Table 2. Age-adjusted means (SE) of parameters obtained from color Doppler imaging in the ophthalmic, central retinal, and posterior ciliary arteries, and in the central retinal vein in participants with and without diabetic retinopathy.

Legend: Data are mean ± SE. Age-adjusted means were calculated using general linear models with Bonferroni correction for multiple comparisons. The difference in the mean of the variables compared with the control group (a) and diabetes group without retinopathy (b). The indices are calculated as follows: resistivity index = (PSV-EDV)/PSV, pulsatile index = (PSV-EDV)/V_mean, with V_mean = 1/3 (PSV-EDV)+EDV. Abbreviations: IGT - impaired glucose tolerance, EDV - end-diastolic velocity, PSV - peak systolic velocity, V_mean - mean time velocity. *p < 0.05, **p < 0.001, for comparisons across all three groups.