In this study, we investigated whether the phenotypic difference observed between two lattice corneal dystrophy type 1 (LCD type 1) cases caused by either a single A546D substitution or a A546D/P551Q double substitution in TGFBIp, can be ascribed to (I) a difference in the proteomes of corneal amyloid deposits, (II) altered proteolysis of TGFBIp or (III) structural changes of TGFBIp introduced by the P551Q amino acid substitution.