This randomized, double-blind, placebo-controlled, parallel-group study evaluated the effects of six-month oral supplementation with Cornus mas fruit lyophilizate in patients with metabolic syndrome. Participants were assigned to receive either 8 g of Cornus mas fruit lyophilizate once daily or a matching placebo. Ophthalmic assessments included best-corrected visual acuity, slit-lamp examination, dilated fundus examination, applanation tonometry, and Doppler ultrasonography of the ophthalmic, central retinal, and posterior ciliary arteries. Cardiometabolic and biochemical parameters were also assessed at baseline and after 3 and 6 months of supplementation.