[Chronic severe uveitis: classification, search for etiology and therapeutic approach].

PURPOSE: Severe chronic and refractory uveitis is a major diagnostic and therapeutic challenge for ophthalmologists and internists. Molecular tools, such as PCR but also new imaging techniques, have significantly changed the diagnostic approach during the last 10 years. Presumed and empirical diagnosis should be excluded in the face of atypical clinical presentations. CURRENT KNOWLEDGE AND KEY POINTS: A retrospective study based on 927 consecutive patients presenting with severe uveitis between 1991-1996, has recently defined the epidemiological characteristics and the visual outcome of this group of patients. An associated condition was determined in 67.5% of cases, divided in 4 different subgroups: infectious uveitis; uveitis associated with a systemic disease; eye-limited, presumed immune-mediated disorder and idiopathic eye-limited disorder. The management of patients with sight-threatening forms of uveitis is efficiently performed in collaboration with internists and depends on a complete diagnostic procedure and a well-adapted treatment. FUTURE PROSPECTS AND PROJECTS: Extensive work-up is mandatory when the therapeutic response seems atypical with resistance to corticosteroids and classical immunosuppressive drugs. Infectious uveitis should be excluded in severe and intractable forms of uveitis. Thereafter, new therapeutic strategies based on type I interferon and anti-TNF molecules can be proposed in order to decrease the potential risk of blindness in this young group of patients.