Evaluation of Factors Associated With Uveitis Onset Timing in Oligoarticular Juvenile Idiopathic Arthritis.

Objective: To evaluate the timing of uveitis onset in patients with oligoarticular juvenile idiopathic arthritis (oJIA) and to identify clinical characteristics associated with its development.

Methods: This medical records review study included 611 oJIA patients followed for at least 6 months between August 2016 and February 2024. Patients were classified as with uveitis (n = 96, 15.7%) or without uveitis (n = 515, 84.3%). Uveitis cases were further stratified by timing: group 1 (n = 65, 10.6%) developed uveitis after arthritis onset, whereas group 2 (n = 31, 5.1%) were diagnosed with uveitis at their first ophthalmologic evaluation. Demographics, clinical features, and treatment characteristics were compared across groups.

Results: Uveitis occurred in 15.7% of oJIA patients. Patients with uveitis had a significantly younger age at arthritis onset with a median of 4.3 years (interquartile range [IQR], 1.9-9.3 years), compared with those without uveitis (8.5 years; IQR, 5-11.5 years) (p < 0.001), and had a higher antinuclear antibody positivity rate (70.8% vs. 45.6%, p < 0.001). Methotrexate was the predominant initial treatment for oJIA, and the median duration of usage was 13 months (IQR, 6.8-26 months) until the onset of uveitis. Among the 81 patients who received etanercept as their initial biologic, 14 (17.3%) developed uveitis during the follow-up period. A total of 25 patients (26%) had ocular complications, with a significantly higher proportion observed in those with uveitis at their initial examination (n = 14, 45.1%) compared with those who develop uveitis after arthritis onset (n = 11, 16.9%) (p = 0.003).

Conclusion: Our study highlights younger age at oJIA diagnosis and antinuclear antibody positivity as significant risk factors for uveitis development. Uveitis in oJIA may occur before, concurrently with or after arthritis onset. Early recognition, routine screening, and timely therapeutic escalations are essential to improve outcomes in patients with oJIA-associated uveitis.