Previous studies have examined visual impairments of Caucasians with type 1 diabetes, but this is the first study analyzing vision loss for African Americans with type 1.

The vision and associated risk factors of approximately 500 African Americans with type 1 were studied over a 6-year period. At follow-up, 4.3 percent of patients realized vision loss in their better eye (visual acuity of 20/40 or worse) and 0.6 percent became blind in their better eye (visual acuity of 20/200 or worse). Nearly 10 percent lost 15 or more letters on the eye chart due to a doubling of the visual angle in their better eye. Another 13.5 percent had this doubling in either eye, which the researchers stated was "particularly high".

Independent predictors of vision loss over the six years were identified as poor blood sugar control, older age, high protein levels in the urine (symptomatic of kidney disease) and diabetic retinopathy, a common degeneration of the retina seen in people with diabetes.