Limbal Stem Cell Transplants for Cornea Disease

The cornea is the clear dome which covers the pupil of the eye and protects it from damage. Unlike other parts of the eye, cells in the cornea are regularly sloughed off and replaced. This function helps the surface of the cornea remain healthy, and protect the underlying structures of the eye.

Stem cells make the regular renewal of the cornea possible. These cells are found in the limbus, the area around the outer end of the cornea. Unlike stem cells in other parts of the eye, these cells are usually active throughout adult life. These cells can divide and create new cells for the lining of the cornea – replacing the surface of the cornea every seven days.

Unfortunately, in some people these limbal stem cells can be damaged by an injury, by auto-immune disease or by an inherited disorder. This can be an extremely painful condition, which can also cause serious vision loss.

In recent years, techniques have been developed to transplant limbal stem cells from a healthy person to someone whose cornea has been injured. If only one eye has been damaged, transplants can also be done from one eye to the other. By implanting new stems cell in the limbus, the cornea can regain the ability to renew itself.

Allan Slomovic, Research Director of the Cornea/External Disease Service at the Donald K. Johnson Eye Institute, led the clinical research necessary to establish this therapy at UHN. He established a multi-disciplinary team of ophthalmologists, immunologists, transplant specialists, nurses, social workers, and pharmacists that provides personalized care and follow-up to each transplant patient, working to prevent the eye from rejecting the transplant, and to safe guard the well-being of the patient and their vision. This innovative, integrated program will be a model for the development of clinical research trials for retinal cell transplants.

Dr. Slomovic’s research continues to add new options for patients with corneal damage.  In March 2011, his team began the transplant of artificial corneas to the treatment program at UHN, for patients with severe ocular stem cell disease who are not candidates for stem cell transplantation. Dr. Slomovic has also founded a national Ocular Regenerative Society which brings together ocular stem cell researchers from across Canada annually at the Canadian Ophthalmological Society meeting.