Purpose:To observe the clinical efficacy of spherical headed silicone implantation in the treatment of chronic dacryocystitis under nasal endoscopy.Methods:Twenty-six patients (31 eyes) with chronic dacryocystitis were subjected to spherical headed silicone implantation under topical anesthesia (lacrimal passage and nasal mucosal surface).Lacrimal passage irrigation was performed daily throughout the first postoperative week,and once each month thereafter. Results:All spherical headed silicone tube placements were successfully performed.The operative time ranged from 6 to 11 minutes.Symptoms of epiphora were immediately ameliorated post-operatively,and irrigation demonstrated patency of the lacrimal system in all patients.All patients were followed from 7 to 24 months,during which symptoms of tearing were improved.The lacrimal ducts of 27 eyes (87.7％) were normal.The lacrimal ducts of 4 others (12.3％) were still blocked.Lacrimal passage irrigation was open and secretion disappeared in 28 eyes (90.3％).Tearing was observed in 3 eyes (9.68％).Conclusion: Spherical headed silicone tube implantation under nasal endoscopy is successful in relieving symptoms of tearing.(Eye Science 2011; 26:217-220)