Could Expand Donor Pool Significantly

In what could be a landmark, federally funded study, a team of scientists and a national team of  researchers have shown that transplantation of corneas from older donors have rates of success similar to those from younger donors.

A report on the study, published in the April issue of Ophthalmology, shows that the five-year transplant success rate for recipients was 86 percent with corneas from donors ages 12 to 65 years and from donors ages 66 to 75.

“These results are likely to expand the donor cornea pool and make scheduling of transplant procedures easier for the patients and the surgeons,” says Walter Stark, M.D., Boone Pickens Professor of Ophthalmology and director of the Stark-Mosher Center for Cataract and Corneal Diseases at the Johns Hopkins University’s Wilmer Eye Institute.  “It’s clear that corneas from older individuals are just as successful when used for transplants as those from young donors.”

For the study, more than 1100 donor corneas were provided by 43 participating eye banks; all of the corneas met the standards and tissue ratings of good to excellent quality for human corneal transplantation outlined by the Eye Bank Association of America (EBAA). The cornea, a clear tissue located in the front of the eye and the eye’s main focusing element, is the most frequently transplanted body part. Surgeons generally use a disc-shaped segment of new tissue to replace diseased or injured corneal tissue.

The Cornea Donor Study (CDS), coordinated by the Jaeb Center for Health Research in Tampa, Florida, included information collected from 1,101 transplant patients from 80 sites, including the Johns Hopkins University School of Medicine’s Wilmer Eye Institute. The Wilmer patients, who ranged between 40 and 80 years of age, received corneas from donors ages 12 to 75 and were followed for five years after their transplants. Success of the surgery was based on whether the patient required a repeat corneal transplant or if the cornea became persistently cloudy.

Donor corneas are refrigerated in a protective fluid with added antibiotics and are usually transplanted within three to seven days of donation, but, can be stored for up to two weeks before transplantation. According to the EBAA, more than 90 percent of all corneal transplants are successful in restoring useful vision.

Investigators for the CDS study say that although the U.S. availability of donor corneas has been adequate for the past decade, with more than 33,000 corneal transplants performed annually, there are shortages and waiting lists. Many eye banks have set the age limit for donors at 65 years or younger because some surgeons have been reluctant to use older corneas.

Stark says recent tightening of the Food and Drug Administration’s (FDA) regulations regarding testing and safety of donor corneas also could lead to decreases in the pool of eligible donors. “It’s possible that by expanding the age requirement, the donor pool could be expanded by as much as 20 to 35 percent and lessen the impact of the new regulations,” Stark added.

Stark says that patients who agree will be followed for at least five more years to gauge long-term effects of donor age and other aspects of corneal transplantation.

Additional support for CDS was provided by: Eye Bank Association of America, Bausch & Lomb Inc., Tissue Banks International, Vision Share Inc., San Diego Eye Bank, The Cornea Society, Katena Products Inc., ViroMed Laboratories Inc., Midwest Eye-Banks (Michigan Eye-Bank, Illinois Eye-Bank), Konan Medical Corporation, Eye Bank for Sight Restoration, SightLife, Sight Society of Northeastern New York (Lions Eye Bank of Albany), and Lions Eye Bank of Oregon.

On the Web:

The Johns Hopkins University School of Medicine’s Wilmer Eye Institute
http://www.hopkinsmedicine.org/wilmer/about/index.html

National Eye Institute
http://www.nei.nih.gov/

National Institutes of Health
http://www.nih.gov/

Eye Bank Association of America

http://www.restoresight.org/