Bionic Eye Lets Blind Woman Experience Vision

An anonymous reader writes "Australian researchers implanted a bionic eye with 24 electrodes in Ms Dianne Ashworth, a 54-year-old who had limited vision due to a inherited condition called retinitis pigmentosa. The implant has allowed her to see flashes of light and shapes when researchers deliver electrical pulses to the device. From the article: 'This early prototype consists of a retinal implant with 24 electrodes. A small lead wire extends from the back of the eye to a connector behind the ear. An external system is connected to this unit in the laboratory, allowing researchers to stimulate the implant in a controlled manner in order to study the flashes of light. Feedback from Ms Ashworth will allow researchers to develop a vision processor so that images can be built using flashes of light. This early prototype does not incorporate an external camera – yet. This is planned for the next stage of development and testing.'"

Comments

Not vision

[BWJones]

Note: This is *NOT* vision. This is an uncoordinated stimulation of neurons that is no more vision than poking your eye and seeing flashes of light or knocking yourself on the back of the head and seeing stars. Vision is a far more complicated matter and these investigators that are promoting this bionic chip have ignored or are ignorant of over a decade of research that shows the neurons in the eye change their wiring in response to retinal degenerative disease. When the wiring in the retina changes, it is no longer able to mediate normal retinal signaling...

Yes, I am a vision scientist.

Re:Not vision

[Samantha Wright]

I don't think they're making any claims about her nerves system being the same as anyone else's; all of the talk in the press release is specifically about dealing with her case. Think about it for a moment—this technology's going to be used for dealing with damaged eyes for a long time much like those of Ms. Ashworth, not healthy optic systems. Perhaps they're taking on a non-minimal test case, but it's really an extremely topical one.

Re:Not vision

[BWJones]

What they are claiming is that the bionic implant will work in a degenerate retina. The substrate circuitry has changed. No chance of it transducing vision... They are either going to have to intervene at an earlier time point (much earlier than most folks realize) or bypass the retina or reconstruct the retina. There is more biology at play here than a simple engineering project.

Re:Not vision

[niftydude]

When the wiring in the retina changes, it is no longer able to mediate normal retinal signaling...

My understanding is that this device bypasses the retina completely, and stimulates the optic nerve directly - it is essentially an array of diamond spikes shooting electricity into the optic nerve. They are hoping that they can then retrain someone's brain to "see" images based on the electric signal they supply

Are you saying that the neurons in the brain completely change their behaviour as a retina degrades, making this technique useless? If so, is this true for all forms of retina failure?

Note that tfa refers to a woman who is experiencing what she calls "flashes of light" from the device. Do you think it will be impossible to arrange those flashes into images?

Re:Not vision

[romanval]

they're working on optic nerve transmissions for people that lost total vision due to macular degeneration or other diseases. See this Ted Talk presentation

Biological eyes encode vision data as electrical impulses sent to our brain; they're trying to reverse engineer the encoded data at the optic nerve level, which will help make prosthetic eyes a reality.

Re:Not vision

[BWJones]

So, which ganglion cell populations are they going to stimulate? The optic nerve contains from 14-16 classes of ganglion cells that project to different areas of brain. Its a tough tough problem because those ganglion cells and the axons in the nerves project not only to LGN, but also to a large number of subcortical areas like the SCN and tectum. Then what about the remnant signals that may be coming from peripheral regions of the retina (in cases of AMD) and central retina (in cases of RP)?

Again, they are moving forward with engineering without necessarily understanding the biology.

Re:Not vision

[BWJones]

For the first part, see my comment to femto above.

As for the neurons changing their behavior, yes... that is exactly what I am saying. It definitely happens in the retina as the retina is reprogrammed and there is some evidence that it happens higher up as well. Though those precise studies have yet to be performed.

So, flashes of light are simply uncoordinated signaling by neurons. Turns out vision is far more complicated than the cochlear system that allows us to engineer bionic solutions for hearing. Provided the cochlea is intact, it is easy to stimulate those neurons in an appropriate manner that people can learn to interpret. Vision is another story entirely and unless you stimulate the *right* neurons with the *right* type of stimulation, its not gonna work.

Re:Not vision

[femto]

The background to this project is that a newly elected government held a big "vox poluli" talk fest called 2020, which was to lay out a "big vision" for Australia. A result was the announcement of $50 million funding for a bionic eye project. It's entirely possible that there is an element of "gung ho" about it in that a large chunk of money was laid down for a project that made politicians look good and was easy for the public to understand.

Having said that, there are some pretty smart people involved. As an Australian taxpayer, I'd hope that they are aware for the problems you raise and, given the grandness of the project, would plan on addressing such tough, tough problems. Given your area of expertise, maybe you should contact them? There might be some pretty exciting work to be done in collaboration?

Re:Not vision

[BWJones]

Yeah, its easy for people to get enthused about rescuing vision loss. Its an important thing and keeps us working at all hours of the day as hard as we can to understand how the visual system works and how to fix it when it goes wrong. We've published before on this issue and I am sure they are aware of the work. My only concern is when promises are made to patients and expectations are built up that these devices will cure blindness when the biology has not been worked out and the engineering is predicated upon that imprecise understanding of the biology.

Re:Not vision

[sjames]

From work already done, we know that even very minimal vision is a vast improvement in quality of life over no vision. Yes, probing blindly (no pun intended) is quite hackish, but if a person gets something vision like that is useful, that's a fine result.

I would argue that 100% of medical treatments we have today from first aid up are all based on moving ahead without necessarily understanding the biology. For example, we have used aspirin for over a century but only recently gained some idea of how it works. Clearly though, that understanding was flawed since the first attempt to produce a better treatment based on the new understanding gave us vioxx, which didn't work out so well. It was quite a long time from when we figured out setting bones and casting to the time we had any idea how the bone then heals. All we know is that if you put the ends more or less back together and support it for a while, it would heal.

I have no doubt that better understanding of the biology will result in better engineering and ultimately better vision, but meanwhile, there are people who are blind right now. It is important not to let perfect be the enemy of functional.

Meanwhile, the entire point of the work in TFA is to learn more about what is actually required to get functional vision this way. It's certainly a lot less risky than implants directly into the visual cortex (which have been tried with some success).

Previous work?

[p0p0]

What's happened to previous work in this field? I remember years ago an implant that let a blind man (how blind he was, I do not know) see the equivalent of a monochrome 16x16 image. It allowed for basic shapes and object recognition. This one seems to be a step back. What gives?

WWW: Wake

[Leinad177]

Now we just have to plug it into a computer and voila, they'll be able to see just as much as most of us.

Correction

[wonkey_monkey]

Bionic Eye Lets Almost-Blind Woman Experience Random Flashes of Light