Background/Purpose: Acute anterior uveitis (AAU) can be associated with axial spondyloarthritis (axSpA). Previous studies even described undetected axSpA in 40% of the patients with noninfectious AAU. Currently, axSpA patients still suffer an important diagnostic delay. The objective was to investigate whether referral of all patients with AAU and chronic back pain results in a high prevalence of newly diagnosed axSpA patients.

Methods: In April 2017 the prospective (ongoing) observational Sp-EYE study was started to include all patients with noninfectious AAU and chronic back pain (≥3 months, started < age of 45 years) who were referred from nine Ophthalmology clinics to the Rheumatology department of the VU university medical center. Exclusion criteria were: history of a rheumatic or other known systemic disease associated with uveitis. At the Rheumatology department sociodemographic, clinical (e.g. duration of back pain, extra-articular manifestations, BASMI), laboratory (HLA-B27, C-reactive protein) and radiographic parameters were collected, as well as patient reported outcome parameters (e.g. BASDAI, ASDAS, ASAS Health Index). The diagnosis of axSpA was made by the rheumatologist. According to the ASAS criteria, diagnosed patients were classified into radiographic or non-radiographic axial spondyloarthritis.

Results: In the first year, 42 patients were referred to the Rheumatology department, of whom 32 (median age 35 years; 47% female) met all the inclusion criteria. See also table 1. At referral, 63% of the patients already had a history of more than one AAU and the median back pain duration was 11 years (table 1). AxSpA was diagnosed in 10 patients (31%, all HLA-B27 positive), of whom four fulfilled the criteria for radiographic and six for non-radiographic axSpA. Another 11 patients (34%, six HLA-B27 positive) were considered to be suspicious for early axSpA. An ASDAS-CRP score corresponding to a high disease activity (ASDAS ≥2.1) was found in 57% of the patients with a new diagnosis or a suspicion for axSpA. Treatment was started in 20 patients, mostly with nonsteroidal anti-inflammatory drugs (in 18). In one patient a tumor necrosis factor alpha inhibitor was started shortly after diagnosis, because of the severity of the axSpA.

Conclusion: In this study the referral of noninfectious AAU patients with chronic back pain led to a notably high number of new diagnoses of axSpA (31%). Another third of the patients was considered to be suspicious for beginning axSpA, requiring further follow up. These results stress the importance of systematic referral of AAU patients from the ophthalmologist to the rheumatologist in order to improve early recognition of axSpA.