(RxWiki News) Patients who need a new cornea — the clear, front surface of the eye — may not need to worry about the age of the donor who will provide that cornea, according to new research.
Two recently published studies found that corneal transplant patients who received a cornea from an older donor had a similar rate of success with their transplant when compared to patients who received a cornea from a younger donor.
However, the researchers did find that the rate of success significantly declined for cornea transplant patients as donor ages reached the 70s.
"Speak with your doctor if you’re experiencing vision problems."
The Cornea Donor Study Research Group conducted two research studies. The first study was led by Mark J. Mannis, MD, at the University of California Davis in Sacramento. The research team examined the relationship between donor age and success of penetrating keratoplasty for corneal endothelial disorders 10 years after surgery.
Penetrating keratoplasty is a surgical procedure where a patient’s cornea is replaced with a donor cornea.
Data was analyzed from 1,090 participants who were receiving penetrating keratoplasty for Fuchs’ dystrophy, corneal edema, or another corneal endothelial disorder. With these corneal disorders patients have a buildup of cloudy material in one or more parts of their cornea which causes unclear vision.
Donor corneas were received from 43 eye banks from donors between 12-75 years old. A total of 707 participants received a cornea from a donor in the 12-65 year old age group and 383 participants received a cornea from a donor in the 66-75 year old age group.
Success was defined as no graft failure. Graft failure happened when a cornea became cloudy and caused vision problems for three months in a row.
The researchers found a 77 percent success rate for patients who received a cornea from a donor between the ages of 12 and 65 years old. They found a 71 percent success rate for patients who received a cornea from a 66- to 75-year-old donor.
The researchers also looked at the rate of success for patients who received a cornea from donors at the opposite ends of the 12-to-75-year-old age group. There was a 96 percent success rate for patients who received a cornea from donors between the ages of 12 and 33. For patients who received a cornea from patients between the ages of 72 and 75, there was a 62 percent rate of success.
The study authors noted that while they found a significant difference in success rates between ages at the opposite ends of the 12-to-75-year-old age range, the drop in success rate for the older donor age group did not occur until six years after the surgery.
The second study was led by Jonathan H. Lass, MD, at Case Western Reserve University and University Hospitals Eye Institute in Cleveland, Ohio. The research team examined the endothelial cell loss in patients who had received penetrating keratoplasty (PKP).
Endothelial cells help keep the cornea clear by pumping out excess fluid. By measuring endothelial cell loss, the researchers could determine how well the cornea was functioning.
Data was analyzed from 176 patients in the Cornea Donor Cohort Study. Patients had received a cornea from a donor between the ages of 12 and 75 years old and had not experienced graft failure for at least 10 years after the surgery.
The researchers found that for patients who received a cornea from a 12- to 65-year-old donor, there was a 76 percent cell loss, compared to a 79 percent cell loss for patients who received a cornea from a 66- to 75-year-old donor.
Dr. Lass and colleagues noted that regardless of age group, there was a significant amount of endothelial cell loss in patients who received PKP, but this was slightly higher with corneas from older donors.
While the researchers did see a decline in rate of success and greater cell loss in corneas from older donors, they noted that this was for donors close to the high end of the 12-75 year age range.
The authors of this study concluded that making use of corneas from older donors could expand the donor pool worldwide and address the international shortage of corneas.
These studies were published on November 15 in Ophthalmology.
Some of the study authors reported potential conflicts of interest with certain organizations, including Bausch & Lomb, Midwest Eye Banks and Cincinnati Eye Banks.