Banking Eyes to Study Blindness

17 December 2012
Published in Health
Written by  Kim Schuske
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Banking Eyes to Study Blindness National Eye Institute, Wikimedia Commons

Bill Hubbard points to a picture of a patient's left eye. In the back of the eye are yellowish spots and blobs.

"Here we have a patient that has macular degeneration, but not in this eye. What they have in this eye is what we call pseudo-drusen and that's usually a precursor for some bad things to come down the road," says Hubbard.

Hubbard is clinical researcher and part of a group at the Moran Eye Center in Salt Lake City that studies age related macular degeneration. It's clear he's concerned the patient may lose vision in their left eye, just like their right.

"This eye looked quite similar to the other one I want to say a year or less. So all this dark, dark black, there's no retina here," says Hubbard while looking at an autoflourescence image.

Macular degeneration is the leading cause of vision loss in people over 60 years old. The disease destroys the center part of the retina, or macula, so they lose their central vision. That makes it difficult to read or recognize people and to drive. Greg Hageman, Director of the Center for Translational Medicine at the Moran Center and head of the research group, says some people lose their eyesight fast.

"We've seen it happen within days. Once the severe form of the disease forms, its very devastating and can occur very quickly," says Hageman.

The wet form is the worst. It happens when vessels overgrow the retina and leak blood and fluid. Hageman says this form only occurs in about 10-percent of people with the disease, but causes about 90-percent of the blindness.

Most people get the dry form, which can lead to loss of light sensing proteins, or photoreceptors, in the middle of the eye. It usually takes longer for central blindness to occur in these patients.

There's no cure for macular degeneration, and only one invasive treatment that helps some people with the wet form see better for longer. For Hageman, the disease is personal.

"My grandmother had macular degeneration 25-years ago and I learned very quickly we didn't know anything about the disease and that triggered my interest in pursuing the field," says Hageman.

A Search for the Cause of Macular Degeneration

That led Hageman to switch from doing research in marine biology to studying macular degeneration.

"Ok, you're going to work on macular degeneration, what are you going to do?" asks Hageman. "Well we did what every scientist does. We went out and looked for a mouse or some animal that has macular degeneration and very quickly learned that there was not an animal model of the disease, and I would argue to this day there is still not a great animal model for this disease."

Hageman says instead they decided to take a big chance and use human eyes that were donated at the time of death. They wanted to figure out what was different between the eyes of people with the disease compared to people without the disease.

This idea led him and his group to find the first gene associated with macular degeneration called, Complement Factor H. It regulates inflammation.

"What we learned over the period of the next fifteen years was that the inflammatory system, a very important part of inflammation was active in eyes from patients with macular degeneration compared to patients without," says Hageman

They later found a second genetic region also associated with the disease.

"The great thing about that for the patient's side is that we're not dealing with a disease that's caused by a hundred different genes, we're dealing with a disease that has two major genetic associations," Hageman adds.

Utah's Eye Bank Plays A Role in Research

Hageman moved his lab from Iowa to Utah in 2009 with the goal of finding treatments for macular degeneration. Critical to this effort is the bank of eyes he has acquired, his is the largest eye bank in the world with around 6,000 pairs. When fresh eyes come in, Marc Toso processes them.

"After we get the eyes we cut them open and flower them like this," describes Toso as he shows an eye that has been cut into quadrants and pinned down. "And then the other ones we take punches out of them, little round punches. And so we have all of these punches, which are then processed for other techniques down the road. Like they'll use to extract proteins from it, DNA, RNA, whatever they need to do."

Hageman's group is also looking at DNA and proteins from the blood of patients with and without macular degeneration. By using genetic information obtained from the eye bank, patient volunteers, and an enormous amount of medical records and family histories he hopes they can find drugs or other treatments to help manage the disease.

He thinks one of their best chances is to figure out if there are other diseases that co-segregate with macular degeneration. Maybe people with the eye disease also frequently have, for example, kidney disease. This would suggest the two diseases might have the same cause in this group of patients and treatments might already exist.

"So, once we identify those associations the hope is there could be drugs available that we can now come back and look at their potential efficacy in macular degeneration," says Hageman.

Surprisingly, Hageman says they believe they've found such co-segregating diseases, but are waiting for additional tests before talking about their findings.

He adds that the Moran eye bank is more than just a resource for his lab. It turns out Utahns are helping researchers throughout the world make new discoveries on eye disease and blindness.

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