PurposeThe aim of this study was to explore the pathological changes of the nasolacrimal duct in rabbits with experimentally induced obstructive dacryocystitis in correlation with lacrimal endoscopic findings.MethodsThe rabbit model of obstructive dacryocystitis was created by injecting 0.15ml of self-curing resin into the lacrimal duct. The control group received 0.15ml of normal saline. Within 16weeks after the obstructive, lacrimal endoscopy and pathological examination of the nasolacrimal duct were conducted at different time points of 1, 2, 4, 8, and 16weeks.ResultsIn the control group, lacrimal endoscopy revealed pink and smooth mucosa; and the pathological analysis revealed an epithelial layer that was composed of superficial columnar cells and a deep basal epithelial layer. The experimental rabbits showed clinical manifestations of obstructive dacryocystitis a week after the injection of self-curing resin. At weeks 1 and 2, the lacrimal endoscopy showed mucosal hyperemia and hemorrhagic spots on the nasolacrimal duct; and the pathological features included epithelial cell swelling and inflammatory cell infiltration. At weeks 4 and 8, the experimental group showed alternatively red and white mucosa under the lacrimal endoscopy, and the pathological features included proliferative epithelium accompanied by papillary hyperplasia. At week 16, the experimental group showed pale and coarse mucosa and white membrane-like layer covering the mucosal surface, and the pathological features included epithelial necrosis, squamous metaplasia, and sub-epithelial fibrosis.ConclusionThe mucosa of the nasolacrimal duct showed different pathological features at different time points after lacrimal duct obstruction, which was well correlated with the endoscopic findings. It is possible to predict the pathological stages by the endoscopic observation in NLOD patients.