with artificial or bionic eye has been going on for almost 20 years now and TI has been partnering with us on it. This work is finally maturing so we hope that in the next few years we can come out with a commercial product that the physician might be able to suggest to patients to buy. Besides that, we are developing a lot of innovative implants.

Many patients with ailments like diabetic retinopathy or glaucoma require medication over a long period of time. Currently there are these injections we give directly into the patients’ eye every 6 weeks to treat such people; to have a needle poked into your eye is not a very pleasant experience for anybody, not even doctors who inject. So we are developing a drug delivery implant device that will sit on the eye. It’s a minor procedure that we do to fix the device on the eye. There will be certain parameters that control it and it will inject a controlled amount of the drug into the eye, at regular intervals. So through this device we can both monitor the disease and take necessary action as well.

Q. How exactly does the implanted device work? Does it have to be activated or does it work independently?

Dr. Agarwal: One way is to have a constant infusion at a regular interval, let’s say once a day. But we have to look at it from various angles. When the pressure of the eye increases it causes damage to the optic nerves at the back and that causes damage to the neuron, which leads to a visual deficit. The intra-ocular pressure in such patients keeps fluctuating. We are therefore developing intra-ocular pressure sensors, which allow us to monitor the pressure in their eyes. If we can bring down the rising pressure we can keep the nerves from getting damaged. Matt was talking about wireless technology-in this context we’ve developed this little device that goes into the eye and monitors intra-ocular pressure and can then relay information through an optical reader to the physician’s office via the Internet. A message can in turn be sent to the device that tells it to inject a certain amount of the drug to control the pressure. All this can be done without the patient knowing anything about it.

At the University of Southern California, where I work, we have an Engineering Research Centre funded by the National Science Foundation. It’s the only engineering research centre in the US focused completely on biomedical devices.

There are two other very interesting projects we are working on. One of them is trying to use glucose in the blood for power generation – the excess glucose in a person’s body can power biomedical devices. Another notes that for the blood to flow through the body the heart has to pump very hard and there is a huge pressure with which this blood flows, so we are trying to develop a hydro-turbine kind of device that can harness this hydro energy.

Q. How long would it take to have something like this available in the market?

Dr. Agarwal: Its going to take some time, since the FDA requirements are really stringent. First of all we need to prove the safety, then show the efficacy part, which involves animal trials, then try to get the approvals for clinical trials – this itself is a long procedure. So it really depends on the complexity of the technology or device involved. The Bionic Eye project was conceived in 1988 or so, the first implant was done in 2001. And even now, after so much work and data we’ve made available, we’ve still not finished. But of course, the FDA is right in being so cautious.

Q. You are trying to bring the clinical trials of the bionic eye to India; will you elaborate on the current status of this news?

Dr. Agarwal: A key problem is that the device is hand-made and it takes as long as about 6 months to make one. It’s also quite expensive, currently costing about USD 50,000, since it’s made of gold and platinum. So it is difficult for any company to produce that many devices. At this point of course we don’t charge the patients anything since we’re doing the clinical trials. But the reasoning is that over time we will be having more patients getting this implant and we’re hoping that the cost is going to come down to about 10% of its cost now.

Another reason is lack of data. This is one of the biggest challenges in India – even for common diseases, let alone specific diseases like this. So we’re compiling the database right now, for which Dr. Rajini Battoo from Narayana Nethralaya is helping us. Also the FDA will have to clear the export of the device. Next is logistics, the company needs to bring their people over to conduct the clinical trials. We have to be very thorough with the paperwork; we have to document every tiny detail. So we need to get everything right and in place before we can actually start with the clinical trials. But we are still hoping to bring in the clinical trials to India by the end of next year.

Q. Final messages for our readers?

Dr. Agarwal: We don’t want to raise false hopes, because it’s but natural that the message that people take home is that it’s magic, which it is not! It involves a lot of hard work on both sides. A patient has to train for long periods with the clinical trials team to start figuring out things through the minimal sight she/he gets. Also different patients will respond differently to the same treatment. We even conduct a psychological uation of patients before we put them on the trial.


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