CLEVELAND — Jonathan Lass, MD, professor of ophthalmology at Case Western Reserve University School of Medicine and University Hospitals Case Medical Center, is one of the authors of a new paper describing the 10-year results from a study to determine if corneas from older donors remain as healthy as those from younger donors.
The Cornea Donor Study, funded by the National Eye Institute (NEI), finds 10 years after a transplant, a cornea from a 71-year-old donor is likely to remain as healthy as a cornea from a donor half that age. Corneas from donors over age 71 perform slightly less well, but still remain healthy for the majority of transplant recipients after 10 years, the study finds.
The study also finds the success rates remain steady at 75 percent for corneal transplants from donors 34 to 71 years old. In the United States, three-fourths of cornea donors are within this age range, and one-third of donors are at the upper end of the range, from 61-70 years old. When the study began in 2000, many surgeons would not accept corneas from donors over 65.
Dr. Lass is medical director of cornea image analysis reading center at UH and Case Western Reserve where analysis of the images of the endothelial cells of the corneas from around the nation was done for the study. UH Case Medical Center was also one of the larger clinical sites for the study.
The study was designed to compare graft survival rates for corneas from two donor age groups, aged 12 to 65 and aged 66 to 75. It was coordinated by the Jaeb Center for Health Research in Tampa, Fla., and involved 80 U.S. clinical sites, including UH Case Medical Center.
The researchers enrolled 1,090 people eligible for transplants, ages 40-80. Donor corneas were provided by 43 eye banks, including the Cleveland Eye Bank. Corneas were given to patients, without respect to patient age, through a transplant procedure called penetrating keratoplasty, in which the central part of the damaged cornea is removed, and a full-thickness donor cornea is sutured in its place.
“We first looked at these groups at five years and found that 86 percent of the transplants were clear in both groups, so that was very exciting,” said Dr. Lass.
However, the researchers did notice a trend of a loss of cells in the older group, and based on those findings, they convinced the NEI to extend the study another five years.
Now at 10 years, the researchers have found that for the majority of donors, ranging from 34 to 71 years of age, there was no difference in the transplant success between the two groups.
“That is very reassuring,” said Dr. Lass. “That for the great majority of donors of available, the success rate is comparable for the two groups.”
He is excited by the results because he said the demand for corneas is only increasing, so knowing there is a larger donor pool available will help meet that demand.
Dr. Lass also is chairing a new study called the Cornea Preservation Time Study occurring at 40 clinical sites around the nation. That study is looking at one group of patients receiving corneas that are up to seven days preserved and a second group of patients receiving corneas from eight to 14 days preserved. The researchers are measuring transplant success rates and endothelial cell counts. If they can show that the longer preserved corneas are as successful as the shorter preserved corneas, they will essentially double the supply of corneas available for transplant in the United States because surgeons will be more accepting of the longer preserved corneas.
More details about the Cornea Donor Study results are available at the NIH Web site: http://www.nei.nih.gov/news/pressreleases/111513.asp