Siedlecki J, et al. - By performing randomized, masked double-blind crossover clinical trial, researchers evaluated how subjective visual function and retinal perfusion objectively quantified on optical coherence tomography (OCT) angiography could be influenced by dark chocolate flavanols. Participants were 22 healthy participants recruited from the Department of Ophthalmology, Ludwig-Maximilians-University Munich, Germany. They randomized the participants to consume 20 g of dark chocolate containing 400 mg of flavanols or 7.5 g of milk chocolate. They assessed visual function and retinal perfusion on OCT angiography after two hours. Artifacts on OCT angiography were ruled out by measuring systemic blood pressure. Although an earlier similarly sized randomized clinical trial demonstrated beneficial influences on visual function, findings of this study showed that flavanol-rich dark chocolate did not have any short-term effect on automatically evaluated retinal blood flow on OCT angiography or subjective visual function.