Examination of the nasolacrimal duct
The nasolacrimal duct serves to pass excess tears from the eye to the nasal or oral cavity. If there is no opening of the nasolacrimal duct in the eye (congenital condition), or if the duct is blocked or damaged, tears drain from the eye socket down the face.
In patients who experience excessive tearing, the function of this duct should be examined. This is done by examination with special catheters, probes, or imaging after injecting contrast into the duct. Some defects of the nasolacrimal system can be surgically corrected with minor procedures, and sometimes it is necessary to make a new nasolacrimal system that will perform its primary function.