Corneal Burns Successfully Treated with Stem Cells

However, more profound burns may damage the limbal stem cells from which the newest treatment derives its usage. For those patients for whom stem cell therapy is not an alternative the prognosis for these cases can be very poor. 

Graziella Pellegrini, co-author of the study is in charge of the cell therapy unit at the Center for Regenerative Medicine at the University of Modena and Reggio Emilia in Modena, Italy. She claims that the new treatment involves harvesting stem cells from the patient's healthy eye or from the eyes of a relative or a friendly donor. Stem cells from the patient's own eyes did not require the use of anti rejection drugs. The corneal scars are removed and the cultured material is transferred or grafted onto the injured cornea in a manner similar to a contact lens. New cells are further created which allows the cornea to start to return to normal.

The researchers created enough cells in a lab culture and then performed the transfer to 112 patients. Reports say that the treatment was successful in 76.6% of the patients and a partial success in 13.1% of the patients. Guidelines for success indicate that all symptoms of light sensitivity, itching and pain will have disappeared and a new, healthy, transparent cornea will have developed. In those cases in which there was no success (about 10.3%) failure was due to surgical complications, or the profound severity of the injuries.  

The procedure succeeded after a single application in 69% of the cases. A second procedure was needed for some patients. Pellegrini said that half of those with deep damage to the eye were able to enjoy restored vision. All of the others were completely cured. The color and appearance of the eye were normal in every respect. Her patients were followed for an average of three years and some for as long as a decade. Although there were no complications during the grafting, postoperative adverse episodes in a few of the patients included hemorrhage and residual fibrin on the third postoperative day. There were also incidents of inflammation, blepharitis with epithelial involvement and herpetic keratitis.

The successful patients were euphoric and felt that the results were miraculous. Dr. Pellegrini replies, "It was not a miracle. It was simply a technique." One of the successful stories involved a man who had severe damage in both eyes as a result of chemical burns suffered in 1948. Stem cells grafted from a small section of the left limbal area were used to graft both eyes. His vision is now close to normal.

The treatment may cost about $20,000 to $30,000. One drawback to be considered is the unknown period of time that the treatment will last. Some patients in this study did well for a period of ten years. Currently, the stem cell treatment is not approved in the U.S., but it is in use in other countries. Pellegrini estimated that the new technique may help 1,000 to 2,000 patients in Europe. Some areas in Europe and developing countries are threatened by the lack of regulations regarding the use of dangerous chemicals. Therefore, the incidence of ocular accidents is most likely to be higher in these locations.

The Italian study and presentation was praised by Dr. Ivan Schwab, an ophthalmology professor and stem cell expert at the Univ of California, Davis. He claimed, "The Italian method is a roaring success.” Unfortunately, there are reports that some researchers were not having the same success as Pellegrini. Their experience did not provide an enduring time of cure for their patients. She feels that the stem cells extracted from the limbus should be cultured in a proper mix with differentiated cells that make up corneal tissue. If stem cells are too few there will be no reserve to form the new cells needed in the recycling mode that will enable the results to last.   

The stem cell culture increased and grew into healthy tissue within a period of two weeks. Some regained sight in two months. The deeper burns usually required a second procedure and patience was rewarded after a year when sight was finally restored. Dr. Schwab adds that a hospital in India has joined the small group involved with limbus derived stem transplants. He further states, "The applications of this work may extend to other organs. This is bigger than just the surface of the eye. Pellegrini may be making a model for how to regenerate livers and other organs." The study was partly funded by the Italian government. The U.S. research is centering attention on new ways to use self supplied stem cells but feel that the work is still preliminary. In the year 2008 there were 2,850 work related chemical burns to the eye according to the US Bureau of Labor Statistics.

For decades, adult stem cells have been used to treat leukemia and sickle cell anemia. Other stem cell studies involve researching therapy for diabetes, bladder, liver and heart failure, but have been met with limited success. Dr. Schwab, with a twinkle in his eye, says, "After all, we are not talking about regenerating the entire liver or heart. The concept that you have to grow a whole liver or a whole heart is a result of wild imagination and should not be taken seriously." It should be pointed out that adult stem cells are derived from different parts of the body. Embryonic stem cells are found in human embryos. The latter activity has caused much ethical concern. Until this time the common therapy for significant corneal burns is to utilize a corneal transplant procedure. 

However, complications have been recorded regarding infection and glaucoma. A case of last resort involves the use of stem cells obtained from a cadaver. This is not considered a prime choice of treatment by our doctors, as well as the patients. Dr. Sophie Deng is a cornea expert at the UCLA's Jules Stein Eye Institute. She observed that the Italian procedures created a big advantage in their amazing progress since they were able to increase the number of cells in the lab. This is less invasive and lowers the chance of injury to the eye.