[Orbital Manifestation of IgG4-Related Disease: Three Case Reports].

IgG4-related orbital disease is rare. It belongs to an entity of a multisystemic disorder - IgG4-related disease - which has emerged recently. Differential diagnosis comprises idiopathic orbital inflammation, endocrine orbitopathy and orbital neoplasms. MRI imaging and orbital biopsy are essential in making the diagnosis. Patients respond well to systemic steroids. We now describe three clinically markedly different manifestations of IgG4-related orbital disease.