Background Uveitis may be associated to systemic immune-mediated diseases or may be due to infectious agents, traumatisms, malignancies or medications. A variable part of uveitis remains idiopathic and few data are available on their evolution.

Objectives The primary aims of the study were: 1) to explore the clinical pattern of the uveitis in a cohort of patients, who have been followed in the last 7 years in a multidisciplinary uveitis clinic of a rheumatologic referral center; 2) to prospectively study the long-term outcome of patients with a previous diagnosis of idiopathic uveitis.

Methods The study design consists of two stages:

1) Cross-sectional study, evaluating the clinical pattern and diagnosis of all consecutive patients with uveitis examined from January 2007 to January 2014.

2) Prospective cohort study, exploring the long-term (at least 5 years of follow-up) outcome of patients with a diagnosis of idiopathic uveitis.

Patients were classified according to International Uveitis Study Group definitions. All patients had a comprehensive rheumatologic and internist evaluation. The diagnosis of autoimmune systemic disease was performed according to international criteria currently used in clinical practice. The diagnosis of infectious uveitis was performed by mean of clinical examination and serology. Moreover, all patients had a comprehensive ophthalmological evaluation, including: ocular clinical history, Snellen visual acuity, slit-lamp examination, applanation tonometry and dilated fundus examination; visual field, fluorescein-angiography and optical coherence tomography were performed when required. Moreover, all patients underwent the standard protocol of serological examinations for uveitis. Patients with a diagnosis of idiopatic uveitis were prospective evaluated every 6 months.

Results One hundred and fifty-seven patients (M/F: 99/58, mean age ± SD: 42±7 years) were studied in the cross-sectional stage. The most common ocular feature was represented by anterior uveitis, that was present in 64 (41%) patients, followed by posterior uveitis reported in 50 (32%); panuveitis was present in 18% of the cohort and intermediate uveitis in 9%. For 92 of 157 (59%) patients with uveitis, a specific etiologic diagnosis was established, while 65 (41%) of patients were found to have an idiopathic uveitis. Fuchs' heterochromic iridocyclitis and Behçet's disease (BD) represented the most common causes of anterior and posterior uveitis respectively, while among infectious uveitis we reported a relatively high frequency of types secondary to herpetic infection. Fifty-six patients out of 65 with a diagnosis of idiopathic uveitis were followed for at least 5 years in the prospective cohort stage. After this period, 10/56 patients had a diagnosis of BD, the other still remained idiopathics

Conclusions Our results have shown that the most common anatomical site of inflammation is still represented by the anterior segment. Notably, data from our prospective cohort study, suggest that also after several years, a significant part of idiopathic uveitis may still express symptoms suggestive of a systemic autoimmune disease, such as BD; this is of particular interest, since a tight control during the follow-up is mandatory in all case of idiopathic uveitis.

Disclosure of Interest None declared