ABCA4 and age-related macular degeneration: Crocin rich-saffron supplementation modestly improved visual function and retinal flicker sensitivity in AMD [15,17]; however, it did not affect the VA and focal electroretinogram (fERG) response of the central retina in adenosine triphosphate (ATP) Binding Cassette Subfamily A Member 4 (ABCA4)-related Stargardt macular dystrophy [29].