The relationship between the nature and severity of inflammatory eye disease was analyzed with respect to HLA antigens and alpha 1-antitrypsin phenotypes. Using standard ophthalmologic criteria, we divided patients with anterior uveitis into acute, chronic (greater than 3-month duration), bilateral, or recurrent disease. There was a significantly increased incidence of alpha 1-antitrypsin-deficient phenotypes in anterior uveitis, especially in those patients with severe (chronic, bilateral, or recurrent) disease. HLA-B27 acts as an independent predisposing factor: it was present in 22% of patients with their first attack of acute uveitis compared with 51% of patients with recurrent disease. Together, these genetic factors are present in 63% of patients with severe anterior uveitis and represent the most significant predisposing and prognostic factors so far detected.