Association between recurrent acute anterior uveitis and ankylosing spondylitis

Introduction: Anterior uveitis stands out as the most frequently encountered extra articular findings of ankylosing spondylitis (AS). Anterior uveitis associated with AS is frequently encountered as acute anterior recurrent uveitis (AARU). Objective: To analyze the association between recurrent acute anterior uveitis and the subsequent incidence of ankylosing spondylitis. Materials and Methods: This retrospective study was conducted in the Department of Ophthalmology and Orthopedics at Akbar Niazi Teaching Hospital, Islamabad Pakistan, from January 2018 to February 2023. AS patients with newly diagnosed acute anterior recurrent uveitis (AARU) (n=200) and matched control subjects without uveitis (n=200) were included in the study. AARU was diagnosed consecutively at 120-day intervals and managed with local or systemic steroids. AS incidence rates were based on the frequency of uveitis episodes, and incidence ratio were determined using the rate of incidence in control group as a reference. Data analyses were conducted using SPSS v 25. Results: AS rate of incidence after first uveitis episode was 40.6, compared to 5.6 in control group (IRR 3.7; 95% CI, 2.5–5.5). After second episode, increased IRR to 8.9 (95% CI, 5.2–15.0). In male patients with AARU, the incidence rates of AS were 94.7 per person year. In patients ≤ 40 years old, the IRR of AARU was 15.6 (95% CI, 6.5–37.2). In patients aged ≥ 60 years, the incidence of AS in AARU did not differ from the control group. Conclusion: The subsequent AS risk increased with frequency of acute anterior recurrent uveitis episodes. This analysis could help establish an importance for additional evaluation for potential systemic association in AARU.