PLAT and snowflake vitreoretinal degeneration: Although the ECASS and NINDS trials showed the efficacy of intravenous tPA in all patients regardless of stroke subtype (The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group 1995; Hacke et al. 1995), a subsequent study proposed that the benefits for patients with SVD may be attributable to a younger age and milder stroke severity (Hsia et al. 2003; Fluri et al. 2010).