IgG4-related ophthalmic disease

Lore & Background

IgG4-related ophthalmic disease can involve one or more orbital structures, with the lacrimal glands, extraocular muscles, infraorbital nerve, supraorbital nerve, and eyelids frequently affected. Symptoms, if any, can be mild even in the presence of significant swelling or masses.

Reader's Guide

IgG4-related ophthalmic disease is significant as a distinct orbital condition that accounts for approximately 25% of all cases of proptosis, eyelid swelling, and other features of orbital swelling. Its recognition allows for targeted steroid therapy, which typically produces a prompt response unless significant fibrosis has already occurred. The condition can cause loss of vision, skin irritation, and loss of brain function. Diagnosis is aided by MRI, which demonstrates the extent of inflammation, and infraorbital nerve enlargement is considered a particularly suspicious sign, defined as the infraorbital nerve diameter exceeding the optic nerve diameter in the coronal plane. The recommended nomenclature includes specific terms for anatomical variations such as IgG4-related dacryoadenitis, dacryocystitis, orbital myositis, orbital nerve lesions, optic neuropathy, orbital inflammation, and pan-orbital inflammation. Previously, cases now considered IgG4-ROD were diagnosed as idiopathic orbital inflammatory disease or orbital pseudotumor.

Did You Know?

• IgG4-related ophthalmic disease is a relatively rare cause of orbital disease; no widely accepted figure of 25% of all orbital swelling cases exists in the literature.
• Infraorbital nerve enlargement (IONE) is defined as the infraorbital nerve diameter being greater than the optic nerve diameter in the coronal plane.
• A prompt response to steroid therapy is characteristic unless significant fibrosis has already occurred.
• Ligneous conjunctivitis is typically linked to plasminogen deficiency, not IgG4-related disease, and is not a recognized association with IgG4-ROD.