Idiopathic uveitis is frequently the most common diagnosis in series from uveitis clinics. This study sought to determine the percentage of patients initially diagnosed as idiopathic, noninfectious uveitis referred to a tertiary uveitis center who were subsequently found to have an identifiable cause of uveitis.

Retrospective case series.

We performed a computerized database analysis of 179 consecutive patients who were referred to our practice with the diagnosis of idiopathic, noninfectious uveitis between 2008 and 2016. Patients were evaluated by a thorough history and ophthalmic examination with selected laboratory testing targeted by clues from the history and examination. Standardization of Uveitis Nomenclature (SUN) criteria were used to better assess different types of uveitis.

Fifty-two out of 179 (29.0%) patients initially diagnosed with idiopathic uveitis were subsequently diagnosed with an underlying condition. Among patients referred with a diagnosis of idiopathic disease, female patients were most commonly affected (121/179; 67.6%). Among subsequent diagnoses, sarcoidosis was the most common (19/52 or 36.5%), followed by HLA-B27-associated uveitis (11/52, 21.1%), infectious uveitis (6/52, 11.5%), tubulointerstitial nephritis with uveitis (6/52, 11.5%), and juvenile idiopathic uveitis (4/52, 7.7%). Other diagnosable conditions included Behçet disease, multifocal choroiditis, panuveitis, Crohn disease, multiple sclerosis, and relapsing polychondritis. An underlying condition was not found in 127 of 179 (70.9%) patients.

We report that 29% of patients referred to our tertiary uveitis center diagnosed as “idiopathic” had an associated identifiable cause. Identifying an underlying condition associated with uveitis could be potentially lifesaving for some illnesses (eg, sarcoidosis with cardiac involvement) and is critical to management (eg, infection). Although we were able to use limited testing to classify many patients who had been previously incorrectly labeled with idiopathic uveitis, idiopathic uveitis remains the most common diagnosis in our uveitis clinic.