With two out of every three people in Iowa checking 'yes' to organ donation on their driver's license, the state boasts the highest donor designation rate in the country.
The University of Iowa Department of Ophthalmology and Visual Sciences and the Iowa Lions Bank work together to utilize donated eye tissue. Robert Mullins, PhD, associate professor and ophthalmology researcher at UI Carver Family Center for Macular Degeneration, talks about the importance of eye donation to research:
Who is eligible to be an eye donor?
Anyone can be an eye donor at the time of their death. The need for donor eyes is extremely high for both cornea transplant and for research.
Does it make a difference in donation if someone wore glasses, had cataracts, or even an eye disease like glaucoma?
None of those conditions would disqualify someone from being an eye donor. When the Iowa Lions Eye Bank obtains consent for eye donation—and this is obtained from the legal next of kin—the Eye Bank staff carefully evaluates the health conditions of the donor, as well as the health of the eye.
At the lab, they have a microscope where they can count the number of cells on the inner layer of the cornea—it's kind of amazing. And by counting the number of cells on that layer, they can determine how suitable the cornea is for transplantation. But the question of whether there are eye diseases that rule out an eye being used for research, the answer is absolutely not. The scientists at the Center for Macular Degeneration study glaucoma, macular degeneration, diabetic retinopathy—and these are diseases that we don't understand how they work—so an eye that's not good for transplantation, could really teach us a lot about disease.
Is there an age limit to be an eye donor?
For research, there certainly is not, and a lot of the diseases that we're studying primarily affect the older population, so we can learn a lot from studying those eyes.
For transplantation, the conventional wisdom used to be that eyes over the age of 65 were less useful for transplantation than corneas from younger donors. But there have been a few recent studies that indicate that the age of the donor eyes for transplantation doesn't affect the five-year rejection rate of the cornea. So it looks like cell density in the cornea is much more important than donor age, and at the Eye Bank they now use eyes for transplant at least up to the age of 75.
Is the cornea what you specifically talk about when you talk about donated eyes and transplantation?
That's right. So the front part of the eye, the cornea, is suitable for transplantation. That's the only part of the eye that can currently be used for transplant.
When a family is told the donation of their loved one's eyes will be used for research, what does that mean?
It turns out that since only the cornea of the eye can be used for transplant, the rest of the eye doesn't really have a medical use but can be used for research to try to understand diseases.
From my end as a scientist, we have folks in the lab who are on call to retrieve these valuable tissues. Because the molecules in the eyes degrade rapidly after death, we have to process these eyes as quickly as possible. We have people coming in to the lab—usually in the middle of the night—to get the donor eyes preserved and stored as quickly as possible.
How important is donated eye tissue to your specific research at the UI Carver Family Center for Macular Degeneration?
It's extremely important. We do a lot of research on animal eyes. Animals have eyes that can be very similar in some ways to human eyes, but most animal eyes lack a specialized region of the retina which is called the macula.
The macula is a region that's about the size of a button on your shirt. It's responsible for visual acuity. This is our ability to focus on an object, to recognize faces, to read, if you play cards—to know what cards you're holding. It's a part of the retina that's really important to our daily lives.
In macular degeneration, the cells in the macula selectively degenerate and deteriorate, but the cells in the rest of the retina tend to do pretty well. So to understand macular degeneration and how the disease works and try to improve outcomes for patients, we need to study eyes that have a macula. And so animal eyes don't really fit the bill, but donor eyes allow us to do that.
If people want their eye tissue to be donated to research when they die, is checking "yes" on their driver's license enough?
The best thing they can do is let their loved ones know their intentions and preferences. I have organ donor checked yes on my driver's license, but really the wishes of the family are what matters. Communicating that to one's loved ones is really important.
Iowans are incredibly generous. We saw that last summer with the flood, and we see it in eye donation, as well. Our scientists are incredibly grateful for the generosity of the donors and their families. We really believe that the progress that we're making in understanding some of these diseases is thanks in large part to the generosity of these donors. |
