Correlation between retinal microcirculation and blood viscosity in patients with hyperviscosity syndrome

Hyperviscosity syndrome leads to vascular disturbances in different organs. In the retina typical ophthalmoscopic changes can be found including dot and blot hemorrhages, retinal and optic nerve head edema, and increased diameter of retinal veins. In this study we examined the retinal microcirculation in patients with hyperviscosity syndrome. Nineteen patients (14 patients with Waldenstroem's macroglobulinemia, two patients with kryoglobulinemia, three patients with plasmacytoma) were examined. All patients underwent a video fluorescein angiography. In all angiograms the arteriovenous passage time (AVP) and the arm retina time (ART) were quantified. In addition, hematocrit (Hct) and plasma viscosity (ETA) were measured. In patients with hyperviscosity syndrome AVP was significantly prolonged in comparison to healthy volunteers (AVP: 2.5+/-1.3 s vs. 1.5+/-0.4 s; p < 0.01). The ART showed no significant differences. Plasma viscosity was doubled in patients as compared with reference values (ETA: 2.57+/-1.5 mPa s vs. 1.24+/-0.08 mPa s; p < 0.01). In this study we showed an increase in plasma viscosity as well as an increase in arteriovenous passage time. This may result in retinal circulatory disturbances and may cause the typical fundus changes in patients with hyperviscosity syndrome.