Relationship between lacrimal sac size and duration of tearing in nasolacrimal duct obstruction

To analyze the relationship among the presence of lacrimal sac mucus retention, the vertical size of the lacrimal sac, and the duration of tearing symptom in patients with nasolacrimal duct obstruction (NLDO).Retrospective case series.We reviewed the medical records of 473 patients (664 eyes) who underwent external dacryocystorhinostomy for primary NLDO.The information about the presence of lacrimal sac mucus retention and vertical size of the lacrimal sac lumen was collected intraoperatively. The vertical size of the lacrimal sac was classified into 3 groups: small (5 mm), medium (5-10 mm), and large (10 mm). The relationship between the lacrimal sac size, presence of mucus retention, and duration of tearing was analyzed.Of the 664 eyes, 138 had a small lacrimal sac, 199 had a medium lacrimal sac, and 327 had a large lacrimal sac. The distribution of the lacrimal sac size groups differed significantly between the eyes with (n = 245) and without (n = 419) mucus retention (p0.001). Among all the subjects of each lacrimal sac size group, there was no significant difference in the duration of symptoms (p = 0.176). However, in patients without mucus retention, the symptom duration in the small lacrimal sac group was significantly longer than that in the large lacrimal sac group (p = 0.017).In cases with mucus retention, a small lacrimal sac is rare. In cases without mucus retention, the duration of tearing symptom was significantly longer in small lacrimal sac group.