Approximately 40% of patients presenting with idiopathic AAU have undiagnosed SpA. A simple to apply algorithm is described with excellent sensitivity and specificity.

AU affects physical aspects of quality of life more than is appreciated by clinical variables, especially in those with pre-existing, undiagnosed SpA. This study is unique in examining the effect of SpA on patients prior to diagnosis. These results highlight the role of the ophthalmologist in identifying patients with SpA who present with AU using the DUET algorithm.