Dopplervelocimetria das artérias oftálmica e central da retina em portadores de anemia falciforme

Abstract

BACKGROUND Sickle cell anemia (SCA) is the most common hemoglobinopathy in Brazil. The disease is characterized by changes in microcirculation, particularly vaso-occlusive phenomena, and ocular abnormalities that remain asymptomatic during many years, culminating with reduction of visual capacity, sometimes irreversible. Doppler velocimetry is a harmless, reproducible exam that can identify disturbances of blood flow in orbital microcirculation. METHODS AND FINDINGS Doppler velocimetry findings of 71 patients with sickle cell anemia and 32 healthy participants were compared. For ophthalmic artery, using t test for two independent samples, there was significant difference between the means of the controls and patients with sickle cell anemia in the following indexes: PSV in all age subgroups ( p 0.026; p 0.005; p 0.001), EDV and MV in subgroups II (p 0.028 and p 0.009) and III ( p 0.011 and p 0.002), RI and PI in subgroup I (p 0.010 and p 0.014) and RI in subgroup III (p 0.030). For the central retinal artery, in the same test, another significant difference was obtained in the following values: PSV in subgroup III ( p 0.008), EDV in all subgroups ( p 0.002, p 0.022, p < 0.000), MV in subgroup III, RI and PI ( p < 0.000) in all subgroups. In the central retinal artery, for RI, Pearson linear correlation values were: -0.665 for RBC, -0.628 for HB and -0.641 for HT; for PI, the findings were: -0.669 for RBC, -0.631 for HB and -0.664 for HT. CONCLUSIONS The results showed increased levels for speeds in the ophthalmic artery and reduced levels in the central retinal artery for the entire group of individuals with sickle cell anemia, as well as statistically significant values for most speed variables, in subgroup analyzes. A strong correlation was found between resistivity and pulsatility rates of the retinal circulation and the variables: numbers of red blood cells, hemoglobin and hematocrit.