The cornea is the clear area that light passes through at the front of the eye. The corneal epithelium is an important barrier layer of cells that is maintinaed by stem cells located at the edge of the cornea, in a region known as the limbus. These so-called limbal stem cells are damaged by many types of injury or disease:
- Trauma (chemical and thermal burns);
- Inflammatory diseases (mucous membrane pemphigoid and Stevens-Johnson syndrome)
- Iatrogenic causes (extensive limbal surgery, radiation and topical chemotherapy).
The result is a corneo-limbal disease known as limbal stem cell deficiency where the corneal surface becomes hazy with blood vessels growing in it, and is prone to frequent breakdown. This results in pain and visual impairment.
Limbal stem cell deficiency is difficult to manage. We have developed an animal cell and product free culture system for limbal stem cells that is currently being used in clinical trials. In addition, we are taking part in a multi-centre trial for allogeneic limbal stem cells with collaborators in Edinburgh and Glasgow. Several patients from St Paul’s Eye Unit who suffer from severe limbal stem cell deficiency have already taken part in this important trial.