THE SANTA-BARBARA-COUNTY DIABETIC-RETINOPATHY SCREENING FEASIBILITY STUDY - SIGNIFICANCE OF DIABETES DURATION AND SYSTOLIC BLOOD-PRESSURE

The objective of this study was to examine the feasbility and utility of screening for eye disease and hypertension in a group of diabetic p atients. A sample of 338 outpatients in Santa Barbara County were incl uded and had non-mydriatic retinal photography and measurement of bloo d pressure and visual acuity. Each patient completed a questionnaire i ncluding age, type of diabetes (type I or type II), duration of diabet es, and smoking history. Photographs were read by an internist and oph thalmologist, and grouped into one of five categories: (1) normal, (2) background retinopathy, (3) preproliferative retinopathy, (4) prolife rative retinopathy, and (5) other abnormality. Patients with abnormali ties were referred for treatment. Thirty-two percent of the population had retinopathy, and 16% had disease requiring urgent referral for tr eatment. Mean systolic blood pressure (MSBP) was found to be higher in patients with all types of retinopathy (132 mm Hg versus 124 mm Hg, p < 0.001). The relationship remained significant when smokers and nons mokers were considered separately. No significant difference was found in MSBP between patients with severe retinopathy (preproliferative or proliferative) and those with background changes (133 mm Hg versus 13 1 mm Hg, respectively, p > 0.5). The other factor found to be related to retinopathy was the duration of diabetes. Type I patients with reti nopathy had diabetes for 19 years versus 12 for those without (p < 0.0 1). Type II patients with retinopathy had diabetes for 10 years versus 6 for those without retinopathy (p < 0.02). The findings confirm the utility of screening asymptomatic subjects for retinopathy and suggest that a degree of systolic blood pressure currently considered normal may be associated with the development of retinopathy in this populati on.