End To Blindness?

Kevin writes "For the first time ever, researchers from a company called Optobionics surgically implanted an artificial retina into three patients who are blind from retinitis pigmentosa. These highly-experimental prosthetic devices, made of silicone computer chips, are intended to restore ambulatory vision, thereby giving people the freedom to walk without the assistance of a cane or guide dog. Researchers are begining to develop computer chips that might function in place of damaged photoreceptor cells."

Comments

Ummm...

[Soko]

..isn't silicone used in other, more uh, cosmetic prosthesies? You mean silicon, I hope...

How weel will this work?

[tie_guy_matt]

I heard that when they restore people's vision after they were blind their entire life, formerly blind people still can't "see" very well. The signals might be going to your brain again but it will take a while for your brain to figure out how to make sense of it all. This is better than nothing but if you really want to cure blindness you have to do it to very young people so they can learn how to use their eyes like everyone else.

Re:How weel will this work?

[Bozinbali]

I've been legally blind since birth, and just had corrective surgery to "fix" my vision. IMO, the problems one will encounter doing this kind of procedure are not medical in nature, they're psychological. Before my surgery, my uncorrected vision was 20/200 in my right eye, and 20/1000 in my left. With correction, I could get down to 20/80 in my right eye and 20/200 in my left; a marked improvement. With special adaptation, I was even able to get my right eye to 20/30 at distance so that I could get and maintain an unrestricted driver's license. I still walked with the aid of a white cane due to my lack of depth perception (since the vision in my eyes was so unbalanced) and peripheral vision. All in all, I was a pretty well adapted, employed, and productive person. The problems I encountered were primarily social. I found that the sighted public in general wants very little to do with anyone who is obviously disabled. Even if someone would initiate a conversation in a social setting, the only thing they'd want to discuss is my vision. Now, maybe I'm at fault here, but after 25 years of talking about my vision with every Tom, Dick, and Harry; I just didn't want to do it any more. So I talked to an opthomologist and scheduled lens implant surgery to try and correct my vision. Although the surgery was deemed a success in medical terms, my useful vision is substantially less than before. The difficulty that I encountered wasn't medical. The medical procedure was perfect. The problem I'm encountering has to do with my perception of the images I see. Having worn thick glasses my entire life, my brain was used to a greatly magnified image of the world. After surgery, that image was no longer magnified at all, and everything seems small and distant. As a result, I'm not able to pick out much detail in the images that I see, which effects my useful vision. Some of the side effects are quite disturbing. For instance, I can no longer read a magazine, or street signs. This has severely impeded my independence as I have a great deal of difficulty even driving myself to work. These types of problems appear to be common in people who had significant vision impairments for most of their lives. The exact same surgery I had has been performed on countless people who had normal vision for most of their lives, but who developed cataracts later in life with no ill effects whatsoever. In fact, most people return to 20/20 vision or better within days. I had the surgery nearly a month ago, and even with glasses I can not see as well as I did before. This type of medical advance is great, and medically it's a quantum leap in the field. The problem is that there is no rehabilitation available to people in situations similar to mine. There must be a way to teach the brain how to deal with "normal" vision when it isn't used to coping with it. This same phenonenon is what causes the "confusion" in people who have been given sight after being blind for most of their lives. A great physical improvement does not always result in a higher quality of life. It certainly hasn't in my case, and I don't believe it will in others who weren't sighted before the procedure.

Wearable computing?

[MustardMan]

And here all this time i've been drooling over the microoptical glasses mount display, Why bother when I can have a chip implanted into my eyeball and just use the hardware to directly superimpose an image on my field of vision.

And the Bad News is...

[empesey]

Now they'll have to be more selective about who they date.

The device

[blakestah]

The device is kinda neat. It is 40 microns thick and consists of solar cells (miniature) connected to stimulating electrodes.

Perhaps it is cooler that someone is simply attempting to cure blindness in such a way. The sensory periphery for audition and vision is amenable to implants - in vision, for example, the retina holds about a million nerve cells arranged in a nice topographic array. In the cochlea there are a few tens of thousands of hair cells in a nice spiral array. A company spawned from the Otolaryngology labs at UCSF makes the only US designed cochlear implants (Advanced Bionics).

Of course, the optobionics device will be out of focus since the eye focusses light on the retina and not on the silicon chip. But hey - it'd be amazing if they could simply get enough current out of their device to stimulate a neuron. You'd need at least 10 microamps. The upside is that you do not need a power supply or wire lead into the retina - a tricky engineering feat for other retinal implant designs.

They didn't report if any of their patients implanted in late June had any vision yet. Guess what - they would be seeing by now if the implant worked. So my guess is that the device is a bust. And unfortunately, you don't really get that many clinical trials to fail in your device, no matter how well capitalized you are.

The other difficult thing about retinal implants is the number of stimulating sites required. You can hear speech with 8 stimulating electrodes and very good temporal fidelity. For vision - temporal fidelity is not so stringent, but you need at least 100 stimulating electrodes, each capable of pushing 10 microamps (AC, for a brief brief period). The problem is that you need to power the chip, and to do that you need a cable running into the eye. That probably necessitates the cutting or at least paralysis of the eye muscles, and a very tricky connection through the cornea. So you can see the allure of the optobionics device.

These guys are, however, great at marketing and fundraising. There will be a flurry of such press releases and fund raising bouts, for optobionics and other retinal stimulation companies. The presidents of the companies will get rich. I just hope one of them recruits a decent engineer so that someone gets to see again too. It doesn't seem like their approach is hopeless - but it certainly needs modification.

Macular Degeneration

[the eric conspiracy]

Unfortunately this posting describes retenitis pigmentosa, a relatively rare from of blindness. By far the most common is macular degeneration which occurs mostly in those 55 and older. The numbers of people affected by this disease are staggering; one in six in this age range experience the affects. The fact that this technology may be useful in cases of AMD is exciting news indeed - it has been estimated that as many as 10 million 'boomers' may go blind due to AMD.

How do blind people visualize?

[Plasmic]

I'm curious about something and I think the follow-up discussion will be interesting:

How do people that have been blind their entire life visualize things?

I don't mean to imply that they can't visualize, only that I'm wondering about the extent of their ability to create mental images and how they differ from my own (FYI, I am not blind). That is, it seems as thought they could feel an object and create some sort of wireframe-like thing in their head. Maybe a more appropriate question would have been directed at what they visualize. Most my visualization consist of a combination of things I've perceived with my eyes, not to mention issues associated with color.

Well, there's my potentially ignorant question that's probably only answerable by either blind people or someone who has close contact with them.

Educate us.

Re:How do blind people visualize?

[hawkfish]

Good question. One of Oliver Sacks' books has an essay on this. _An Anthropologist on Mars_ maybe?

The simple answer is that they can't. The first experiments to restore sight in the late 1700s with cataract replacement surgery were a failure because there is a small window of opportunity in the development of the visual cortex. Even people who are not born blind but have been blind a long time have a lot of trouble becoming visual again and many don't succeed. Blind people seem to have significantly different models of the world (e.g. they generally conceptualize distance in terms of time, not spacial referents) and changing back is often more than most can manage.

By the same token, people who are sighted often have a lot of trouble adapting to being blind because they are not wired correctly either.

Re:Viewing resolution

[JabberWokky]

I can see at 1600x1200 what about you?

Actaully, you can only see at something less than 200x200, with horribly lossy images. Your brain interpolates everything you see. Interesting factoid: your optic nerve carries more information to the retina than it carries to the brain.

When you get into real neurology 101, things get really interesting (even if you're auditing for amusement as an armchair scientist).

Has anybody else noticed morie effects in real life? There is a stretch of I-95 in Palm Beach Country, as you pass over Lake Worth Road... heading north, you can see the side of the water treatment plant. The side has close horizontal slats, all painted an off-white color. As you drive towards it on a bright day, it comes alive with "dancing bugs", similar to two morie patterns overlaid and rotating. The distance at which this occurs is different for different individuals. Some people can't see it, but that may be because they didn't know what to look for.

--
Evan

What I'd like to know..

[haaz]

Could this help people with detached retinas?

Back in March, April, and May, I had sugery to reattach my retina after I got hit by that drunk driver. (I had surgery two or three times to do that!) What I'm wondering is, if it gets really bad, and they can't do anything for the retina, will one of these help? And would it help me ride a motorcylce again? ;-)

-- jason, who's so looking forward to riding again.

Haaz: Co-founder, LinuxPPC Inc., making Linux for PowerPC since 1996.