Diagnostic vitrectomy for the diagnosis and management of posterior uveitis of unknown etiology

Purpose of review Diagnostic vitrectomy is performed in cases of posterior segment inflammation that are suspicious for malignancy or infection and require tissue confirmation. Advances in vitrectomy technique and laboratory tests have improved the diagnostic yield in these challenging cases. The methods for obtaining vitreous specimens and the diagnostic tests used to analyze them are discussed. Recent findings Ancillary tests have been invaluable in addressing the diagnostic limitations of traditional histopathologic and microbiologic analyses. Flow cytometry, gene rearrangement studies, and cytokine measurements are useful adjuncts to cytology for the diagnosis of malignancy, in particular primary intraocular lymphoma. Microbial DNA amplification by polymerase chain reaction and intraocular antibody measurement has been shown to detect the presence of infection by organisms that are difficult to culture. Summary When performed appropriately, diagnostic vitrectomy with carefully selected ancillary testing can lead to a definitive diagnosis in a large proportion of cases.