PurposeTo determine the relation between the fluorescein transit test time and postoperative relief of epiphora in patent dacryocystorhinostomies.MethodsA retrospective study of 40 patients who underwent 42 external dacryocystorhinostomies between January 1994 and January 2000 was performed. Postoperative symptomatic success was assessed by a questionnaire. Intranasal rigid endoscopy was performed to measure the fluorescein transit test time, defined as the time from instillation of fluorescein to its free flow from the osteotomy site. The main outcome measures were symptomatic success, fluorescein transit test time, and anatomic patency to irrigation. Statistical analysis was performed with the use of the Fisher exact test.ResultsOf the 42 dacryocystorhinostomies studied, 92.8% were patent to irrigation. There was a statistically significant association between a fluorescein transit test time of ≤45 seconds and subjective success (P<0.001), with 96% of patients reporting a successful postoperative outcome. A slow fluorescein transit test, with an average time of 138.9 seconds, was associated with symptomatic failure (P<0.001), with 56.2% of this group reporting significant postoperative epiphora.ConclusionsThe fluorescein transit test provides a quantitative measure of lacrimal drainage function after dacryocystorhinostomy, with a fluorescein transit test time of ≤45 seconds being the relevant parameter to characterize symptomatic success. Postoperative failure in external dacryocystorhinostomy, as evidenced by slow transit times, may result from surgical interference with the lacrimal pump.