Four cases of macular dystrophy in siblings were studied, 2 brothers and 2 sisters (49, 52, 55, 57 years old). The two youngest had an associated cornea guttata. We performed histologic, transmission, and scanning electron microscopic studies, and in addition a morphometric analysis of Descemet's membrane and of guttata excrescences. Previous studies have been confirmed and the problem of the relationship between the two conditions of macular dystrophy and guttate excrescences is emphasised.