New findings from a groundbreaking clinical study published in Ophthalmology Science indicate that a second-generation bionic eye may provide substantial improvement in vision and overall quality of life (QoL) for retinitis pigmentosa (RP) patients.
Let’s begin with the bionic eye.
The Bionic Eye System was developed by Bionic Vision Technologies (BVT), a privately held Australian company founded in 2010 and based in Carlton South, Victoria, Australia.
- What it is: A wearable device and visual implant (akin to cochlear hearing implants)
- What it does: Translates images via a camera mounted on an eyeglass frame into electrical signals that stimulate the nerves through electrodes positioned behind the retina (aka the suprachoroidal space)
- The result: Delivering visual information to the brain
Note: BVT partnered with U.S.-based Cirtec Medical, a medical technology company, in 2021 to advance the development and manufacturing of this system.
Explain how this works, exactly.
Essentially, it’s a three-step process that involves:
- A camera capturing images in real-time
- Those images are then sent to a processing unit
- From there, encoded stimuli are transferred to the implant via a wireless interface (located under the scalp) to the electrode array within the suprachoroidal space (ie: the retina)
Thus: The electrical stimuli are delivered to the retina.
Who are the target patients for this technology?
With a design fit for comfort and ease-of-use—blind patients.
See here for a glimpse of how the system is worn.
And what are the intended advantages of this for wearers?
The company has noted a few benefits to this implant for blind patients, particularly regarding its ability to:
- Avoid damage to an already compromised retina
- Not block or damage a patient’s remaining vision
- Be surgically implanted by a retinal specialist as an out-patient procedure
- Have advanced software and hardware easily updated
- Not prevent patients from participating in gene therapy studies
Alrighty, now talk about this research.
Investigators from the Center for Eye Research Australia, Bionics Institute, University of Melbourne, and the Royal Victorian Eye and Ear Hospital conducted the prospective, single-arm, unmasked interventional clinical trial on what’s referred to as the “second-generation (44 channel) suprachoroidal retinal prosthesis.”
- Otherwise unknown as: The Bionic Eye System
Note: This was a follow-up study to an initial proof-of-concept trial conducted between 2012 and 2014.
And the participants?
The trial (NCT03406416) enrolled four participants (aged 39-66; mean age of 54; three males) with the following criteria:
- Diagnosis of advanced retinitis pigmentosa (RP)
- Remaining visual acuity (VA) of bare light perception or less in both eyes
- History of 10+ years of useful form vision in the worse-seeing eye
See here for additional criteria, including exclusion details.
How was the study set up?
Participants were tracked starting from their implant surgery of the Bionic Eye System—into their worse-seeing eye (left eye for three patients; right eye for one)—in 2018 through to 2021.
What was measured?
The primary outcome measure was the number and severity of any device-related serious adverse events (SAEs) over a 2-year period, as compared to other retinal prostheses.
Secondary measures—also measured across 2 years—included:
- Efficacy (visual response)
- Visual function and functional vision
- Based on range of acuity, orientation, and daily living task activities
- Quality of life (QoL)
- Based on survey and self-reporting via the Functional Low-Vision Observer Assessment (FLORA) questionnaire
So what were the findings?
Overall, there were no device-related SAEs throughout the study period.
- Meaning: The trial met its primary endpoint.
However, a mild postop subretinal hemorrhage was observed in two patients, which then cleared (spontaneously) within 2 weeks of development.
In terms of device positioning: Optical coherence tomography (OCT) scans confirmed the device was stable and positioned under the macula.
Go on …
The investigators also reported that all four participants had localization ability improvements in screen-based, tabletop, as well as orientation and mobility tasks.
Plus:
- 75% of participants also recorded improvements in motion discrimination
- 50% recorded substantial improvements in spatial discrimination and tabletop object identification
Author input?
Principal investigator Penelope Allen, FRACO, FRACS, of the Centre for Eye Research Australia, noted that the bionic eye enabled blind patients to locate doorways, avoid obstacles, and find items on table-tops.
“They reported greater confidence in navigation, were more likely to explore new environments and had reduced need for assistance when traveling to the local shops,” she stated.
What else did patients report?
As far as unsupervised device use … they reported: “exploring new environments, detecting people, and safely navigating around obstacles.”
- Further: Allen also noted that the participants used the bionic eye as a supplement to cane and guide dog use.
- To note: Patients’ emotional well-being was not impacted by wearing/using the device, the investigators stated.
So what does all this mean?
This data indicates that the device demonstrates both stability and durability over a longer period of time (2.7 years, by the end) behind the retina, with no complications and 97% of electrodes still functioning.
What’s next?
With this promising new data on the generation 2 version of the Bionic Eye System, BVT CEO Ash Attia, PhD, FAICD, stated that the company is finalizing development plans for its next generation (Generation 3) of the device.
The ultimate goal: For the Bionic Eye System to achieve global regulatory approval and become readily accessible for RP patients.