The Bionic Eye prototype: Professor Rob Shepherd at TEDxUWollongong

Summary

This video explores the development of a bionic eye aimed at treating retinitis pigmentosa, an inherited form of blindness. The technology involves implanting electrodes near surviving retinal ganglion cells to stimulate them, similar to cochlear implants for hearing. The project focuses on creating a prosthetic device with up to 100 electrodes, potentially advancing to 1,000 electrodes for improved visual function. The work includes collaborations with retinal surgeons and the development of biocompatible, stable materials. While there's still significant work ahead, the team is optimistic about small clinical trials within the year, offering hope for those affected by blindness.

Takeaways

• 😀 Retinitis pigmentosa is an inherited blindness affecting 1.5 million people worldwide, leading to complete vision loss over time.
• 😀 The goal of Bionic Vision Australia is to develop a bionic eye to help treat patients with retinal diseases by stimulating surviving retinal ganglion cells.
• 😀 The bionic eye works similarly to a cochlear implant, using a camera, a visual processor, and a wireless stimulator to deliver electrical signals to the retina.
• 😀 The first phase of development involves creating an electrode array with 100 electrodes, five times more complex than the 22 electrodes used in cochlear implants.
• 😀 Platinum electrodes and medical-grade silicon are used to ensure long-term safety, biocompatibility, and durability of the device.
• 😀 The electrode array is implanted via a small incision in the sclera, and the device needs to remain stable to avoid misdirecting neural signals.
• 😀 Mechanical stability is key to success, as eye movements must not shift the electrodes, which could lead to incorrect stimulation of retinal nerves.
• 😀 The second phase of development aims to increase the electrode density to 1,000 electrodes, providing more detailed vision for patients.
• 😀 Conductive diamond electrodes are being developed for higher electrode density, and the implants will be placed on the retina using retinal tack surgery.
• 😀 The bionic eye device is being rigorously tested for durability, with cables undergoing millions of simulated eye movements to ensure long-term reliability.
• 😀 While the technology is still in development, a small clinical trial is expected within a year, with the goal of allowing patients to read large print.

Q & A

What condition does the bionic eye aim to treat?

The bionic eye aims to treat retinitis pigmentosa, an inherited form of blindness that affects the retina, leading to progressive vision loss. It can result in legal blindness and eventual loss of useful vision.

What is the role of the retina in vision?

The retina contains photoreceptor cells that convert light into nerve impulses. These impulses are transmitted via the retinal ganglion cells through the optic nerve to the brain, where they are interpreted as visual information.

Why are the retinal ganglion cells important for the bionic eye?

Retinal ganglion cells are important because, while the photoreceptors in the retina are damaged in conditions like retinitis pigmentosa, these ganglion cells often remain intact. The bionic eye aims to stimulate these surviving retinal ganglion cells to restore vision.

How does the bionic eye work to provide visual information?

The bionic eye works by using glasses with a video camera that captures the visual scene. A visual processor then analyzes the scene and maps it to a series of electrodes implanted in the retina. These electrodes use electrical stimulation to activate the retinal ganglion cells, sending visual signals to the brain.

What technological challenges are involved in developing the bionic eye?

Key challenges include developing an electrode array with many electrodes, ensuring the safe implantation of these devices, making sure the electrodes stay stable in the eye despite constant eye movements, and ensuring the materials used are biocompatible for long-term use.

How many electrodes does the current bionic eye prototype use?

The current prototype of the bionic eye uses an electrode array with 100 electrodes, which is a significant increase compared to the 22 electrodes used in cochlear implants.

What materials are being used for the bionic eye's electrodes?

The electrodes are made from platinum and medical-grade silicon, materials that have a proven track record for safety and long-term implantation in the human body, similar to those used in cochlear implants.

What role does surgery play in the implantation of the bionic eye?

Surgery involves creating a small incision in the sclera (the white part of the eye), where a tissue pocket is formed to insert the electrode array. A lead wire then exits the eye to connect to an implantable stimulator placed outside the eye. The surgery is performed with the help of retinal surgeons to ensure safe electrode placement.

What are the future plans for increasing the electrode count in the bionic eye?

In future work, the team plans to develop a higher-density electrode array with up to 1,000 electrodes, using conductive diamond materials. These electrodes would be placed on the front surface of the retina to improve visual resolution and allow patients to perform tasks like reading large font print.

What challenges does the team face in ensuring the durability of the bionic eye?

The team must ensure that the electrode wires and system can withstand the movement of the eye—up to 150,000 micro and macro saccades per day—without breaking. To test this, they have performed experiments simulating these eye movements, ensuring the system's durability over long-term use.