The effect of uveitis and undiagnosed spondyloarthritis: a systematic review and meta-analysis.

Delay diagnosis of spondyloarthritis (SpA) is associated with poor functional ability and quality of life. Uveitis is the most frequent extraarticular manifestation in SpA, and its prevalence increases with longer disease duration. This study examines the effect of uveitis on the disease activity and functional outcome of undiagnosed SpA. We reviewed published and unpublished studies. Data were pooled using the random-effects model; pooled means, and mean differences (MDs) were calculated. In the included 14 studies, disease activity, functional index, and inflammatory markers were measured in 2581 patients with SpA with uveitis and 13,972 without. The pooled mean delay in diagnosis of SpA with uveitis (6.08 years; 95% CI 4.77 to 7.38) was longer than those without (5.41 years; 95% CI 3.94 to 6.89). The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score was the highest for a delay of 2-5 years (5.60, 95% CI 5.47 to 5.73) and the Bath Ankylosing Spondylitis Functional Index (BASFI) score was the lowest for a delay of < 2 years (2.92, 95% CI 2.48 to 3.37) and gradually increased to delay of > 10 years (4.17, 95% CI 2.93 to 5.41). Patients with SpA with uveitis had higher trend of Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP and BASDAI. The delay to diagnosis was longer in SpA with uveitis, and disease activity was often higher than those without uveitis. Early diagnosis of SpA with timely initiation of an appropriate management plan may reduce the adverse effects of the disease and improve functional ability.