FRIDAY, Jan. 14 (HealthDay News) -- Blacks with diabetes who consume too many calories and too much sodium increase their risk for eye disease, a new study finds.

The research involved 469 black participants who had type 1 diabetes. Six years later, they underwent blood testing, had a complete eye examination and had photos taken of their eyes to determine the progression of diabetic retinopathy, which is the leading cause of blindness among Americans aged 20 to 64 who have diabetes.

People who had high caloric and sodium intake at the start of the study were more likely to have vision-threatening retinopathy after six years. The disease includes proliferative retinopathy (growth of new blood vessels in the retina) and macular edema (leakage of fluid into the macula, the part of the eye responsible for sharp vision).

"In African-American patients with type 1 diabetes, high caloric and sodium intakes are significant and independent risk factors for progression to severe forms of diabetic retinopathy," concluded study authors Dr. Monique S. Roy, of the University of Medicine and Dentistry of New Jersey, and Malvin N. Janal, of the New York University College of Dentistry.

"These results suggest that low caloric and sodium intakes in African-American individuals with type 1 diabetes mellitus may have a beneficial effect on the progression of diabetic retinopathy and thus might be part of dietary recommendations for this population," they wrote.

Their study is in the January issue of the Archives of Ophthalmology.

More information

The U.S. National Eye Institute has more about diabetic eye disease.