Features of Ocular Blood Flow in Malignant Arterial Hypertension of Renal Origin

Color Doppler imaging allows a detailed non-invasive assessment of the state of blood flow in the retrobulbar vessels in patients with various vascular pathologies. Malignant hypertension (MH) is a clinical syndrome characterized by severe diastolic arterial hypertension (140 mm Hg or more), leading to ischemic damage to various organs — kidneys, heart, brain, eyes. Patients with MH often present with thrombotic microangiopathy (TMA), a rare life-threatening condition characterized by multiple systemic thromboses of the microvasculature. Purpose: to assess the state of blood flow in retrobulbar vessels by color Doppler imaging in TMA associated with MH. Methods: 10 patients (20 eyes) (age 43.5 ± 6.2 years) with TMA associated with MH underwent a study of the state of blood flow in the vessels of the retrobulbar space by color Doppler imaging. Qualitative and quantitative analyzes of retinal and choroidal circulation were assessed. Results. Analysis of the Doppler spectrum of blood flow in TMA associated with MH revealed a statistically significant increase in maximum systolic (Vsyst) and finale diastolic blood flow velocity (Vdiast) in the ophthalmic artery (OA), as well as Vsyst in the medial short posterior ciliary arteries (SPCA), compared with the control group ( p < 0.05). In 2 patients (20 %) of the study group, a significant bilateral decrease in the diastolic component of the spectrum was found up to the isoline (Vdiast = 0) and a maximum increase in the peripheral resistance index (RI = 1.0). Statistically significant correlations were found between some laboratory parameters of blood serum (hemoglobin, lactate dehydrogenase, creatinine), as well as the estimated glomerular filtration rate and hemodynamic parameters in the central retinal artery (CRA), lateral (SPCA) and OA ( p < 0.05). Conclusion. The results of the study of ocular hemodynamics using color Doppler imaging in TMA associated with MH are presented for the first time. TMA associated with MH is characterized by a statistically significant increase in the maximum systolic blood flow velocity in the OA and SPCA with the development of an ischemic state in the retinal and choroidal microcirculation in some patients. An increase in TMA activity in MH leads to a change in the microcirculation of the retina and choroid of an ischemic nature. An increase in blood creatinine in patients with TMA with MH is statistically significantly associated with a decrease in systolic blood flow velocity