Clues to Retinopathy from Survivors of 50+ Years of DiabetesTuesday, October 26, 2010
Doctors assume that the longer a person has diabetes, the more likely he or she is to develop serious eye disease and, if untreated, become blind. But a new study of patients who have had type 1 diabetes for at least 50 years tells a different story. Many of these patients appear to be protected against proliferative diabetic retinopathy (PDR), and the majority of them escape vision loss despite extremely long-duration diabetes, according to Jennifer Sun, MD, Beetham Eye Institute at Joslin Diabetes Center, a Harvard School of Medicine affiliate.
With one exception, development of PDR occurred within the first two decades in these Joslin patients (in 96 of 97 patients). If PDR did not develop during that period, then retinopathy progressed slowly and in some cases stopped altogether. PDR development was associated with higher blood pressure, but not with glycemic (blood sugar) control. This confirmed an earlier, larger study`s surprising finding that neither glycemic control nor duration of diabetes correlated with the severity or presence of diabetic retinopathy (DR) in patients who successfully survived 50 or more years with type 1diabetes. Decreased blood levels of the protein tyrosine phosphatase SHP-1 was also associated with protection from development of any DR, and Dr. Sun recommends further study of SHP-1 to learn whether it might be a target for treatment.
"There is no doubt that lack of glycemic control is a major factor in the development of eye complications for patients with shorter-duration diabetes. But our data from this unique group of individuals who have survived extremely long-duration diabetes may help identify other factors that protect against retinopathy complications," said Dr. Sun. "These findings also suggest that protective mechanisms are activated very early in diabetes."
Source: American Academy of Ophthalmology Press Release
Originally posted by DiabetesCare.net on October 26, 2010.