OBJECTIVE The aim of this article was to study the lower punctum parameters in patients with acquired punctal stenosis using spectral-domain anterior segment optical coherence tomography. METHODS This was a prospective nonrandomized study that included two groups. Group 1 was composed of 32 puncta from 32 subjects (11 males and 21 females, aged 40-62 years) with epiphora and clinically diagnosed punctal stenosis. Group 2 (control group) included 30 puncta from 30 normal subjects (10 males and 20 females, aged 43-63 years). Anterior segment optical coherence tomography was employed to evaluate lower punctum parameters in all subjects; the inner and outer punctal diameters as well as punctal depth were measured. RESULTS External punctal diameter (mean: 466.1 ± 120.3 μm), internal punctal diameter (mean: 173.4 ± 55.6 μm) and punctal depth (mean: 188.4 ± 67 μm) values in Group 1 were statistically significantly lower than those in Group 2 (mean: 745.7 ± 156.9 μm, mean: 384 ± 119.1 μm, and mean: 284.9 ± 57.7 μm, respectively). CONCLUSIONS Anterior segment optical coherence tomography could possibly be used as a noncontact and noninvasive diagnostic modality for evaluating and measuring the lower punctum in patients with punctal stenosis. Further research is required to develop a normative database and grading system for stenosed puncta and to correlate the degree of stenosis with the severity of epiphora.