Quantitative lacrimal scintillography.

In a study of 100 asymptomatic lacrimal systems, we have found that quantitative lacrimal scintillography provided a sensitive and reproduceable test of canalicular function. This technique, at the present time, appears to have no role in the clinical evaluation of tear passage through the nasolacrimal duct to the nose. A revision of the currently accepted theory of lacrimal drainage is proposed. Lacrimal drainage is best approached as a bimodel system. The first part, from conjunctiva to lacrimal sac, is dependent upon the "lacrimal pump." The second part, by which tears drain from the sac to the inferior meatus of the nose at basal tearflow levels, is dependent on gravity and the resistance of the nasolacrimal duct.