A new study offers hope in preserving the vision of millions of people in the United States living with type-1 or type-2 diabetes. Initial results in a multicenter international trial, chaired by researchers at Joslin Diabetes Center in Boston, demonstrated that 32 milligrams per day of a new compound called ruboxistaurin (RBX) was not only well tolerated but also helped reduce the risk of moderate vision loss, especially in patients with diabetic macular edema.

Vision loss is a common complication of diabetes, resulting from two primary conditions--diabetic retinopathy and diabetic macular edema. In retinopathy, tiny blood vessels in the retina become damaged. Initially, there may be no symptoms, but over time, new abnormal blood vessels proliferate, a process called neovascularization, which can cause severe vision loss.

In diabetic macular edema, leaky blood vessels cause swelling in the macula, which is responsible for fine, detailed vision. Current la ser treatment for diabetic eye disease may help prevent severe vision loss and reduce the leakiness of the blood vessels, but it also destroys areas of the retina, resulting in potential reduction in peripheral and/or night vision.

In the double-masked study, 252 patients with type-1 or type-2 diabetes received either RBX or a placebo over a three- to four-year period. The study, published in the July issue of the medical journal Diabetes, measured the effects of three oral dosages of RBX for progression of diabetic retinopathy, moderate visual loss, and sustained moderate visual loss.

Oral RBX inhibits, or blocks, the activity of an enzyme called protein kinase C (PKC). PKC is essential to the normal production of energy in the body, but a specific form of the enzyme--PKC-beta--has been linked to diabetic complications of the eye and other parts of the body. Thus RBX was designed to be selective for inhibiting the single PKC-beta isoform, a fact that contributes to the inhibitor's excellent safety profile to date, according to researchers.

Good Glucose Control

People who maintain vigilant control of their glucose levels are at a significantly lower risk of heart disease, according to researchers at the annual scientific meeting of the American Diabetes Association.

"The longer we follow patients, the more we're impressed by the lasting benefits of tight glucose control," said Saul Genuth, M.D., of Case Western Reserve University of Cleveland, Ohio, who chairs the follow-up study of the Diabetes Control and Complications Trial (DCCT).

Called the Epidemiology of Diabetes Interventions and Complications (EDIC) study, this follow-up research is looking at the long-term effects of prior intensive versus conventional blood glucose control. Intensive treatment meant keeping hemoglobin A1c (HbA1c) levels as close as possible to the normal value of 6 percent or less. (The HbA1c blood test reflects a person's average blood sugar over two to three months.)

"The good news is that intensively controlling glucose significantly reduces heart disease as well as damage to the eyes, nerves, and kidneys in people with type-1 diabetes," said Massachusetts General Hospital's David Nathan, M.D., who co-chaired the DCCT/EDIC research group.

Developing a Smart Shoe

A new shear and plantar pressure sensor from researchers at the University of Washington in Seattle could pave the way to a "smart shoe" that can help prevent people with diabetes from developing debilitating foot ulcers.

Dr. Wei-Chih Wang of the University of Washington and colleagues reported on their invention that incorporates fiberoptic technology in the May/June issue of the Journal of Rehabilitation Research & Development.

While trauma to the foot after loss of sensation is now agreed to cause most foot ulcers in people with diabetes, the researchers note that the role of shear stress in the development of such ulcers is poorly understood.

The researchers developed their sensor so it could be used inside a shoe and would be compatible with skin. Put simply, pressure on the fibers reduces light output. The technology could be used to construct a shoe that could monitor and relieve stress changes in the foot.

Researchers hope that the new sensor (prototype shown at right) could also be used to help monitor not only skin ulcers caused by prosthesis use but also skin stresses to prevent injury in wheelchair users and bedridden patients.