THURSDAY, July 1 (HealthDay News) -- Corneal transplant
rejection is more likely to occur in people who have abnormal
vessel growth in their eyes before undergoing the surgery, a team
of German and British researchers reports.
However, people with the condition -- known as
neovascularization -- might improve their chances of a successful
transplant, the researchers say, if they were given
growth-inhibiting drugs beforehand.
Known as antiangiogenics, such drugs include bevacizumab and
ranibizumab. In addition, other drugs that work at the genetic
level to control such problematic growth are currently under
"The presence of corneal neovascularization before surgery makes it about 30 percent more likely that the transplant will fail and more than doubles the risk of graft rejection," researcher Dr. Claus Cursiefen said in a news release from the American Academy of Ophthalmology. "We also found that the risks of failure and rejection rise with the extent of vascularization -- the more extensive the [abnormal vessel growth in the eye], the higher the risks."
"In the future, preconditioning a vascularized cornea before transplantation may be a useful strategy to promote survival of the graft," he added.
The findings, reported in the July issue of
Ophthalmology, were based on a review of 19 studies that included nearly 24,500 corneal transplants.
The researchers also found that being older and male appeared to
raise the risk for transplant failure, but they cautioned that
those particular factors needed to be verified with further
In the United States, about 40,000 corneal transplants are
conducted every year to restore sight to people whose outer eye
surface has been damaged in some form. The surgery is the most
frequently performed transplant operation and is generally
considered one of the more successful ones, as well, according to
People who do not have vascularization when they undergo
transplantation have a greater than 80 percent chance of retaining
good eye health five years after their surgery, the researchers
Currently, various precautions are taken before surgery to
improve the chances of success, including matching donor and
corneal recipient tissues as closely as possible and tamping down
the immune response of the person receiving the transplant.
The U.S. National Library of Medicine has more on