PRTN3 and optic nerve disorder: Similarly, a Japanese case series by Matsuo reported that patients with MPO-ANCA-associated vasculitis frequently develop ocular manifestations such as scleritis, peripheral keratitis, retinal vein occlusion, and optic neuropathy [10]. These observations suggest that although ocular involvement is less common in MPO-ANCA-positive GPA than in PR3-ANCA-positive disease overall, ocular vasculitic complications can still occur and may present with variable severity and morphology across populations.