Comparative Study of Orbital Doppler Parameters in Hypertensive Patients With and Without Retinopathy

Abstract

Background: Hypertensionis a major risk factor for the development of cardiovascular disorders. Years before end organ damage is clinically evident, hypertension is considered a silent killer. Since retinal arterioles share anatomical and physiological properties with cerebral and coronary microcirculation, and can be monitored easily and non-invasively, it can thus be considered an in vivo window into the human circulation. Color Doppler Imaging (CDI) is a well-established technology for determining the parameters of orbital blood flow. Aim of Study:To compare changes of color Doppler imaging (CDI) in the ophthalmic artery and its branches in hypertensive patients with retinopathy and without retinopathy in relation to their fundoscopic changes.Patients and Methods: This observational study included 80 hypertensive patients, divided into 3 groups according to Wong and Mitchell Classification: No retinopathy (Group 1), with mild-moderate Retinopathy (Group 2), and with severe Retinopathy (Group 3). All did Orbital CDI in which Ophthalmic Artery (OA), Central Retinal Artery (CRA) and Ciliary Arteries (CA) were identified. Peak systolic velocity (PSV), End Diastolic velocity (EDV) and Resistivity Index (RI) were measured.Results: CRA RIwas highest in G3 (p=0.05). OA EDV was significantly higher in G1 vs G3 (p=0.013). On the contrary, OA RI was lower in G1 vs G2 (p=0.010), and vs G3 (p=0.000). HTN duration showed a significant negative correlation with CRA EDV (r=-0.237, p=0.034); a significant positive correlationwith CRA RI (r=0.280, p=0.012) as well as with CA RI (r=0.288, p=0.010). Regarding HTN control, CRA PSV and EDV were significantly higher in stage 1 HTN (p=0.033 and 0.036 respectively), while CRA RI was significantly higher in isolated systolic HTN (p-value 0.029). OA PSV was signficnatly lower among patients with isolated systolic HTN vs controlled and stage 1 HTN patients (p=0.004 and 0.009).