Role of haemorheological factors in patients with retinal vein occlusion

Department of Medical and Surgical Critical Care, Thrombosis Centre, University of Florence, Viale Morgagni 85, 50134 Florence, Italy.
Thrombosis and Haemostasis (Impact Factor: 4.98). 12/2007; 98(6):1215-9. DOI: 10.1160/TH07-04-0247
Source: PubMed


Retinal vein occlusion (RVO) is an important cause of permanent visual loss. Hyperviscosity, due to alterations of blood cells and plasma components, may play a role in the pathogenesis of RVO. Aim of this case-control study was to evaluate the possible association between haemorheology and RVO. In 180 RVO patients and in 180 healthy subjects comparable for age and gender we analysed the whole haemorheological profile: [whole blood viscosity (WBV), erythrocyte deformability index (DI), plasma viscosity (PLV), and fibrinogen]. WBV and PLV were measured using a rotational viscosimeter, whereas DI was measured by a microcomputer-assisted filtrometer. WBV at 0.512 sec(-1) and 94.5 sec(-1) shear rates as well as DI, but not PLV, were found to be significantly different in patients as compared to healthy subjects. At the logistic univariate analysis, a significant association between the highest tertiles of WBV at 94.5 sec(-1) shear rate (OR: 4.91, 95% CI 2.95-8.17; p < 0.0001), WBV at 0.512 sec(-1) shear rate (OR: 2.31, 95% CI 1.42-3.77; p < 0.0001), and the lowest tertile of DI (OR: 0.18, 95% CI 0.10-0.32; p < 0.0001) and RVO was found. After adjustment for potential confounders, the highest tertiles of WBV at 0.512 sec(-1) shear rate (OR: 3.23, 95% CI 1.39-7.48; p = 0.006), WBV at 94.5 sec(-1) shear rate (OR: 6.74, 95% CI 3.06-14.86; p < 0.0001) and the lowest tertile of DI (OR: 0.20,95% CI 0.09-0.44, p < 0.0001) remained significantly associated with the disease. In conclusion, our data indicate that an alteration of haemorheological parameters may modulate the susceptibility to the RVO, by possibly helping to identify patients who may benefit from haemodilution.

Download full-text


Available from: Francesco Sofi,
  • Source
    • "These alterations affect the macrocirculation to a lesser extent, while it has a significant effect on microcirculation. The relevance of the rheological alteration in ocular disease has been investigated by Sofi F et al. [16]. The authors of this article studied the hemorheological profile in 180 patients with retinal vein occlusion (RVO) and in 180 healthy subjects comparable for age and gender. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Gingko biloba has been used for hundreds of years to treat various disorders such as asthma, vertigo, fatigue and, tinnitus or circulatory problems. Two of the main extracts are EGb761 and LI 1370. Most pharmacological, toxicological and clinical studies have focused on the neuroprotective value of these two main extracts. Neuroprotection is a rapidly expanding area of research. This area is of particular interest due to the fact that it represents a new avenue of therapy for a frustrating disease that may progress despite optimal treatment. One such disease is glaucoma. Glaucoma leads to the loss of retinal ganglion cells and their axons but also to tissue remodelling which involves both the optic nerve head and the retina. In the retina the astrocytes get activated. In addition, the optic nerve gets thinner and the cells of the lateral geniculate ganglion disappear partially. On average, ocular blood flow (OBF) is reduced in glaucoma patients in various tissues of the eye. Increased intraocular pressure (IOP) is a major risk factor for glaucomatous damage. Nevertheless, there is little doubt that other risk factors besides IOP are involved. One such risk factor is a primary vascular dysregulation (PVD) occurring in patients with a disturbed autoregulation, another risk factor is oxidative stress.
    Molecular vision 02/2012; 18:390-402. · 1.99 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Blood viscosity plays a key role in regulating microvascular flow and alte - rations of hemorheological variables can lead to hyperviscosity, thus favo- ring the occurrence of occlusive thrombotic events. In the last few years an association between alterations in the hemorheologic profile and the seve - rity of blood flow disturbances has been emphasized in several clinical and experimental conditions, possibly contributing to a better understanding of the pathophysiology of vascular disorders. The presence of alterations in he- morheological variables proved to be associated in several studies with an increased risk of cardiovascular disease and a higher mortality. The role of blood viscosity has also been analyzed in retrospective studies, which de- monstrated that alterations in some hemorheological variables may increase the incidence of embolic events in patients with atrial fibrillation and may influence the responsiveness to antiplatelet drugs in patients with acute coro - nary syndromes. Recently, alterations of some hemorheological parameters were shown to be associated with complete occlusion of coronary arteries, favoring the occurrence of myocardial infarction with ST-segment elevation. In patients with this clinical condition, an increase in blood viscosity and some of its determinants was associated with increased infarct size and worse acute left ventricular dysfunction. Finally, the results of some observational clinical studies have shown that alterations of hemorheological variables may help to explain the pathophysiological mechanisms of some clinical disorders in which microvascular damage has been demonstrated, such as idiopathic sud- den sensorineural hearing loss, retinal vein occlusion, and systemic sclerosis. (G Ital Nefrol 2009; 26 (Suppl. S46): S20-9)
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with polycythemia vera (PV) have a JAK2 (a cytosolic tyrosine kinase) mutation and an increased risk of vascular thrombosis related to red blood cell (RBC) mass and platelet activation. We investigated functional RBC abnormalities that could be involved in thrombosis. RBC adhesion to human umbilical vein endothelial cells (HUVECs) was measured by a radiometric technique and in a flow system by video microscopy, and adhesion molecule expression was determined using specific antibodies (against CD36, CD49d, ICAM-4, Lu/BCAM, CD147, and CD47) and flow cytometry in a group of 38 patients with PV and a group of 36 healthy volunteers. Adhesion of PV RBCs was 3.7-fold higher than that of normal RBCs (P < .001). Adhesion was inhibited when PV RBCs were incubated with anti-Lutheran blood group/basal cell adhesion molecule (Lu/BCAM) or when HUVECs were treated with anti-laminin alpha(5) and to a lesser extent with anti-alpha(3) integrin. Lu/BCAM was constitutively phosphorylated in PV RBCs. Transfection of K562 cells with JAK2 617V>F resulted in increased expression and phosphorylation of Lu/BCAM. Phosphorylation of Lu/BCAM increases RBC adhesion. Our results indicate that JAK2 mutation might be linked to Lu/BCAM modification and increased RBC adhesiveness, which may be a factor favoring thrombosis in PV.
    Blood 08/2007; 110(3):894-901. DOI:10.1182/blood-2006-10-048298 · 10.45 Impact Factor
Show more