[Etiological studies in cases of uveitis--the value of diagnostic tests]

In clinical practice it may be difficult to determine the cause of uveitides because the etiopathogenic mechanisms are not yet well known. From the present state of our knowledges, it appears that an etiological research must concern 1) the causal agents (bacterial, viral, parasitic or fungal), 2) the mechanisms (allergy, association to HLA antigens...), 3) systemic diseases associated to uveitis (for example sarcoidosis) and 4) clinical entities (such as sympathetic ophthalmia, Fuchs' cyclitis...). Concerning methodology, an etiological research in uveitis patients must begin with a careful clinical examination and an elaborate anamnesis which will give information about a possible etiology to be confirmed by appropriate laboratory tests.