Does CMV infection cause corneal transplant failure in the UK?

Overview

Around 4000 corneal transplant operations take place each year in the UK. The cornea is the clear front window of the eye.

The need for a transplant can be due to any of several conditions, for example Fuchs dystrophy or keratoconus. They involve removing some or all of the patient’s corneal and grafting on tissue from a donor instead.

Many corneal transplants are a success and give people better vision. But some transplants so fail, for a range of reasons, possibly including infection with cytomegalovirus (CMV).

CMV is a common type of herpes virus that’s found in the general UK population. It is more common in some parts of the world than others. Just under half (49%) of white women born in the UK have CMV and almost all (98%) of South Asian women born in Asia do too.

It is not routine practise to test for CMV infection in corneal graft rejection in the UK. This is partly because the test is invasive and partly because accurate lab tests have only become available recently.

Testing for CMV infection in corneal donor tissue or from corneal donors, is not done at UK eye banks as it wasn’t thought to be a pathogenic organism in corneal transplantation. But new knowledge from Asia suggests that CMV infection could be a possible cause in some eyes and has prompted the research team to investigate this in the UK.