The Breakthrough T1D-supported Joslin  50-Year Medalist Study has shown that more than  40 percent of people who  have had type 1 diabetes (T1D) for at least 50 years have no or mild  diabetic retinopathy, or eye disease, suggesting that many  of the Medalists are somehow protected from this common complication of diabetes. New research findings reveal  that the protected Medalists exhibit slow  onset  and/or progression of eye disease  rather than regression (or reversal) of more  serious forms of retinopathy.

Diabetic retinopathy occurs when high  blood-glucose levels damage blood vessels in the eye. Eighty-six percent of people who  have lived with T1D for at least 20 years will experience some degree of diabetic retinopathy, the leading cause of blindness in working-age (20-74 years) adults in the United States and other developed countries worldwide. A handful of treatments are available to halt progression of late-stage retinopathy and stop further vision loss, but  these treatments do not  cure retinopathy. No therapies are currently known to prevent the onset  of diabetic retinopathy.

The Joslin  Diabetes Center in Boston created the 50-Year Medalist Program to honor people who  have lived with T1D for 50 years or more for their achievements in diabetes self-management. About 85 percent of people who  receive 50-Year Medals subsequently agree  to participate in the Medalist Study, a clinical research study aimed at identifying the genetic, environmental, psychological, and physiological factors that contribute to long-term survival in individuals with T1D. As a group, the Medalists have lower than  expected rates of all major diabetes complications of T1D, including kidney disease  and nerve damage in addition to retinopathy.

George King, M.D., the lead investigator on the Medalist Study, and his colleagues reported their latest findings on retinopathy in the Medalists at the American Diabetes Association’s
72nd Scientific Sessions in Philadelphia in June 2012. The study team wanted to understand whether the Medalists who  seemed to be protected from the most advanced forms of retinopathy had slow  progression of eye disease or if they  had developed advanced retinopathy at some point that regressed over  time to a milder form of the disease. This distinction could point the way to new treatments for preventing, slowing, or even reversing diabetic retinopathy.

The researchers reviewed the medical charts of 158 Medalists who had received repeated eye exams at Joslin  over  the course of 16 years on average. In Medalists who  did not develop advanced retinopathy, researchers observed a slower rate of progression than  in those  who  did develop the most serious  form of the disease. No evidence of substantial regression was observed in Medalists who  had intermediate levels of retinopathy. Of interest, once  a Medalist had reached 20 years of T1D duration, he or she rarely experienced further progression of eye disease.

In future studies, Dr. King  and the Medalist Study team are keen to identify the factors that halt or slow progression of diabetic retinopathy and confer protection from advanced eye disease  in some people with longstanding T1D.

The Joslin  50-Year Medalist Study is an important component in the Breakthrough T1D portfolio of research to prevent or treat complications of T1D. According to Helen Nickerson, Ph.D., Breakthrough T1D senior  scientific program manager of complications therapies, “The Medalists have survived so long  with type 1 diabetes and some of them have very few complications, so we know they have something to teach us. Some of that might be lifestyle, but  the reason that Breakthrough T1D supported the Medalist Study is to consider whether there are biological or genetic factors that might account for their long  duration of diabetes with few complications. Joslin’s  efforts to characterize diabetic retinopathy in the Medalists are an important starting point for preventing or treating this complication in order to protect other people with type 1 diabetes from vision  loss or blindness.”

Key point: In the Breakthrough T1D-funded Medalist Study of individuals who  have lived  with T1D for at least 50 years, researchers have discovered that  some Medalists are protected from advanced diabetic retinopathy because they  have a slow rate of retinopathy onset  or progression. Further, after 20 years of T1D, progression of retinopathy appears to halt. Researchers can now  search for factors that  mediate this slow disease progression and exploit them to develop new strategies to prevent or treat diabetic retinopathy.