Retinal ischemia (capillary nonperfusion) in diabetic retinopathy of patients with and without systemic hypertension.

In a study of 138 patients with diabetic retinopathy and good fluorescein angiograms, areas of CNP were found in 66.5% using a macular centered photograph. There was no statistically significant correlation between the appearance of CNP, their size and number with the level of systolic and diastolic blood pressures, the duration of diabetes (at the onset of diabetic retinopathy), the age at onset of diabetes, the age at examination, the control of the diabetes and the treatment of hypertension. The only borderline statistically significant difference was found between patients with constant hypertension when compared to patients with labile hypertension.