Association Between Silymarin Use and Age-related Macular Degeneration in Patients With Chronic Hepatic Diseases: a Population-based Retrospective Cohort Study

Silymarin is a bioflavonoid compound mostly used in patients with chronic hepatic diseases (CHDs). It has been shown to inhibit retinal angiogenesis in in vitro and in vivo animal studies. Age-related macular degeneration (AMD) is a leading cause of vision impairment worldwide, and no definite preventive measures for AMD exist at present. Through this study, we aimed to investigate whether the use of silymarin affects the risk of AMD in patients with CHDs. Cox proportional hazard models were used to assess the hazard ratio (HR) of AMD in this population-based retrospective cohort study. The CHDs was associated with a higher risk of AMD (adjusted hazard ratio (aHR): 1.33, 95% CI 1.22–1.46), and the use of silymarin reduced the risk of AMD among patients with CHDs (aHR: 0.76, 95% CI: 0.67–0.87). A higher accumulative dose (defined daily dose [DDD] < 631 mg) of silymarin was associated with a lower risk of AMD, but the difference was nonsignificant. In conclusion , CHDs were associated with a higher incidence of AMD, and the use of silymarin was associated with a reduced risk of AMD in patients with CHDs. However, a higher accumulative DDD of silymarin did not reduce the risk of AMD.