A foot ulcer was defined as a full-thickness lesion penetrating through the dermis. Abundant callus was defined as callus formation requiring treatment (i.e., sharp debridement), a blister as collection of fluid underneath the epidermis, and a fissure as a crack-like lesion of the skin. Before the study started, the two observers assessed a patient in front of each other to discuss
presence of signs of diabetic foot disease and to reach uniformity in evaluation.