Behind the eye of the beholder

In April, the Australian medical device company Bionic Vision Technologies (BVT) announced an important milestone: it had raised $18 million to develop and commercialise its bionic eye. This device holds potential for the thousands of people worldwide with retinitis pigmentosa; in short, restoring sight to the blind.

The device was conceived in 2010, when Bionic Vision Australia (BVA), a consortium of five leading universities and research institutes, received a A$50 ($35.7) million grant from the Australian Research Council. The hope was that BVA might be able to do for retinal implants what Cochlear Limited had done for hearing aids.

Over the next six years, BVA designed an early prototype and tested the device in its Melbourne laboratory. Although the implant was not yet commercial, the consortium was careful to capture the intellectual property that resulted. BVT was duly established in order to hold the rights to the technology. “Throughout the course of our research programme, we had a successful clinical trial of our first prototype device,” says Julie Anne Quinn, the CEO of BVT. “We were able to successfully prove that the approach we took could elicit a sense of vision in three patients who had blindness due to retinitis pigmentosa. So, armed with that data, we developed our next device. But commercial funding was necessary in order to take this device to a clinical trial.”

After pursuing a number of investors, BVT eventually struck gold in the form of Hong Kong-based companies China Huarong International Holdings and State Path Capital. Alastair Lam, the chairman of State Path Capital, has said that the technology has the potential to transform the lives of millions of people addressing a large unmet need.

A universal problem

At present, patients with retinitis pigmentosa have no treatment options. The condition, one of the leading causes of inherited blindness, is characterised by the progressive loss of photoreceptor cells and peripheral vision, and affects around 1.5 million people worldwide.

“The incidences of this condition vary depending on where you live in the world, with the highest rates in India and China,” says Quinn. “Generally, people with this condition start having poor eyesight in their teens and into early adulthood, and progressively their vision deteriorates. Usually by their 30s, or even earlier in some cases, they may not be able to see anything at all.”

BVT hopes its bionic eye will be able to reverse this trajectory, allowing sufferers to navigate their environments without relying on a guide dog or cane.

“We believe our device will help people become more independent, and certainly that’s what our prototype studies showed,” says Quinn. “They won’t see vision perfectly, but there will be shapes and outlines, and contrasts, and dark and light – and, ultimately, we hope they can read large print. Hopefully, technology will one day give them the ability to see faces, but that’s a way off yet.”

Visionary procedures

BVT’s devices work via a complex technology, with several steps involved. “The patient wears a pair of glasses with a camera attached, and that camera then signals through to a processing unit about the size of a cellphone, which the patient wears externally,” says Quinn. “The message is then transmitted through a wire up to a stimulator that is implanted just above the ear, which in turn gives a message through to an implant that is planted just behind the eye.”

The implant in question contains electrodes, which pulse once the message arrives. This stimulates the remaining retinal nerve cells to communicate with the visual cortex. Over time, the patient learns to interpret the corresponding visual patterns, enabling them to ‘see’ what’s in front of them. This outcome is only possibly thanks to the immense plasticity of the brain.

Although this is not, in itself, a novel technique – all bionic eyes function in a similar way – BVT believes its technology is safer and more effective than what has come before. According to Quinn, the product has two clear advantages over its competitors.

“One is that we use a much safer and more straightforward surgical procedure,” she says. “Other companies tack their device on top of the retina, meaning there’s the potential for air interference, and it’s hard to remove the device without causing damage to the eye. But because ours is placed behind the eye in the suprachoroidal space, we believe surgeons will like the procedure a lot more.”

When BVT tested its prototype device, there were no reports of serious adverse effects. If this holds true of its current device, it will represent a clear upgrade from other bionic eyes on the market, for which the surgery has caused a risky increases in intraocular pressure and a high rate of infection.

“Another advantage is in our visionprocessing software,” says Quinn. “Having had the benefit of a government research grant, we have put a lot of effort into developing computer vision algorithms, which we believe will be far superior.”

Into the real world

At present, BVT is negotiating with its research partners to commence its next clinical trial. Like the proof of concept study, the trial will recruit a handful of patients and monitor them for up to two years. However, while the proof of concept study only monitored patients in the clinic, this time they will be able to use the device in a real-world setting, with a view to assessing their mobility and independence.

“Over the coming months, the patients will be implanted with their device here in Melbourne, and then once they’ve recovered from the surgery, they’ll come back into the laboratory,” says Quinn. “At this stage, we have to tailor the signals for every patient and train them in how to use the system, and then they’ll be able to use the device at home. They will continue to come into the laboratory periodically so we can check their eye health and make any tweaks that are needed.”

BVT will also continue to work on its broader technology pipeline, which revolves around novel approaches to electrode arrangement and stimulation. The data that comes out of the clinical trial will help inform the product development.

The next step will be to set up largerscale manufacturing, as well as seeking a bigger cohort of patients for the next round of testing. This will most likely be conducted outside Australia. Should everything go according to plan, BVT will then seek regulatory approval across key markets, paving the way for a commercial launch.

“Obviously, we’ll start in Australia, but we really need to get international regulatory approval,” says Quinn. “Initially, we would like to get the CE-mark approval, which would mean we could sell into Europe and would enable us to move pretty swiftly through the regulatory bodies in Asian countries.”

She adds that, because the investment has come from Hong Kong, the investors are particularly interested in the health of the Chinese population, making China an obvious market to head into. Broadly, though, the company is hoping to bring the device to the communities that need it most.

“The device could hit these markets within the next three years,” says Quinn. “But let’s see how it goes.”

3D printing of bionic eye in sight

A team of researchers at the University of Minnesota have, for the first time, fully 3D printed an array of light receptors on a hemispherical surface.

Researchers started with a hemispherical glass dome to show how they could overcome the challenge of printing electronics on a curved surface. Using their custom-built 3D printer, they started with a base ink of silver particles. The dispensed ink stayed in place and dried uniformly instead of running down the curved surface. The researchers then used semiconducting polymer materials to print photodiodes, which convert light into electricity. The entire process took about an hour.

“Bionic eyes are usually thought of as science fiction, but using a multimaterial 3D printer, we are closer than ever,” says Michael McAlpine, a co-author of the study, which was published in August’s Advanced Materials.

McAlpine says the most surprising part of the process was the 25% efficiency they achieved in converting the light into electricity with the fully 3D-printed semiconductors.

“We have a long way to go to routinely and reliably print active electronics, but our 3D-printed semiconductors are now starting to show that they could potentially rival the efficiency of semiconducting devices fabricated in microfabrication facilities,” McAlpine said. “Plus, we can easily print a semiconducting device on a curved surface.”

McAlpine and his team are known for integrating 3D printing, electronics and biology on a single platform. They received international attention a few years ago for printing a bionic ear. Since then, they have 3D printed life-like artificial organs for surgical practice, electronic fabric that could serve as bionic skin, electronics directly on to a moving hand, and cells and scaffolds that could help people living with spinal cord injuries regain some function.

He says the next steps are to create a prototype with more light receptors that provide greater efficiency. They’d also like to find a way to print on a soft hemispherical material that can be implanted into a real eye.