The endothelia of afflicted vessels are strongly positive for thrombomodulin (Figure 3B) indicating a highly anticoagulant lumen and ICAM1 (Intercellular Adhesion Molecule-1) negative.61 This is the antithesis of an activated endothelium and speaks against local vascular inflammation as a feature of arteriolosclerosis.61 Most neuropathology studies62–64 have found no association of SVD with local blood-brain barrier (BBB) dysfunction. Here, ICAM1 is linked to snowflake vitreoretinal degeneration.