A prospective study on the etiology of uveitis.

We prospectively studied and classified 152 cases of endogenous uveitis treated at the Ophthalmological Clinic in Split, Yugoslavia, according to clinical presentation, several immunologic parameters including HLA subtyping, and the presence of an associated systemic disease. Using our diagnostic criteria we successfully classified 91.4% of patients. Anterior uveitis was the most common form of clinical presentation (94 patients, 61.8%), whereas an intermediate uveitis was present in only 5.3% of patients (8 patients). By HLA typing we found that 115 patients (75.7%), were positive for HLA-B27 (57 patients, 50%), B5 (30 patients, 26%) and B35 (28 patients, 24%) risk antigens. Of these patients 96 (83%) had an associated systemic illness. In the 8.6% of cases (13 cases) in which the etiology of an endogenous uveitis was not determined, none were associated with an HLA-B risk antigen. Our study emphasizes the association of HLA-B risk antigens and concurrent systemic disease in patients with endogenous uveitis.