March 11, 2009
Images: The choroid is a network of blood vessels (pictured, top) that nourishes the cells of the retina. Photoreceptor cells in the retina convert light into electrical signals that travel to the brain. Rob Mullins, Ph.D., (bottom)researches how damage to the choroid may have a role in development of age-related macular degeneration, which stems from breakdown of retinal cells and may lead to blindness.
Eye donation: a gift that gives twice
On average, two out of three Iowans mark "yes" to organ donation on their driver's license. The state boasts the highest donor designation rate in the country.
This is good news for patients with eye disorders, and University of Iowa physicians and scientists also laud Iowans' generosity. March is National Eye Donation Awareness Month and highlights the year-round efforts of UI experts and the Iowa Lions Eye Bank who work together to utilize the donated tissue.
"Iowa Lions Eye Bank facilitates the gift of sight through transplant and the gift of answers through research," said Katie Charter, director of donor development at the eye bank. "They are both equally important in sight restoration and preservation."
Only the cornea and sclera can be transplanted; the cornea is the clear dome, which covers the front of the eye, that helps focus light, and the sclera is the white fibrous tissue that protects the eye.
Surgeons perform about 40,000 cornea transplants each year in the United States. In 95 percent of cases, the procedure successfully restores a recipient's vision. The Iowa Lions Eye Bank, founded in 1955, has provided more than 15,000 corneas for transplantation, and helped the UI obtain the latest devices for these procedures.
Eye donations lead to additional opportunities for helping patients; scientists can use donated ocular tissue for research and teaching.
Other than a call from the eye bank to retrieve a sample, few other circumstances could rouse researchers in the UI Department of Ophthalmology and Visual Sciences from their beds at 4 a.m. One such scientist is Robert Mullins, Ph.D., a UI associate professor. His team uses the donated tissue to study a potential cause of macular degeneration, a common eye disorder.
Seeking ways to diagnose and treat macular degeneration in its early stages, UI scientists have been awarded millions of dollars in NIH funding to study multiple facets of the disorder. Macular degeneration is largely responsible for blindness in the elderly population in industrialized countries. It affects one in seven adults older than age 75, and is often known as age-related macular degeneration. The macula is part of the retina, the layer of the eye that contains photoreceptor cells. When cells in the macula get damaged, vision loss -- sometimes severe -- can result.
At his lab in the UI Carver Family Center for Macular Degeneration, Mullins and his team explore how the blanket of blood vessels nourishing the retina has a role in disease development.
However, Mullins said researchers face one major hurdle. With the exception of primates, the animal models available do not have maculas. For his research findings to eventually reach clinical practice, Mullins relies on donated human eye tissue. His colleagues and team members are on call at all times, ready to whisk a sample to the lab to make sure the cells do not start to break down.
"The field suffered a lot from the lack of appropriate models," Mullins said. "That's why eye donations are a precious resource -- we have to treat them in a responsible way and learn as much as we can from the samples. Our scientists share these valuable specimens to try to understand the biological causes of diseases like macular degeneration and glaucoma."
Nearby on the health campus, Rachel Asbury, a social worker with the Family Support Program at UI Hospitals and Clinics, may also receive a call at odd hours regarding organ and tissue donation. Asbury knows too well that the kindness of strangers is often rooted in tragedy, for example a fatal car accident. She is specially trained to help families through the difficult time and works with the Iowa Donor Network to offer the opportunity of donation. Her job meshes crisis intervention and advocacy for the grieving families.
Should a family choose to make a donation, Asbury works with the physicians and nurses to evaluate medical suitability and coordinates activities with the Iowa Lions Eye Bank. She also answers questions that donor families may have about how the tissue will be used. She said that "research" initially seems like an abstract term, but learning about UI scientists' work can be reassuring to a potential donor's relatives.
"We don't leave it at 'donate to research' and make that the end of the sentence," she said. "When I tell them it's for macular degeneration, families say, 'Oh, I think Aunt Beth had that.' Then it hits home."
With both research and transplant as options, essentially anyone can donate eye tissue. Even those with poor eyesight, cataracts or cancer can give. Individuals who mark "yes" to donation on their driver's license give consent for tissue to be used for transplants only. People who wish to donate to research can register with the Iowa Donor Registry at http://www.iowadonorregistry.org.
For details about Mullins' research visit: http://www.choroidlab.org.
Additional information is available at the following Web sites:
University of Iowa Carver Family Center for Macular Degeneration: http://www.c4md.org.
University of Iowa Department of Ophthalmology and Visual Sciences: http://www.uihealthcare.com/eyecare.
STORY SOURCE: University of Iowa Health Care Media Relations, 5137 Westlawn, Iowa City, Iowa 52242-1178
MEDIA CONTACT: Becky Soglin, 319-335-6660, email@example.com;