Panuveitis of undetermined origin after diagnostic pars plana vitrectomy: clinical characterization and long-term outcome from a tertiary referral center

Purpose To identify the characteristics and outcome of panuveitis of undetermined origin (PUO) after diagnostic vitrectomy.Methods Retrospective analysis of all patients who underwent vitrectomy for diagnostic/therapeutic purposes from 2013 to 2020, whose vitreous biopsies turned out negative and final diagnoses were not clinically supported.Results Of 122 operated eyes, 36 eyes (29.5%) were defined as PUO (67.8 +/- 14.9 years). The presenting clinical picture revealed a predominantly bilateral condition (70% of eyes) with significant posterior segment involvement: 3.1 +/- 0.6 vitritis, 61.1% of eyes with retinal vasculitis, 44.4% with macular edema, and 30.6% with exudative retinal detachment. Presenting visual acuity was 1.2 +/- 0.7 logMAR, and up to 90% remained stable or improved vision over a similar to 3.5 year observation period. None of the presenting clinical features turned out to be predictive of final visual outcome or survival.Conclusions PUO is present in up to 30% of cases after diagnostic/therapeutic vitrectomy. This mainly bilateral condition shows chronic and overall stable long-term outcome, generally with retained steady visual function.