A simple aid to successful probing of congenitally obstructed nasolacrimal ducts.

For successful probing of congenitally obstructed nasolacrimal ducts in infants, the probe must reach the inferior nasal meatus. Previous methods to determine the position of the probe in the nose require intranasal examination method using two probes of equal length. The first probe is placed inside the lacrimal outflow system and the second probe is placed against the nose. The second probe can be used to measure the distance between the point of the first probe and the anterior narial margin. This method may be particularly valuable in those cases in which the probe point is less than 5 mm below the anterior narial margin.