There are many occasions where a specific evaluation of the punctum is needed in analyzing epiphora. Is the punctum draining tears from the lacrimal lake and passing them into the canaliculus? This must be the first question answered in evaluating patency of each level of the lacrimal passage. The dye test outlined in this paper gives a rapid, accurate answer to this question.
Available tests of punctal function1-3 are based on the demonstration of fluorescein in the nose, following its instillation in the lower fornix. These tests demonstrate the patency of the entire lacrimal tract, including the punctum. Looking for the dye in nasal secretions, or on cotton-tipped applicators placed beneath the inferior nasal turbinate, is time consuming and contains many false negative results. In actual practice these tests are infrequently done.
Irrigation of fluid from the canaliculus, through the sac, and down the nasolacrimal duct into the nose
JOSEPH AMDUR. A Dye Test for the Canalicular Punctum. Arch Ophthalmol. 1965;73(3):359–360. doi:10.1001/archopht.1965.00970030361013