Circulatory parameters in the retrobulbar central retinal artery and vein of patients with diabetes and medically treated systemic hypertension

Background  We aim to study the circulatory parameters in the retrobulbar central retinal artery and vein in diabetic patients with and without medically treated systemic hypertension. Methods  The study included 108 patients with diabetes that were allocated in four different groups according to the presence of diabetic retinopathy (DR) and hypertension: group 1—patients without DR and without hypertension (n = 23), group 2—patients without DR and with hypertension (n = 21), group 3—patients with nonproliferative DR and without hypertension (n = 36), group 4—patients with nonproliferative DR and with hypertension (n = 28). The circulatory parameters that were evaluated were: peak systolic blood velocity (PSV), end-diastolic blood velocity (EDV), maximum venous velocity (Vmax), minimum venous velocity (Vmin) and the Pourcelot index which were measured using color Doppler imaging. Non-parametric tests were used to test inter-group differences. Spearman’s coefficient of correlation was tested between ocular perfusion pressure and the circulatory parameters in each of the patient groups. Contingency table was performed to test the relation of diabetic retinopathy and hypertension to the PSV in the central retinal artery. Results  The PSV and EDV in the central retinal artery was significantly higher in group 1 (p = 0.02, p = 0.04) and group 2 (p = 0.02, p = 0.02) than in group 3. The Pourcelot index in the central retinal vein was significantly lower in group 1 than in group 4 (p = 0.02), and in group 2 than in groups 3 and 4 (p = 0.02, p < 0.01). A significant relationship was detected between the presence of hypertension, the stage of diabetic retinopathy and the PSV in the central retinal artery of our patients (χ² = 8.29; p = 0.04). Conclusion  Medically treated hypertension affects the retrobulbar circulatory parameters in the central retinal artery and vein in diabetes.