To describe the relation of retinal arteriolar and venular caliber tothe incidence and progression of diabetic retinopathy in people with type1 diabetes mellitus.
Incidence findings in a population-based study of diabetic retinopathyin Wisconsin. Participants included 996 persons diagnosed as having diabetesmellitus before 30 years of age who took insulin and underwent the baselineexamination, 891 in the 4-year follow-up, 765 in the 10-year follow-up, and634 in the 14-year follow-up. Retinal photographs of 7 standard fields weretaken at all examinations. Computer-assisted grading was performed from adigitized image of field 1 to determine the average diameter of retinal arteriolesand venules and their ratio. Main outcome measures included incidence andprogression of retinopathy, incidence of proliferative retinopathy, and macularedema.
While adjusting for other factors, larger arteriolar (relative risk[RR] for the fourth vs first quartile range, 2.04; 95% confidence interval[CI], 1.20-3.47; test of trend, P = .008) and venulardiameters (RR, 2.33; 95% CI, 1.37-3.95; test of trend, P = .005) were associated with greater 4-year progression of retinopathy.Larger venular diameters (RR, 4.28; 95% CI, 1.50-12.19; test of trend, P = .006) but not arteriolar diameters were associatedwith greater 4-year incidence of proliferative retinopathy. In multivariableanalyses, arteriolar and venular calibers were not associated with the 4-yearincidence of retinopathy. While adjusting for other factors, arteriolar andvenular calibers were not associated with incidence of macular edema at 4years. There were few associations of arteriolar or venular caliber with the10- or 14-year incidence or the progression of retinopathy.
Larger arteriolar and venular caliber, independent of retinopathy severitylevel, is related to the progression of retinopathy, and larger venular caliberis associated with the 4-year incidence of proliferative retinopathy. Caliberof retinal vessels is not associated with incident retinopathy. These datasuggest a quantitative measure of retinal vascular caliber provides additionalinformation regarding risk for progression of retinopathy.