NASA Technology Could Lead To Artificial Retinas

NewtonsLaw writes "In this story it is reported that NASA has been working on technologies that could be used to restore the site of people with damaged retinas. It seems that they've developed some highly light-sensitive oxides that could be used in conjunction with "space-aged ceramics" to create an overlay that would be placed in the back of the eye and wired to the optic nerve. Science fiction becoming science-fact?"

ObWilliamGibson

[scjody]

Cool! But be sure to stay away from Sendai eyes; everyone knows they cause permanent nerve damage.

Re:Not So Fast

[Unknown Poltroon]

I.A.A.N.S. (I aint a neurosurgeon) but im pretty sure the brain is able to adapt to weird visual changes. I've see examples of people who wear glasses that invert their vision, and after a couple of days, its back to normal for them(Untill they take them off, then tye need to relearn again). ALso, look at the people who wear multicolored lenses in their glasses. And there is also the facotr of ANY improvement over being blind is probably good. Hell, if im totally blind, id be happy with 16 shades of green.

Re:"No wires" is just plain inaccurate.

[MOBE2001]

Someone above mentioned retinotopic mapping, which is of course a big ol' issue. However, if all they do is detect the light and trigger a stimulus at a corresponding point on the retina (and if there are still ganglion cells left to pick up the current), they should be able to get the mapping "for free".

True. But that would be a hell of a registration job. The stimulus input lines would have to be at the precise positions over center ganglion cells and their surround cells. We're talking about microns. I would be mightily impressed by such a feat.

I think a more promising route to a cure for blindness is to use our knowledge of genes and our in-vitro tissue generation technologies to grow an entire eye ball and optic nerve using the patient's own DNA. Of course, that is probably decades in the future.

Well Done

[kanada]

Once again, I must say Well done NASA
Those space dudes rock.

Re:Not So Fast

[kanada]

No kidding. Well also techniqually see everything upside down, but our brain reformates the image to right side up. I would think if the brain is capable of anything, it's figuring stuff out using guess and check. Mmm brain... yummy...

Incredible things that they are doing these days..

[House of Usher]

I guess what bugs me is the fact that this story will probably not get much press in the general media, even though by doing such things, NASA is going to revolutionize what optometry is all about.

"Gee, it seems that your retina was burnt out when you were in the lab somehow. Not a problem, five minutes and we'll have a new one for your."

Of course this will be big news when Tiger Woods receives such care, however until then, it will be something that only us Nerds know about.

Great!

[tzanger]

Now I can keep doing it even if I'll go blind! Mom can't stop me now!

And not a moment too soon...

[unitron]

Perhaps I should be a candidate for this. When I saw it in the slashbox I could have sworn that it said "NASA Technology Could Lead To Artificial Russians".

Re:"No wires" is just plain inaccurate.

[Alik]

True. But that would be a hell of a registration job. The stimulus input lines would have to be at the precise positions over center ganglion cells and their surround cells. We're talking about microns. I would be mightily impressed by such a feat.

I disagree somewhat with your statement. Chances are, if you just plunk a, say, 100x100 array of dumb light->stimulus transducers into the back of the retina, most of those stimulating electrodes are going to be capable of stimulating at least one cell.

I think I understand what you're saying: they'll miss the lateral inhibition components that come in earlier in the retinal pathway. However, there are already some papers that show that you can probably fix that by implementing the local inhibition in the transduction circuitry. Now, how much that adds to the power consumption, I'm not sure offhand; I don't recall the necessary circuits. I wouldn't call it a limiting factor, though.

Re:Not So Fast

[MOBE2001]

but im pretty sure the brain is able to adapt to weird visual changes

Good post. It's true that the brain is adaptable. The experiment you mentioned (speical glasses that turn everything in the field of vision upside down) is an excellent example of adaptation within the cortex. However glasses do not alter retinotopic mapping. Our sensation of color does not come from the retina but from the visual cortex and this is intact with glasses. Same with the detection of motion, edges, etc... This part of the brain is not as adatable as you think. It is for the most part pre-wired. If you suddenly send motion signals to color layers and vice versa, IMO, it will be extremely hard for these layers to process this information.

Even the center-surround arrangement of retinal cells is preserved in the target layers (area 17) of the primary visual cortex. These are prewired for the perception of edges, fine lines, etc... It is a good bet that color information coming into this area will be filtered out completely.
Another thing that is important for vision is eye saccades. Our eyes are continually making minute movements called saccades, even when we are focusing on a dot. The brain uses saccades to scan fine lines and points. This is basically how we detect edges. Saccades are generated by an automatic feedback circuit that involves retinal cells. If this circuit is missing or damaged by the retinal implant, it will result in impaired vision, probably forcing the subject to consciously and constantly scan the visual field.

And there is also the facotr of ANY improvement over being blind is probably good. Hell, if im totally blind, id be happy with 16 shades of green.

Agreed.

"No wires" is just plain inaccurate.

[Alik]

True, it won't be like the Dobelle prosthesis, where there are wires running into the skull. However, the fact remains that the eye is not set up to use ceramic films as its detector. You'll need *something* to transduce the signal into a stimulus for the optic nerve, and that means you're going to need power. Power isn't easy, especially for something like this which has to be very low-heat (boiled eyeball, anyone?). That can probably be handled with something like the4 inductive transfer setups they use for heart pumps, but it's not just "stick it in your eye and forget about it".

Someone above mentioned retinotopic mapping, which is of course a big ol' issue. However, if all they do is detect the light and trigger a stimulus at a corresponding point on the retina (and if there are still ganglion cells left to pick up the current), they should be able to get the mapping "for free".

I actually saw a grant come out of a lab I worked in at CMU that wanted to do something very similar, except that instead of using ceramic films they wanted to use bacterial protein as the light detector. Pretty cool stuff. Didn't get funded, but I'm rewriting the parts I liked and trying to turn it into a thesis.

not quite a "cure", a first step

[caite]

The first people to receive the benefits of new technology would probably begin by being able to see only light, the team's research shows.

They expect it to get better, of course, but human trials aren't expected to start for at least a year. It's a small step, and there are a lot of people who'd like a way to see again. Especially the people who were blinded after a lifetime of seeing, and that's one of the kinds of blindness "cured" by this procedure.

Like the curing dog blindness discussion [slashdot.org], I'm not sure that everyone will be happy. There are a lot of blind people who think that being blind is what makes them special. It would be great if blindness really could be cured even if some people opted against it.

As for it being science fiction leading the science, it will be a long time until we get the built-in cameras and zoom features. Too bad!

Not So Fast

[MOBE2001]

There are approximately one million fibers from the retina that make their way to the visual cortex via the thalamus. There is a one to one retinotopic mapping between the output of the retinal ganglion cells and cells in various layers of the visual cortex. Fibers that represent colors, for example, are processed in separate areas from fibers that are associated with motion. The latter are extremely sensitive to the direction of motion and must be arranged in a center-surround formation. Unless the NASA scientists at the University of Houston can maintain the proper retinotopic mapping and the center surround formations, the brain won't know what to make of those signals. The poor patient might just go insane.