Standard retinal photographs are taken and scored, based upon the number of microaneurysms, hemorrhages, exudates, and other abnormalities 14 Primary prevention at nine years, the incidence of new retinopathy was 12% in the intensive therapy group versus 54 percent in the conventional therapy group There was a continuous relation between the degree of glycemic control and the incidence of retinopathy (the only complication for which such data were reported): the rate of progression increased from one per 100 patient-years at a mean A1C value of 5.5 percent up to 9.5 per 100 patient-years at a mean A1C value of 10.5 percent; progressive retinopathy was uncommon at A1C values below 7 percent.