Long-term risk of dry eye disease following gastrectomy and colectomy in a nationwide cohort study

Dry eye disease (DED) is a complex symptomatic disorder characterized by a multifactorial etiology. Among those factors, the gut microbiome is one of the emerging factors related to dry eye disease (DED). But the relationship between gastrointestinal (GI) surgery, one of the obvious factors that alters gut microbiome, and DED has not been studied. This study evaluated the incidence of DED after gastrectomy and colectomy. The Korean National Health Insurance Service-National Sample Cohort (2002-2019) was used. A total of 2346 patients who underwent gastrectomy and 3086 who underwent colectomy, and 1:4 matched controls were included. Cox proportional hazards models with overlap weighting were used to estimate adjusted hazard ratios (HRs). Gastrectomy was significantly associated with increased DED risk (adjusted HR: 1.09; 95% CI 1.02-1.16; p = 0.007), while colectomy was not significantly associated with DED (HR: 1.00; 95% CI 0.94-1.07). In subgroup analysis, total gastrectomy showed a stronger association than subtotal gastrectomy (HR: 1.40; 95% CI 1.29-1.52). Gastrectomy, particularly total gastrectomy, is associated with ea higher incidence of dry eye disease. Colectomy showed no such association. These findings suggest the importance of ocular monitoring after gastric surgery.