Purpose: To determine prospectively whether cardiovascular autonomic neuropathy is a risk factor for proliferative diabetic retinopathy.
Methods: A five-year follow-up study of 88 diabetic persons was performed at a center providing primary and specialized care for diabetes. Participants were white, insulin-dependent patients with diabetes of 15 to 21 years' duration. The primary end point was the presence of proliferative diabetic retinopathy, seen either on fundus photography or ophthalmologic examination. Cardiovascular autonomic neuropathy was measured at baseline by using a standard protocol.
Results: Fourteen patients developed proliferative diabetic retinopathy during follow-up. One measure of cardiovascular autonomic neuropathy, the 30:15 ratio, the heart rate variation at the 30th beat compared with that at the 15th beat, was lower among patients with proliferative diabetic retinopathy (P = .0049) The risk of proliferative diabetic retinopathy in patients with an abnormal cardiovascular autonomic neuropathy index was 2.59, although the estimate was not statistically significant because of the small number of patients who developed proliferative diabetic retinopathy.
Conclusions: This study provides prospective evidence that cardiovascular autonomic neuropathy is associated with proliferative diabetic retinopathy. In addition to ocular determinants of proliferative diabetic retinopathy, systemic risk factors also should be considered when examining patients with diabetes mellitus.