Objective: To evaluate the importance of diagnostic-therapeutic pars plana vitrectomy in patients with clinical manifestations of endogenous uveitis. PatientsandMethods:Thediagnostic-therapeuticpars plana vitrectomy(DTPPV) has been performed at the Eye Clinic of General Faculty Hospital and 1st Medical Faculty on Prague on 62 eyes in 49 patients at the mean age of 45 years. The DT PPV was indicated in patients with uveitis of unusual clinical picture or poorly reacting to treatment, suspected infection or tumor etiology. In the beginning of PPV, 0.5 to 1.5 ml of undiluted vitreous body was samples and subsequently examined by microbiology, immunology and molecular genetic methods. PPV was performed on both eyes in 10 patients, on one eye twice in each of three patients. The authors evaluated 62 samples of vitreous body on the whole. The patients were observed for up to 96 months. Results: Laboratory examination of the samples of vitreous body from 22 eyes (35.4 %) supported our notion on infection etiology of intraocular inflammation, manifestations of intraocular tumor were in 12 eyes (19.3 %), vascular or vitreoretinal pathology was present in 6 eyes (9.6 %). Nonspecific inflammatory changes were detected in 22 eyes (35.4 %). Drugs were administered into the vitreous body in 16 eyes. In the observation period the authors detected marked late complications in connection with DD PPV in 18 eyes (29 %). Visual acuity improved by two or more lines of the Snellen optotypes in 43 eyes (69.3 %), remained unchanged in 11 (17.7 %) eyes. The vision deteriorated in 8 eyes (12.9 %). Conclusion: Based on this experience the authors are of the opinion that DT PPV is indicated in patients with uveitis for giving more precision to the diagnosis of intraocular inflammation or a masking syndrome. DT PPV also represents a therapeutic procedure to cure complications connected with a severe formof inflammation and makes it possible to save central visual acuity.

        Key words: endogenous uveitis, diagnostic-therapeutic pars plana vitrectomy, vitreous body, laboratory examination, vision, late complications