Researchers at Indiana University, Bloomington, have discovered new early warning signs of the potential sight loss associated with diabetes. This could have a big impact on the diagnosis and treatment of diabetic retinopathy, which potentially impacts more than 25 million Americans.

In studying early signs in volunteer research subjects whose eyes were not thought to have very advanced disease, the researchers found that there was indeed damage already spread widely across the retina, including changes to blood vessels that were not thought to occur until the more advanced disease states. Existing diagnostic techniques did not detect these early-warning signs.

The new technology, based on adaptive optics, consists of an instrument using small mirrors with tiny moveable segments to reflect light into the eye to overcome the optical imperfections of each person’s eye. It allowed the researchers to see large areas of retina with insufficient blood circulation.

The changes to the subjects in the study included corkscrew-shaped capillaries. The capillaries were not just thicker, which made them distorted, but the blood vessel walls grew longer as well, making loops visible only at microscopic levels.