This presentation involves diffuse stenosis along the course of the distal nasolacrimal duct. Unlike a focal obstruction at the duct's entry into the nares, the resistance here is distributed along the distal segment. During probing, this produces a characteristic gritty or crunchy sensation — as though the probe is passing through sand or gravel — rather than a single discrete stopping point.
This pattern of diffuse distal stenosis calls for a targeted interventional technique. Balloon catheter dilation (BCD) is specifically relevant in this setting and may improve success compared with standard probing alone.