Successful glucocorticoid treatment case for IgG4-related long-standing optic neuropathy.

Immunoglobulin G4-related disease (IgG4-RD) is a systemic rheumatic disease characterised by the infiltration of IgG4-positive plasma cells and swelling or hypertrophic lesions in various organs. IgG4-RD also involves optic lesions, which is known as IgG4-related ophthalmic disease (IgG4-ROD). IgG4-ROD involves the surrounding tissues, causing optic neuropathy when it affects the optic nerve. Impairment of the optic nerve is often progressive, with delayed diagnosis and treatment leading to permanent visual loss. However, optic neuropathy due to IgG4-RD is rare and the visual prognosis is unclear. Herein, we present a case of long-standing optic neuropathy in IgG4-ROD with loss of light perception.