Blood rheology in acute anterior ischemic optic neuropathy

Abstract

Rheological parameters (hematocrit, plasma viscosity, red blood cell aggregation and red blood cell rigidity) and the plasma proteins fibrinogen, alpha-2-macroglobulin and immunglobulin M were measured in 70 patients with acute anterior ischemic optic neuropathy (AION). In all patients AION was diagnosed by acute decrease of central visual acuity and visual field, typical ophthalmoscopic and angiographic fundus changes and exclusion of other causes of papilledema.

The mean values of hematocrit (men 46 ± 4% ,women 43 ± 5%), RBC aggregation (14,0 ± 5,0, normals: 14,6 ± 3,2) and RBC rigidity (0,99 ± 0,07, normals: 1,01 ± 0,09) were equal to normals. Plasma viscosity (1,40 ± 0,14 mPas, normals: 1,24 ± 0,05 mPas) was increased. A significant correlation was found between plasma viscosity and the plasmaproteins fibrinogen (0,55) and (in women) Immunglobulin M (0,46).

Patients with AION and giant cell arteritis showed higher plasma viscosity than patients with AION and no giant cell arteritis. In patients with non-arteritic AION the presence or absence of hypertension or diabetes mellitus seems not to influence the blood rheology. The altered plasma viscosity in AION may be one of the reasons for disturbed microcirculation in AION.