The Case of IgG4-related Ophthalmic Disease Accompanied by Compressive Optic Neuropathy.

A 76-year-old woman was diagnosed with thyroid-associated orbitopathy (TAO) associated with hypothyroidism at another clinic. Magnetic resonance imaging showed enlargements of the extraocular muscles. Because her best-corrected visual acuity (BCVA) was 0.01OD, she was referred to the Chiba University Hospital. She had an elevation of serum IgG4. She was diagnosed with possible IgG4-related ophthalmic disease (IgG4-ROD) accompanied by optic nerve compression with the mass. She underwent methylprednisolone pulse therapy, and, two months later, her BCVA and visual field defect were greatly improved. Our findings indicate that ophthalmologists should be aware that IgG4-ROD can be masked by lesions associated with TAO.