Objective To describe the relationship of change in retinal vessel diameters to the subsequent 6-year incidence and progression of diabetic retinopathy (DR) and incidence of proliferative diabetic retinopathy (PDR) and macular edema (ME) in persons with diabetes mellitus.
Design A total of 1098 persons with diabetes who had DR graded from fundus photographs and had computer-assisted measurements of the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) participated in examinations in 1980-1982, 1984-1986, and 1990-1992.
Results During the first 4-year period, the mean change in CRAE and CRVE was −0.37 and 2.54 μm, respectively. The 6-year incidence and progression of DR and the incidence of PDR and ME from 1984-1986 to 1990-1992 were 56%, 39%, 15%, and 11%, respectively. In multivariate analyses, while controlling for duration, diabetes type, and other factors, an increase of 10 μm in CRVE from 1980-1982 to 1984-1986 was associated with increases in the 6-year incidence of DR (odds ratio [OR], 1.26; 95% CI, 1.10-1.43), progression of DR (OR, 1.21; 95% CI, 1.12-1.30), incidence of PDR (OR, 1.19; 95% CI, 1.07-1.32), and incidence of ME (OR, 1.16; 95% CI, 1.03-1.31). No interactions of these associations by diabetes type were found (data not shown). Change in CRAE was unrelated to the incidence or progression of DR (data not shown).
Conclusions Independent of DR severity level, glycemic control, and other factors, widening of the retinal venular but not arteriolar diameter was associated with subsequent incidence and progression of DR. The CRVE may provide additional information regarding the risk of incidence and progression of DR beyond traditional risk factors.