Ocular manifestations of small-vessel vasculitis

Ophthalmic manifestations of vasculitis can be orbital, ocular (affecting the globe), or intraocular. Orbital inflammation manifests as sudden onset of pain, erythema, and proptosis, and can be sight-threatening. In the globe, red eye is typical in both episcleritis and scleritis. Episcleritis is usually otherwise asymptomatic with blanching upon instillation of topical phenylephrine, whereas scleritis is painful and does not blanch. Infectious and rheumatic diseases are present in nearly 50% of patients with scleritis. The symptoms of keratitis are similar to those of scleritis; superficial keratitis is benign but peripheral ulcerative keratitis can be sight-threatening. Anterior uveitis is the most frequent ocular manifestation of Behçet disease. Approximately 30% of patients with granulomatosis with polyangiitis (Wegener's granulomatosis) have ocular involvement, with orbital disease being most common. With ophthalmic manifestations of vasculitis, tissue biopsy of any site that is amenable to biopsy is recommended. Biopsy must be interpreted within the context of treatment.