Isovolemic Hemodilution in Ischemic and Non-Ischemic Retinal Vein Occlusion

Abstract

107 patients with retinal vein occlusion were treated by isovolemic hemodilution (IHD) within the first 8 weeks after appearing of symptoms. Hematocrit was stepwise lowered to 0.3 (to 0.35 in patients older than 75 years) by repeated exchanges of whole blood for plasma and dextran 40. IHD was repeated about 10 times over a period of six weeks. Fluorescein angiograms and rheological measurements (whole blood viscosity, plasma viscosity, red cell aggregability and filtrability) were done before and after IHD. Of 67 patients with central retinal vein occlusion 30 were of the ischemic type (≥. 10 cotton wool spots, arteriovenous passage time ≥ 20s). 43 % of this type showed an improvement of visual acuity after IHD, whereas only 17 % of patients with non-ischemic CRVO had a better visual acuity. Of 41 patients with retinal branch vein occlusion (RBVO) 20 were classified as ischemic types (≥ 3 cotton wool spots, defective foveolar arcade). 65 % of these ischemic types of RBVO improved after IHD, however, an increase of visual acuity after 3 months could only be observed in about 15 % of patients with non-ischemic RBVO. Rheological measurements were not different in ischemic and non-ischemic retinal vein occlusion.