AIM: To investigate the efficacy of valve removal technology in improved endoscopic dacryocystorhinostomy.METHODS: Prospective randomized controlled study. A total of 92 patients(98 eyes)with nasolacrimal duct obstruction who underwent endoscopic dacryocystorhinostomy in our hospital from November 2020 to September 2022 were selected as the study subjects and they were randomly divided into group A(traditional group)and group B(improved group). The nasal mucosal flap was preserved after incision of the nasal mucosa in group A, the lacrimal sac flap and nasal mucosal flap were trimmed to an appropriate shape after the incision of the lacrimal sac, and the lacrimal sac flap the nasal mucosal flap were matched up. Group B made a “□” shaped incision on the nasal mucosa to remove the complete square nasal mucosa tissue. After the lacrimal sac was incised, the lacrimal sac mucosa was preserved as much as possible, and then the residual nasal mucosa was trimmed to make the lacrimal sac flap close to but not in contact with the residual nasal mucosa. Furthermore, the intraoperative bleeding volume and surgical duration of two groups of patients were recorded, and follow up until 3 mo postoperative. Nasal endoscopy and lacrimal duct flushing examinations were performed at 1 and 3 mo postoperative, respectively. The proliferation of granulation tissue within 5 mm of the ostial postoperative and the therapeutic effect were observed.RESULTS: At 3 mo postoperatively, 6 patients(7 eyes)who were lost to follow-up were excluded. A total of 44 eyes were included in group A, and 47 eyes were included in group B. The bleeding volume [27.00(22.00, 41.00)mL] and the surgical duration [35.00(33.00, 42.00)min] in group B were significantly lower than those in the group A(P<0.001). At 1 mo postoperatively, granulation tissue hyperplasia was observed within 5 mm of the ostial in 12 eyes of group A. In group B, granulation tissue hyperplasia was observed within 5 mm of the ostial in 1 eye. At 3 mo postoperatively, there were 9 eyes in group A with ostial adhesions but incomplete closure, and 2 eyes with complete closure; group B had 1 eye with mild adhesions at the ostial site and no ostial closure. The postoperative complications in the group B were significantly less than those in the group A(P<0.05), and the therapeutic effect was better than that in the group A(P<0.05).CONCLUSION: The application of valve removal technology in improving endoscopic dacryocystorhinostomy not only significantly reduces intraoperative bleeding and surgical duration, but also effectively reduces postoperative complications and improves surgical efficacy.