Dry eye syndrome: an underappreciated extraintestinal manifestation of inflammatory bowel disease? A systematic review and meta-analysis

Objective Ocular extraintestinal manifestations (O-EIMs) of inflammatory bowel disease (IBD) are known to include uveitis, scleritis and episcleritis; however, the relationship of dry eye syndrome (DES) with IBD is unclear. We aimed to determine if IBD is associated with DES. Design/method A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, searching four databases for studies comparing DES in patients with IBD versus non-IBD. OR and weighted mean differences (WMDs) of objective ocular parameters (ie, Schirmer I test (tear production); tear breakup time (TBUT; tear film stability) and Ocular Surface Disease Index (OSDI; dry eye symptom rating scale)) were meta-analysed using a random-effects model. Results We included eight cohort studies for a total of 55 211 patients with IBD and 54 870 patients without IBD. Compared with non-IBD controls, patients with IBD had significantly increased odds of DES (OR=2.54; 95% CI: 1.47 to 4.36, p=0.0008) and increased OSDI score (WMD=4.57 points, 95% CI: 1.80 to 7.35, p=0.0012). For the Schirmer I test, patients with IBD had significantly lower tear production compared with controls (WMD=−3.63 mm, 95% CI: −5.52 to −1.74, p=0.0002). For TBUT, patients with IBD had greater tear film instability compared with controls (WMD=−3.33 s, 95% CI: −4.97 to −1.70, p<0.0001). Conclusions DES may be an underappreciated EIM of IBD. Clinicians should consider screening for the presence of DES during a review of EIMs, as treatment of DES can significantly improve quality of life. PROSPERO registration number CRD420251076843.