ANCA‐associated optic neuropathy

Antineutrophil autoantibodies (ANCAs) directed against either antiproteinase3 (anti‐PR3) or myeloperoxidase (anti‐MPO) are associated with a small vessel vasculitis in which the characteristic feature is a focal necrotizing damage of capillaries, venules and arterioles. The ANCA‐associated vasculitic syndromes are; granulomatosis with polyangiitis (formerly know as Wegener’s granulomatosis), microscopic polyangiitis, Churg‐Strauss syndrome and idiopathic necrotizing crescentic glomerulonephritis. Ocular and orbital manifestations may be a presenting manifestation of Wegener’s granulomatosis, in particular optic perineuritis. This presentation will review ANCA‐associated optic perineuritis and how it is distinguished from idiopathic optic perineuritis.