Clinical features of infectious posterior segment uveitis

OBJECTIVE: To assess the clinical findings and microbiology investigations in patients with suspected infectious posterior segment uveitis (PSU). DESIGN: Retrospective case study. METHODS: Between January and December 2014, medical records of 270 patients with PSU were reviewed. Baseline ocular examination, presumed and final diagnoses, microbiology investigations from aqueous or vitreous fluid, and peripheral blood were reviewed. RESULTS: Infectious PSU was suspected in 28 patients among 270 PSU cases (10.4%, 28/270), and 11 cases were of infectious origin (4.1%, 11/270). Six patients were immunocompromised: 5 patients in the confirmed infectious PSU group (45.5%, 5/11) and 1 in the confirmed noninfectious group (5.9%, 1/17; p = 0.002). Initial visual acuity was 1.8 ± 0.35 logMAR and 0.9 ± 0.23 logMAR for patients with confirmed infectious and noninfectious PSU, respectively (p = 0.04). Anterior chamber reaction was worse in patients with confirmed infectious PSU (1.8 ± 0.49) than confirmed noninfectious cases (0.5 ± 0.1; p = 0.003). The frequency of chorioretinitis among patients with confirmed infectious and noninfectious PSU is 54.5% (6/11) and 11.8% (2/17; p = 0.03), respectively. Onset of confirmed infectious uveitis was more acute (≤6 weeks in duration) than noninfectious cases (p = 0.0015). Among the 11 patients with positive blood culture or serology, 6 had anterior and vitreous chamber fluid analysis. The rate of positive cultures and PCR is 16.7% (1/6) for aqueous humour and 50% (3/6) for vitreous samples. CONCLUSIONS: Clinical features more suggestive of infectious PSU include immunosuppression, worse initial visual acuity, acute onset, worse anterior chamber reaction, and chorioretinitis. Further studies are needed to enhance the diagnostic yields of aqueous and vitreous fluid analyses.