BackgroundWe aimed to analys and explore the changes in the lacrimal system before and after endoscopic dacryocystorhinostomy (EN-DCR).MethodsA series of case studies was reviewed. The clinical data of 104 patients (120 eyes) who underwent EN-DCR in our hospital from March 2019 to October 2019 were selected for the study. The tear meniscus height (TMH) and the Schirmer I test (SIt) values were compared preoperatively and 1 month and 3 months postoperatively and statistically analysed by Mauchly's test of sphericity and the Pearson correlation coefficient.ResultsThe TMH decreased across all 3 timepoints, and the differences were statistically significant (P<0.05). The TMH values were measured 3 times in 120 eyes and showed three patterns: increased steadily (34 eyes), descended first and then ascended (32 eyes), and decreased steadily (54 eyes); the changes in the three patterns were statistically significant (P<0.05). There were a significant increases in SIt values among the three timepoints, and the SIt values gradually increased when the SIt values were < 10 mm/5 min preoperatively. However, there was no significant difference in SIt values when the SIt values were ≥ 10 mm/5 min preoperatively. The TMH was highly correlated with the SIt value preoperatively (r = 0.763), moderately correlated at 1 month postoperatively (r = 0.515), and not correlated at 3 months postoperatively (r = 0.097).ConclusionsEN-DCR has a certain degree of influence on the tear system, which is not only reflected in the tear drainage system, but also in the tear secretion system and the interaction between the two systems; however, excess tear drainage, can also alleviate dry eyes.Funding programmeJoint Fund Project of Hubei Provincial Health Select Committee (No. WJ2019H318); General Key Projects of Medical Research in Wuhan City, Hubei Province (No. WX19A03)