Experimental pancreas transplants, used to cure the blood sugar imbalance caused by diabetes, do not seem to halt the progressive blindness that diabetes causes, University of Minnesota doctors reported.
The researchers said the discovery, reported Thursday in the New England Journal of Medicine, is a disappointment because they had hoped that eye deterioration, one of the hallmarks of diabetes, could be arrested, or even reversed, when blood sugar levels became carefully controlled after a pancreas transplant.
In tests on 22 patients for whom the transplanted pancreas worked for at least a year, the research team led by Dr. Robert Ramsay found no difference in vision loss when the patients were compared with 16 other diabetics for whom the transplant did not control the diabetes.
The study, carried out for an average of two years, concluded that successful pancreas transplants neither reversed nor prevented the progression of the eye deterioration, known as diabetic retinopathy.
The researchers said, however, that there were some signs in the study that, if the transplanted pancreas kept working for an additional year, there might be benefits for a person's eyesight.
They said the results suggested that pancreas transplantation may have a late beneficial effect that becomes evident only after three years.