Category Archives: Eye

Scientists Set Their Sights on First Whole-Eye Transplant

By Alan Mozes

HealthDay Reporter

THURSDAY, Oct. 30, 2014 (HealthDay News) — In the world of 21st-century medicine, organ transplantation is nothing new.

The first kidney transplant took place in 1950, followed by the first liver transplant in 1963 and the first human heart transplant in 1967. By 2010, doctors had even managed the transplantation of a patient’s entire face.

One major organ still eludes the transplant surgeon, however: the entire human eye. But if one team of U.S. scientists has its way, that dream may become reality, too.

“Until recently, eye transplants have been considered science fiction,” said Dr. Vijay Gorantla, an associate professor of surgery in the department of plastic surgery at the University of Pittsburgh. “People said it was crazy, bonkers.”

However, “with what we now know about transplantation and, more importantly, nerve regeneration, we are finally at the point where we can have real confidence that this is something that actually can be pursued and eventually achieved,” he said.

Whole-eye transplants would be of enormous benefit for many of the 180 million blind or severely visually disabled people around the world, including nearly 3.5 million Americans, experts say.

“Macular degeneration and glaucoma are the root cause of much the world’s visual impairment,” explained Dr. Jeffrey Goldberg, director of research at the Shiley Eye Center at University of California, San Diego.

Certainly, there are therapies that often help restore sight in these cases, or in people who’ve lost sight through injury. “But for some people the eye is too damaged or too far gone,” Goldberg said. “For patients with a devastating eye injury where there’s no remaining connective optic nerve — or perhaps not even an eyeball in their eye socket — restorative approaches are simply not enough.”

In these cases, transplantation of a healthy donor eye would be a solution. “It’s a scientific long shot,” Goldberg said. “But it’s a very attractive long shot.”

So, Gorantla and Goldberg — and their two universities — have teamed up to push whole-eye transplantation from theory into practice. The effort is funded by the U.S. Department of Defense.

One of the biggest challenges is how to regenerate and regrow delicate optical nerves.

“The chief problem,” Goldberg explained, “is that when you switch out an eyeball you have to completely cut all connections between the optic nerve and the eye. So then you need to reconnect the donor eye’s nerve fibers back to the recipient’s brain in order to achieve vision restoration. But we know that once you make that cut, the nerve fibers just do not regrow on their own. That doesn’t happen automatically.”

“That’s what distinguishes an eye transplant from most other types of transplants,” Gorantla added. In other organ transplants, the chief hurdle is simply reconnecting a proper blood supply. “For example, if you get the plumbing connected and the blood going, then a transplanted heart will beat in the recipient patient immediately,” Gorantla said.

“But an eye transplant actually has more parallels with a hand or face transplant,” he said. The eye may appear healthy because of a renewed blood supply, but without reconnecting the optic nerve, “there’s no motor activity and no sensation or eyesight,” Gorantla said. “The result is functionless and lifeless.”

Luckily, various laboratories “have made significant progress” in fostering the long distance regrowth of nerve fibers, Goldberg said. “In animals with optic nerve injury or degeneration we’ve even started to see fibers regrow all the way back to the brain,” he noted.

The regeneration of cells called retinal ganglia cells — key to achieving discernible vision — has also met with recent success in a lab setting. “The recent indications that such nerve generation is actually possible raises optimism that eye transplantation can really be viable,” said Gorantla, who is also administrative medical director of the Pittsburgh Reconstructive Transplant Program at the University of Pittsburgh Medical Center.

Still, any first attempt at a whole-eye transplant in humans remains years away, the experts cautioned.

“There’s a significant amount of work to be done before anything like this can be tried on patients,” Goldberg said. “But when you survey people, losing one’s vision comes in just a smidge below death as a thing we fear. There are few things people value more than their vision, so while it may be audacious, it’s worth the effort.”

More information

For more information on eye disease and blindness American Academy of Ophthalmology.

SOURCES: Jeffrey Goldberg, M.D., Ph.D., professor, director of research, Shiley Eye Center, University of California, San Diego; Vijay Gorantla, M.D., Ph.D., associate professor of surgery, department of plastic surgery, University of Pittsburgh, and administrative medical director, Pittsburgh Reconstructive Transplant Program at University of Pittsburgh Medical Center

Last Updated: Oct 30, 2014

via Scientists Set Their Sights on First Whole-Eye Transplant.

What’s it like: To have a corneal transplant

By Jaclyn Cosgrove, The Oklahoman, Oklahoma City
McClatchy-Tribune Information Services
Oct. 12–Why do people need corneal transplants?

The cornea is the clear outer region of the front part of the eye. A corneal transplant, or keratoplasty, is one of the most common types of transplants performed. The transplant can help restore vision, reduce pain and improve the appearance of a damaged or diseased cornea.

A person might need a corneal transplant because he or she suffers from vision problems because of a thinning cornea. Another reason to get a corneal transplant would be because of scarring of the cornea from severe infections or injuries. Also, the only cure for people who suffer from Fuchs’ dystrophy — an eye disease that causes the cells lining the inner surface of the cornea to slowly start to die — is a corneal transplant.

Unlike other transplants, there is generally no wait time for a corneal transplant.

Also, it’s not required to match donors for corneal transplants.

What happens during surgery?

There are two main types of corneal transplant: partial-thickness transplants and full-thickness transplants.

For a full-thickness transplant, you’ll be placed under some version of anesthesia. You might be partially awake, although it will depend on your surgery needs. The surgeon will measure your cornea, mark it and then prepare the donor tissue, which usually comes from a person who has died and donated their tissue. For people with multiple failed transplants, a surgeon might use an artificial cornea.

The surgeon will use a device known as a trephine, similar to a cookie cutter, to remove the central portion of the cornea. The surgical team will cut the piece of the donation that they need, and quickly, place the new cornea on the eye. The donated cornea is stitched in place with usually between 16 and 24 tiny sutures. While stitching, the surgical team will place fluid in the eye to better ensure the eye doesn’t decompress, a major but rare complication of corneal transplants. If the eye decompresses, its contents can come out of the hole made when the cornea is removed.

After surgery, you likely will wake up with a patch and shield over your eye. Unlike cataract surgery, your vision won’t likely be drastically improved promptly after surgery.

What’s the cost?

The tissue itself costs between $1,000 to $2,000. The surgery cost ranges from $16,500 to about $20,000, although this can vary widely, depending on your surgeon and the hospital.

Insurance, including Medicare, frequently covers the surgery. For people who are uninsured, some facilities offer assistance programs that offer the surgery at a low cost or no charge.

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What are the risks of surgery?

Because it’s a transplant, there’s a risk of rejection. Estimates of rejection rates vary among medical research. Some research shows rejection occurs in about one out of three patients in the first five years. Other research suggests rejection occurs in about 20 percent of cornea transplants. And another estimate is that about 10 percent of transplants over 10 years for first time full thickness transplant will end in rejection, while about 5 percent over 10 years will fail.

Other risks include bleeding, infection, glaucoma, cataracts, scarring and swelling of the cornea.

To reduce the risk of rejection, your doctor likely will prescribe steroid eye drops that you will take regularly for at least a year, usually about four times a day to start with. The number of times you have to use the eye drops daily usually reduces over time. However, some patients must take the eye drops for the rest of their lives.

Patients with full-thickness transplants are at risk of dislocating their transplant if they have trauma to their eye, such as being punched in the face. This can cause the transplant to come apart, and the inside of the eye can come out.

What’s the recovery time?

It takes about a year for full-thickness transplant patients to fully recovery and notice an improvement in vision. Unlike your skin, which has a lot of blood vessels, the cornea generally doesn’t have any blood vessels. This means the wound can take a year before its solid enough to take the stitches out.

Also, the body heals irregularly, meaning your eye could heal tighter in one area than in another. This can cause astigmatism, where the cornea is no longer round. When it’s not round, it doesn’t bend light properly, so it can make it difficult for you to see. Your doctor will remove stitches periodically over the year after surgery to try to normalize the surface of the eye so you can see.

Meanwhile, it will take between one month and three months for a partial-thickness transplant to heal. For this procedure, you will have an air bubble in your eye that floats the new tissue up against the old tissue. That tissue and air bubble have to sit side by side for 24 hours to 72 hours for the tissues to stick together. This means a patient will be on his or her back for one to three days.

Full-thickness transplants can last for several years. Because partial-thickness transplants have been performed in the U.S. for only about 10 years, long-range data isn’t available. However, projections show that these transplants should last as long as full-thickness transplants.

Source: Dr. Alex Cohen, an ophthalmologist at Dean McGee Eye Institute; the Mayo Clinic; the National Institutes of Health; National Eye Institute; Cornea Research Foundation of America; and The Eye Bank Association of America.

via What’s it like: To have a corneal transplant.

Military Funds UCSD Study of Eye Transplant Techniques – Times of San Diego

POSTED BY CHRIS JENNEWEIN ON SEPTEMBER 27, 2014 IN TECH

With $1 million in funding from the Defense Department, researchers at the University of California, San Diego School of Medicine are studying techniques for transplanting an entire human eye.

“A whole eye transplant could be a holy grail for vision restoration,” said Jeffrey Goldberg, MD, PhD, professor of ophthalmology and grant co-recipient with colleagues at the University of Pittsburgh Medical Center and Boston Children’s Hospital/Harvard University. “It is in the realm of scientific plausibility.”

An estimated 186,855 eye injuries were incurred by deployed U.S. military personnel from 2000 to 2010, usually related to traumatic brain injury. Some of these cases might be remedied through eye transplants in the future, according to UC San Diego.

Past experiments at University of Pittsburgh Medical Center have demonstrated the ability to perform whole eye transplants in rats. But while retinal tissue in the transplanted eyes appeared healthy, the optic nerves did not recover and regenerate connections, eliminating the possibility of restored sight.

“We know from previous experiments that the biggest scientific hurdle is not hooking up all the eye’s tiny blood vessels or its musculature,” said Goldberg, who is also director of research at UC San Diego Shiley Eye Center. “It’s that when you cut the optic nerve, the nerve cells do not regrow.

“Our goal for this project is to be able to transplant a whole eye in an animal model and successfully demonstrate neuronal regrowth from the donor’s eye to the recipient’s optic nerve,” he said.

via Military Funds UCSD Study of Eye Transplant Techniques – Times of San Diego.