Updates of ocular involvement in granulomatosis with polyangiitis

Granulomatosis with polyangiitis (GPA) is a systemic inflammatory disease characterized by necrotizing vasculitis of the small-to-medium-sized vessels. GPA results from irregular autoimmune response with elevation of anti-neutrophil cytoplasmic antibody (ANCA) and inflammatory damage of vascular endothelial cells and other tissues. Ocular involvement is common in GPA with various manifestations due to the different ocular tissues suffered, but mostly, it causes orbital mass, dacryocystitis, scleritis, conjunctivitis, and keratitis. The diagnosis of GPA is based on a comprehensive analysis of systemic manifestations of vasculitis, imaging examinations, laboratory test especially serum levels of ANCA, and histological biopsy. Immunosuppressive therapy has greatly lowered the mortality and improved the prognosis of GPA, and the emergence of biological therapy indicates a promising prospect for GPA treatment strategy. In this narrative review, we integrate the latest literature on GPA-induced ocular disorders, presenting the previous views and new understandings especially on epidemiology, etiology, molecular mechanism, clinical manifestation, diagnosis, and treatment of GPA-related ocular involvement.