Inflammatory Eye Disease

The eye and orbit are frequently the targets of immune-mediated inflammation, either as the sole organ involved or as part of a multi-organ system disease. The uveal tract is divided into anterior, intermediate, and posterior segments. “Anterior uveitis” and “iritis” are synonyms. Systemic inflammatory disorders tend to involve the eye in characteristic manners. As examples, disorders associated with HLA-B27 often cause a highly symptomatic anterior uveitis; Behçet’s disease can cause a panuveitis or a subclinical but ultimately vision-threatening posterior uveitis; and granulomatosis with polyangiitis (GPA) is associated with scleritis, peripheral ulcerative keratitis, and orbital pseudotumor. The diagnosis of systemic disease can therefore be inferred from the specific types of ocular involvement. Diagnosis of the eye manifestation is also assisted by clues from the involvement of extra-ocular organs. Thyroid eye disease, which is the most common cause of orbital inflammation, may be either unilateral or bilateral. “Idiopathic orbital inflammation” is quite common and can only be diagnosed after diagnostic testing to exclude identifiable etiologies. A complete evaluation includes a biopsy. IgG4-related orbital disease is an increasingly recognized cause of disease in this area, providing an explanation now for many cases of disease previously judged to be “idiopathic.” IgG4-related orbital disease can affect several structures within the orbit, particularly the extra-ocular muscles. The lacrimal gland is often affected by systemic diseases (e.g., IgG4-related disease, GPA, and sarcoidosis).