Seeing is believing: how some scientists – including two funded by CIRM – are working to help the blind see

retinitis pigmentosas_1

How retinitis pigmentosa destroys vision – new stem cell research may help reverse that

“A pale hue”. For most of us that is a simple description, an observation about color. For Kristin Macdonald it’s a glimpse of the future. In some ways it’s a miracle. Kristin lost her sight to retinitis pigmentosa (RP). For many years she was virtually blind. But now, thanks to a clinical trial funded by CIRM she is starting to see again.

Kristin’s story is one of several examples of restoring sight in an article entitled “Why There’s New Hope About Ending Blindness” in the latest issue of National Geographic.  The article explores different approaches to treating people who were either born without vision or lost their vision due to disease or injury.

Two of those stories feature research that CIRM has funded. One is the work that is helping Kristin. Retinitis pigmentosa is a relatively rare condition that destroys the photoreceptors at the back of the eye, the cells that actually allow us to sense light. The National Geographic piece highlights how a research team at the University of California, Irvine, led by Dr. Henry Klassen, has been working on a way to use stem cells to replace and repair the cells damaged by RP.

“Klassen has spent 30 years studying how to coax progenitor cells—former stem cells that have begun to move toward being specific cell types—into replacing or rehabilitating failed retinal cells. Having successfully used retinal progenitor cells to improve vision in mice, rats, cats, dogs, and pigs, he’s testing a similar treatment in people with advanced retinitis pigmentosa.”

We recently blogged about this work and the fact that this team just passed it’s first major milestone – – showing that in the first nine patients treated none experienced any serious side effects. A Phase 1 clinical trial like this is designed to test for safety, so it usually involves the use of relatively small numbers of cells. The fact that some of those treated, like Kristin, are showing signs of improvement in their vision is quite encouraging. We will be following this work very closely and reporting new results as soon as they are available.

The other CIRM-supported research featured in the article is led by what the writer calls “an eyeball dream team” featuring University of Southern California’s Dr. Mark Humayun, described as “a courteous, efficient, impeccably besuited man.” And it’s true, he is.

The team is developing a stem cell device to help treat age-related macular degeneration, the leading cause of vision loss in the US.

“He and his fellow principal investigator, University of California, Santa Barbara stem cell biologist Dennis Clegg, call it simply a patch. That patch’s chassis, made of the same stuff used to coat wiring for pacemakers and neural implants, is wafer thin, bottle shaped, and the size of a fat grain of rice. Onto this speck Clegg distributes 120,000 cells derived from embryonic stem cells.”

Humayun and Clegg have just started their clinical trial with this work so it is likely going to be some time before we have any results.

These are just two of the many different approaches, using several different methods, to address vision loss. The article is a fascinating read, giving you a sense of how science is transforming people’s lives. It’s also wonderfully written by David Dobbs, including observations like this:

“Neuroscientists love the eye because “it’s the only place you see the brain without drilling a hole,” as one put it to me.”

For a vision of the future, a future that could mean restoring vision to those who have lost it, it’s a terrific read.

 

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