Effective treatment is available for some forms of diabetic retinal disease, and people with diabetes can often prevent loss of vision, according to an ophthalmologist at New York University Medical Center.

"Certain changes in the retina that were not treatable before can now be treated with laser surgery, preventing serious consequences - including loss of vision," said Ronald E. Carr, M.D., professor of ophthalmology at the Medical Center.

An article in an upcoming issue of the New York University Medical Center Health Letter describes the development of diabetic retinopathy, a sight-threatening condition that occurs to some degree in 40 percent of people with diabetes.

"It is associated with decreased blood flow through the tiny vessels of the eye," Carr explained. "In turn, this reduces the supply of oxygen to the retina, the light-sensitive tissue at the back of the eye that transmits visual messages to the brain."

To compensate for the decreased oxygen supply, the retina grows new vessels, which are abnormal and leak blood into the retina. If allowed to continue, this process may lead to partial or total loss of vision.

"An individual with early retinopathy may experience a decrease in vision, either from fluid accumulating in the retina or because of hemorrhages," Carr noted. Often, however, there are no early symptoms, and the presence of retinopathy can only be detected by an ophthalmic examination.

In its early stages, diabetic retinopathy may be treated by laser photocoagulation, which is generally performed during an office visit.

The narrow laser beam pinpoints tiny areas of the retina; there, it may close off new blood vessels or seal off areas of fluid leakage. More extensive laser treatment leads to a disappearance of the new vessels.