Approach to the diagnosis of the uveitides.

PURPOSE: To describe an approach to diagnosing the uveitides, a collection of about 30 separate diseases characterized by intraocular inflammation.
DESIGN: Perspective.
METHODS: Integration of clinical approach with a more formal, informatics-derived approach to characterization and a Bayesian approach to laboratory testing.
RESULTS: The patient's uveitis is characterized along several dimensions: course, laterality, anatomic location of the inflammation, morphology, presence of active infection, and the host (age, presence of a systemic disease). Posterior uveitis can be characterized further by whether it is primarily a retinitis, choroiditis, or retinal vasculitis; by whether it is paucifocal or multifocal; and by the morphology of the lesions. This characterization narrows the differential diagnosis to 1 or, at most, a few diseases. Laboratory screening (ie, testing all patients) should be reserved for those diseases that can present as any type of uveitis, whereas targeted testing (ie, testing a subset with specific features) is used selectively. Laboratory testing should be used to identify an infection (which will alter therapy) or a systemic disease that will affect the patient's health. A uveitis that is not one of the established diagnoses is designated as "undifferentiated" with the course, laterality, and anatomic location (eg, undifferentiated bilateral chronic anterior uveitis). We avoid the term "idiopathic" uveitis as most identified noninfectious uveitic diseases are idiopathic, and most systemic diseases associated with uveitis also are idiopathic (eg, juvenile idiopathic arthritis).
CONCLUSION: This approach should lead to the correct diagnosis of the specific uveitic disease in the large majority of cases without overuse of laboratory testing.