ISU researcher performs first veterinary corneal implant procedure in US

May 12, 2008
ISU researcher performs first veterinary corneal implant procedure in US
Dixie's cloudy cornea is removed by Grozdanic before the new, plastic cornea is implanted.

Sinisa Grozdanic an assistant professor of Veterinary Clinical Sciences performed the surgery that restored sight to 7-year-old Dixie, a Mountain Cur breed owned by Brett Williams of Runnells.

"We are excited for Dixie," said Grozdanic. "She was our patient for such a long time and nothing really worked. She was gradually going down visually and we were finally able to do something to definitely improve her quality of life."

"She is my pet and my friend," said Williams. "She is the best dog I've ever had. Even when she was almost blind, she was still my best dog."

Dixie, who had gained weight due to inactivity from her blindness, has lost seven pounds since the surgery.

"She used to walk right behind me when we'd go for a walk. She couldn't see and was scared," said Williams. "Now she wants to run ahead."

Dixie's sight was restored through a two-step surgical procedure that involves cutting into the eye to take out the cloudy cornea and inserting a permanent, plastic cornea. The new cornea is sutured, or stitched, into place. The entire eye including the new, plastic cornea is then covered with tissue from the dog to help the eye heal from the surgery. Because of the tissue and the bandages, the dog cannot see after this procedure.

After several weeks, the bandages are removed and a hole is cut into the tissue exposing the new, plastic cornea.

In addition to being the first such procedure in North America, it was one of only a few in the world. The technology is still being developed.

A German company called Acrivet is developing the plastic corneas. When Grozdanic met a company representative at a conference a few years ago, he became interested in the possibilities of doing the procedure on canine patients at Iowa State.

"These are special prototypes," said Joyce Wickham from Acrivet's U.S.-based office in Salt Lake City. "They are not made routinely, and are not yet available commercially."

Wickham is eager to get the full report from Grozdanic. Depending on what he tells the company, the corneas may soon be available to more veterinary doctors.

"Anytime you develop something, you want to know how it's going to work," she said. "If it's something that is going to work, we'll move forward with it."

The new cornea is working for Dixie, but she has very little peripheral vision, Grozdanic said.

"She is visual," he said. "For Dixie, it's like looking through a peephole."

One of the tests doctors used to see how Dixie's vision is progressing is done by simply dropping a cotton ball in front of her.

If she follows the ball with her head and eyes, they know she can see it. When they preformed the test in front of her owner and she tracked the ball, Williamson was excited.

"When I came in to watch, and they dropped that cotton ball, I thought 'I got my dog back,'" he said.

Months before the surgery, when Grozdanic described the process to Williams, he didn't hesitate to give his approval, even though the procedure was new.

"It could have failed," Williams said. "But I thought it was worth trying to see what they could do. I hope they continue to research this. It's a great lesson for everybody about taking risks."

While Grozdanic recognizes that the procedure was noteworthy because it was the first, he is most excited about the improvement in Dixie's quality of life.

"It's not a good thing because it's the first one in North America. That's really secondary," he said. "We are excited because of Dixie. She was our patient for such a long time and nothing really worked. It is interesting from the research side of it, but if you can fix something that is thought to be unfixable, it gives you a huge amount of pleasure. I think all of us here feel that way. The biggest reward comes from the patient. It's great to see a completely transformed dog, and an owner who is pleased."

Dixie has been a patient of Grozdanic for four years during which he had worked to restore, or at least retain, Dixie's deteriorating eyesight.

According to Grozdanic, corneal transplants -- using live corneal tissue from other dogs -- have a low success rate because of the high likelihood of rejection.

Canine implant corneas being produced by Acrivet are not made from biomaterial so rejection is unlikely.

Another problem with getting a transplant from a donor dog is that the cornea may turn into scar tissue during the healing process.

"It's just a fact of the species," Grozdanic said.

Artificial corneal implants are somewhat common in humans. They have been performed for several years. It has taken time for the procedure to take place in dogs.

"Humans need to work and drive cars and read, so they are more likely to have the surgery," said Grozdanic. "As long as dogs can see and have a pretty good quality of life, owners are reluctant to put them through this type of procedure. And my advice to them would be 'Don't take the risk.' But when the quality of life is severely affected, those are candidates for this procedure. We're very glad it worked out for Dixie."

Source: Iowa State University

Explore further: Experts call for higher exam pass marks to close performance gap between international and UK medical graduates

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Obese British man in court fight for surgery

Jul 11, 2011

A British man weighing 22 stone (139 kilograms, 306 pounds) launched a court appeal Monday against a decision to refuse him state-funded obesity surgery because he is not fat enough.

2008 crisis spurred rise in suicides in Europe

Jul 08, 2011

The financial crisis that began to hit Europe in mid-2008 reversed a steady, years-long fall in suicides among people of working age, according to a letter published on Friday by The Lancet.

New food labels dished up to keep Europe healthy

Jul 06, 2011

A groundbreaking deal on compulsory new food labels Wednesday is set to give Europeans clear information on the nutritional and energy content of products, as well as country of origin.

Overweight men have poorer sperm count

Jul 04, 2011

Overweight or obese men, like their female counterparts, have a lower chance of becoming a parent, according to a comparison of sperm quality presented at a European fertility meeting Monday.

User comments : 0

More news stories

Low tolerance for pain? The reason may be in your genes

Researchers may have identified key genes linked to why some people have a higher tolerance for pain than others, according to a study released today that will be presented at the American Academy of Neurology's 66th Annual ...

How to keep your fitness goals on track

(HealthDay)—The New Year's resolutions many made to get fit have stalled by now. And one expert thinks that's because many people set their goals too high.

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.

Easter morning delivery for space station

Space station astronauts got a special Easter treat: a cargo ship full of supplies. The shipment arrived Sunday morning via the SpaceX company's Dragon cargo capsule.