Behçet's disease.

Behçet's disease is characterized by three primary components: iridocyclitis (historically with hypopyon), aphthous lesions in the mouth, and ulceration of the genitalia. Erythema nodosum, arthropathy and thrombophlebitis often accompany these manifestations, but the ocular symptoms may be the most important and serious manifestations of the disease. Central nervous system involvement, most often due to necrotizing vasculitis, may be the most protean manifestation of the disease, leading to death. The frequency of ocular manifestations is 70-85% in patients with the disease; the underlying disease mechanism in all organ systems is an occlusive vasculitis. Although the most common ocular symptom is that of anterior uveitis, often with hypopyon as a very late sign, the presence of necrotizing retinal vascular lesions is well known and often obscured by the severity of the anterior reaction. Definitions, incidence, clinical characteristics, differential diagnosis, and management of Behçet's ocular disease are discussed, as are the interrelationships of the different organ manifestations. The ophthalmologist should be familiar with the full spectrum of disease presentation since he or she may be the first physician to encounter the Behçet's patient.