The herpes simplex virus (HSV) can infect the eye and sometimes causes so much damage that the person’s cornea must be replaced with a transplant. (The cornea is the clear covering of the front of the eye that helps focus light for vision.) Doctors knew transplants were more likely to fail in people with HSV than in patients with other disorders, such as keratoconus, an abnormal steepening of the cornea.

This higher failure rate occurred even when HSV infection did not appear to be active in patients. Researchers at the Kellogg Eye Center, University of Michigan, theorized that such patients might have corneal inflammation that could not be detected upon clinical examination but might increase the risk of transplant rejection.

Unlike organ transplants, in corneal procedures the new tissue is placed on a bed of existing tissue. Though HSV had been inactive for six months before surgery in 81 percent of patients, microscopic evidence of inflammation was found in 74 percent, and the transplant failure rate did indeed correlate with the presence of this biomarker.

“It is also possible that treating inflammation intensively before corneal transplant surgery would reduce the risk of rejection,” said Dr. Roni M. Shtein, MD, MS, cornea specialist and lead author of the report.

For the full article, please refer to http://www.sciencedaily.com/releases/2009/07/090701082702.htm