Idiopathic multicentric osteolysis is a very rare syndrome characterized by progressive loss of bone, usually the capsal and tarsal bones, resulting in deformity and disability, as well as chronic renal failure in many cases. The bone and renal disorders are sometimes associated with intellectual deficit and facial abnormalities.

Distance between the inner canthi more than two standard deviations above the mean (objective); or, apparently increased distance between the inner canthi.