Abstract
Abstract: :
Purpose:Hyperviscosity syndrome (HVS) is a common complication of Waldenström’s macroglobulinemia (WM), a malignant monoclonal IgM gammopathy. Retinopathy with visual disturbance and central retinal vein occlusion–like appearance is the most prominent symptom of HVS. Therefore, the retina provides a unique opportunity to diagnose HVS and to examine the response of the vasculature to reduced serum viscosity following plasmapheresis treatment. The purpose of this study was to investigate the effect of plasmapheresis on retinal hemodynamics and retinopathy in patients with WM–associated HVS. Methods: Six patients (5 males and 1 female, average age 60.5 yrs) with WM were studied. All underwent slitlamp biomicroscopy, indirect ophthalmoscopy with scleral depression, fundus photography, blood pressure check, and laser Doppler retinal blood flow testing (Canon Laser Doppler Flowmeter, CLBF 100) before and after plasmapheresis. Serum viscosity (SV) and IgM levels were also measured before and after treatment. The Wilcoxon Signed Rank Test was used for pre– and post–treatment comparisons, and linear regression analysis was used to examine correlations. Results:Plasmapheresis caused a significant reduction in serum IgM (mean reduction 39%, p<0.028), SV (mean reduction 38%, p<0.028), systolic (mean reduction 12%, p<0.043) and diastolic blood pressures (mean reduction 15%, p<0.043). Retinal veins showed a significant mean reduction in diameter of 14% (p<0.005). In contrast, venous retinal blood speed increased significantly (mean increase 44%, p<0.028). This combination yielded a non–significant mean blood flow increase of 5.1%, indicating a well–functioning retinal blood flow autoregulation system in these patients. After plasmapheresis, patients showed fewer retinal hemorrhages, less venous tortuousity, and decreased disc edema if initially present. We found a significant correlation between the changes in SV and retinal vein diameter (p<0.005, Rsq=0.892), and between the changes in IgM levels and retinal vein diameter (p<0.02, Rsq=0.776). Conclusions:Plasmapheresis is effective in reducing HVS–related retinopathy and normalizes retinal hemodynamics. Changes in SV and IgM levels are well correlated with changes in retinal vein diameters following treatment. Examination of the retina may be useful in identifying the symptomatic threshold of plasma viscosity levels in patients with HVS.
Keywords: blood supply • retina • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled