Willerslev A, Larsen M, Rothenbuehler SP, et al. - Using optical coherence tomography (OCT), researchers sought to image retinal blood vessels in patients with Waldenström's macroglobulinemia. They investigated fundus photographs and OCT scans of 16 eyes in eight patients with Waldenström's macroglobulinemia. Six out of eight patients showed normal intravascular reflectivity and retrovascular shadowing in cross-sectional OCT scans of larger retinal vessels (diameter > 100 μm). According to findings, Waldenström's macroglobulinemia and total IgM > 60 g/l were linked to abnormal intravascular reflectivity and retrovascular shadowing on OCT. Awareness of these indications of hyperviscosity could possibly allow the previous detection of critical conditions in patients with Waldenström's macroglobulinemia and enhance the evaluation of severity and effect of treatment.