We aimed to survey the risk of external eye diseases in those with ankylosing spondylitis (AS) via the National Health Insurance Research Database (NHIRD) in Taiwan. We conducted a retrospective cohort study, and subjects diagnosed with AS were selected from the NHIRD. Then, the AS patients were matched 1:1 by propensity-score matching (PSM) to non-AS patients, and a total of 6754 participants were included in the AS and non-AS groups. The main outcomes were regarded as the occurrence of dry eye disease (DED), superficial keratopathy and corneal ulcers. We used Cox proportional hazard regression to yield the adjusted hazard ratios (AHR) with 95% confidence intervals (CI) between the AS and non-AS groups. There were 709 and 408 external eye disease events that occurred in the AS and non-AS groups after a tracking interval of up to 17 years. The incidence of all external eye diseases was significantly higher in the AS group than the non-AS group (AHR: 1.826, 95% CI: 1.616−2.063, p < 0.0001). Additionally, the rates of DED (AHR: 1.973, 95% CI: 1.701−2.290, p < 0.0001) and superficial keratopathy (AHR: 1.593, 95% CI: 1.347−1.883, p < 0.0001) were significantly higher in the AS group than the non-AS group. In the sub-group analyses, the possibility of any external eye disease (p = 0.0030) and DED (p = 0.0386) was decreased in the older age group compared to those in the middle-aged group. In conclusion, AS is significantly correlated to subsequent external eye diseases, mainly the DED and superficial keratopathy.
Keywords: ankylosing spondylitis; dry eye disease; inflammation; keratopathy; population-based.