Purpose: We report a case of bilateral infraorbital nerve enlargement (IONE) associated with immunoglobulin (Ig)G4-related ophthalmic disease and describe the associated histopathologic findings.
Case: An otherwise healthy 59-year-old man presented with bilateral exophthalmos and right visual disturbance. Orbital magnetic resonance imaging showed bilateral IONE and a soft tissue mass in the right orbit. Excisional biopsy in the left infraorbital canal was performed. Histopathologic assessment revealed IgG4-related disease involving the epineurium of the infraorbital nerve. The patient received systemic steroid therapy, to which he responded well.
Conclusion: IONE in IgG4-related ophthalmic disease is due to IgG4-related disease involving the epineurium.