FULL DIAGNOSTIC VITRECTOMY WITH POSTERIOR VITREOUS DETACHMENT INDUCTION FOR THE DIAGNOSIS OF VITRITIS DUE TO UNCERTAIN ETIOLOGY.

PURPOSE: To report on the diagnostic outcomes and safety of full diagnostic vitrectomy (FDV) with surgical posterior vitreous detachment induction for diagnosing vitritis of uncertain etiology. METHODS: Forty-nine patients underwent primary FDV using the cassette washings for histopathological analysis. In addition, an undiluted core vitreous sample was obtained for microbial analysis in suspected infective cases. Cases were retrospectively given a diagnosis of inflammatory, infective, or neoplastic based on the results at final follow-up and the outcome of primary FDV categorized as diagnostic or nondiagnostic. The success of FDV was evaluated in relation to the final diagnosis. The need for additional intraocular biopsies and intraoperative or postoperative complications was also recorded. RESULTS: Full diagnostic vitrectomy was diagnostic in 26/49 cases (53%) and nondiagnostic in 23 (47%). The diagnostic success rate was greatest in neoplastic (16/20, 80%) and infective cases (9/13, 69%). Seven cases (14%) required additional biopsies to establish the diagnosis, and in 15/49 cases (31%), no cause of vitritis was identified. Intraoperative retinal breaks occurred in 3/49 cases (6%) and retinal detachment in 1/49 cases (2%). Three of 49 cases (6%) developed transiently elevated intraocular pressure postoperatively. CONCLUSION: Full diagnostic vitrectomy in combination with an undiluted core vitreous biopsy for suspected infections is safe and effective at securing a diagnosis in vitritis, particularly in cases of neoplasia.